bluuebunny/crossref_metadata_2025 huggingface dataset:
Wastewater treatment in Antarctica
Authors: Connor M. A.
Published: January 2008

Since the exploration of Antarctica began, procedures for dealing with human wastes have changed considerably. The establishment of research stations made it necessary to provide for sewage disposal. However, the introduction of advanced wastewater treatment processes has been driven largely by an intensifying concern to protect the Antarctic environment. A key step was the adoption by Antarctic Treaty nations of the so-called Madrid Protocol, in which minimum standards for sewage treatment and disposal are prescribed. The provisions of this protocol are not particularly onerous and some countries have elected to go beyond them, and to treat Antarctic research station wastewater as they would at home. Transferring treatment technologies to Antarctica is not simple because the remoteness, isolation, weather and other local conditions impose a variety of unusual constraints on plant design. The evolution of advanced treatment plant designs is examined. Most countries have opted for biofilm-based processes, with Rotating Biological Contactors (RBC) favoured initially while more recently contact aeration systems have been preferred. Sludges are now generally repatriated, with a diversity of sludge dewatering techniques being used. The evolution of treatment process designs is expected to continue, with growing use, especially at inland stations, of sophisticated processes such as membrane technologies and thermally efficient evaporative techniques.
Cost-effectiveness analysis of the introduction of a quadrivalent human papillomavirus vaccine in France
Authors: Bergeron Christine , Largeron Nathalie , McAllister Ruth , Mathevet Patrice , Remy Vanessa
Published: January 2008

Objectives:A vaccine to prevent diseases due to human papillomavirus (HPV) types 6, 11, 16, and 18 is now available in France. The objective of this study was to assess the health and economic impact in France of implementing a quadrivalent HPV vaccine alongside existing screening practices versus screening alone.

Methods:A Markov model of the natural history of HPV infection incorporating screening and vaccination, was adapted to the French context. A vaccine that would prevent 100 percent of HPV 6, 11, 16, and 18-associated diseases, with lifetime duration and 80 percent coverage, given to girls at age 14 in conjunction with current screening was compared with screening alone. Results were analyzed from both a direct healthcare cost perspective (DCP) and a third-party payer perspective (TPP). Indirect costs such as productivity loss were not taken into account in this analysis.

Results:The incremental cost per life-year gained from vaccination was €12,429 (TPP) and €20,455 (DCP). The incremental cost per quality-adjusted life-year (QALY) for the introduction of HPV vaccination alongside the French cervical cancer screening program was €8,408 (TPP) and €13,809 (DCP). Sensitivity analyses demonstrated that cost-effectiveness was stable, but was most sensitive to the discount rate used for costs and benefits.

Conclusions:Considering the commonly accepted threshold of €50,000 per QALY, these analyses support the fact that adding a quadrivalent HPV vaccine to the current screening program in France is a cost-effective strategy for reducing the burden of cervical cancer, precancerous lesions, and genital warts caused by HPV types 6, 11, 16, and 18.
Early technology assessment of new medical devices
Authors: Pietzsch Jan B. , Paté-Cornell M. Elisabeth
Published: January 2008

Objectives:In the United States, medical devices represent an eighty-billion dollar a year market. The U.S. Food and Drug Administration rejects a significant number of applications of devices that reach the investigational stage. The prospects of improving patient condition, as well as firms' profits, are thus substantial, but fraught with uncertainties at the time when investments and design decisions are made. This study presents a quantitative model focused on the risk aspects of early technology assessment, designed to support the decisions of medical device firms in the investment and development stages.

Methods:The model is based on the engineering risk analysis method involving systems analysis and probability. It assumes use of all evidence available (both direct and indirect) and integrates the information through a linear formula of aggregation of probability distributions. The model is illustrated by a schematic version of the case of the AtrialShaper, a device for the reduction of stroke risk that is currently in the preprototype stage.

Results:The results of the modeling provide a more complete description of the evidence base available to support early-stage decisions, thus allowing comparison of alternative designs and management alternatives.

Conclusions:The model presented here provides early-stage decision-support to industry, but also benefits regulators and payers in their later assessment of new devices and associated procedures.
Adoption of cost consciousness: Attitudes, practices, and knowledge among Israeli physicians
Authors: Wilf-Miron Rachel , Uziel Liad , Aviram Alexander , Carmeli Abraham , Shani Mordechai , Shemer Joshua
Published: January 2008

Objectives:In a resource-constrained reality, physicians are facing polar demands—those of healthcare managements to adopt cost-conscious behaviors and those of ethical standards that obligate physicians to consider only their patients' best interests. In our study, we aimed to determine the attitudes, practices, and knowledge of healthcare costs among Israeli physicians.

Methods:A questionnaire was developed and mailed to a representative sample of physicians in Israel. The overall response rate was 51 percent. The study reviewed self-reported levels of cost consciousness in practice, attitudes, obstacles related to cost containment, and knowledge of the costs of medical resources.

Results:Forty-two percent of the physicians reported high levels of cost consciousness in their daily practice; 70 percent reported greater current cost consciousness in comparison to 5 years ago; 76 percent of the responses legitimized institutional demands for cost containment. Although 83 percent of the physicians that responded expressed the belief that economic thinking was inherently the role of management, only 39 percent thought it was part of the physician's role. It was found that predominant predictors of agreement to cost consciousness concepts were employment by a community health plan, a managerial position, participation in health economics seminars, and male gender.

Conclusions:Cost consciousness among physicians is related to a broad array of parameters. Interventions must emphasize the benefits of evidence-based medicine as an anchor for both cost containment and quality care, as well as providing assistance to physicians in accepting economic decision-making as part of their professional role.
Assessing the performance of health technology assessment organizations: A framework
Authors: Lafortune Louise , Farand Lambert , Mondou Isabelle , Sicotte Claude , Battista Renaldo
Published: January 2008

In light of growing demands for public accountability, the broadening scope of health technology assessment organizations (HTAOs) activities and their increasing role in decision-making underscore the importance for them to demonstrate their performance. Based on Parson's social action theory, we propose a conceptual model that includes four functions an organization needs to balance to perform well: (i) goal attainment, (ii) production, (iii) adaptation to the environment, and (iv) culture and values maintenance. From a review of the HTA literature, we identify specific dimensions pertaining to the four functions and show how they relate to performance. We compare our model with evaluations reported in the scientific and gray literature to confirm its capacity to accommodate various evaluation designs, contexts of evaluation, and organizational models and perspectives. Our findings reveal the dimensions of performance most often assessed and other important ones that, hitherto, remain unexplored. The model provides a flexible and theoretically grounded tool to assess the performance of HTAOs.
Value of Information of a clinical prediction rule: Informing the efficient use of healthcare and health research resources
Authors: Singh Sonia , Nosyk Bohdan , Sun Huiying , Christenson James Malcolm , Innes Grant , Anis Aslam Hayat
Published: January 2008

Objectives:The aim of this study was to estimate the potential cost-effectiveness and expected value of perfect information of a recently derived clinical prediction rule for patients presenting to emergency departments with chest discomfort.

Methods:A decision analytic model was constructed to compare the Early Disposition Prediction Rule (EDPR) with the current standard of care. Results were used to calculate the potential cost-effectiveness of the EDPR, as well as the Value of Information in conducting further research. Study subjects were adults presenting with chest discomfort to two urban emergency departments in Vancouver, British Columbia, Canada. The clinical prediction rule identifies patients who are eligible for early discharge within 3 hours of presentation to the emergency department. The outcome measure used was inappropriate emergency department discharge of patients with acute coronary syndrome (ACS).

Results:The incremental cost-effectiveness ratio of the EDPR in comparison to usual care was (negative) $2,999 per inappropriate ACS discharge prevented, indicating a potential cost-savings in introducing the intervention. The expected value of perfect information was $16.3 million in the first year of implementation, suggesting a high benefit from conducting further research to validate the decision rule.

Conclusions:The EDPR is likely to be cost-effective; however, given the high degree of uncertainty in the estimates of costs and patient outcomes, further research is required to inform the decision to implement the intervention. The potential health and monetary benefits of this clinical prediction rule outweigh the costs of doing further research.
Bovine respiratory syncytial virus infection: immunopathogenic mechanisms
Authors: Gershwin Laurel J.
Published: January 2008

Bovine respiratory syncytial virus (BRSV) causes severe respiratory disease in young cattle. Much like the human respiratory syncytial virus, BRSV induces immunomodulation in the infected host, favoring a Th2 response. Several groups have demonstrated IgE responses to BRSV proteins during infection and particularly in response to vaccination with formalin-inactivated vaccine in the field and experimentally. Newer vaccine modalities that favor a shift to Th1 cytokine production have provided promising results. Infection with BRSV is a major contributor to the multi-pathogen disease, bovine respiratory disease complex. This review stresses the unique immunomodulatory aspects of BRSV infection, vaccination and its interaction with the host's immune system.
FabG Mediates Polyhydroxyalkanoate Production from Both Related and Nonrelated Carbon Sources in Recombinant Escherichia coli LS5218
Authors: Nomura Christopher T. , Tanaka Tomoyo , Eguen Tenai E. , Appah Alexandria S. , Matsumoto Ken'ichiro , Taguchi Seiichi , Ortiz C. Leo , Doi Yoshiharu
Published: January 2008

Polyhydroxyalkanoates (PHAs) composed of a mixture of short‐chain‐length‐medium‐chain‐length (SCL‐MCL) hydroxyacyl monomers are biologically produced polyesters that have properties ranging from thermoplastic to elastomeric, dependent on the molar ratio of SCL to MCL monomers incorporated into the copolymer. Because of the potential wide range of properties and applications for SCL‐MCL PHA copolymers, it is important to develop and characterize novel metabolic pathways for SCL‐MCL PHA production. The current study shows that coexpression of fabG genes from either E. coli or Pseudomonas sp. 61–3 with fabH(F87T) and PHA synthase genes enhances the production of SCL‐MCL PHA copolymer from both related and nonrelated carbon sources in Escherichia coli LS5218, indicating the flexibility of FabG as a monomer‐supplying enzyme for biological PHA production.
Reliabilität und Validität der deutschsprachigen Version der Generalized Expectancies for Negative Mood Regulation (NMR) Scale
Authors: Backenstrass Matthias , Pfeiffer Nils , Schwarz Thomas , Catanzaro Salvatore J. , Mearns Jack
Published: January 2008

Zusammenfassung. Generalisierten Erwartungen über die Regulation negativer Stimmungen (im englischen Original: generalized expectancies for negative mood regulation; NMR) wird in Bezug auf die Affektregulation große Bedeutung beigemessen. Catanzaro und Mearns (1990) hatten zur Messung dieser Erwartungen einen Fragebogen mit 30 Items konstruiert (NMR Scale). An mehreren Stichproben konnten sie die psychometrische Güte der NMR Scale bestätigen. Die vorliegende Studie untersuchte mit einer Stichprobe von N = 474 Personen die Reliabilität und Validität der deutschen Form der NMR Scale. Die Gesamtskala wies ein Cronbachs Alpha von .84 und eine Retest-Reliabilität von .88 über ein Zeitintervall von 4 Wochen auf. Eine explorative Faktorenanalyse legte eine eindimensionale Struktur des Itempools nahe. Bedeutsame Zusammenhänge zum Geschlecht oder Alter der Probanden ergaben sich nicht. Die NMR Skala korrelierte signifikant mit Maßen des affektiven und insbesondere depressiven Befindens (PANAS und BDI), was im Einklang mit den theoretischen Annahmen stand. Weiterhin ergaben sich bedeutsame Zusammenhänge der NMR Skala mit locus-of-control Variablen (FKK) und den “Big Five“ (NEO-FFI). Die Ergebnisse replizierten somit die Resultate, die mit der Originalversion ermittelt worden waren, so dass auch bei der deutschen Adaptation der NMR Scale von einem reliablen und validen Instrument auszugehen ist.
Paleoearthquakes of the Düzce fault (North Anatolian Fault Zone): Insights for large surface faulting earthquake recurrence
Authors: Pantosti D. , Pucci S. , Palyvos N. , De Martini P. M. , D'Addezio G. , Collins P. E. F. , Zabci C.
Published: January 2008

The 12 November 1999 Mw 7.1 earthquake ruptured the Düzce segment of the North Anatolian Fault Zone and produced a ∼40‐km‐long surface rupture. To improve knowledge about earthquake recurrence on this fault, we undertook paleoseismological trench investigations. We found evidence for repeated surface faulting paleoearthquakes predating the 1999 event during the past millennium. Dating was based on radiocarbon, 210Pb analyses, and archaeological considerations. In addition to the 1999 earthquake, prior surface faulting earthquakes are dated as follows: A.D. 1685–1900 (possibly end of 19th century), A.D. 1495–1700, and A.D. 685–1020 (possibly A.D. 890–1020). The A.D. 967 and A.D. 1878 historical earthquakes are good candidates to have ruptured the Düzce fault correlating with the oldest and penultimate paleoearthquakes. No obvious correlation for the third paleoearthquake (A.D. 1495–1700) exists. These results shows that the Düzce fault considerably participates, along with the parallel Mudurnu fault sections, in the seismogenic deformation taking place along this part of the North Anatolian Fault. Four events since A.D. 685–1020 (possibly A.D. 890–1020) would yield an average recurrence time for the Düzce fault of 330–430 years (possibly 330–370 years). The three most recent earthquakes, including 1999, occurred within 500 years. Merging results from other paleoseismological studies along the Düzce fault show a consistency of results and yields average recurrence times for the past 2000 years of 320–390 years. Assuming that the 1999 slip (2.7 m average, 5 m maximum) is representative of the behavior of this fault, the above recurrence times yield a reference figure of fault slip rate in the range 6.9–15.6 mm/a.
Plasma properties of superstorms at geosynchronous orbit: How different are they?
Authors: Liemohn M. W. , Zhang J.‐C. , Thomsen M. F. , Borovsky J. E. , Kozyra J. U. , Ilie R.
Published: January 2008

Plasma measurements at geosynchronous orbit are examined via superposed epoch analysis for various storm categories to assess whether superstorms have an unusually altered source population for the storm‐time ring current. It is found that certain characteristics of this near‐Earth plasma distribution during superstorms are similar to those of moderate or intense storms, or extensions of the trends seen in these lesser storms. These similarities include the dawn sector development of cold, dense plasma. However, other characteristics are unique to superstorms, such as the existence of cold, dense plasma at dusk and midnight. It is concluded that the ring current source during superstorms is a combination of the usual storm‐time characteristics as well as an unusually altered component.
Space Technology 5 multi‐point measurements of near‐Earth magnetic fields: Initial results
Authors: Slavin J. A. , Le G. , Strangeway R. J. , Wang Y. , Boardsen S. A. , Moldwin M. B. , Spence H. E.
Published: January 2008

The Space Technology 5 (ST‐5) mission successfully placed three micro‐satellites in a 300 × 4500 km dawn‐dusk orbit on 22 March 2006. Each spacecraft carried a boom‐mounted vector fluxgate magnetometer that returned highly sensitive and accurate measurements of the geomagnetic field. These data allow, for the first time, the separation of temporal and spatial variations in field‐aligned current (FAC) perturbations measured in low‐Earth orbit on time scales of ∼10 sec to 10 min. The constellation measurements are used to directly determine field‐aligned current sheet motion, thickness, and current density. In doing so, we demonstrate two multi‐point methods for the inference of FAC current density that have not previously been possible in low‐Earth orbit: 1) the “standard method,” based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the “gradiometer method” which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST‐5 data set and expand to include geomagnetic field gradient analyses as well as field‐aligned and ionospheric currents.
Lunar degree 2 potential Love number determination from satellite tracking data
Authors: Goossens S. , Matsumoto K.
Published: January 2008

The lunar potential Love number k2 has been determined using available satellite tracking data coming from the Lunar Orbiters I‐V, the Apollo 15 and 16 subsatellites, Clementine and Lunar Prospector. Some SMART‐1 spacecraft tracking data are also included. A previous determination using spacecraft data reported k2 = 0.026 ± 0.003 (ten times the formal error), whereas lunar laser ranging results report lower values, around k2 = 0.0210 ± 0.0025. The best estimate obtained here results in k2 = 0.0213 ± 0.0075 (ten times the formal error as well), closer in agreement with the lunar laser ranging values.
Storminess and cold air outbreaks in NE America during AD 1790–1820
Authors: van der Schrier G. , Jones P. D.
Published: January 2008

Two hypotheses have been put forward to explain the anomalously deep trough in winter sea‐level pressure in the northwestern Atlantic sector during the AD 1790–1820 period. One relates it to an increase in cyclolysis in this area, the other to a change in the general planetary circulation. In an attempt to distinguish between these hypotheses, storminess and cold air outbreaks (CAO) in the northeastern USA during 1790–1820 are studied, based on a record of daily pressure and temperature observations at Salem (Massachusetts, USA). Frequency changes of CAO act as proxy for planetary circulation changes. It is found that CAO in the early period were both more persistent and severe than those in the modern control period. No evidence of elevated levels of storminess in the 1790–1820 period was found. This suggests that the anomalously deep trough can be attributed mainly to a change in the planetary circulation.
Signatures of vegetational functional diversity in river basins
Authors: Muneepeerakul Rachata , Rinaldo Andrea , Levin Simon A. , Rodriguez‐Iturbe Ignacio
Published: January 2008

Using radiative reflectance as the discriminatory functional trait, we find scale‐free signatures of local functional diversity density of vegetation in river basins, implying a high likelihood of locations with very high diversity relative to the overall diversity of the riparian systems (i.e., riparian diversity hot spots). The spatial series of average local functional diversity exhibits correlation structures that indicate long‐range communication of diversity information along river networks. The riparian area of a randomly selected streamlink is found to be exponentially distributed. Our findings suggest that landscape structure and dispersal directionality play crucial roles in determining biodiversity patterns, and thus should be addressed in comprehensive biodiversity theories and fieldwork and conservation campaigns. Finally, the connection between the spectral‐group‐based functional diversity signatures and those associated with the actual species richness is yet to be verified and quantified; such connection will significantly enhance the importance of the already meaningful signatures reported here.
Temporal evolution of methane cycling and phylogenetic diversity of archaea in sediments from a deep-sea whale-fall in Monterey Canyon, California
Authors: Goffredi Shana K , Wilpiszeski Regina , Lee Ray , Orphan Victoria J
Published: January 2008

Whale-falls represent localized areas of extreme organic enrichment in an otherwise oligotrophic deep-sea environment. Anaerobic remineralization within these habitats is typically portrayed as sulfidogenic; however, we demonstrate that these systems are also favorable for diverse methane-producing archaeal assemblages, representing up to 40% of total cell counts. Chemical analyses revealed elevated methane and depleted sulfate concentrations in sediments under the whale-fall, as compared to surrounding sediments. Carbon was enriched (up to 3.5%) in whale-fall sediments, as well as the surrounding sea floor to at least 10 m, forming a ‘bulls eye’ of elevated carbon. The diversity of sedimentary archaea associated with the 2893 m whale-fall in Monterey Canyon (California) varied both spatially and temporally. 16S rRNA diversity, determined by both sequencing and terminal restriction fragment length polymorphism analysis, as well as quantitative PCR of the methyl-coenzyme M reductase gene, revealed that methanogens, including members of the Methanomicrobiales and Methanosarcinales, were the dominant archaea (up to 98%) in sediments immediately beneath the whale-fall. Temporal changes in this archaeal community included the early establishment of methylotrophic methanogens followed by development of methanogens thought to be hydrogenotrophic, as well as members related to the newly described methanotrophic lineage, ANME-3. In comparison, archaeal assemblages in ‘reference’ sediments collected 10 m from the whale-fall primarily consisted of Crenarchaeota affiliated with marine group I and marine benthic group B. Overall, these results indicate that whale-falls can favor the establishment of metabolically and phylogenetically diverse methanogen assemblages, resulting in an active near-seafloor methane cycle in the deep sea.
Molecular anchor Cu–S formed on a thiophene mediated Si(111)-(7×7) surface
Authors: Zhang Y. P. , Yong K. S. , Xu G. Q. , Gao X. Y. , Wang X. S. , Wee A. T. S.
Published: January 2008

Thiophene molecule selectively binds to the adjacent adatom-rest atom pair on the Si(111)-(7×7) surface through its α-carbon atoms, leading to the covalent attachment of a C–S–C linkage and remaining CC (β-carbon) bond onto the surface. Photoemission studies show that Cu atom readily adsorbs onto the S atom of the functional group to form the Cu–S molecular anchor in two forms: one points away from the thiophene CC group; the other points toward the CC group.
Electron paramagnetic resonance investigation of metalloendofullerene derived carbon nanotube peapods
Authors: Jakes P. , Gembus A. , Dinse K.-P. , Hata K.
Published: January 2008

Single Wall Carbon Nanotubes (SWCNT) prepared by the “super growth” method and arc-grown material were used as templates for peapod preparation with La@C82. A qualitative change of the electron paramagnetic resonance (EPR) properties of La@C82 is observed after incorporation into SWNT. The loss of lanthanum hyperfine interaction in combination with the observed increase of EPR susceptibility by two orders of magnitude after peapod preparation when comparing with signals from “empty” tubes is indicative for the generation of itinerant spins by charge and spin transfer from La@C82 to the tubes. This interpretation is supported by the observation of fast spin dephasing, detected with pulsed EPR techniques.
Analysis of hysteretic behavior in a FeCoB-based nanocrystalline alloy by a Preisach distribution and electron holography
Authors: Long Jianguo , McHenry M. E. , Laughlin D. E. , Zheng C. , Kirmse H. , Neumann W.
Published: January 2008

First order reverse curves have been used to investigate the Preisach distribution and electron holography to observe the spatial variation of the magnetization in Fe40Co40Nb4B13Ge2Cu1 nanocomposite alloys after annealing at 500, 550, 610, and 960°C for 1h. Grain sizes observed for these annealing temperatures varied from 10to200nm. The Preisach distribution reveals that the magnetization process in the sample annealed at 500°C for 1h was dominated by reversible processes, consistent with a small coercivity and mobile domain walls in an external field. At higher annealing temperatures, the irreversible magnetization processes became dominant with increasing grain size. Electron holography observations of the domains show that, for the sample annealed at 500°C, the magnetic flux distribution was uniform with few pinning barriers to domain wall motion consistent with reversible magnetization. The sample annealed at 610°C exhibited irregularity in the shape of magnetic flux lines attributed to the inhomogeneous magnetization distribution due to the α-FeCo and (FeCoNb)23B6 phases present after secondary crystallization.
Comparative study of ordered and disordered Y1−xSrxCoO3−δ
Authors: Fukushima S. , Sato T. , Akahoshi D. , Kuwahara H.
Published: January 2008

We have succeeded in preparing A-site ordered and disordered Y1∕4Sr3∕4CoO3−δ with various oxygen deficiencies δ, and have made a comparative study of their structural and physical properties. In the A-site ordered structure, oxygen vacancies order, and δ=0.34 sample shows a weak ferromagnetic transition beyond 300K. On the other hand, in the A-site disordered structure, no oxygen-vacancy ordering is observed, and δ=0.16 sample shows a ferromagnetic metallic transition around 150K. A-site disordering destroys the orderings of oxygen vacancies and orbitals, leading to the strong modification of the electronic phases.
Contribution of Langevin behavior to the low temperature maximum in zero-field cooled magnetization of the discontinuous Fe films
Authors: Shiratsuchi Yu , Nakatani Ryoichi , Yamamoto Masahiko
Published: January 2008

The dominant factor of low temperature maximum of zero-field cooled (ZFC) magnetization has been investigated using a discontinuous ultrathin Fe film which is superparamagnetic at room temperature. The peak temperature of ZFC magnetization increases with increasing magnetic field strength, contrary to the Nèel-Brown model. It is explained by the Langevin behavior of superparamagnetic particles dominating the low temperature maximum of ZFC magnetization due to the wide energy barrier distribution. For the case, the peak temperature should not be a good estimation of the blocking temperature since thermal activation of magnetization does not have a significant role in the low temperature maximum of ZFC magnetization.
On validation of turbulent mixing simulations for Rayleigh–Taylor instability
Authors: Lee Hyunsun , Jin Hyeonseong , Yu Yan , Glimm James
Published: January 2008

The purpose of this paper is to analyze the validation achieved in recent simulations of Rayleigh–Taylor unstable mixing. The simulations are already in agreement with experiment; mesh refinement or insertion of a calibrated subgrid model for mass diffusion will serve to refine this validation and possibly shed light on the role of unobserved long wavelength perturbations in the initial data. In this paper we present evidence to suggest that a subgrid model will have a barely noticeable effect on the simulation. The analysis is of independent interest, as it connects a validated simulation to common studies of mixing properties. The average molecular mixing parameter θ for the ideal and immiscible simulations is zero at a grid block level, as is required by the exact microphysics of these simulations. Averaging of data over volumes of (4Δx)3 to (8Δx)3 yields a conventional value θ∼0.8, suggesting that fluid entrainment in front tracked simulations produces a result similar to numerical mass diffusion in untracked simulations. The miscible simulations yield a nonzero θ∼0.8 in agreement with experimental values. We find spectra in possible approximate agreement with the Kolmogorov theory. A characteristic upturn especially in the density fluctuation spectrum at high wave numbers suggests the need for a subgrid mass diffusion model, while the small size of the upturn and the analysis of θ suggest that the magnitude of the model will not be large. We study directly the appropriate settings for a subgrid diffusion coefficient, to be inserted into simulations modeling miscible experiments. This is our most definitive assessment of the role for a subgrid model. We find that a Smagorinsky-type subgrid mass diffusion model would have a diffusion coefficient at most about 0.15% of the value of the physical mass diffusion for the (mass diffusive) experiment studied.
Quantum effects on Rayleigh–Taylor instability in magnetized plasma
Authors: Cao Jintao , Ren Haijun , Wu Zhengwei , Chu Paul K.
Published: January 2008

The effects of the quantum mechanism and magnetic field on Rayleigh–Taylor (RT) instability in an ideal incompressible plasma are investigated. The explicit expression of the linear growth rate is obtained in the presence of fixed boundary conditions. It is shown that the magnetic field has a stabilizing effect on RT instability similar to the behavior in classical plasmas and RT instability is affected significantly by quantum effects. Quantum effects are also shown to suppress RT instability with the appropriate physical quantities. Some astrophysical parameters are discussed as an example to investigate the new effects.
Ultrasensitive ultraviolet-visible 20fs absorption spectroscopy of low vapor pressure molecules in the gas phase
Authors: Schriever C. , Lochbrunner S. , Riedle E. , Nesbitt D. J.
Published: January 2008

We describe an ultrasensitive pump-probe spectrometer for transient absorption measurements in the gas phase and in solution. The tunable UV pump and the visible (450–740nm) probe pulses are generated by two independently tunable noncollinear optical parametric amplifiers, providing a temporal resolution of 20fs. A homebuilt low gain photodetector is used to accommodate strong probe pulses with a shot noise significantly lower than the overall measurement noise. A matched digitizing scheme for single shot analysis of the light pulses at kilohertz repetition rates that minimizes the electronic noise contributions to the transient absorption signal is developed. The data processing scheme is optimized to yield best suppression of the laser excess noise and thereby transient absorbance changes down to 1.1×10−6 can be resolved. A collinear focusing geometry optimized for a 50mm interaction length combined with a heatable gas cell allows us to perform measurements on substances with low vapor pressures, e.g., on medium sized molecules which are crystalline at room temperature. As an application example highlighting the capability of this instrument, we present the direct time-domain observation of the ultrafast excited state intramolecular proton transfer of 2-(2′-hydroxyphenyl)benzothiazole in the gas phase. We are able to compare the resulting dynamics in the gas phase and in solution with a temporal precision of better than 5fs.
Magnetic properties of Fe-5d (Os, Ir, and Pt) nanowires encapsulated in carbon nanotubes
Authors: Wang Junhua , Jo Chulsu , Wu Ruqian
Published: January 2008

Using the first-principles density functional calculations, we explored the magnetic properties of Fe–X (X=Os, Ir, and Pt) nanowires encapsulated in a (4,4) carbon nanotubes. It is found that these wires possess giant magnetic anisotropy energies due to sizable spin-orbit coupling along with induced magnetization of 5d metals.
Annual variation of the steady-state chlorophyll fluorescence emission of evergreen plants in temperate zone
Authors: Soukupová Julie , Cséfalvay Ladislav , Urban Otmar , Košvancová Martina , Marek Michal , Rascher Uwe , Nedbal Ladislav
Published: January 2008

Remotely sensed passive chlorophyll fluorescence emission has a potential to become one of the major global-scale reporter signals on vegetation performance and stress. In contrast to the actively probed parameters such as maximal (FM′) or minimal (F0′) emission, the steady-state chlorophyll fluorescence, Chl-FS, (FM′ > Chl-FS > F0′) has not been adequately studied. Using fluorescence imaging of leaves, we explored the modulation of Chl-FS by actinic irradiance and by temperature in laboratory, as well as the changes that occurred in three coniferous and broadleaf plant species grown in field. The experiments revealed that Chl-FS is largely insensitive to the incident irradiance once this is above early morning or late evening levels. The characteristic, pre-noon measured Chl-FS correlated positively with the CO2 assimilation rate when measured in field during the year. It was low and stable in the cold winter months and steeply increased with the spring onset. The high values of the characteristic Chl-FS persisted throughout the vegetation season and rapidly decreased in the fall. The seasonal Chl-FS transitions coincided with the last spring frosts or the first fall frosts that persisted for several consecutive nights. The transitions were marked by an elevated variability of the Chl-FS signal. We propose that the signal variability occurring during the transition periods can be used to detect from satellites the beginning and the end of the photosynthetic activity in evergreen canopies of the temperate zone.
Inoculation of female American black bears (Ursus americanus) with partially purified porcine zona pellucidae limits cub production
Authors: Lane V. M. , Liu I. K. M. , Casey K. , vanLeeuwen E. M. G. , Flanagan D. R. , Murata K. , Munro C.
Published: January 2008

The present 2-year study investigated the feasibility of using porcine zona pellucidae (pZP) as antigen for immunocontraception in American black bears. Sows, 3–6 years of age, were administered either two doses of 250 µg pZP with Freund’s adjuvant (n = 10) or adjuvant alone (n = 5), one in April and one in May, and were kept away from the boars until June. Serum samples were collected before injections and before denning (November). The presence of sows with cubs at side was observed during premature emergence from denning. First-year results indicated that anti-pZP antibody titres in vaccinated sows were 2.5–9.0-fold (range) higher compared with non-vaccinated sows and that the vaccinated sows were threefold less likely to become pregnant (P = 0.167). Control and vaccinated bears produced 1.6 and 0.2 cubs per sow, respectively (P = 0.06). The second-year study investigated the feasibility of using pZP sequestered in a controlled-release pellet and a water-soluble adjuvant (QS-21) to avoid regulatory problems associated with Freund’s adjuvant. Sows in the treatment group (n = 22) were administered a single dose of an emulsion of 250 µg pZP and 150 μg QS-21 plus a pellet containing 70–90 µg pZP for delayed release as booster dose. Control sows (n = 5) received the QS-21 adjuvant in pellet alone. Serum samples were collected before inoculations (April) and before denning (November). Seven cubs were born to the five control sows, but none was born to the 22 vaccinated sows (P < 0.001). Anti-pZP antibody mean absorbance ratios in control sows remained at background levels, whereas vaccinated sows had ratios fourfold higher than controls. Two-dimensional polyacrylamide gel electrophoresis and immunohistochemical localisation confirmed immunoreactivity of sera from inoculated bears. We conclude that cub production in the American black bear can be effectively limited with either two injections of 250 μg pZP or a single inoculation of partially purified pZP sequestered in controlled-release pellets.
Changes in cell cycle and extracellular matrix gene expression during placental development in deer mouse (Peromyscus) hybrids
Authors: Duselis Amanda R. , Obergfell Craig , Mack Jennifer A. , O'Neill Michael J. , Nguyen Quang K. , O'Neill Rachel J. , Vrana Paul B.
Published: January 2008

Crosses between two species of the rodent genus Peromyscus produce defects in both growth and development. The defects are pronounced in the hybrid placentas. Peromyscuys maniculatus (strain BW) females mated to P. polionotus (strain PO) males produce placentas half the size of the parental species, as well as growth-retarded embryos. In contrast, PO females mated to BW males result in defective conceptuses that display embryonic and placental overgrowth. These ‘parent-of-origin’-dependent phenotypes are consistent with previous studies that demonstrated altered expression of imprinted genes and genetic linkage of the overgrowth phenotypes to imprinted domains. In the present study, we take a broader approach in assessing perturbations in hybrid placental gene expression through the use of Mus musculus cDNA microarrays. In verifying classes of genes identified in microarray screens differentially regulated during hybrid placental development, we focused on those influencing the cell cycle and extracellular matrix (ECM). Our work suggests that cell cycle regulators at the G1/S phase check-point are downregulated in the large hybrid placenta, whereas the small hybrid placenta is more variable. The ECM genes are typically downstream targets of cell cycle regulation and their misregulation is consistent with many of the dysmorphic phenotypes. Thus, these data suggest imbalances in proliferation and differentiation in hybrid placentation.
Female reproductive tract fluids: composition, mechanism of formation and potential role in the developmental origins of health and disease
Authors: Leese Henry J. , Hugentobler Sasha A. , Gray Susan M. , Morris Dermot G. , Sturmey Roger G. , Whitear Sarah-Louise , Sreenan Joseph M.
Published: January 2008

The oviduct and uterus provide the environments for the earliest stages of mammalian embryo development. However, little is known about the mechanisms that underlie the formation of oviduct and uterine fluids, or the extent to which the supply of nutrients via these reproductive tract tissues matches the nutrient requirements of early embryos. After reviewing our limited knowledge of these phenomena, a new experimental paradigm is proposed in which the epithelia lining the endosalpinx and endometrium are seen as the final components in a supply line that links maternal diet at one end and embryo uptake of nutrients at the other. When considered in this way, the oviduct and uterine epithelia become, for a few days, potentially the most critical maternal tissues in the establishment of a healthy pregnancy. In fulfilling this ‘gatekeeper’ role, female reproductive tract fluids have a key role in the ‘developmental origins of health and disease’ concept.
To QC or not to QC: the key to a consistent laboratory?
Authors: Lane Michelle , Mitchell Megan , Cashman Kara S. , Feil Deanne , Wakefield Sarah , Zander-Fox Deirdre L.
Published: January 2008

A limiting factor in every embryology laboratory is its capacity to grow ‘normal’ embryos. In human in vitro fertilisation (IVF), there is considerable awareness that the environment of the laboratory itself can alter the quality of the embryos produced and the industry as a whole has moved towards the implementation of auditable quality management systems. Furthermore, in some countries, such as Australia, an established quality management system is mandatory for clinical IVF practice, but such systems are less frequently found in other embryology laboratories. Although the same challenges of supporting consistent and repeatable embryo development are paramount to success in all embryology laboratories, it could be argued that they are more important in a research setting where often the measured outcomes are at an intracellular or molecular level. In the present review, we have outlined the role and importance of quality control and quality assurance systems in any embryo laboratory and have highlighted examples of how simple monitoring can provide consistency and avoid the induction of artefacts, irrespective of the laboratory’s purpose, function or species involved.
Epigenetic regulation during mammalian oogenesis
Authors: Bromfield John , Messamore Will , Albertini David F.
Published: January 2008

The advent of the epigenetic era has sparked a new frontier in molecular research and the understanding of how development can be regulated beyond direct alterations of the genome. Thus far, the focal point of epigenetic regulation during development has been chromatin modifications that control differential gene expression by DNA methylation and histone alterations. But what of events that alter gene expression without direct influence on the DNA itself? The present review focuses on epigenetic pathways regulating development from oogenesis to organogenesis and back that do not involve methylation of cytosine in DNA. We discuss target components of epigenetic modification such as organelle development, compartmentalisation of maternal factors and molecular mediators in the oocyte and how these factors acting during oogenesis impact on later development. Epigenetic regulation of development, be it via cytosine methylation or not, has wide-ranging effects on the subsequent success of a pregnancy and the intrinsic health of offspring. Perturbations in epigenetic regulation have been clearly associated with disease states in adult offspring, including Type II diabetes, hypertension, cancers and infertility. A clear understanding of all epigenetic mechanisms is paramount when considering the increased use of assisted reproductive techniques and the risks associated with their use.
Experimental design, power and sample size for animal reproduction experiments
Authors: Chapman Phillip L. , Seidel, Jr. George E.
Published: January 2008

The present paper concerns statistical issues in the design of animal reproduction experiments, with emphasis on the problems of sample size determination and power calculations. We include examples and non-technical discussions aimed at helping researchers avoid serious errors that may invalidate or seriously impair the validity of conclusions from experiments. Screen shots from interactive power calculation programs and basic SAS power calculation programs are presented to aid in understanding statistical power and computing power in some common experimental situations. Practical issues that are common to most statistical design problems are briefly discussed. These include one-sided hypothesis tests, power level criteria, equality of within-group variances, transformations of response variables to achieve variance equality, optimal specification of treatment group sizes, ‘post hoc’ power analysis and arguments for the increased use of confidence intervals in place of hypothesis tests.
115 RAT EPIDERMAL GROWTH FACTOR GENE EXPRESSION CONTROLLED BY PROGESTERONE DURING PREGNANCY
Authors: Byun H.-S. , Ko S.-H. , Lee G.-S. , Hyun S.-H. , Jeung E.-B.
Published: January 2008

The implantation of the developing blastocyst into the uterine wall is regulated by a precisely timed interplay of the ovarian hormones estrogen and progesterone, which control a set of regulatory factors that make the uterus receptive to implantation. These factors include EGF receptor (Egfr) and members of the epidermal growth factor (Egf) family, namely, EGF, heparin-binding EGF (Hbegf), transforming growth factor-alpha (Tgfa), and amphiregulin (Areg). However, the exact role(s) these factors play in pregnancy remain unclear. To address this, a group of three rats was euthanized every day from gestation day (GD) 0 through to GD21. The uterus, attached uterus (these tissues are mostly composed of stromal cells), and placenta were rapidly excised and used directly for total RNA. We used real-time PCR with the TaqMan system (Applied Biosystems, Foster City, CA, ISA) to examine the uterine expression patterns of these factors in rats during the entire pregnancy. Data were analyzed by nonparametric one-way analysis of variance using the Kruskal-Wallis test, followed by Dunnett's test for multiple comparisons. Egf and Egfr mRNA levels increased significantly at implantation, especially on GD3 and GD6, after which their expression gradually decreased. Hbegf and Tgfa showed a modest spike of transcription around the implantation period (GD4 and GD3, respectively) but were much more strongly expressed at mid-pregnancy, which is when progesterone is secreted at high levels. Areg expression peaked strongly around implantation (GD4) and at mid-pregnancy (GD12). Treatment of pregnant rats on GD5 or GD8 with the progesterone receptor antagonist RU486 (2.5 mg per rat) blocked the expression of all of the genes on the days of treatment. Moreover, injection of immature rats with progesterone induced the uterine expression of all of the genes except Hbegf, while injection with estrogen or estrogen plus progesterone had no effect. Taken together, all genes tested may be assumed to regulate the implantation process. Moreover, Hbegf, Tgfa, and Areg may participate during mid-pregnancy. In addition, all of these activities are likely to be controlled by progesterone in the uterus of rats during pregnancy.