bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of specific factors generating 2-cell block in AKR mouse embryos
Authors: Yoneda Akihiro , Okada Aki , Wakayama Teruhiko , Ueda Junji , Watanabe Tomomasa 
Published: May 2006

SummaryThe phenomenon of the developmental arrest at the 2-cell stage of 1-cell embryos from some mouse strains duringin vitroculture is known as the 2-cell block. We investigated the specific factors involved in the 2-cell block of AKR embryos by means of a modified culture system, the production of reconstructed embryos by pronuclear exchange and a cross experiment. In a culture medium with phosphate, 94.6% of 1-cell embryos from the C57BL mouse strain developed to the blastocyst stage, but 95.7% of embryos from the AKR mouse strain showed 2-cell block. Phosphate-free culture medium rescued the 2-cell block of AKR embryos and accelerated the first cell cycle of the embryos. Co-culture with BRL cells and a BRL-conditioned medium fractionated below 30 kDa also rescued the 2-cell block of AKR embryos. Examinations ofin vitrodevelopment of reconstructed embryos and of embryos from F1 females between AKR and C57BL strains clearly demonstrated that the AKR cytoplast caused the 2-cell block. In the backcrossed female progeny between (AKR × C57BL) F1 males and AKR females, about three-quarters of the embryos were of the 2-cell blocking phenotype and about one-quarter were of the non-blocking phenotype. These results suggest that two genes are responsible for the 2-cell block of AKR embryos.
Na+/Ca2+exchanger contributes to asterosap-induced elevation of intracellular Ca2+concentration in starfish spermatozoa
Authors: Islam M. Sadiqul , Kawase Osamu , Hase Sumitaka , Minakata Hiroyuki , Hoshi Motonori , Matsumoto Midori 
Published: May 2006

SummaryAsterosap, a group of equally active isoforms of sperm-activating peptides from the egg jelly of the starfishAsterias amurensis, functions as a chemotactic factor for sperm. It transiently increases the intracellular cGMP level of sperm, which in turn induces a transient elevation of intracellular Ca2+concentration ([Ca2+]i). Using a fluorescent Ca2+-sensitive dye, Fluo-4 AM, we measured the changes in sperm [Ca2+]iin response to asterosap. KB-R7943 (KB), a selective inhibitor of Na+/Ca2+exchanger (NCX), significantly inhibited the asterosap-induced transient elevation of [Ca2+]i, suggesting that asterosap influences [Ca2+]ithrough activation of a K+-dependent NCX (NCKX). An NCKX activity of starfish sperm also shows K+dependency like other NCKXs. Therefore, we cloned an NCKX from the starfish testes and predicted that it codes for a 616 amino acid protein that is a member of the NCKX family. Pharmacological evidence suggests that this exchanger participates in the asterosap-induced Ca2+entry into sperm.
Soil state and surface hydrology diagnosis based on MOSES in the Met Office Nimrod nowcasting system
Authors: Smith R. N. B. , Blyth E. M. , Finch J. W. , Goodchild S. , Hall R. L. , Madry S. 
Published: May 2006

AbstractA system has been developed and made operational at the Met Office for the real‐time diagnosis of soil state and surface hydrology. It is based on the Met Office Surface Exchanges Scheme (MOSES) modified to take account of unresolved soil and topographic heterogeneity when calculating surface runoff by incorporating a Probability Distributed Moisture (PDM) scheme developed by the Centre for Ecology and Hydrology. The implementation of MOSES‐PDM in the Met Office's Nimrod nowcasting system is described. High resolution soil characteristics and land cover data, together with Nimrod's analyses of precipitation amount and type, cloud cover and near‐surface atmospheric variables are used to drive MOSES‐PDM. Hourly values of snowmelt, runoff, net surface radiation, evaporation, potential evaporation, soil temperature, soil moisture and soil moisture deficit are calculated on a 5 km grid. Copyright © 2006 Royal Meteorological Society.
Statistical methods for the prediction of night‐time cooling and minimum temperature
Authors: Emmanouil G. , Galanis G. , Kallos G. 
Published: May 2006

AbstractFour different models for the prediction of frost events caused by air cooling due to thermal radiation are presented in this paper. Three of them are based on polynomial functions that simulate different types of temperature variations in comparison with an exponential one. The fourth, a post‐processing method based on Kalman filters, is proposed for those cases where a systematic type of bias has emerged. Copyright © 2006 Royal Meteorological Society.
A flow regime diagram for forecasting lee waves, rotors and downslope winds
Authors: Sheridan P. F. , Vosper S. B. 
Published: May 2006

AbstractThe influence of a strong low‐level temperature inversion on the occurrence of lee waves, rotors and hydraulic jumps has been investigated using high resolution numerical model simulations. The aim of the work is to develop tools for forecasting hazardous winds downstream of mountains. Two‐dimensional simulations were conducted for a range of inversion heights and strengths and a fixed hill shape; lee waves, rotors and hydraulic jumps were found to occur. The flow type depends largely on the ratio of mountain height to inversion height and the upstream Froude number. A flow regime diagram based on these two parameters has been constructed and suggests that rotors could be forecast using upstream profiles, which are generally readily available from numerical weather prediction models.The applicability of the regime diagram for two‐dimensional flow to flows over real terrain has been tested using three‐dimensional simulations of flows over East Falkland, South Atlantic, under a range of upstream conditions. The flow type is found to be determined largely by the upstream profiles of wind and temperature, and the maximum height of orography directly upstream, indicating that the flow regime diagram can be used to predict flow type downstream of such terrain. Various three‐dimensional flow phenomena occur, such as flow channelling through gaps, and could be taken into account to improve the information available from the regime diagram. Copyright © 2006 Royal Meteorological Society.
A feasibility study of daytime fog and low stratus detection with TERRA/AQUA‐MODIS over land
Authors: Bendix Jörg , Thies Boris , Nauß Thomas , Cermak Jan 
Published: May 2006

AbstractA scheme for the detection of fog and low stratus over land during daytime based on data of the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument is presented. The method is based on an initial threshold test procedure in the MODIS solar bands 1–7 (0.62–2.155µm). Fog and low stratus detection generally relies on the definition of minimum and maximum fog and low stratus properties, which are converted to spectral thresholds by means of radiative transfer calculations (RTC). Extended sensitivity studies reveal that thresholds mainly depend on the solar zenith angle and, hence, illumination‐dependent threshold functions are developed. Areas covered by snow, ice and mid‐/high‐level clouds as well as bright/hazy land surfaces are omitted from the initial classification result by means of a subsequent cloud‐top height test based on MODIS IR band 31 (at 12 µm) and a NIR/VIS ratio test. The validation of the final fog and low stratus mask generally shows a satisfactory performance of the scheme. Validation problems occur due to the late overpass time of the TERRA platform and the time lag between SYNOP and satellite observations. Apparent misclassifications are mainly found at the edge of the fog layers, probably due to over‐ or underestimation of fog and low stratus cover in the transition zone from fog to haze. Copyright © 2006 Royal Meteorological Society.
THE UNDISCOVERED FLIGHT PATHS OF THE ‘MUSICAL BEE’: NEW LIGHT ON HUMMEL’S MUSICAL QUOTATIONS
Authors: STEWART-MACDONALD ROHAN 
Published: May 2006

Hummel’s quoting of music by other composers has been mentioned briefly in a number of studies. While some of these quotations are explicit, others are a good deal more problematic. This article investigates explicit quotations that appear in two of Hummel’s string quartets dating from 1803–1804 and the finale of a piano sonata from 1807. The fourth movement of the String Quartet in G major, Op. 30 No. 2, twice quotes J. S. Bach’s Goldberg Variations, BWV988, the slow movement of Op. 30 No. 3 refers to Handel’s Messiah and the finale of the F minor piano sonata cultivates a complex relationship with the last movement of Mozart’s ‘Jupiter’ Symphony. My objective is to demonstrate the sophistication and subtlety with which Hummel manipulates the quoted material in these three cases.Hummel’s obvious quotation of Bach and Handel in particular is related to a multi-faceted preoccupation with archaic styles and earlier works that had taken root in the later eighteenth century and that continued to expand into the nineteenth and beyond. Although England was the first nation to develop a performance tradition around the ‘ancient’ musical repertory, it was the accumulation of a didactic tradition around the keyboard works of J. S. Bach in north Germany and its steady migration to centres like Vienna that is of more direct relevance here. And when one surveys the (supposed) quotations by Haydn, Mozart, Beethoven and Clementi of works by Bach and Handel and compares them with Hummel’s, Hummel’s remain outstanding in their exactness and also in their frequent lightheartedness of tone. Whereas many straightforward quotations or instances of modelling appear reverential or seek to exalt the basic idiom, Hummel’s either are humorous or seem calculated to reduce the potency of the original in order to assimilate the earlier idiom into the later one. The three pieces considered here illustrate the spectrum of techniques used by Hummel to manipulate quoted material in his works. The quotations in the two quartets have drawn very little comment; the references to Mozart’s ’Jupiter’ Symphony in the finale of Op. 20 have been remarked on more frequently, but the relationship between the two finales is a good deal more intricate than has previously been shown. The ‘contrapuntal deconstruction’ that takes place late in the third movement of Hummel’s Op. 20, between the most explicit reference to the ‘Jupiter’ finale and the coda, is lighthearted in character – amusing, even – and is in some ways the most ingenious and vibrant episode in the movement.
Super solutions of the dynamical Yang-Baxter equation
Authors: Karaali Gizem 
Published: May 2006

Solutions of the classical dynamical Yang-Baxter equation on a Lie superalgebra are called super dynamical

r
−

r-

matrices. A super dynamical

r
−

r-

matrix

r
r

satisfies the zero weight condition if
\[

[
h
⊗
1
+
1
⊗
h
,
r
(
λ
)
]
=
0
for all
h
∈

h

,
λ
∈

h

∗

.

[h\otimes 1 + 1 \otimes h, r(\lambda )] = 0 \text { for all } h \in \mathfrak {h}, \lambda \in \mathfrak {h}^*.

\]
In this paper we classify super dynamical

r
−

r-

matrices with zero weight.
Identifying sequence regions undergoing conformational change via predicted continuum secondary structure
Authors: Bodén Mikael , Bailey Timothy L. 
Published: May 2006

Abstract
Motivation: Conformational flexibility is essential to the function of many proteins, e.g. catalytic activity. To assist efforts in determining and exploring the functional properties of a protein, it is desirable to automatically identify regions that are prone to undergo conformational changes. It was recently shown that a probabilistic predictor of continuum secondary structure is more accurate than categorical predictors for structurally ambivalent sequence regions, suggesting that such models are suited to characterize protein flexibility.
Results: We develop a computational method for identifying regions that are prone to conformational change directly from the amino acid sequence. The method uses the entropy of the probabilistic output of an 8-class continuum secondary structure predictor. Results for 171 unique amino acid sequences with well-characterized variable structure (identified in the ‘Macromolecular movements database’) indicate that the method is highly sensitive at identifying flexible protein regions, but false positives remain a problem. The method can be used to explore conformational flexibility of proteins (including hypothetical or synthetic ones) whose structure is yet to be determined experimentally.
Availability: The predictor, sequence data and supplementary studies are available at and are free for academic use.
Contact: mikael@itee.uq.edu.au
Endotoxaemia induces resistance to activated protein C in healthy humans
Authors: De Pont Anne‐Cornélie J. M. , Bakhtiari Kamran , Hutten Barbara A. , De Jonge Evert , Vlasuk George P. , Rote William E. , Levi Marcel , Büller Harry R. , Meijers Joost C. M. 
Published: May 2006

SummarySystemic inflammation activates the tissue factor/factor VIIa complex (TF/FVIIa), leading to a procoagulant state, which may be enhanced by impairment of physiological anticoagulant pathways, such as the protein C system. Besides impaired protein C activation, resistance to activated protein C (APC) may occur. We studied the effect of endotoxemia on APC resistance, analysed its determinants and evaluated the effect of TF/FVIIa inhibition on endotoxin‐induced APC resistance. Sixteen healthy male volunteers participated in the study, eight receiving endotoxin alone and eight receiving the combination of endotoxin and recombinant Nematode Anticoagulant Protein c2 (rNAPc2), a potent inhibitor of TF/FVIIa. Parameters of coagulation were subsequently studied. The sensitivity to APC was determined by two tests: a test based on the endogenous thrombin potential and a test based on the activated partial thromboplastin time. In response to endotoxemia, both tests detected a transient APC resistance that was predominantly mediated by an increase in factor VIII and was not influenced by TF/FVIIa inhibition. In vitro tests confirmed that an increase in factor VIII induced APC resistance, as measured by both tests. This finding suggests that APC resistance might play a role in the procoagulant state occurring during human endotoxemia.
Rapid rescreening of cervical smears as a quality control method in a high‐risk population
Authors: Michelow P. , McKee G. , Hlongwane F. 
Published: May 2006

Objective:  Cancer of the cervix is one of the commonest cancers in South Africa. Accurate cytological diagnosis is one of the prerequisites for an effective cervical screening programme and requires the implementation of appropriate quality assurance modalities. This study was undertaken to determine if rapid review of reportedly negative cervical smears is a useful internal quality assurance modality in an unscreened population with very high rates of cervical carcinoma.Method:  Approximately 26% of all cervical smears received at the study institution between 1 January 1998 and 31 December 2003, and initially reported as negative or inadequate, underwent rapid review.Results:  A total of 62 866 (26%) cervical smears out of 241 796 reportedly negative or inadequate cervical smears underwent rapid review. An amended report was sent out in 373 (0.59%) of these 62 866 cervical smears. This included 101 cases of high‐grade squamous intraepithelial lesion (HSIL) and high‐grade atypical squamous cells (ASC‐H), 143 low‐grade squamous intraepithelial lesions, 54 atypical squamous cells of undetermined significance (ASC‐US) and 33 atypical glandular cells that were not reported initially. The false‐negative proportion for HSIL and ASC‐H (combined) in this study was 5.76%. No squamous cell carcinomas were diagnosed on rapid review but one patient with HSIL/ASC‐H on review had squamous cell carcinoma on biopsy. Three cytotechnologists had a lower sensitivity of primary screening and required retraining.Conclusions:  Rapid review is beneficial as an internal quality assurance modality in an unscreened high‐risk population and increases the detection of women with significant cervical lesions requiring treatment. The relatively low cost of rapid review compared with other rescreening modalities makes this an attractive option in low resource settings.
Expression of CD30 (Ber‐H2) in nasopharyngeal carcinoma, undifferentiated type and lymphoepithelioma‐like carcinoma. A comparison study with anaplastic large cell lymphoma
Authors: Kneile J R , Tan G , Suster S , Wakely P E 
Published: May 2006

Aims : Undifferentiated nasopharyngeal non‐keratinizing carcinoma (UNPC), formerly known as lymphoepithelioma, frequently metastasizes at an early stage to regional lymph nodes and, thus, may be difficult to distinguish from Hodgkin's lymphoma (HL) or anaplastic large cell lymphoma (ALCL). CD30 expression is a useful diagnostic stain in both HL and ALCL, but its expression in UNPC deserves clarification. The aim of this study was to evaluate CD30 expression in UNPC and lymphoepithelioma‐like carcinoma (LELC) from other anatomic locations and compare it with ALCL and squamous cell carcinoma (SCC).Methods and results : CD30 immunoreactivity was examined in 38 cases of primary or metastatic UNPC, six cases of LELC, 10 cases of SCC and seven cases of ALCL. CD30 immunoreactivity was observed in four of 38 (10.5%) cases of UNPC. CD30 staining was absent in all cases of LELC (0/6) and SCC (0/10). All cases of ALCL (7/7) were strongly positive for CD30.Conclusions : The majority of cases of UNPC are immunohistochemically negative for CD30; however, a small subset of cases expresses CD30 antigen. These findings provide additional evidence that CD30 expression is not restricted to neoplasms of lymphoid origin. This should be taken into consideration when interpreting CD30 immunohistology and the possibility of UNPC.
Carbon turnover in Alaskan tundra soils: effects of organic matter quality, temperature, moisture and fertilizer
Authors: SHAVER GAIUS R. , GIBLIN A. E. , NADELHOFFER K. J. , THIELER K. K. , DOWNS M. R. , LAUNDRE J. A. , RASTETTER E. B. 
Published: May 2006

SummaryNorthern ecosystems may lose large amounts of soil C as the global climate warms over the next few decades. This study describes how soil C loss is related to temperature, moisture and chemical composition of organic matter in Alaskan tundra soils, including soils that were fertilized annually for 8 years prior to the study.Fertilized and unfertilized soils from four vegetation types (tussock, intertussock, sedge and heath) were incubated at 7 or 15 °C, under saturated or well‐drained conditions, through four 100‐day ‘seasons’ separated by 25‐ to 45‐day frozen periods.Losses of CO2were monitored and total C loss was determined by difference between initial and final C stocks. Initial and final organic matter composition was determined by separation into non‐polar extractable (NPE, mainly fats, oils, and waxes), water‐soluble (WS, mainly soluble carbohydrates and phenolics), acid‐soluble (AS, mainly cellulose and related compounds), and acid‐insoluble (AIS, ‘lignin’) fractions. An isotopic label (99%13C‐enriched glucose) was added to track transformations among the C fractions.Total C loss during the experiment was 3–32% of initial C mass depending on soil type and treatment, with most of the loss as CO2. Wet sedge tundra soils, with the largest AS and AIS fractions, lost the least CO2and total C. The added13C ended up in all C fractions, indicating production, as well as loss of all fractions.The greatest CO2and total C losses occurred under warm, well‐drained conditions, in all soils. The effects of fertilizer treatment were occasionally significant but never large relative to the other treatments.Despite the long incubation under standard conditions, there was no evidence for convergence in C chemistry among soils as indicated by changes in relative abundances of the four C fractions.Large and constant rates of C loss even after 4 ‘seasons’ of incubation suggest that a large portion of the C pool is potentially mineralizable in all soil types.Warming of the Arctic climate and associated thawing of permafrost and the increase in soil drainage have the potential to cause a large release of C. This C, currently stored in soil organic matter, will be released to the atmosphere, creating a positive feedback on future climate changes.
Spatial distributions of plants and gross N transformation rates in a forest soil
Authors: BENGTSON PER , FALKENGREN‐GRERUP URSULA , BENGTSSON GÖRAN 
Published: May 2006

Summary
This work demonstrates that spatial distribution of understorey vegetation and gross N transformation rates in a mixed beach‐oak forest is closely correlated within a distance of a few metres. The findings imply that plant diversity and productivity have a major influence on gross rates of N transformation and vice versa.
A geostatistical analysis was used to evaluate the spatial relationships between abundance and species composition of the understorey vegetation and in situ gross N mineralization, immobilization and nitrification rates.
The gross N transformation rates and the plants spatial variation were correlated within the forest, but plant distribution was more dependent on the fraction of mineralized N that was nitrified than on individual N transformation rates.
The total cover of the understorey vegetation varied more in space than the species composition, and was higher in areas with high N transformation rates.
Plant species benefiting from high net nitrification rates were more common in areas with a low activity of mineralizing and nitrifying microorganisms, possibly because the net and gross rates were independent of each other. In fact, those species occurred most often in areas in which a large fraction of mineralized N was nitrified.
Beech and oak trees also had an effect on the spatial variation of the understorey vegetation. Beech trees provided conditions more suitable for plants benefiting from , whereas the vascular plant cover was greater under oak trees, probably in response to a higher light interception than under beech trees.
Oak generally had a positive impact on gross N transformation rates compared with beech, perhaps reflecting differences in litter quality and climate caused by the two species.
The influence of trees alone could not explain the full magnitude of the variation of N transformation rates or the presence of overlapping areas with high mineralization and immobilization rates. These were probably caused by other factors, such as soil moisture content.
This work sheds new light on the small‐scale spatial links between above‐ground plant diversity and abundance, and below‐ground microbial N transformations.