bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanogel–Calcium Phosphate Hybrid Nanoparticles with Negative or Positive Charges for Potential Biomedical Applications
Authors: Yamane Setsuko , Sugawara Ayae , Sasaki Yoshihiro , Akiyoshi Kazunari
Published: March 2009

Self-assembled polysaccharide nanogels with negative or positive charges were used as templates for mineralization of calcium phosphate for potential biomedical application. The formation of stable and negatively- or positively-charged amorphous calcium phosphate nanoparticles was confirmed by transmission electron microscopy, energy-dispersive X-ray spectroscopy, and ζ-potential measurements.
Key issues concerning environmental enrichment for laboratory-held fish species
Authors: Williams T D , Readman G D , Owen S F
Published: March 2009

An improved knowledge and understanding of the fundamental biological requirements is needed for many of the species of fish held in captivity and, without this knowledge it is difficult to determine the optimal conditions for laboratory culture. The aim of this paper is to review the key issues concerning environmental enrichment for laboratory-held fish species and identify where improvements are required. It provides background information on environmental enrichment, describes enrichment techniques currently used in aquatic ecotoxicology studies, identifies potential restrictions in their use and discusses why more detailed and species-specific guidance is needed.
Echocardiographic assessment of global left ventricular function in mice
Authors: Stypmann Jörg , Engelen Markus A , Troatz Clemens , Rothenburger Markus , Eckardt Lars , Tiemann Klaus
Published: March 2009

Doppler-echocardiographic assessment of cardiovascular structure and function in murine models has developed into one of the most commonly used non-invasive techniques during the last decades. Recent technical improvements even expanded the possibilities. In this review, we summarize the current options to assess global left ventricular (LV) function in mice using echocardiographic techniques. In detail, standard techniques as structural and functional assessment of the cardiovascular phenotype using one-dimensional M-mode echocardiography, two-dimensional B-mode echocardiography and spectral Doppler signals from mitral inflow respective aortal outflow are presented. Further pros and contras of recently implemented techniques as three-dimensional echocardiography and strain and strain rate measurements are discussed. Deduced measures of LV function as the myocardial performance index according to Tei, estimation of the mean velocity of circumferential fibre shortening, LV wall stress and different algorithms to estimate the LV mass are described in detail. Last but not least, specific features and limitations of murine echocardiography are presented. Future perspectives in respect to new examination techniques like targeted molecular imaging with advanced ultrasound contrast bubbles or improvement of equipment like new generation matrix transducers for murine echocardiography are discussed.
Reducing variation in a rabbit vaccine safety study with particular emphasis on housing conditions and handling
Authors: Verwer Cynthia M , van der Ark Arno , van Amerongen Geert , van den Bos Ruud , Hendriksen Coenraad F M
Published: March 2009

This paper describes the results of a study of the effects of modified housing conditions, conditioning and habituation on humans using a rabbit model for monitoring whole-cell pertussis vaccine (pWCV)-induced adverse effects. The study has been performed with reference to previous vaccine safety studies of pWCV in rabbits in which results were difficult to interpret due to the large variation in experimental outcome, especially in the key parameter deep-body temperature ( Tb). Certain stressful laboratory conditions, as well as procedures involving humans, e.g. blood sampling, inoculation and cage-cleaning, were hypothesized to cause this large variation. The results of this study show that under modified housing conditions rabbits have normal circadian body temperatures. This allowed discrimination of pWCV-induced adverse effects in which handled rabbits tended to show a dose-related increase in temperature after inoculation with little variance, whereas non-handled rabbits did not. Effects of experimental and routine procedures on body temperature were significantly reduced under modified conditions and were within the normal Tb range. Handled animals reacted less strongly and with less variance to experimental procedures, such as blood sampling, injection and cage-cleaning, than non-handled rabbits. Overall, handling had a positive effect on the behaviour of the animals. Data show that the housing modifications have provided a more robust model for monitoring pWCV adverse effects. Furthermore, conditioning and habituation of rabbits to humans reduce the variation in experimental outcome, which might allow for a reduction in the number of animals used. In addition, this also reduces distress and thus contributes to refining this animal model.
Soft-hydrothermal processing of red cedar bedding reduces its induction of cytochrome P450 in mouse liver
Authors: Li Z , Okano S , Yoshinari K , Miyamoto T , Yamazoe Y , Shinya K , Ioku K , Kasai N
Published: March 2009

Red cedar-derived bedding materials cause changes in cytochrome P450-dependent microsomal enzyme systems in laboratory animals. We examined the effect of essential oil of red cedar (EORC), as well as the effect of bedding from which it had been removed, on the hepatic expression cytochrome P450s in mice. EORC was obtained from liquid extracts of red cedar bedding by a soft-hydrothermal process and was administered orally to mice. Between days 1 and 2 after administration, hepatic P450s were significantly induced as follows: CYP3As, 7.1×; CYP1As, 1.6×; CYP2E1, 1.5×; CYP2Cs, 1.6×. A housing study of mice indicated that red cedar bedding increased the levels of these P450s in mouse liver, whereas mice housed in cedar bedding from which EORC had been removed (ST-cedar bedding) showed significantly lower levels of P450s, especially CYP3As, CYP1As and CYP2E1. Soft-hydrothermal processing partially removed many components of EORC. In particular, several volatile sesquiterpenes, naphthalene-derived aromatics and 4,4-dimethyl-13α-androst-5-ene were decreased in the ST-cedar bedding, suggesting that these may be responsible for P450 induction. This study demonstrated that the removal of these volatile compounds by soft-hydrothermal processing can decrease the hepatic P450-inducing effect of red cedar bedding.
A review of the need and possible uses for genetically standardized Atlantic salmon (Salmo salar) in research
Authors: Grimholt U , Johansen R , Smith A J
Published: March 2009

Large numbers of Atlantic salmon ( Salmo salar) are used as research animals in basic research and to solve challenges related to the fish-farming industry. Most of this research is performed on farmed animals provided by local breeders or national breeding companies. The genetic constitution of these animals is usually unknown and highly variable. As a result, large numbers of fish are often needed to produce significant results, and results from one study are often impossible to reproduce in another facility. The production of standardized salmon could in many cases reduce the number of animals used in research and at the same time provide more reproducible results. This paper provides an overview of the methods available for the production of standardized Atlantic salmon, and discusses the pros and cons of each technique. The use of zebrafish and other well-defined laboratory fish species as a model for salmon is also discussed. Access to genetically defined fish would greatly benefit the scientific community, in the same way as genetically defined lines of rodents have revolutionized mammalian research.
A Direct Test of Risk Aversion and Regret in First Price Sealed-Bid Auctions
Authors: Engelbrecht-Wiggans Richard , Katok Elena
Published: March 2009

Why do bidders tend to bid higher than the risk-neutral Nash equilibrium in sealed-bid first price auction experiments? The effect of risk aversion has long been offered as a possible explanation. More recently, several studies proposed regret as another explanation, citing strong experimental evidence. But which effect is more important? We design an experiment to separate the effects of risk aversion from those of regret. We find overwhelming evidence in support of the regret model, and virtually no support for the constant relative risk aversion model.
Anchor Selection and Group Dynamics in Newsvendor Decisions—A Note
Authors: Gavirneni Srinagesh , Xia Yusen
Published: March 2009

We conducted a newsvendor experiment in which (i) the subjects were presented with multiple pieces of information that they could possibly use to anchor their decision and (ii) the subjects participated either as individuals or in groups of three. The primary objective was to determine whether the subjects tended to consistently anchor to the mean or change their anchor based on the experimental setting. The secondary objective was to study the impact of group dynamics on their decision-making approach. We observed that the subjects did not anchor to any one particular value, but rather chose an anchor that was closer to the optimal value. In addition, we observed that although there was no difference in their relative tendencies to anchor, the subjects in groups demonstrated a lower propensity for error than their individual counterparts.
Large-Scale, Less-than-Truckload Service Network Design
Authors: Jarrah Ahmad I. , Johnson Ellis , Neubert Lucas C.
Published: March 2009

We present a novel formulation for the service network design problem in the context of large-scale, less-than-truckload (LTL) freight operations. The formulation captures the basic network design constraints; the load-planning requirement that all freight at a location, irrespective of the freight's origin, loads to the same next terminal; and other important LTL-specific requirements. Our modeling scheme fragments the underlying massive network design model with up to 1.3 million 0–1 variables and 1.3 million rows into a separate and efficient integer programming (IP) problem for each destination terminal along with a coordinating master network design problem. We produce high-quality solutions in very reasonable CPU times (∼2 hours) using slope scaling and load-planning tree generation with corresponding potential annual savings of $20–25 million dollars for the target company for which the research was conducted.
Near-Optimal Dynamic Lead-Time Quotation and Scheduling Under Convex-Concave Customer Delay Costs
Authors: Ata Barış , Olsen Tava Lennon
Published: March 2009

We consider a make-to-order system where customers are dynamically quoted lead times (and prices). Customers are homogenous but have general (nonlinear) disutility for delay. Because the firm is a monopolist, the pricing problem is trivial and the dynamic problem reduces to one of lead-time quotation and order sequencing. We also consider the (static) problem of up-front capacity installation. We use a large-capacity asymptotic regime to make the problem tractable. We provide recommended policies for convex, concave, and convex-concave lead-time cost functions and prove that these policies are asymptotically optimal. The policies are both highly intuitive and readily implementable. Moreover, they provide delay guarantees for all served customers. They are tested numerically; we find that significant benefits can accrue by using the prescribed dynamic policies instead of first-come-first-served type policies.
Dynamics of New Product Introduction in Closed Rental Systems
Authors: Bassamboo Achal , Kumar Sunil , Randhawa Ramandeep S.
Published: March 2009

We study a rental system where a fixed number of heterogeneous users rent one product at a time from a collection of reusable products. The online DVD rental firm Netflix provides the motivation. We assume that rental durations of each user are independent and identically distributed with finite mean. We study transient behavior in this system following the introduction of a new product that is desired by all the users. We represent the usage process for this new product in terms of an empirical distribution. This allows us to characterize the asymptotic behavior of the usage process as the number of users increases without bound, via appropriate versions of Glivenko-Cantelli and Donsker's theorems. Analyzing the usage process, we demonstrate that an increase in the variability of the rental duration distribution can actually help the firm by allowing it to set lower capacity levels to provide a desired quality of service. Further, we show that the firm is better off not imposing any deadlines for the return of the product.
We don't have language at our house: Disentangling the relationship between phonological awareness, schooling, and literacy
Authors: Alcock K. J. , Ngorosho D. , Deus C. , Jukes M. C. H.
Published: March 2009

Background

A strong link between phonological awareness (PA) and literacy exists, but the origins of this link are difficult to investigate, since PA skills are hard to test in young, pre‐literate children, and many studies neither include such children nor report children's initial literacy levels.

Aims

To examine PA and literacy in children who are attending or not attending school in rural East Africa.

Sample

One hundred and eight children ages 7–10 years, with no education, or in grade 1 or 2, randomly selected from a community survey of all children in this age group.

Methods

PA skill, reading, cognitive abilities, and socio‐economic status were examined.

Results

Implicit and explicit PA skill with small or large units is related to letter reading ability, and this effect is independent of age, schooling, and cognitive ability. Some PA tasks are performed above chance levels by children who cannot recognize single letters.

Conclusions

Basic PA develops prior to the attainment of literacy, and learning to read improves PA both quantitatively and qualitatively.
Patterns of attachment to organizations: Commitment profiles and work outcomes
Authors: Somers Mark John
Published: March 2009

Commitment profiles were studied with a sample of 572 hospital workers. Seven of the eight commitment profiles in Meyer and Herscovitch's (2001) typology emerged using K‐means clustering including: highly committed, affective dominant, continuance dominant, affective‐continuance dominant, affective‐normative dominant, continuance‐normative dominant, and uncommitted. Outcome variables included: turnover intentions, turnover, absenteeism, and person–organization value congruence. Results were consistent with prior findings in that normative commitment alone and in conjunction with continuance commitment enhanced the benefits of affective commitment. Turnover rates were much higher for poorly socialized employees suggesting that there is a self‐corrective effect in which uncommitted employees are more likely to leave their organizations.
Dealing with Missing Predictor Values When Applying Clinical Prediction Models
Authors: Janssen Kristel J M , Vergouwe Yvonne , Donders A Rogier T , Harrell Frank E , Chen Qingxia , Grobbee Diederick E , Moons Karel G M
Published: March 2009

Background: Prediction models combine patient characteristics and test results to predict the presence of a disease or the occurrence of an event in the future. In the event that test results (predictor) are unavailable, a strategy is needed to help users applying a prediction model to deal with such missing values. We evaluated 6 strategies to deal with missing values.

Methods: We developed and validated (in 1295 and 532 primary care patients, respectively) a prediction model to predict the risk of deep venous thrombosis. In an application set (259 patients), we mimicked 3 situations in which (1) an important predictor (D-dimer test), (2) a weaker predictor (difference in calf circumference), and (3) both predictors simultaneously were missing. The 6 strategies to deal with missing values were (1) ignoring the predictor, (2) overall mean imputation, (3) subgroup mean imputation, (4) multiple imputation, (5) applying a submodel including only the observed predictors as derived from the development set, or (6) the “one-step-sweep” method. We compared the model’s discriminative ability (expressed by the ROC area) with the true ROC area (no missing values) and the model’s estimated calibration slope and intercept with the ideal values of 1 and 0, respectively.

Results: Ignoring the predictor led to the worst and multiple imputation to the best discrimination. Multiple imputation led to calibration intercepts closest to the true value. The effect of the strategies on the slope differed between the 3 scenarios.

Conclusions: Multiple imputation is preferred if a predictor value is missing.
Hockey Education Program (HEP): A Statewide Measure of Fair Play, Skill Development, and Coaching Excellence
Authors: Smith Aynsley M. , Jorgenson Mark , Sorenson Matthew C. , Margenau David , Link Andrew A. , MacMillan Michael , Stuart Michael J.
Published: March 2009

Following the death of a youth hockey coach in a fight with a parent in 2000, the Mayo Clinic Sports Medicine Center and Minnesota Hockey collaborated to implement a three-component Hockey Education Program (HEP). HEP was initiated in 2003 to ensure youth players develop sportsmanship, skills, and a Fair Play approach to the game. Another goal was to decrease attrition of players, coaches, and officials. Coaching Excellence, a component of HEP, is based on 25 years of youth sport research. The HEP manuals Coaches Who Never Lose and Sports and Your Child contain the philosophy, objectives, and guidelines to ensure implementation of HEP components across players, coaches, and parents. The Skill Development component emphasizes learning age-appropriate hockey skills though skill progression. Increasing the practice-to-game ratio to 3–4 practices per game greatly increases the maximum time players skate with the puck during developmental years. Pre- and post-season Skills Challenges allow coaches, players, and parents to gauge improvement, and structure practices to address identified skill deficits. The Fair Play (FP) component emphasizes sportsmanship. Teams earn a FP point each game if they incur less than a preset number of penalty minutes. A coach receiving a game misconduct or a parent/spectator asked to leave the game will cause the team to forfeit their FP point. FP points are factored into league standings across the state. This past season, 17 678 records of game data were obtained and 25 % (4420) were randomly selected for analysis. The data analysis permits comparison across seasons and changes are made accordingly. Based on four years of data, most Minnesota youth hockey games are played in a sportsmanlike manner. Checking from behind and head contact penalties have decreased since the penalty minutes for these dangerous infractions were increased.
Development and Preliminary Testing of a Crack Detection Sensor for Crack Velocity Measurement of an Edge-Notched Disk
Authors: Hsieh Chi-Tai , Wang Chein-Lee , Wang Shih-Hui
Published: March 2009

In the present study, a crack velocity measuring system is developed based on the electrical method. The proposed crack velocity measuring system and an available crack gage system were attached on opposite sides of an edge-notched granite disk specimen to measure the velocity of crack propagation on each side of the surface crack. Three sensing materials were assessed for their applicability in crack detection. It was found that the sensing materials have a strong effect on the measurement of the crack velocity. Several observations on crack propagation and some aspects of the proposed measuring technique are discussed in this study.
Aufrechtes Dasein: Von den Haltungen des Lebens
Authors: Eickhoff Hajo
Published: March 2009

Die Evolution des Lebens, betrachtet unter der Perspektive der Haltung, zeigt, dass Lebewesen ihre Haltung im Kampf mit Beutetieren und Verfolgern gewinnen. Die Aufrichtung der Wirbeltiere  von der Horizontalen des Fisches zur Vertikalen des Menschen  ist die Entwicklung hin zu Freiheit und Haltungserfindung. Kulturhaltungen wie das Stuhlsitzen haben einen großen Einfluss auf die geistige Entwicklung des Menschen, indem sie seinen Körper disziplinieren und fixieren und er aus der Fixierung heraus die Technisierung der Welt befördern. Will der Mensch seine Freiheit bewahren, muss er Haltungssucher bleiben und Meister seiner Haltungen sein.
Zur menschlichen Natur. Bekenntnisse eines Essentialisten
Authors: Stagl Justin
Published: March 2009

Es wird zu zeigen versucht,warum wir um einen Begriff der menschlichen Natur nicht herumkommen können.Dann wird ein Modell derselben vorgestellt, das aus vier Schichten besteht: Biologisches Erbe und sozio-kulturelles Erbe des Menschen, exklusivere Einheiten,in die Menschen hineingeboren werden (Ethnien, Kulturen, Gesellschaften) und die menschliche Selbstbestimmungsfähigkeit. Sie sind stammesgeschichtlich verschieden alt, jedoch interdependent.
Menschliches Glück
Authors: Körner Jürgen
Published: March 2009

Menschen können Glück empfinden, weil sie  im Gegensatz zu den allermeisten Tieren  reflexiv sind und gelernt haben, aktuelle Situationen unter den Bedingungen ihres Anspruchsniveaus, ihrer Erwartungen an sich selbst und an ihre soziale Welt zu bewerten. Diese Bewertungsprozesse unterliegen ihrerseits situativen Einflüssen, wie z. B. der Erfahrung von Erfolg oder Misserfolg, aber sie sind auch von langfristig wirksamen Dispositionen abhängig, etwa von der Fähigkeit eines Menschen, Misserfolge oder Enttäuschungen zugunsten einer Selbstzufriedenheit auszubalancieren. In psychoanalytischer Perspektive entwickeln Menschen ihre Fähigkeit, Glück zu empfinden, erst im Verlaufe eines langen Sozialisationsprozesses. Wie die Beispiele der Entwicklung von Esskultur und der Fähigkeit zur symbolischen Repräsentation zeigen, führt der individuelle Weg zur Glücksfähigkeit notwendigerweise über eine große Zahl unlustvoller, entsagungsreicher Erfahrungen.
Leib und Ehr’. Perspektiven der Ethik
Authors: Brenner Andreas
Published: March 2009

Der dominant gewordene Diskurs der Philosophie hat die Vorstellung von unserem Leib verdrängt. Die Folgen davon zeigen sich in den Verhältnissen einer eingeschränkten Selbstwahrnehmung und Selbstwertschätzung. Wenn man in der Wiedererinnerung des Leibes die leibliche Fundierung von Scham- und Ehrgefühlen erkennt, so wird die leibliche Authentizität des Menschen sichtbar, welche es zu schützen gilt.
Lebende Kunst. Gesten der Profanierung
Authors: Schuhmacher-Chilla Doris
Published: March 2009

Wenn das Wesentliche des Lebens die sich in der Zeit vollziehende Vitalität, die Lebendigkeit ist, kann diese nicht manifestiert und nicht veranschaulicht werden. Sie kann in ihrer in der linearen Zeit verlaufenden Einmaligkeit nicht gezeigt, sondern nur dokumentiert und reflektiert werden und so auf einer transformierten Ebene noch einmal bewusst gemacht werden.

In diesem Verfahren wird die Zeitlichkeit gebannt und an ein Medium gebunden, z. B. an den Film, die Fotografie oder an eine Aufführung.

Wenn man das Leben veranschaulichen will oder das, was es ausmacht, darstellen will, hat man nur die Möglichkeit zu dokumentieren oder zu symbolisieren. Nur aus diesem Grund kann Kunst nicht Leben sein und Leben nicht Kunst.
Gibt es ein Leben ohne Erzählung?
Authors: Delory-Momberger Chrstine
Published: March 2009

Die Erzählung transformiert Ereignisse, Aktionen und Personen des Lebens in Episoden, Handlungen und Protagonisten; sie ordnet Ereignisse in der Zeit und konstruiert zwischen ihnen Beziehungen von Ursache, Folge und Ziel, sie weist so dem Gelegentlichen, dem Zufälligen, dem Heterogenen einen Ort und einen Sinn zu. Durch die Erzählung werden die Menschen zu Protagonisten ihres Lebens und machen aus diesem eine Geschichte. Dieses Konfigurationsverfahren, das Paul Ricoeur mit dem Begriff mise en intrigue beschrieben hat, vollzieht sich in der Sprache. Die Erzählung als Diskursgenre ist dafür nicht nur das Mittel, sondern die Stätte: Das Leben findet in der Erzählung statt, es findet statt als Geschichte. Was dem Leben und der Erfahrung der Menschen Form gibt, sind die Erzählungen, die sie daraus machen. Das Erzählen ist demnach nicht nur das symbolische System, in dem die Menschen das Empfinden ihrer Existenz auszudrücken vermögen: das Erzählen ist die Stätte, wo die menschliche Existenz ihre Form erhält, wo sie sich in Form einer Geschichte ausarbeitet und entwirft.
Das nackte Leben: Vom Labor zum Lager
Authors: Schwarte Ludger
Published: March 2009

Die Experimentalwissenschaft ist mit modernen Herrschaftstechniken verzahnt. Das Lager, Inbegriff der modernen Herrschaft über das Leben, ist ohne diese beiden Seiten, ohne das getestete Wissen und den automatisierten Befehl, nicht zu begreifen. Mein Text stellt den Versuch dar, den Begriff des nackten Lebens durch die Analyse der historischen und systematischen Bezüge zwischen Labor und Lager zu klären.
Extraction of K+, Rb+ and Tl+ from Water into Nitrobenzene by Using Cesium Dicarbollylcobaltate in the Presence of Hexaethyl Calix[6]arene Hexaacetate
Authors: Makrlík E. , Vanura P.
Published: March 2009

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+(aq)+CsL+(nb) ↔ ML+(nb)+Cs+(aq) taking place in the two-phase water-nitrobenzene system (M+ = K+, Rb+, Tl+; L = hexaethyl calix[6]arene hexaacetate; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the ML+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the cation order K+< Rb+< Tl+.
Extraction of Microamounts of Calcium and Strontium into Nitrobenzene by Using Hydrogen Dicarbollylcobaltate in the Presence of “Classical” CMPO
Authors: Makrlík E. , Vanura P. , Selucky P.
Published: March 2009

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of octyl-phenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (“classical” CMPO, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL+, HL2
+, CaL2+, CaL2
2+, CaL3
2+, SrL2
2+, SrL3
2+ and SrL4
2+ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.
Modeling Process Partitioning of Biomolecules in Polymer-Polymer and Polymer-Salt Aqueous Two-Phase Systems (ATPS) using an Extended Excess Gibbs Energy Model
Authors: Pazuki G.R. , Taghikhani V. , Vossoughi M.
Published: March 2009

A new local composition model was used to study the phase behavior of polymer-polymer and polymer-salt aqueous two-phase systems. The proposed model has three terms which account for the combinatorial, the long-range and the short-range effects in solution. The Flory-Huggins and the Debye-Hückel models were used for the combinatorial and long-range contributions. The interaction parameters of the model studied in this work can be regressed using a non-liner regression between the experimental data and those obtained from the proposed model. Also, this model was applied for modeling the partitioning of biomolecules in polymer-polymer and polymer-salt aqueous two-phase systems. The results showed that the proposed model has a good accuracy in correlating the partitioning coefficients of biomolecules in aqueous two-phase systems.
Spindle assembly checkpoint-related failure perturbs early embryonic divisions and reduces reproductive performance of LT/Sv mice
Authors: Maciejewska Zuzanna , Polanski Zbigniew , Kisiel Katarzyna , Kubiak Jacek Z , Ciemerych Maria A
Published: March 2009

The phenotype of the LT/Sv strain of mice is manifested by abnormalities in oocyte meiotic cell-cycle, spontaneous parthenogenetic activation, teratomas formation, and frequent occurrence of embryonic triploidy. These abnormalities lead to the low rate of reproductive success. Recently, metaphase I arrest of LT/Sv oocytes has been attributed to the inability to timely inactivate the spindle assembly checkpoint (SAC). As differences in meiotic and mitotic SAC functioning were described, it remains obscure whether this abnormality is limited to the meiosis or also impinges on the mitotic divisions of LT/Sv embryos. Here, we show that a failure to inactivate SAC affects mitoses during preimplantation development of LT/Sv embryos. This is manifested by the prolonged localization of MAD2L1 on kinetochores of mitotic chromosomes and abnormally lengthened early embryonic M-phases. Moreover, LT/Sv embryos exhibit elevated frequency of abnormal chromosome separation during the first mitotic division. These abnormalities participate in severe impairment of preimplantation development and significantly decrease the reproductive success of this strain of mice. Thus, the common meiosis and mitosis SAC-related failure participates in a complex LT/Sv phenotype.
sparse inflorescence1, barren
inflorescence1 and barren stalk1 Promote Cell Elongation in Maize Inflorescence Development
Authors: Barazesh Solmaz , Nowbakht Cima , McSteen Paula
Published: March 2009

The sparse inflorescence1 (spi1), Barren inflorescence1 (Bif1), barren inflorescence2 (bif2), and barren stalk1 (ba1) mutants produce fewer branches and spikelets in the inflorescence due to defects in auxin biosynthesis, transport, or response. We report that spi1, bif1, and ba1, but not bif2, also function in promoting cell elongation in the inflorescence.
Amino Acid Covariation in a Functionally Important Human Immunodeficiency Virus Type 1 Protein Region Is Associated With Population Subdivision
Authors: da Silva Jack
Published: March 2009

The frequently reported amino acid covariation of the highly polymorphic human immunodeficiency virus type 1 (HIV-1) exterior envelope glycoprotein V3 region has been assumed to reflect fitness epistasis between residues. However, nonrandom association of amino acids, or linkage disequilibrium, has many possible causes, including population subdivision. If the amino acids at a set of sequence sites differ in frequencies between subpopulations, then analysis of the whole population may reveal linkage disequilibrium even if it does not exist in any subpopulation. HIV-1 has a complex population structure, and the effects of this structure on linkage disequilibrium were investigated by estimating within- and among-subpopulation components of variance in linkage disequilibrium. The amino acid covariation previously reported is explained by differences in amino acid frequencies among virus subpopulations in different patients and by nonsystematic disequilibrium among patients. Disequilibrium within patients appears to be entirely due to differences in amino acid frequencies among sampling time points and among chemokine coreceptor usage phenotypes of virus particles, but not source tissues. Positive selection explains differences in allele frequencies among time points and phenotypes, indicating that these differences are adaptive rather than due to genetic drift. However, the absence of a correlation between linkage disequilibrium and phenotype suggests that fitness epistasis is an unlikely cause of disequilibrium. Indeed, when population structure is removed by analyzing sequences from a single time point and phenotype, no disequilibrium is detectable within patients. These results caution against interpreting amino acid covariation and coevolution as evidence for fitness epistasis.
Molecular Basis for Differential Metabolic Responses to Monosulfuron in Three Nitrogen-Fixing Cyanobacteria
Authors: Shen Jianying , DiTommaso Antonio , Shen Mingquan , Lu Wei , Li Zhengming
Published: March 2009

Nitrogen-fixing cyanobacteria are vital photosynthetic microorganisms that contribute to soil fertility by fixing atmospheric nitrogen and are also important for maintaining ecosystem stability. These microorganisms can be very sensitive to herbicides because they possess many characteristics of higher plants. Six days after the application of monosulfuron at 0.03 to 0.3 nmol L−1under laboratory conditions, growth of the nitrogen-fixing cyanobacteriaAnabaena flos-aquae,Anabaena azollae, andAnabaena azoticawas stimulated, but at higher concentrations (30 to 300 nmol L−1) protein synthesis was inhibited. The production of 16 amino acids inA. flos-aquaewas reduced from 7 to 69% with increasing monosulfuron concentration. Application of monosulfuron at 3 to 300 nmol L−1substantially inhibited in vitro acetolactate synthase (ALS) activity as indicated by 50% inhibition index values of 3.3, 65.2, and 101.3 nmol L−1forA. flos-aquae,A. azollae, andA. azotica, respectively. In contrast, extractable ALS activity was not affected in these algal species with monosulfuron treatments ranging from 0.03 to 300 nmol L1except inA. flos-aquaeat higher concentrations (30 to 300 nmol L−1). The most sensitive species to monosulfuron wasA. flos-aquae, followed byA. azollaeandA. azotica. Molecular analyses showed that the genomic DNA ofA. azollaeandA. azoticadiffered in only one amino acid. Results from photogenetic analyses revealed a high degree of homology between these algae. In contrast, the genomic DNA ofA. flos-aquaediffered from that ofA. azollaeandA. azoticain 44 and 45 amino acids, respectively. Our findings support the view that monosulfuron toxicity in these three nitrogen-fixing cyanobacteria is due to interference with protein metabolism via inhibition of branch-chain amino acid biosynthesis, and particularly ALS activity.
Modeling With Limited Data: The Influence of Crop Rotation and Management on Weed Communities and Crop Yield Loss
Authors: Canner Stephen R. , Wiles L. J. , Erskine Robert H. , McMaster Gregory S. , Dunn Gale H. , Ascough James C.
Published: March 2009

Theory and models of crop yield loss from weed competition have led to decision models to help growers choose cost-effective weed management. These models are available for multiple-species weed communities in a single season of several crops. Growers also rely on crop rotation for weed control, yet theory and models of weed population dynamics have not led to similar tools for planning of crop rotations for cost-effective weed management. Obstacles have been the complexity of modeling the dynamics of multiple populations of weed species compared to a single species and lack of data. We developed a method to use limited, readily observed data to simulate population dynamics and crop yield loss of multiple-species weed communities in response to crop rotation, tillage system, and specific weed management tactics. Our method is based on the general theory of density dependence of plant productivity and extensive use of rectangular hyperbolic equations for describing crop yield loss as a function of weed density. Only two density-independent parameters are required for each species to represent differences in seed bank mortality, emergence, and maximum seed production. One equation is used to model crop yield loss and density-dependent weed seed production as a function of crop and weed density, relative time of weed and crop emergence, and differences among species in competitive ability. The model has been parameterized for six crops and 15 weeds, and limited evaluation indicates predictions are accurate enough to highlight potential weed problems and solutions when comparing alternative crop rotations for a field. The model has been incorporated into a decision support tool for whole-farm management so growers in the Central Great Plains of the United States can compare alternative crop rotations and how their choice influences farm income, herbicide use, and control of weeds in their fields.
Relative Competitiveness of Protoporphyrinogen Oxidase-Resistant Common Waterhemp (Amaranthus Rudis)
Authors: Duff Michael G. , Al-Khatib Kassim , Peterson Dallas E.
Published: March 2009

Research was conducted to determine the competitiveness and fitness of a protoporphyrinogen oxidase (protox)-resistant common waterhemp biotype. Protox-resistant and protox-susceptible biotypes were grown under noncompetitive and competitive arrangements in the greenhouse. In the noncompetitive study, a single plant of each biotype was planted separately in 15-cm-diam pots. Photosynthesis, leaf area, and plant biomass were measured 10, 20, 30, and 40 d after transplanting (DATP). In general, photosynthesis rate and plant biomass were similar between biotypes. However, the protox-resistant biotype had higher leaf area than the susceptible biotype at 20, 30, and 40 DATP. A replacement series study was conducted in the greenhouse to evaluate the relative competitiveness of protox-resistant and protox-susceptible common waterhemp. Photosynthesis, leaf area, plant height, and plant biomass were measured 7, 14, 21, and 28 DATP. Protox-resistant and -susceptible common waterhemp were equally competitive 28 DATP. Relative crowding coefficient values 28 DATP were 0.86, 0.89, 1.09, and 1.13 for photosynthesis, leaf area, plant height, and plant biomass, respectively. This suggests protox-resistant and -susceptible common waterhemp were equally competitive and the frequency of protox-resistant biotype is unlikely to decrease in the absence of protox–herbicide selection pressure.
Goatsrue (Galega Officinalis) Seed Biology
Authors: Oldham Michelle , Ransom Corey V.
Published: March 2009

Goatsrue is an introduced perennial plant which has proven to have great invasive potential, leading to its classification as a noxious weed in many states and at the federal level. Very little research has been done on its basic biology. Physical dormancy of mature goatsrue seed was tested through scarification with sulfuric acid for up to 60 min resulting in 100% germination. Comparison of dormancy for 26-yr-old and 6-mo-old goatsrue seed indicated that aged seeds had reduced dormancy levels compared to newly harvested seeds. Maximum germination was similar among the 6-mo old and 26-yr-old seed lots, suggesting no loss of viability had occurred in seed stored dry for 26 yr. Goatsrue seedling emergence was inversely related to burial depth, and decreased as burial depth increased. Emergence of seed buried at 0.5 to 3.0 cm soil depth was 93 to 87%, respectively, and no emergence occurred from 12 and 14 cm. When the soil seed bank of five goatsrue-infested areas was sampled, the largest density of seeds found was 74,609 seeds m−2 while the lowest was 14,832 seeds m−2. Viability and dormancy of seeds recovered from the soil seed bank survey ranged from 91 to 100% and 80 to 93%, respectively. Management, which reduces the soil seed bank and controls emerging seedlings, is as essential as control of mature goatsrue plants in order to avoid seedling establishment and reinvasion of a location.
Software Tools for Weed Seed Germination Modeling
Authors: Spokas Kurt , Forcella Frank
Published: March 2009

The next generation of weed seed germination models will need to account for variable soil microclimate conditions. To predict this microclimate environment we have developed a suite of individual tools (models) that can be used in conjunction with the next generation of weed seed germination models. The three tools that will be outlined here are GlobalTempSIM, GlobalRainSIM, and the soil temperature and moisture model (STM2). Each model was compared with several sets of observed data from worldwide locations. Overall, the climate predictors compared favorably. GlobalTempSIM had a bias between −2.7 and +0.9 C, mean absolute errors between 1.9 and 5.0 C, and an overall Willmott d-index of 0.79 to 0.95 (where d = 1 represents total agreement between observed and modeled data) for 12 global validation sites in 2007. GlobalRainSIM had a bias for cumulative precipitation ranging from −210 to +305 mm, a mean absolute error between 29 and 311 mm, and a corresponding d-index of 0.78 to 0.99 for the sites and years compared. The high d-indices indicate that the models adequately captured the annual patterns for the validation sites. STM2 also performed well in comparisons with actual soil temperatures with a range of −2 to +4.6 C biases and mean absolute errors between 0.7 and 6.8 C, with the d-index ranging from 0.83 to 0.99 for the soil temperature comparisons. The soil moisture prediction annual bias was between −0.09 and +0.12 cm3 cm−3, mean absolute errors ranging from 0.02 to 0.16 cm3 cm−3, and possessed a d-index between 0.32 and 0.91 for the validation sites. These models were developed in JAVA, are simple to use, operate on multiple platforms (e.g., Mac, personal computer, Sun), and are freely available for download from the U.S. Department of Agriculture Agricultural Research Service website (http://www.ars.usda.gov/Services/docs.htm?docid=11787).
How Important Are Foreign Shocks in a Small Open Economy? The Case of Slovakia
Authors: Horvath Roman , Rusnak Marek
Published: March 2009

In this article, we provide evidence on the nature and the relative importance of domestic and foreign shocks – with a focus on monetary shocks – in the Slovak economy based on the block-restriction vector autoregression model during the years 1999–2007. We document a well-functioning monetary transmission mechanism in Slovakia. Subject to various sensitivity checks, we find that contractionary monetary policy shock has a temporary negative effect on the degree of economic activity and price level. We find that using output gap instead of GDP alleviates the price puzzle. In general, prices are driven mainly by foreign factors and the European Central Bank monetary policy shock on Slovak prices is more powerful than that of the National Bank of Slovakia. The Slovak Central Bank interest rate policy seems to follow the ECB's interest rates. On the other hand, spectacular Slovak economic growth is primarily driven by domestic factors suggesting the positive role of recently undertaken Slovak economic reforms.
An Examination of Exchange Rate Pass-Through to U.S. Motor Vehicle Products and Auto-Parts Import Prices
Authors: Turkcan Kemal , Ates Aysegul
Published: March 2009

A distinctive feature of present globalization is the development of international production sharing activities (i.e. production fragmentation). The recent developments in transportation and communication technologies led to a surge in intermediate goods trade. However, intermediate goods trade is often neglected in the empirical studies of the exchange rate pass-through (ERPT). Using import unit values of 79 motor vehicle products and 245 auto-part products, which are classified by the 10-digit level of Harmonized Tariff Schedule (HTS), this study examines the pass-through of exchange rate changes into the U.S. auto-industry import prices from 5 major trading partners for the period of 1998.01 to 2006.12. Nonstationary panel data estimation techniques and tests for cointegration are employed in this study. Secondly, this study aims to compare the ERPT for the motor vehicle products (final goods) to the ERPT for the auto-parts (intermediate goods) in the U.S. The results suggest that import prices do not respond proportionately to the exchange rates and the estimated pass-through elasticities for motor vehicle products are lower than that for auto-parts.
A Proposal for an Asian Rice Insurance Mechanism
Authors: Mendoza Ronald U.
Published: March 2009

The food price shocks that erupted in 2008 revealed the vulnerability of many developing countries, notably those in Asia, from volatility in the international foodgrain markets. For instance, by March of 2008, the price of traded rice had increased by well over 70 percent compared to year-before levels. Addressed primarily to policymakers in the Asian region, this paper outlines a proposal for a regional risk sharing arrangement—an Asian rice insurance mechanism (ARIM)—which could form part of the region's long-term response to the food security issue. The ARIM could serve as a regional public good by helping countries in the region more efficiently manage the risks related to volatile rice production and trade, arising from emerging structural factors such as the rising and evolving food demand of large Asian countries like China, India and Indonesia, as well as the effects of climate change (and climatic shocks) on the agricultural sector more broadly.
The Effects of Mobile Phones and Hands-Free Laws on Traffic Fatalities
Authors: Kolko Jed D
Published: March 2009

Using state-level panel data on mobile phone ownership, hands-free laws, and traffic fatalities, this paper finds that mobile phone ownership is associated with higher traffic fatalities, but only in bad weather or wet road conditions. The limited experience of a few states suggests that hands-free laws reduce traffic fatalities, but again only in bad weather or wet road conditions, and possibly also in rush-hour traffic. The findings suggest that the benefits of hands-free laws depend on driving conditions, and an important policy implication is hands-free laws should be more strongly enforced when driving conditions are more difficult. These findings on hands-free laws differ from other research, which consistently finds that hands-free and handheld phone usage have similar effects on driver distraction and accident risk, calling into question the usefulness of hands-free laws.
When Worlds Collide: Applying the Nonobviousness and Novelty Requirements of Patent Law to Tax Strategy Patents
Authors: Sawyers Roby B. , Baumer David L. , Chumney Wade M.
Published: March 2009

A proliferation of newly issued tax-related patents has resulted in concern and confusion among tax practitioners. Tax practitioners argue that the tax strategies claimed in the patents have been used for many years and do not meet the novel and nonobvious requirements of patent law. Additionally, tax professionals are concerned that enforcement of these patents will limit their ability to serve as advocates for their clients and recommend tax strategies that legally minimize their clients' taxes. Tax professionals also worry that they may be in jeopardy of being sued as defendants in tax-related patent infringement cases.

In this paper, the authors review the basics of patent law, discuss business method patents, and analyze five tax strategy patents in order to determine whether the inventions claimed in the patents meet the nonobviousness and novelty requirements of patent law. The authors examine articles, IRS Revenue Rulings, Private Letter Rulings, continuing education materials, and other evidence in publicly available printed publications and conclude that the “prior art” in the field was sufficient at the time of the patent applications in order to potentially question the validity of the patents.