bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplementation of fructose in chemically defined protein-free medium enhances the in vitro development of bovine transgenic cloned embryos
Authors: Uddin Bhuiyan M.M. , Kang S-K. , Lee B-C.
Published: July 2007

The present study evaluated the possible embryotrophic role of fructose supplementation in chemically defined protein-free KSOM on in vitro development of bovine transgenic cloned embryos. Bovine fetal fibroblasts transfected with expression plasmids for bovine prion protein (PrP) mutant gene with GFP marker gene were used as donor nuclei for reconstruction of slaughterhouse-derived in vitro matured oocytes. The reconstructed oocytes were cultured in KSOM supplemented with 0.01% PVA (KSOM–PVA) at 39 °C in a humidified atmosphere of 5% CO2, 5% O2 and 90% N2 for 192 h. In Experiment 1, when reconstructed oocytes were cultured in KSOM–PVA supplemented with glucose (0.2 mM), fructose (1.5 mM) or combined glucose and fructose (0.2 and 1.5 mM, respectively), significantly (p < 0.05) higher blastocyst (19.2%) and hatching/hatched blastocyst (13.1%) formation rates were obtained in combined fructose and glucose supplemented medium than glucose supplemented counterpart (10.0% and 5.7%, respectively). In Experiment 2, when reconstructed oocytes were cultured in KSOM–PVA supplemented with 0.0, 0.2, 1.5, 3.0 and 5.6 mM fructose in combination with 0.2 mM glucose, the blastocyst formation rate was significantly higher (17.6%) in 1.5 mM fructose supplemented group than that of no fructose supplemented counterpart (9.7%; p > 0.05). In conclusion, supplementation of combined fructose (1.5 mM) and glucose (0.2 mM) in chemically defined protein-free KSOM enhances the in vitro development of bovine transgenic cloned embryos.
Identification of sperm morphometric subpopulations in the canine ejaculate: do they reflect different subpopulations in sperm chromatin integrity?
Authors: Núñez-Martinez I. , Moran J.M. , Peña F.J.
Published: July 2007

A statistical approach using sequentially principal component analysis (PCA) clustering and discriminant analysis was developed to disclose morphometric sperm subpopulations. In addition, we used a similar approach to disclose subpopulations of spermatozoa with different degrees of DNA fragmentation. It is widely accepted that sperm morphology is a strong indicator of semen quality and since the sperm head mainly comprises the sperm DNA, it has been proposed that subtle changes in sperm head morphology may be related to abnormal DNA content. Semen from four mongrel dogs (five replicates per dog) were used to investigate DNA quality by means of the sperm chromatin structure assay (SCSA), and for computerized sperm morphometry (ASMA). Each sperm head was measured for nine primary parameters: head area (A), head perimeter (P), head length (L), head width (W), acrosome area (%), midpiece width (w), midpiece area (a), distance (d) between the major axes of the head and midpiece, angle (θ) of divergence of the midpiece from the head axis; and four parameters of head shape: FUN1 (L/W), FUN2 (4π A/P2), FUN3 ((L – W)/(L + W)) and FUN 4 (π LW/4A). The data matrix consisted of 2361 observations, (morphometric analysis on individual spermatozoa) and 63 815 observations for the DNA integrity. The PCA analysis revealed five variables with Eigen values over 1, representing more than 79% of the cumulative variance. The morphometric data revealed five sperm subpopulations, while the DNA data gave six subpopulations of spermatozoa with different DNA integrity. Significant differences were found in the percentage of spermatozoa falling in each cluster among dogs (p< 0.05). Linear regression models including sperm head shape factors 2, 3 and 4 predicted the amount of denatured DNA within each individual spermatozoon (p< 0.001). We conclude that the ASMA analysis can be considered a powerful tool to improve the spermiogram.
Assembly of ovarian follicles in the caeciliansIchthyophis tricolorandGegeneophis ramaswamii:light and transmission electron microscopic study
Authors: Beyo R.S. , Sreejith P. , Divya L. , Oommen O.V. , Akbarsha M.A.
Published: July 2007

Though much is known about various aspects of reproductive biology of amphibia, there is little information on the cellular and mechanistic basis of assembly of ovarian follicles in this group. This is especially true of the caecilians. Therefore, taking advantage of the abundant distribution of caecilians in the Western Ghats of India, two species of caecilians,Ichthyophis tricolorandGegeneophis ramaswamii, were subjected to light and transmission electron microscopic analysis to trace the sequential changes during the assembly of ovarian follicles. The paired ovaries of these caecilians are elongated sac-like structures each including numerous vitellogenic follicles. The follicles are connected by a connective tissue stroma. This stroma contains nests of oogonia, primary oocytes and pregranulosa cells as spatially separated nests. During assembly of follicles the oocytes increase in size and enter the meiotic prophase when the number of nucleoli in the nucleus increases. The mitochondrial cloud or Balbiani vitelline body, initially localized at one pole of the nucleus, disperses through out the cytoplasm subsequently. Synaptonemal complexes are prominent in the pachytene stage oocytes. The pregranulosa cells migrate through the connective tissue fibrils of the stroma and arrive at the vicinity of the meiotic prophase oocytes. On contacting the oocyte, the pregranulosa cells become cuboidal in shape, wrap the diplotene stage oocyte as a discontinuous layer and increase the content of cytoplasmic organelles and inclusions. The oocytes increase in size and are arrested in diplotene when the granulosa cells become flat and form a continuous layer. Soon a perivitelline space appears between the oolemma and granulosa cells, completing the process of assembly of follicles. Thus, the events in the establishment of follicles in the caecilian ovary are described.
“BLACK HOLES” OF CALCUTTA AND LONDON: INTERNAL COLONIES INVANITY FAIR
Authors: Zoli Corri
Published: July 2007

WILLIAM MAKEPEACE THACKERAY'SVanity Fair(1847–48) makes a passing reference to a seemingly insignificant trope, the “Black Hole of Calcutta.” Part of an eighteenth-century legacy of unofficial rule in India by the East India Trading Company, this reference to a prison incident in June 1756 rehashes the event that occurred there – nearly one hundred years before the novel was published. The name, the “Black Hole,” evokes the prison itself: an enormous pit dug deep into the ground “eighteenth feet long by fourteen feet, ten inches wide,” according to social historian Brijen K. Gupta. It was “British” in the sense that East India Company agents stationed on-the-ground in Calcutta controlled this makeshift dungeon, using it to enforce local trade agreements with native authorities. Those who intervened were deemed traitors, the worst offenders of state.
“FAC-SIMILES OF NATURE”: VICTORIAN WAX FLOWER MODELLING
Authors: Shteir Ann B.
Published: July 2007

THE GIGANTIC WATER LILY WHOSEseeds were brought to England from the Amazon in 1847 had been sighted a decade earlier in British Guiana by Sir Robert Schomburgk and described in 1837. NamedVictoria regiaand now known asVictoria amazonica, the spectacular specimen had huge leaves five feet in diameter and seventeen feet in circumference, and flowers more than twelve inches in diameter. Germination of the seeds took some time, but in 1849 three plants developed, and the race was on to propagate the first flower. The triumphal first bud in England opened in early November 1849, its flower measuring three feet in circumference, at the Chatsworth estate of the Duke of Devonshire where the gardener and landscape architect, Joseph Paxton, had designed a greenhouse and water tanks for this purpose; Margaret Darby has detailed the precise attention that Paxton gave to the levels of light, moisture, and heat so as to approximate the plant's native habitat. TheVictoria regiaproduced 126 large, beautiful, and fragrant white and pink tinted flowers. It was a popular wonder and received clamorous public attention for its size, beauty, and surprising strength. Paxton presented a leaf and flower to the Queen and Prince Albert at Windsor, and a well-known engraving in theIllustrated London News, November 17, 1849, showed Paxton's eight-year old daughter Annie standing on one of the leaves. Publication in 1851 ofVictoria Regia; or Illustrations of the Royal Water-Lilywith life-sized drawings and lithographs by Walter Hood Fitch and descriptions by the botanist Sir William Jackson Hooker brought further celebrity to the plant. Soon after, John and Horatio Mintorn, wax flower artists in London, were commissioned to make a model of the flower of this huge plant in different stages of development – “from the large and bristly bud to the white opening petals, and the full-blown flower, in its beautiful variegation of form and tint” (theDaily NewsJuly 17, 1850). Exhibition of the wax model generated wide press coverage about the “fac-simile…of one of the most curious botanical phenomenon of the present age” (Mintorn 1844, ii-iii).
Morphological and Chemical Characteristics of Airborne Tungsten Particles of Fallon, Nevada
Authors: Sheppard Paul R. , Toepfer Paul , Schumacher Elaine , Rhodes Kent , Ridenour Gary , Witten Mark L.
Published: July 2007

Morphological and chemical characteristics were determined for airborne tungsten particles in Fallon, Nevada, a town that is distinguishable environmentally by elevated airborne tungsten and cobalt. From samples of airborne dust collected previously at six different places in Fallon, tungsten-rich dust particles were isolated and analyzed with automated electron microprobe and wavelength-dispersive spectrometry. Representative W particles were further analyzed using transmission electron microscopy. Morphologically, Fallon W particles are angular and small, with minimum and maximum sizes of ≤1 μm and 5.9 μm in diameter, respectively. The number and size of tungsten-rich particles decrease in Fallon with distance from a hard-metal facility located near the center of town. Chemically, Fallon airborne W particles include mixtures of tungsten with cobalt plus other metals such as chromium, iron, and copper. No W-rich particles were identifiable as CaWO4(scheelite) or MnWO4(huebnerite). From d-spacings, Fallon particles are most consistent with identification as tungsten carbide. Based on these multiple lines of evidence, airborne W particles in Fallon are anthropogenic in origin, not natural. The hard-metal facility in Fallon processes finely powdered W and W-Co, and further investigation using tracer particles is recommended to definitively identify the source of Fallon's airborne tungsten.
Atomic Force Microscopy of Removal of Dentin Smear Layers
Authors: Batista Luiz Henrique Carvalho , Júnior José Ginaldo da Silva , Silva Milton Fernando Andrade , Tonholo Josealdo
Published: July 2007

The regular periodontal practice of scaling and root planing produces a smear layer on the root surface that is detrimental to the readhesion of tissues during subsequent regeneration therapy. Although it has been demonstrated that gels containing the chelating agent ethylenediaminetetraacetic acid (EDTA) can assist in the removal of this contaminating layer, no quantitative method is yet available by which to evaluate the efficiency of the treatment. In this article, the power of atomic force microscopy (AFM) as a technique for monitoring and mapping the surfaces of dentinal roots is demonstrated. Roughness parameters of teeth that had been scaled and root planed were determined from AFM images acquired both before and after treatment with EDTA. The results confirmed that EDTA is an efficient cleaning agent and that dentinal samples free from a smear layer are significantly rougher than the same samples covered by a contaminating layer. AFM analysis is superior to alternative methods involving scanning electron microscopy because the same sample section can be analyzed many times, thus permitting it to be used as both the control and the treatment surface.
High Resolution FESEM and TEM Reveal Bacterial Spore Attachment
Authors: Panessa-Warren Barbara J. , Tortora George T. , Warren John B.
Published: July 2007

Transmission electron microscopy (TEM) studies in the 1960s and early 1970s using conventional thin section and freeze fracture methodologies revealed ultrastructural bacterial spore appendages. However, the limited technology at that time necessitated the time-consuming process of imaging serial sections and reconstructing each structure. Consequently, the distribution and function of these appendages and their possible role in colonization or pathogenesis remained unknown. By combining high resolution field emission electron microscopy with TEM images of identical bacterial spore preparations, we have been able to obtain images of intact and sectioned Bacillus and Clostridial spores to clearly visualize the appearance, distribution, resistance (to trypsin, chloramphenicol, and heat), and participation of these structures to facilitate attachment of the spores to glass, agar, and human cell substrates. Current user-friendly commercial field emission scanning electron microscopes (FESEMs), permit high resolution imaging, with high brightness guns at lower accelerating voltages for beam sensitive intact biological samples, providing surface images at TEM magnifications for making direct comparisons. For the first time, attachment structures used by pathogenic, environmental, and thermophile bacterial spores could be readily visualized on intact spores to reveal how specific appendages and outer spore coats participated in spore attachment, colonization, and invasion.
Engineering the substrate and inhibitor specificities of human coagulation Factor VIIa
Authors: Larsen Katrine S. , Østergaard Henrik , Bjelke Jais R. , Olsen Ole H. , Rasmussen Hanne B. , Christensen Leif , Kragelund Birthe B. , Stennicke Henning R.
Published: July 2007

The remarkably high specificity of the coagulation proteases towards macromolecular substrates is provided by numerous interactions involving the catalytic groove and remote exosites. For FVIIa [activated FVII (Factor VII)], the principal initiator of coagulation via the extrinsic pathway, several exosites have been identified, whereas only little is known about the specificity dictated by the active-site architecture. In the present study, we have profiled the primary P4–P1 substrate specificity of FVIIa using positional scanning substrate combinatorial libraries and evaluated the role of the selective active site in defining specificity. Being a trypsin-like serine protease, FVIIa had P1 specificity exclusively towards arginine and lysine residues. In the S2 pocket, threonine, leucine, phenylalanine and valine residues were the most preferred amino acids. Both S3 and S4 appeared to be rather promiscuous, however, with some preference for aromatic amino acids at both positions. Interestingly, a significant degree of interdependence between the S3 and S4 was observed and, as a consequence, the optimal substrate for FVIIa could not be derived directly from a subsite-directed specificity screen. To evaluate the role of the active-site residues in defining specificity, a series of mutants of FVIIa were prepared at position 239 (position 99 in chymotrypsin), which is considered to be one of the most important residues for determining P2 specificity of the trypsin family members. This was confirmed for FVIIa by marked changes in primary substrate specificity and decreased rates of antithrombin III inhibition. Interestingly, these changes do not necessarily coincide with an altered ability to activate Factor X, demonstrating that inhibitor and macromolecular substrate selectivity may be engineered separately.
The mammalian oxysterol-binding protein-related proteins (ORPs) bind 25-hydroxycholesterol in an evolutionarily conserved pocket
Authors: Suchanek Monika , Hynynen Riikka , Wohlfahrt Gerd , Lehto Markku , Johansson Marie , Saarinen Hannu , Radzikowska Anna , Thiele Christoph , Olkkonen Vesa M.
Published: July 2007

OSBP (oxysterol-binding protein) homologues, ORPs (OSBP-related proteins), constitute a 12-member family in mammals. We employed an in vitro [3H]25OH (25-hydroxycholesterol)-binding assay with purified recombinant proteins as well as live cell photo-cross-linking with [3H]photo-25OH and [3H]photoCH (photo-cholesterol), to investigate sterol binding by the mammalian ORPs. ORP1 and ORP2 [a short ORP consisting of an ORD (OSBP-related ligand-binding domain) only] were in vitro shown to bind 25OH. GST (glutathione S-transferase) fusions of the ORP1L [long variant with an N-terminal extension that carries ankyrin repeats and a PH domain (pleckstrin homology domain)] and ORP1S (short variant consisting of an ORD only) variants bound 25OH with similar affinity (ORP1L, Kd=9.7×10−8 M; ORP1S, Kd=8.4 ×10−8 M), while the affinity of GST–ORP2 for 25OH was lower (Kd=3.9×10−6 M). Molecular modelling suggested that ORP2 has a sterol-binding pocket similar to that of Saccharomyces cerevisiae Osh4p. This was confirmed by site-directed mutagenesis of residues in proximity of the bound sterol in the structural model. Substitution of Ile249 by tryptophan or Lys150 by alanine markedly inhibited 25OH binding by ORP2. In agreement with the in vitro data, ORP1L, ORP1S, and ORP2 were cross-linked with photo-25OH in live COS7 cells. Furthermore, in experiments with either truncated cDNAs encoding the OSBP-related ligand-binding domains of the ORPs or the full-length proteins, photo-25OH was bound to OSBP, ORP3, ORP4, ORP5, ORP6, ORP7, ORP8, ORP10 and ORP11. In addition, the ORP1L variant and ORP3, ORP5, and ORP8 were cross-linked with photoCH. The present study identifies ORP1 and ORP2 as OSBPs and suggests that most of the mammalian ORPs are able to bind sterols.
Identification of Protor as a novel Rictor-binding component of mTOR complex-2
Authors: Pearce Laura R. , Huang Xu , Boudeau Jérôme , Pawłowski Rafał , Wullschleger Stephan , Deak Maria , Ibrahim Adel F. M. , Gourlay Robert , Magnuson Mark A. , Alessi Dario R.
Published: July 2007

The mTOR (mammalian target of rapamycin) protein kinase is an important regulator of cell growth. Two complexes of mTOR have been identified: complex 1, consisting of mTOR–Raptor (regulatory associated protein of mTOR)–mLST8 (termed mTORC1), and complex 2, comprising mTOR–Rictor (rapamycininsensitive companion of mTOR)–mLST8–Sin1 (termed mTORC2). mTORC1 phosphorylates the p70 ribosomal S6K (S6 kinase) at its hydrophobic motif (Thr389), whereas mTORC2 phosphorylates PKB (protein kinase B) at its hydrophobic motif (Ser473). In the present study, we report that widely expressed isoforms of unstudied proteins termed Protor-1 (protein observed with Rictor-1) and Protor-2 interact with Rictor and are components of mTORC2. We demonstrate that immunoprecipitation of Protor-1 or Protor-2 results in the co-immunoprecipitation of other mTORC2 subunits, but not Raptor, a specific component of mTORC1. We show that detergents such as Triton X-100 or n-octylglucoside dissociate mTOR and mLST8 from a complex of Protor-1, Sin1 and Rictor. We also provide evidence that Rictor regulates the expression of Protor-1, and that Protor-1 is not required for the assembly of other mTORC2 subunits into a complex. Protor-1 is a novel Rictor-binding subunit of mTORC2, but further work is required to establish its role.
A double-blind randomized multicentre clinical trial to evaluate the efficacy and safety of two doses of etomoxir in comparison with placebo in patients with moderate congestive heart failure: the ERGO (etomoxir for the recovery of glucose oxidation) study
Authors: Holubarsch Christian J. F. , Rohrbach Martin , Karrasch Matthias , Boehm Erich , Polonski Lech , Ponikowski Piotr , Rhein Siegfried
Published: July 2007

Etomoxir is an inhibitor of mitochondrial CPT1 (carnitine palmitoyltransferase 1) and thereby switches energy metabolism from fatty acids to glucose oxidation. Such a metabolic change may be beneficial in CHF (congestive heart failure). The ERGO (etomoxir for the recovery of glucose oxidation) study was designed in which etomoxir was tested at a dose of 80 and 40 mg compared with placebo for a period of 6 months in patients with CHF. As the principle measure of efficacy, a maximal exercise tolerance test and a submaximal 6-min corridor walk test were used. Secondary end points were echocardiographical dimensions and quality-of-life assessment scores. A total of 350 patients were planned to be screened, with the expectation that end point data would be available from approx. 260 patients. However, the study had to be stopped prematurely, because unacceptably high liver transaminase levels were detected in four patients taking etomoxir. At the termination of the study, 121 patients were randomized to placebo, 118 to 40 mg of etomoxir and 108 to 80 mg of etomoxir. At that time, 21 patients in the placebo group, 16 in the 40 mg of etomoxir group and 14 patients in the 80 mg of etomoxir group had completed the study. The mean increases in exercise time were 3.3, 10.2 and 19.4 s for the placebo, 40 mg of etomoxir and 80 mg of etomoxir groups respectively (P value was not significant). No changes were obvious in the 6-min corridor walk test or in echocardiographical parameters from baseline. The number of patients that completed the study was too small to demonstrate significant effects on exercise time, although there was a tendency towards an increase in exercise time. Therefore, before rejecting the hypothesis that inhibition of fatty acid oxidation might be beneficial in CHF, similar studies have to be performed using different inhibitors of fatty acid oxidation targeting CPT1 and other enzymes in this metabolic pathway.
Increased expression and phosphorylation of focal adhesion kinase correlates with dysfunction in the volume-overloaded human heart
Authors: Lopes Maurício M. , Ribeiro Gustavo C. A. , Tornatore Thais F. , Clemente Carolina F. M. Z. , Teixeira Vicente P. A. , Franchini Kleber G.
Published: July 2007

FAK (focal adhesion kinase) has been shown to mediate the hypertrophic growth of the left ventricle. Experimental results also suggest that FAK may contribute to the structural and functional deterioration of the chronically overloaded left ventricle. In the present study, we postulated that FAK expression and phosphorylation may be altered in the volume-overloaded heart in humans. FAK expression and phosphorylation at Tyr397 were detected by Western blotting and immunohistochemistry in samples from endomyocardial biopsies from patients with MR (mitral regurgitation; n=21) and donor subjects (n=4). Hearts from patients with MR had degenerated cardiac myocytes and areas of fibrosis. In this group, the myocardial collagen area was increased (18% in MR hearts compared with 3% in donor hearts respectively) and correlated negatively with left ventricular ejection fraction (r=−0.74; P>0.001). FAK expression and phosphorylation at Tyr397 (a marker of the enzyme activity) were increased in samples from MR hearts compared with those from donor hearts (3.1- and 4.9-fold respectively). In myocardial samples from donor hearts, anti-FAK staining was almost exclusively restricted to cardiac myocytes; however, in myocardial samples from MR hearts, staining with the anti-FAK antibody was found to occur in myocytes and the interstitium. There was a positive correlation between collagen and the interstitial areas stained with the anti-FAK antibody (r=0.76; P>0.001). Anti-FAK and anti-vimentin staining of the interstitial areas of samples from MR hearts were extensively superimposed, indicating that most of the interstitial FAK was located in fibroblasts. In conclusion, FAK expression and phosphorylation are increased and may contribute to the underlying structural and functional abnormalities in the volume-overloaded heart in humans.
Outdoor Environments, Activity and the Well-Being of Older People: Conceptualising Environmental Support
Authors: Sugiyama Takemi , Thompson Catharine Ward
Published: July 2007

Although the outdoor environment provides older people with various opportunities to enhance their quality of life (QOL), few studies have investigated the extent to which this environment is influential in practice. In order to enable empirical research on this topic, in this paper we propose and examine the concept of environmental support. On the basis of a review of recent literature in gerontology, public health, environmental psychology, landscape architecture, and urban design, we argue that the supportiveness of neighbourhood environments that make outdoor activity (eg, walking) easy and enjoyable is conducive to a better QOL for older people. We introduce three ways of conceptualising environmental support focusing on the following: personally meaningful outdoor activities, environmental attributes found relevant to people's activities, and unmet needs for daily activities. Several conceptual frameworks that incorporate environmental support, QOL and other potentially salient constructs are also presented. We suggest possible future research directions employing this concept.
‘Berlin is Not a Foreign Country, Stupid!’—Growing up ‘Global’ in Eastern Germany
Authors: Hörschelmann Kathrin , Schäfer Nadine
Published: July 2007

In this paper we analyse how young East Germans come to be differentially placed in global network space through their socioeconomically and culturally specific engagements with globalised mediascapes and ethnoscapes. We call for greater awareness of the power differentials which shape globalisation, and draw on the theoretical work of Pierre Bourdieu to show how unequal access to social and cultural capital influences and is reflected in the ‘glocal’ connections through which young people develop and perform their identities. Further, we seek to understand how these differential engagements impact on young people's future trajectories through the development of different competencies. We contend that, precisely how young people are positioned in networks of global–local connectivity matters profoundly, both for the performance of their present identities, and for their future life chances.
Global Production Networks and Local Institution Building: The Development of the Information-Technology Industry in Suzhou, China
Authors: Wang Jenn-Hwan , Lee Chuan-Kai
Published: July 2007

We discuss how global production networks interact with local institutions to shape the ways in which economic development occurs within a region; the region concerned being the Suzhou municipality in China. We argue that the development of Suzhou's information-technology industry has largely resulted from (1) the transformation of global production networks in the 1990s, in which Taiwanese firms played an important role; (2) the local states' active role in transforming local institutions to fit the needs of foreign firms; and (3) Taiwanese investors' engagement in mediating and transplanting related institutions into the locality to meet the demand of global logistics for speed and flexibility. All these have resulted in Suzhou municipality's rapid growth in the information-technology industry and its embeddedness in the fusion of the global and local contexts. However, we will also demonstrate that the power asymmetry of global players and local states in this area has resulted in the creation of industrial clusters that are institutionally embedded but technologically delinked from the localities.
Zero tillage and nitrogen fertiliser application in wheat and barley on a Vertosol in a marginal cropping area of south-west Queensland
Authors: Thomas G. A. , Dalal R. C. , Weston E. J. , Holmes C. J. , King A. J. , Orange D. N. , Lehane K. J.
Published: July 2007

Winter cereal cropping is marginal in south-west Queensland because of low and variable rainfall and declining soil fertility. Increasing the soil water storage and the efficiency of water and nitrogen (N) use is essential for sustainable cereal production. The effect of zero tillage and N fertiliser application on these factors was evaluated in wheat and barley from 1996 to 2001 on a grey Vertosol. Annual rainfall was above average in 1996, 1997, 1998 and 1999 and below average in 2000 and 2001. Due to drought, no crop was grown in the 2000 winter cropping season.
Zero tillage improved fallow soil water storage by a mean value of 20 mm over 4 years, compared with conventional tillage. However, mean grain yield and gross margin of wheat were similar under conventional and zero tillage. Wheat grain yield and/or grain protein increased with N fertiliser application in all years, resulting in an increase in mean gross margin over 5 years from $86/ha, with no N fertiliser applied, to $250/ha, with N applied to target ≥13% grain protein. A similar increase in gross margin occurred in barley where N fertiliser was applied to target malting grade. The highest N fertiliser application rate in wheat resulted in a residual benefit to soil N supply for the following crop.
This study has shown that profitable responses to N fertiliser addition in wheat and barley can be obtained on long-term cultivated Vertosols in south-west Queensland when soil water reserves at sowing are at least 60% of plant available water capacity, or rainfall during the growing season is above average. An integrative benchmark for improved N fertiliser management appears to be the gross margin/water use of ~$1/ha.mm. Greater fallow soil water storage or crop water use efficiency under zero tillage has the potential to improve winter cereal production in drier growing seasons than experienced during the period of this study.
Supplementary feeding with grain improves the performance of sheep grazing saltbush (Atriplex nummularia) in autumn
Authors: Franklin-McEvoy J. , Bellotti W. D. , Revell D. K.
Published: July 2007

Merino wethers aged 1.5 years grazed a saltland pasture comprising old man saltbush (Atriplex nummularia) with an inter-row of senesced grasses and medic for 6 weeks in autumn, in a cereal–livestock zone with a Mediterranean-type environment in South Australia. The experimental treatments were a control (old man saltbush, SB), supplementation with 250 g/sheep.day barley straw (SB + S), supplementation with 250 g/sheep.day barley grain (SB + G) and supplementation with 250 g/sheep.day barley straw + 250 g/sheep.day barley grain (SB + S + G). The sheep in SB + G finished the experimental period significantly heavier (53.6 kg, P < 0.001) than SB (51.0 kg), SB + S (50.5 kg) or SB + S + G (51.1 kg) animals. Feeding grain also increased length of wool grown daily by 16% and would have increased the value of the sheep by being able to sell them ‘out of season’ when prices are higher. Sheep supplemented with grain alone had a higher liveweight than those provided with grain and straw, a result that cannot be explained but may be associated with altered grazing behaviour. It appears that, while old man saltbush provides sheep with an acceptable intake of protein and minerals, the addition of a cereal grain supplement improves energy balance and optimises rumen protein capture to improve liveweight and wool growth performance.
Modelling pesticide residues on greasy wool: a comparison of alternative models of pesticide breakdown
Authors: Horton B. J. , Campbell N. J.
Published: July 2007

A comparison was made of a range of different models of wool pesticide breakdown. Linear models, with a constant rate of breakdown as the wool grows, were always inferior to models that allowed the breakdown rate to decrease as the length of wool increased. Two-pool models were usually satisfactory and only minor or no improvement was gained by inclusion of additional pools or more complex models. There was little difference in fit between models with two-way diffusion compared with one-way transfer. The ‘standard’ model, reported previously, uses two exponential functions rather than multiple pools and was usually the best fit or at least as good a fit as the two- or three-pool models. We recommend that this model continue to be used, although the two-pool model is adequate and may be easier to implement and visualise. However, the three-pool model without transfer is also satisfactory and much faster to evaluate.
The relationship of lamb growth from birth to weaning and the milk production of their primiparous crossbred dams
Authors: Morgan J. E. , Fogarty N. M. , Nielsen S. , Gilmour A. R.
Published: July 2007

The growth rate of 667 single cross lambs from birth to 4 weeks (Period 1) and 4 weeks to weaning at 12 weeks (Period 2) was measured, along with the milk production of their 520 primiparous crossbred ewe dams over 3 years. The lambs were the progeny of Poll Dorset rams and first cross ewes lambing for the first time at 12 and 19 months of age. The first cross ewes were the progeny of Merino ewes mated to 30 individual sires from several maternal sire breeds, including Border Leicester, East Friesian, Finnsheep and Coopworth. Milk production of the ewes was measured at ~3, 4 and 12 weeks of lactation using a 4-h milk test. The effect of ewe milk production on lamb growth rate in Period 1 included a significant interaction with lamb birth and rearing type (P < 0.001). These regressions were 52 ± 18 g/day per kg/day for single born and reared, 24 ± 17 g/day per kg/day for multiple born and single reared and 18 ± 17 g/day per kg/day multiple born and reared lambs. The regression of ewe milk production in Period 2 on lamb growth rate in Period 2 was also significant (P < 0.001), although milk production in Period 1 accounted for more variation in lamb growth. There were significant interactions of ewe weight gain (from mid pregnancy to lamb weaning) with season in Period 1 (P < 0.01) and year in Period 2 (P < 0.001). There was also a significant interaction (P < 0.001) of year with ewe mid-pregnancy weight for lamb growth in Period 2. Lamb birthweight had a significant effect on lamb growth rate in Period 2 (regression coefficient 6.68 ± 2.57 g/day.kg, P < 0.01).
G protein–independent Ras/PI3K/F-actin circuit regulates basic cell motility
Authors: Sasaki Atsuo T. , Janetopoulos Chris , Lee Susan , Charest Pascale G. , Takeda Kosuke , Sundheimer Lauren W. , Meili Ruedi , Devreotes Peter N. , Firtel Richard A.
Published: July 2007

Phosphoinositide 3-kinase (PI3K)γ and Dictyostelium PI3K are activated via G protein–coupled receptors through binding to the Gβγ subunit and Ras. However, the mechanistic role(s) of Gβγ and Ras in PI3K activation remains elusive. Furthermore, the dynamics and function of PI3K activation in the absence of extracellular stimuli have not been fully investigated. We report that gβ null cells display PI3K and Ras activation, as well as the reciprocal localization of PI3K and PTEN, which lead to local accumulation of PI(3,4,5)P3. Simultaneous imaging analysis reveals that in the absence of extracellular stimuli, autonomous PI3K and Ras activation occur, concurrently, at the same sites where F-actin projection emerges. The loss of PI3K binding to Ras–guanosine triphosphate abolishes this PI3K activation, whereas prevention of PI3K activity suppresses autonomous Ras activation, suggesting that PI3K and Ras form a positive feedback circuit. This circuit is associated with both random cell migration and cytokinesis and may have initially evolved to control stochastic changes in the cytoskeleton.
Heterochromatin is refractory to γ-H2AX modification in yeast and mammals
Authors: Kim Jung-Ae , Kruhlak Michael , Dotiwala Farokh , Nussenzweig André , Haber James E.
Published: July 2007

Double-strand break (DSB) damage in yeast and mammalian cells induces the rapid ATM (ataxia telangiectasia mutated)/ATR (ataxia telangiectasia and Rad3 related)-dependent phosphorylation of histone H2AX (γ-H2AX). In budding yeast, a single endonuclease-induced DSB triggers γ-H2AX modification of 50 kb on either side of the DSB. The extent of γ-H2AX spreading does not depend on the chromosomal sequences. DNA resection after DSB formation causes the slow, progressive loss of γ-H2AX from single-stranded DNA and, after several hours, the Mec1 (ATR)-dependent spreading of γ-H2AX to more distant regions. Heterochromatic sequences are only weakly modified upon insertion of a 3-kb silent HMR locus into a γ-H2AX–covered region. The presence of heterochromatin does not stop the phosphorylation of chromatin more distant from the DSB. In mouse embryo fibroblasts, γ-H2AX distribution shows that γ-H2AX foci increase in size as chromatin becomes more accessible. In yeast, we see a high level of constitutive γ-H2AX in telomere regions in the absence of any exogenous DNA damage, suggesting that yeast chromosome ends are transiently detected as DSBs.
Type Iγ phosphatidylinositol phosphate kinase is required for EGF-stimulated directional cell migration
Authors: Sun Yue , Ling Kun , Wagoner Matthew P. , Anderson Richard A.
Published: July 2007

Phosphatidylinositol 4,5-bisphosphate (PI4,5P2) modulates a plethora of cytoskeletal interactions that control the dynamics of actin assembly and, ultimately, cell migration. We show that the type Iγ phosphatidylinositol phosphate kinase 661 (PIPKIγ661), an enzyme that generates PI4,5P2, is required for growth factor but not G protein–coupled receptor–stimulated directional migration. By generating PI4,5P2 and regulating talin assembly, PIPKIγ661 modulates nascent adhesion formation at the leading edge to facilitate cell migration. The epidermal growth factor (EGF) receptor directly phosphorylates PIPKIγ661 at tyrosine 634, and this event is required for EGF-induced migration. This phosphorylation regulates the interaction between PIPKIγ661 and phospholipase Cγ1 (PLCγ1, an enzyme previously shown to be involved in the regulation of EGF-stimulated migration). Our results suggest that phosphorylation events regulating specific PIPKIγ661 interactions are required for growth factor–induced migration. These interactions in turn define the spatial and temporal generation of PI4,5P2 and derived messengers required for directional migration.
The secretory peptide gene EPF1 enforces the stomatal one-cell-spacing rule
Authors: Hara Kenta , Kajita Ryoko , Torii Keiko U. , Bergmann Dominique C. , Kakimoto Tatsuo
Published: July 2007

Stomata are innovations of land plants that allow regulated gas exchange. Stomatal precursor cells are produced by asymmetric cell division, and once formed, signal their neighbors to inhibit the formation of stomatal precursors in direct contact. We report a gene of Arabidopsis thaliana, EPIDERMAL PATTERNING FACTOR 1 (EPF1) that encodes a small secretory peptide expressed in stomatal cells and precursors and that controls stomatal patterning through regulation of asymmetric cell division. EPF1 activity is dependent on the TOO MANY MOUTHS receptor-like protein and ERECTA family receptor kinases, suggesting that EPF1 may provide a positional cue interpreted by these receptors.
piRNAs—the ancient hunters of genome invaders: Figure 1.
Authors: Hartig Julia Verena , Tomari Yukihide , Förstemann Klaus
Published: July 2007

In addition to miRNAs and siRNAs, a third small RNA silencing system has been uncovered that prevents the spreading of selfish genetic elements. Production of the Piwi-associated RNAs (piRNAs), which mediate the silencing activity in this pathway, is initiated at a few master control regions within the genome. The nature of the primary piRNA-generating transcript is still unknown, but RNA interference (RNAi)-like cleavage events are likely defining the 5′-ends of mature piRNAs. We summarize the recent literature on piRNA biogenesis and function with an emphasis on work in Drosophila, where genetics and biochemistry have met very successfully.
Different effects of ribosome biogenesis inhibition on cell proliferation in retinoblastoma protein‐ and p53‐deficient and proficient human osteosarcoma cell lines
Authors: Montanaro L. , Mazzini G. , Barbieri S. , Vici M. , Nardi‐Pantoli A. , Govoni M. , Donati G. , Treré D. , Derenzini M.
Published: July 2007

Abstract.  Objectives: To evaluate the effects of rRNA synthesis inhibition on cell cycle progression and cell population growth according to the RB and p53 status. Material and methods: RB‐ and p53‐proficient U2OS cells and the RB‐ and p53‐deficient SAOS‐2 cells were used, rRNA transcription hindered by actinomycin D, and cell cycle analysed by flow cytometry. Results: One hour of actinomycin D treatment induced in U2OS cells a block at the cell cycle checkpoints G1‐S and G2‐M, which was removed only after rRNA synthesis was resumed. rRNA synthesis inhibition did not influence cell cycle progression in SAOS‐2 cells. No effect on cell cycle progression after actinomycin D‐induced rRNA inhibition was also found in U2OS cells silenced for RB and p53 expression. A mild perturbation of cell cycle progression was observed in U2OS cells silenced for the expression of either RB or p53 alone. We also treated U2OS and SAOS‐2 cells with actinomycin D for 1 h/day for 5 days. This treatment lightly reduced growth rate of the U2OS cell population, whereas cell population growth of SAOS‐2 cells was completely inhibited. A marked reduction of ribosome content occurred in SAOS‐2 cells after the long‐term actinomycin D treatment, whereas no modification was observed in U2OS cells. Conclusions: These results demonstrate that inhibition of ribosome biogenesis does not hinder cell cycle progression in RB‐ and p53‐deficient cells. A daily‐repeated transitory inhibition of ribosome biogenesis leads to a progressive reduction of ribosome content with the consequent extinction of cancer cell population lacking RB and p53.
Differential impact of Cetuximab, Pertuzumab and Trastuzumab on BT474 and SK‐BR‐3 breast cancer cell proliferation
Authors: Brockhoff G. , Heckel B. , Schmidt‐Bruecken E. , Plander M. , Hofstaedter F. , Vollmann A. , Diermeier S.
Published: July 2007

Abstract.  Objectives: The potential of epidermal growth factor receptor (EGFR)‐ and Her2‐targeted antibodies Cetuximab, Pertuzumab and Trastuzumab, used in combination to inhibit cell proliferation of breast cancer cells in vitro, has not been extensively investigated. It is anticipated that there would be differences between specific erbB receptor co‐expression profiles that would affect tumour cell growth. Materials and methods: We have examined the effects of Cetuximab, Pertuzumab and Trastuzumab, applied separately or in combination, on cell proliferation of BT474 and SK‐BR‐3 breast cancer cell lines. Cell cycle progression of BT474 and SK‐BR‐3 cells was statically and dynamically assessed using flow cytometry. In order to discover a potential influence of differential EGFR co‐expression on sensitivity to antibody treatment, EGFR was down‐regulated by siRNA in SK‐BR‐3. An annexinV/propidium iodide assay was used to identify potential induction of apoptosis. Results: Treatment with Pertuzumab and Trastuzumab, both targeted to Her2, resulted in a reduced fraction of proliferating cells, prolongation of G1 phase and a great increase in quiescent BT474 cells. Cetuximab had no additional contribution to the effect of either Pertuzumab or Trastuzumab when administered simultaneously. Treatment with the antibodies did not induce an appreciable amount of apoptosis in either BT474 or SK‐BR‐3 cells. In contrast to SK‐BR‐3, the BT474 cell line appears to be more sensitive to antibody treatment due to low EGFR content besides Her2 overexpression. Conclusion: The extent of decelerated or blocked cell proliferation after antibody treatment that is targeted to EGFR and to Her2 depends both on EGFR and Her2 co‐expression and on antibody combination used in the treatment setting. Cetuximab did not enhance any inhibitory effect of Trastuzumab or Pertuzumab, most probably due to the dominant overexpression of Her2. Cell susceptibility to Trastuzumab/Pertuzumab, both targeted to Her2, was defined by the ratio of EGFR/Her2 co‐expression.
Mitochondrial function, apoptosis and cell cycle delay in the WEHI‐3B leukaemia cell line and its variant Ciprofloxacin‐resistant WEHI‐3B/CPX
Authors: Pessina A. , Bonomi A. , Casati S. , Collotta A. , Croera C. , Marafante E. , Palitti F. , Gribaldo L.
Published: July 2007

Abstract.  Objective: The susceptibility of two cell lines, WEHI‐3B myelomonocytic leukaemia and its variant Ciprofloxacin‐resistant WEHI‐3B/CPX to undergo apoptosis induced by Ciprofloxacin was studied and compared. Materials and methods: Apoptosis was checked by measuring the DNA fragmentation and determining the ratio of apoptotic/necrotic cells. The relationship between the induction of apoptosis and G1, S or G2 block in the cell cycle has also been investigated and cytogenetical evaluation of chromosomal aberrations in both cell lines has been carried out. The regulation of expression of Bax and Bcl‐2 was also checked by western blotting after Ciprofloxacin treatment. Results: We observed that the resistance of the subline was caused by a small percentage of cells that underwent apoptosis during continuous exposure to Ciprofloxacin in comparison with the parental cell line, whereas the percentage of necrotic cells remained unchanged. The WEHI‐3B cells showed a G2 block and a higher degree of cytogenetic damage after drug exposure. The two cell lines expressed the same level of Bax and Bcl‐2 following stimulation by Ciprofloxacin. Only in the resistant subclone, the ratio Bcl‐2/Bax reversed in the anti‐apoptotic gene expression. Conclusion: The resistance to ciprofloxacin observed is not related to mitochondrial function and although Bcl‐2/Bax ratio behaviour does not fully explain the resistance of the WEHI3B/CPX subclone it is consistent with phenotypic character of resistance to CPX. The toxic effect on sensitive cells could be mediated by the cell cycle arrest whereas in the resistant clone, the prolonged G2 phase could play a key role to favour cell cycle progression and proliferation.
Driving forces shaping phytoplankton assemblages in two subtropical plateau lakes with contrasting trophic status
Authors: ZHANG XIA , XIE PING , CHEN FEIZHOU , LI SIXIN , QIN JIANHUI
Published: July 2007

1. We studied driving forces shaping phytoplankton assemblages in two subtropical plateau lakes with contrasting trophic status, the oligotrophic deep Lake Fuxian and the eutrophic shallow Lake Xingyun.

2. Phytoplankton samples were taken monthly for a year and phytoplankton species were sorted into the main taxonomic groups and associations proposed by Reynolds. A canonical correspondence analysis (CCA) was used to test the occurrence of these classification schemes and to determine their discriminatory power.

3. The results suggest that the major driving forces in Lake Fuxian were physical variables, and particularly the underwater light climate, whereas, nutrients were the important driving force in Lake Xingyun.

4. Top–down control through zooplankton grazing in Lake Fuxian was hardly ever a significant determinant itself, because of the scarcity of zooplankton and their low grazing efficiency of predation while a dominance of inedible cyanobacteria throughout the year rendered top–down controls ineffective failing in Lake Xingyun. Hence phytoplankton communities in both lakes appear to be regulated primarily by bottom–up controls.