bluuebunny/crossref_metadata_2025 huggingface dataset:
The Arabidopsis co‐expression tool (act): a WWW‐based tool and database for microarray‐based gene expression analysis
Authors: Jen Chih‐Hung , Manfield Iain W. , Michalopoulos Ioannis , Pinney John W. , Willats William G.T. , Gilmartin Philip M. , Westhead David R.
Published: March 2006

We present a new WWW‐based tool for plant gene analysis, the Arabidopsis Co‐Expression Tool (act), based on a large Arabidopsis thaliana microarray data set obtained from the Nottingham Arabidopsis Stock Centre. The co‐expression analysis tool allows users to identify genes whose expression patterns are correlated across selected experiments or the complete data set. Results are accompanied by estimates of the statistical significance of the correlation relationships, expressed as probability (P) and expectation (E) values. Additionally, highly ranked genes on a correlation list can be examined using the novel clique finder tool to determine the sets of genes most likely to be regulated in a similar manner. In combination, these tools offer three levels of analysis: creation of correlation lists of co‐expressed genes, refinement of these lists using two‐dimensional scatter plots, and dissection into cliques of co‐regulated genes. We illustrate the applications of the software by analysing genes encoding functionally related proteins, as well as pathways involved in plant responses to environmental stimuli. These analyses demonstrate novel biological relationships underlying the observed gene co‐expression patterns. To demonstrate the ability of the software to develop testable hypotheses on gene function within a defined biological process we have used the example of cell wall biosynthesis genes. The resource is freely available at http://www.arabidopsis.leeds.ac.uk/ACT/
A spatiotemporal analysis of enzymatic activities associated with carbon metabolism in wild‐type and mutant embryos of Arabidopsis using in situ histochemistry
Authors: Baud Sébastien , Graham Ian A.
Published: March 2006

Arabidopsis as a molecular genetic model offers many advantages for the study of seed development, but these do not extend to biochemical and enzymatic studies, which are often compromised by the limited amount of material available from the small developing embryos. A set of assays based on the coupling of an enzymatic reaction to the reduction of NAD, NADP or FAD, and subsequent reduction and precipitation of a tetrazolium salt, have been adapted to investigate 18 enzyme activities associated with carbon metabolism in developing Arabidopsis embryos. The use of organelle‐specific marker enzymes demonstrates the utility of the method for detection of activities in mitochondria, plastids and peroxisomes as well as the cytosol. The temporal staining patterns obtained allow classification of the activities into three main categories based on whether they peak in the early, intermediate or late stages of maturation. An interesting switch from ATP to pyrophosphate consuming pathways occurs at the onset of the maturation phase, which involves key steps in primary carbon metabolism such as phosphofructokinase. This spatiotemporal characterization of carbon metabolism has also been applied to various mutants disrupted in embryo development including gnom (gn), acetyl‐CoA carboxylase1 (acc1), schlepperless (slp), and wrinkled1 (wri1). The data obtained demonstrate that the extent to which carbon metabolism is affected in mutants is not necessarily correlated to the severity of the mutation considered. Through the advanced characterization of trehalose‐6‐P synthase1 (tps1) embryos, this approach finally provides new insight into the regulatory role played by trehalose metabolism in embryo development.
CYP707A3, a major ABA 8′‐hydroxylase involved in dehydration and rehydration response in Arabidopsis thaliana
Authors: Umezawa Taishi , Okamoto Masanori , Kushiro Tetsuo , Nambara Eiji , Oono Youko , Seki Motoaki , Kobayashi Masatomo , Koshiba Tomokazu , Kamiya Yuji , Shinozaki Kazuo
Published: March 2006

Abscisic acid (ABA) catabolism is one of the determinants of endogenous ABA levels affecting numerous aspects of plant growth and abiotic stress responses. The major ABA catabolic pathway is triggered by ABA 8′‐hydroxylation catalysed by the cytochrome P450 CYP707A family. Among four members of Arabidopsis CYP707As, the expression of CYP707A3 was most highly induced in response to both dehydration and subsequent rehydration. A T‐DNA insertional cyp707a3‐1 mutant contained higher ABA levels in turgid plants, which showed a reduced transpiration rate and hypersensitivity to exogenous ABA during early seedling growth. On dehydration, the cyp707a3‐1 mutant accumulated a higher amount of stress‐induced ABA than the wild type, an event that occurred relatively later and was coincident with slow drought induction of CYP707A3. The cyp707a3 mutant plants exhibited both exaggerated ABA‐inducible gene expression and enhanced drought tolerance. Conversely, constitutive expression of CYP707A3 relieved growth retardation by ABA, increased transpiration, and a reduction of endogenous ABA in both turgid and dehydrated plants. Taken together, our results indicate that CYP707A3 plays an important role in determining threshold levels of ABA during dehydration and after rehydration.
HLA‐E and immunobiology of pregnancy
Authors: Tripathi P. , Naik S. , Agrawal S.
Published: March 2006

Recently, it has been suggested that non‐classical antigens such as human leukocyte antigen (HLA)‐G and HLA‐E may interact with KIR receptors of NK cells which results into downregulation of immune response and helps in the maintenance of pregnancy. In the present study, we have investigated HLA‐E polymorphism in normal fertile women and recurrent spontaneous aborters to assess the effect of HLA‐E alleles on the success of pregnancy. Allele E*0101 was found to be significantly higher in patients with recurrent spontaneous abortion (χ2 = 4.097 and P = 0.0430). Differential expression, peptide affinity, and stability of E*0101 may be one of the reasons.
Antigen‐presenting cells expressing glutamate decarboxylase 67 were identified as epithelial cells in glutamate decarboxylase 67‐GFP knock‐in mouse thymus
Authors: Maemura K. , Yanagawa Y. , Obata K. , Dohi T. , Egashira Y. , Shibayama Y. , Watanabe M.
Published: March 2006

Glutamate decarboxylase (GAD), which has two isoforms, GAD65, and GAD67, is responsible for synthesis of the major inhibitory neurotransmitter, γ‐aminobutyric acid. GAD is expressed predominantly in the central nervous system; recent reports suggest that GAD is also expressed in non‐neuronal organs including the pancreas. In the pancreatic islets, GAD serves as one of the autoantigens in type I diabetes mellitus. Recent flow cytometric analyses have shown that a variety of self‐antigens, including GAD, are ectopically transcribed and expressed in particular cell populations of the thymus, although consensus concerning the cellular phenotype has not been obtained. The aim of this study was to clarify the localization and cellular phenotype of GAD67‐expressing cells in the thymus at a cellular level with a novel approach using GAD67‐green fluorescent protein (GFP) knock‐in mice, in which GFP is expressed specifically in GAD67‐positive cells. GFP‐positive cells were detected in the thymic medulla and were identified as epithelial cells by immunohistochemistry. Almost all GFP‐positive cells were positive for major histocompatibility complex (MHC) class II antigen staining and were positive for both cytokeratin and Ulex Europaeus Agglutinin I, markers of medullary thymic epithelial cells, but were negative for CD11c, Gr‐1, and CD45, markers of dendritic cells, macrophages, and B‐lymphocytes, respectively.
HLA‐B27 testing in Thai patients using the PCR‐SSP technique
Authors: Nathalang O. , Tantimavanich S. , Nillakupt K. , Arnutti P. , Jaruchaimontree C.
Published: March 2006

We develop the HLA‐B27 test kit using the PCR‐SSP technique. Five hundred forty blood samples were tested for HLA‐B27 by microlymphocytotoxicity test (LCT) and PCR‐SSP. It was found that 127 (23.5%) and 134 (24.8%) of these samples were positive for HLA‐B27 by LCT and PCR‐SSP, respectively. The sensitivity and specificity of the PCR‐SSP were 94.8 and 100%, respectively, when using LCT as the standard method. The PCR‐SSP positive predictive value was 100%, negative predictive value was 98.3%, and a concordance rate of 98.7%. This study shows that the PCR‐SSP is simple, convenient, and a more cost‐effective in‐house test kit.
Regulation of MHC class II expression, a unique regulatory system identified by the study of a primary immunodeficiency disease
Authors: Krawczyk M. , Reith W.
Published: March 2006

Major histocompatibility complex class II (MHC‐II) molecules are of central importance for adaptive immunity. Defective MHC‐II expression causes a severe immunodeficiency disease called bare lymphocyte syndrome (BLS). Studies of the molecular defects underlying BLS have been pivotal for characterization of the regulatory system controlling the transcription of MHC‐II genes. The precisely controlled pattern of MHC‐II gene expression is achieved by a very peculiar and highly specialized molecular machinery that involves the interplay between ubiquitous DNA‐binding transcription factors and a highly unusual, tightly regulated, non‐DNA‐binding coactivator called the MHC class II transactivator (CIITA). CIITA single handedly coordinates practically all aspects of MHC‐II gene regulation and has therefore been dubbed the master controller of MHC‐II expression. Several of the unusual features of the MHC‐II regulatory system may be a consequence of the fact that CIITA originated from an ancient family of cytoplasmic proteins involved in inflammation and innate immunity. The function of CIITA in transcriptional regulation of MHC‐II genes could thus be a recent acquisition by an ancestral protein having a role in an unrelated system.
Aetiological factors related to a positive direct antiglobulin test result in human immunodeficiency virus‐infected patients
Authors: Lai M. , D’Onofrio G. , Visconti E. , Tamburrini E. , Cauda R. , Leone G.
Published: March 2006

Background and Objectives The aim of this study was to examine the clinical importance and causes of a positive result in the direct antiglobulin test (DAT) in human immunodeficiency virus‐infected (HIV+) patients. We therefore studied haematological parameters in outpatient samples, and also analysed the impact of highly active anti‐retroviral therapy (HAART) on the DAT results.

Study Design and Methods Haematological parameters, clinical stages, chemo‐antibiotic treatments and HAART treatment were studied to determine any relationships with DAT results in 115 consecutive HIV+patients.

Results Significantly lower haemoglobin (Hb) levels were detected in patients with HIV who had a positive DAT result. Hepatitis C virus (HCV) co‐infection (odds ratio 2·529) and trimethoprim‐suphamethoxazfole (TMP‐SMX) prophylaxis (odds ratio 3·751) had a significant association with DAT positivity. Patients receiving HAART were less likely to have a positive DAT [odds ratio (OR) 0·383;P = 0·035]. Among the patients treated with TMP‐SMX, those with a positive DAT had lower Hb levels (11·9 g/dl) than those with a negative DAT (14·2 g/dl;P = 0·04). HCV antibody positivity and TMP‐SMX prophylaxis showed a cumulative effect on positive DATs (OR 4·533). The surface exploratory analysis indicated the distribution of the positive DATs in relationship with the CD4+count and Hb levels.

Conclusions Significantly lower Hb levels were detected in DAT‐positive HIV+patients. HCV co‐infection and TMP‐SMX prophylaxis appear to confer an increased risk of DAT positivity. The presence of red blood cell autoantibodies may be associated with anaemia in HIV disease in the absence of overt haemolysis.
Economies of scale in blood banking: a study based on data envelopment analysis
Authors: Pereira A.
Published: March 2006

Background and Objectives  Exploitation of economies of scale is often argued in favour of blood‐bank consolidation into large regional centres, despite a lack of adequate empirical support. This study was aimed at testing the economies of scale hypothesis in a sample of blood centres in the USA.

Materials and Methods  An input‐orientated data envelopment analysis (DEA) was used to calculate the technical efficiency scores of blood centres, and to determine whether they were operating under increasing returns to scale (IRS), constant returns to scale (CRS) or decreasing returns to scale (DRS). Correlation between the blood‐centre efficiency score and the demographic and socioeconomic characteristics of the service area was further investigated.

Results  Seventy‐one blood centres were included in the analysis. The scale of operations ranged from 7270 to 275 500 red blood cell (RBC) units per year. Six (8%) centres operated under CRS, 29 (55%) under IRS, and most of their technical inefficiency was scale‐independent, and 26 (37%) operated under DRS, and most of their technical inefficiency was size‐related. Efficiency scores were unrelated to any demographic or socioeconomic characteristics of the blood centre service area.

Conclusions  Within the size range of blood centres included in this study, expanding the level of operations beyond a certain point leads to DRS.
Correlation of in vitro platelet quality measurements with in vivo platelet viability in human subjects
Authors: Goodrich Raymond P. , Li Junzhi , Pieters Henry , Crookes Robert , Roodt Jan , Heyns Anthon du P.
Published: March 2006

Background and Objectives  Changes in in vitro platelet quality parameters during platelet storage are associated with a decrease of in vivo platelet viability after platelet transfusion. Many attempts have been made to identify the most predictable in vitro parameters for in vivo performance. We used a riboflavin‐based ultraviolet (UV) light treatment process designed to inactivate pathogens and white blood cell (WBC) contaminants in blood products as a model system in which to study the correlation of in vitro cell quality with in vivo viability.

Materials and Methods  Platelet products (n = 18) were collected by a standard Trima apheresis procedure and treated with one of three dose levels of UV light (0, 7·2 or 12·4 J/ml) in the presence of 50 µm riboflavin. Lactate production, glucose consumption and P‐selectin expression, pH, pCO2, pO2, hypotonic shock response and swirl were measured during 5 days of platelet storage post‐UV/RB treatment. Aliquots of these products were radiolabelled on day 5 of storage and were subsequently used to determine platelet recovery and survival time in autologous subjects.

Results  The responses of in vitro cell quality were observed to occur in a UV dose‐dependent manner. Lactate production and pH were identified as the parameters most strongly correlated with platelet in vivo recovery, which ranged from 5 to 82%. The correlation coefficients (r) for lactate production and pH with in vivo recovery in human subjects were 0·9090 and 0·8831 with P‐values of 0·007 and 0·031, respectively. Lactate production and pH were also found to be correlated with platelet survival time, with correlation coefficients of 0·8063 and 0·8384 (the P values were 0·01 and 0·001, respectively).

Conclusions  Using conditions of riboflavin‐based UV light treatment, lactate production and pH were identified as having the highest correlations with recovery and survival of radiolabelled platelets in healthy subjects.
Factors Associated with High Milk Test Day Somatic Cell Counts in Large Dairy Herds in Brandenburg. I: Housing Conditions
Authors: Köster G. , Tenhagen B.‐A. , Heuwieser W.
Published: March 2006

The aim of this study was to examine influences of housing conditions on the udder health in 80 German dairy herds with a herd size between 100 and 1100 cows. Data were collected using a standardized questionnaire for the farm manager and a farm visit using a standardized data capture form on hygiene and management. The somatic cell counts of all lactating cows on each farm were collected monthly by the local dairy herd improvement association and analysed to assess udder health status. Factor analysis was used to analyse the variables describing the environmental hygiene. The values derived for the extracted components were classified into good, moderate and poor. The association of the categories was then analysed for their influence on log somatic cell count of the current month (CMSCC) and the year before the farm visit (YASCC) by a one‐way anova. In comparison to other housing systems, free stalls with cubicles had the lowest geometric mean somatic cell count. Three components were derived from the factor analysis. Of those, acceptance of the cubicles by the cows and barn hygiene were determined as components influencing the CMSCC and YASCC significantly, while the association of hygiene of the milking parlour with somatic cell counts was only significant for YASCC. The results of the study show that the cow comfort and housing hygiene have a substantial impact on milk quality and should therefore become the focus of further research on the farm management practices.
First Experience on the Effect of In‐feed Lincomycin for the Control of Proliferative Enteropathy in Growing Pigs
Authors: Alexopoulos C. , Tassis P. D. , Kyriakis C. S. , Tzika E. D. , Papatsiros V. , Kyriakis S. C.
Published: March 2006

This trial's aim was to evaluate the effect of in‐feed lincomycin for the control of proliferative enteropathy (PE; also known as ileitis) in growing pigs, in which it is associated with significant morbidity levels. Investigation regarding the efficacy of this substance in growing pigs has never been carried out before in a field trial. The trial farm had a previous history of PE outbreaks. On day 1 of the trial (age of 62 ± 1.5 days), 240 pigs were divided into two groups of 120 pigs/group which were allocated into five pens of 24 pigs each. Therefore, a randomized block design was used with two experimental groups (T1–T2) and five replicates (pens) per group. T1 group served as negative control (NC) animals which were receiving no medication and conversely T2 group received in‐feed lincomycin at the dose of 110 mg/kg of feed. The treatment period lasted for 3 weeks, followed by an observation period of 4 weeks up to the age of 111 ± 1.5 days which was the end of the grower stage. Administration of lincomycin at a dose of 110 mg/kg of feed had beneficial effects compared with the NC group. The pigs of T2 group showed significant improvement of their production parameters in terms of average daily body gain (ADG) and feed conversion ratio (FCR) not only during the treatment period (ADG: 0.515 ± 0.050 versus 0.481 ± 0.071 and FCR: 2.38 ± 0.05 versus 2.56 ± 0.08, for T2 and T1 groups respectively), but also during the remaining period until the end of the grower stage (observation period: ADG: 0.687 ± 0.019 versus 0.646 ± 0.044 and FCR: 2.58 ± 0.02 versus 2.74 ± 0.02 respectively). Other effects in the T2 group refer to the reduction of diarrhoea prevalence (mean pen diarrhoea score during the whole grower stage: 0.200 ± 0.060 versus 0.632 ± 0.041 respectively), morbidity rates (morbidity rates during the whole grower stage: 15.83% versus 45.00% respectively) and the reduction ofLawsonia intracellularisprevalence as shown by polymerase chain reaction diagnostic method (at the end of the treatment period: 10.0% versus 60.0% respectively). In conclusion, treatment with 110 mg lincomycin/kg of feed for 21 consecutive days had a beneficial effect on the control of PE in growing pigs.
The Influence of Intramammary Lipopolysaccharide Infusion on Serum Ca, P, Vitamin D, Cytokines and Cortisol Concentrations in Lactating Sows
Authors: Wang J. F. , Wang M. , Ma J. L. , Jiao L. G. , Zhou X. Y. , Lindberg J. E.
Published: March 2006

Ten multiparous lactating sows were used to investigate whether intramammary infusion of lipopolysaccharides (LPS;Escherichia coli0111:B4; 2.0 μg/kg of body weight) would affect the circulating concentrations of Ca, P, 25‐hydroxyvitamin D (25‐OHD), tumour necrosis factor‐α(TNF‐α), interleukin‐6 (IL‐6) and cortisol. The sows were randomly allotted to either control group (control) or LPS‐treated group with five individuals per group and were infused with either physiological saline solution or LPS solution. The rectal temperature and udder quarter appearance were recorded at 0 (just before infusion), 1, 3, 7, 12 or 24 h after infusion. Blood samples were taken at 0, 1, 3, 7, 12 or 24 h after infusion. Before infusion, the rectal temperatures of all sows were below 39.2°C. At 3 and 7 h after infusion, the sows in the LPS group had a rectal temperature over 39.4°C. At 24 h after infusion, the rectal temperatures returned to pre‐infusion levels. Serum Ca and P concentrations in the LPS group decreased (P < 0.05) after LPS infusion compared with the control group at 1 h after infusion. No significant differences (P > 0.05) in the concentrations of 25‐OHD were observed between groups control and LPS at any sampling time. Increased (P < 0.01) concentrations of serum TNF‐α, IL‐6 and cortisol were observed in the LPS group compared with the control group at 3 and 7 h after infusion respectively. In conclusion, the elevation of serum concentrations of TNF‐α, IL‐6 and cortisol and the alterations of circulating concentrations of Ca and P following LPS infusion indicate that the immune system has been activated and immune activation may affect macromineral homeostatic regulation, which might have important implications for metabolic health of lactating sows. Lowered serum Ca and P following immune activation also shows a causative mechanism whereby immune activation increases the risk of secondary disorders such as mastitis‐metritis‐agalactia syndrome. However, immune activation did not affect circulating concentrations of vitamin D metabolites.
Mouse Bioassay forin vivoScreening of Oestrogen and Progesterone Antagonists
Authors: ŠKarda J. , Köhlerová E.
Published: March 2006

This study tested and compared the anti‐proliferative and proliferative activities of two anti‐oestrogens and three anti‐progestins on four separate mouse model systems: young intact and adult ovariectomized (OV‐X) females, and young intact and adult castrated males. Pure steroidal anti‐oestrogen ICI 182,780 (ICI) decreased mammary and uterine growth stimulated by endogenous hormones in young intact females and by exogenous hormones [progesterone (Prog), 17β‐oestradiol (E) or E plus Prog] in both young intact and adult ovariectomized (OV‐X) females. Non‐steroidal anti‐oestrogen EM‐800 (EM), on the other hand, had no effect on mammary and uterine growth stimulated by endogenous hormones in young intact females and in adult OV‐X females. Uterine growth was even stimulated by EM alone, and a combination of EM plus Prog not only stimulated uterine growth but also mammary growth (an oestrogenic agonistic activity). However, EM showed anti‐oestrogenic activities in both mammary and uterine tissues in females treated with E or E plus Prog. In males, ICI and EM decreased mammary growth stimulated by exogenous hormones (E or E plus Prog) in both young intact and adult castrated animals. In young intact, but not in adult castrated males, ICI increased seminal vesicle growth affected by both endogenous and exogenous (Prog, E or E plus Prog) hormones. EM, on the other hand, decreased seminal vesicle weights in E or E plus Prog and increased its weights in Prog‐treated young intact males. Thus, under certain conditions EM possess mixed agonist and antagonist activity in the mammary gland, uterus and seminal vesicles. Norethindrone acetate (NA)‐stimulated mammary growth was decreased by anti‐progestins onapristone (ON), RU 46556 (RU), and RU 38486 (MI) by 34–59% in females and by 35–93% in males. Uterine weights of NA‐treated females were decreased by ON and RU by 29–55% but not by MI. In NA‐treated young intact males, seminal vesicle weights were stimulated by RU (by 63%) and not affected by ON and MI. In NA‐treated adult castrated males, seminal vesicle weights were decreased by ON, increased by RU and not affected by MI. The results obtained in these and our earlier studies show clearly that mouse four‐model systems could serve asin vivotool for the detection of steroid hormone agonist and antagonist activities of natural and man‐made chemicals.
Effect of Dried Oregano Leaves Versus Neomycin in Treating Newborn Calves with Colibacillosis
Authors: Bampidis V. A. , Christodoulou V. , Florou‐Paneri P. , Christaki E.
Published: March 2006

Treatment with neomycin (as a positive control) and dried oregano leaves on mortality, number of days scouring and severity of scours due to Escherichia coli were examined in 30 Holstein calves. Calves were assigned to one of the treatments following clinical signs of diarrhoea (i.e. faecal score >2), and treated either with an oral solution of neomycin sulphate, to provide 10 mg neomycin sulphate per kg calf body weight per 24 h, or dried oregano leaves, to provide 10 mg oregano essential oil per kg calf body weight per 24 h. The number of scouring days, severity of scouring and mortality rates were similar between the treatments. This study indicates that dried oregano leaves administered as an oral solution to calves with diarrhoea may be as effective in the treatment of colibacillosis as neomycin.
Polioencephalomalacia in Cattle: A Consequence of Prolonged Feeding Barley Malt Sprouts
Authors: Kul O. , Karahan S. , Basalan M. , Kabakci N.
Published: March 2006

Polioencephalomalacia (PEM) in ruminants has been recognized as a consequence of excess sulphur intake. The present study describes clinical, gross and histopathological findings of PEM following an abrupt change of diet in two ranches housing 2750 dairy and 2300 beef cattle. As a result of severe PEM, 256 cattle died or were slaughtered. Clinical findings included circling, hypersensitivity, excessive salivation, hypermetria, incoordination, blindness and death. The first clinical signs occurred in beef calves (6–8 months old) at a holding facility. Clinical signs of the disorder continued intermittently during the 5‐month period in both ranches and were more evident in calves and lactating dairy cows. The affected cattle did not respond to thiamine injections. Clinical signs disappeared gradually following removal of barley malt sprouts from the diet. Although macroscopic lesions were not apparent in the brain tissues of some animals, histopathology typical of PEM was found in most cases: spongiosis in the neuropil and neuronal necrosis, haemorrhage, capillary hyperplasia, fibrinoid degeneration in arterioles, multifocal liquefaction necroses in the grey matter and abundance of gitter cells with vacuolar large cytoplasm. Sulphide in rumen fluid of a clinically affected animal was measured as 1.55 mg/dl, which is considerably higher than that collected from two control cows (mean 0.21 mg/dl). The total sulphur content of the diet containing barley malt sprouts was estimated to be 0.45%, which is also higher than the National Research Council (NRC) maximum tolerable levels. In conclusion, PEM can result from excess barley malt sprout intake because of its higher sulphur content. Clinical signs may occur shortly after the intake of barley malt sprout as outbreaks with a higher number of deaths or as an ongoing periodic condition.
The Effects of Cryopreservation on the Morphometric Dimensions of Iberian Red Deer (Cervus elaphus hispanicus) Epididymal Sperm Heads
Authors: Esteso MC , Fernández‐Santos MR , Soler AJ , Montoro V , Quintero‐Moreno A , Garde JJ
Published: March 2006

Contents

Computer‐automated sperm‐head morphometry was used in this study to determine the effects of cryopreservation on red deer sperm‐head morphometry. Epididymal sperm samples were collected from 40 mature stags and were divided. One portion was diluted at room temperature in a Tris‐citrate egg yolk medium, containing 6% glycerol. A microscope slide was prepared from single extended sperm samples prior to freezing. The remainder of each sample was frozen in nitrogen vapours. After thawing, sperm smears were prepared as described above. All slides were air dried and stained with Hemacolor. The sperm‐head dimensions for length, width, area, perimeter and shape factor (length/width), for a minimum of 135 spermatozoa were determined for each slide by means of the Sperm‐Class Analyser® (SCA). Firstly, our results show that cryopreservation substantially reduced (p < 0.001) sperm motility and plasma membrane and acrosome integrities. In addition, sperm heads were significantly smaller in cryopreserved spermatozoa than in the companion extended samples for area (32.05 μm2vs 32.56 μm2; p < 0.05), length (8.46 μm vs 8.53 μm; p < 0.0001) and shape factor (1.833 vs 1.849; p < 0.0001) for all stags. These differences were found within 29 of 40 stags (75%) for at least three of the morphometric parameters. The individual variability (CV) of sperm head measurements from extended samples was negatively correlated (p < 0.005) with the per cent of change in sperm head measurements after cryopreservation for area (r = −0.465), width (r = −0.483) and perimeter (r = −0.375). Thus, the lower the sperm head variability in the extended samples, the greater the sperm change as a consequence of the cryopreservation. These results suggest that the variability (heterogeneity) in sperm head dimensions of individual stags may be a good indicator of sperm freezability.
Integrated description of deformation modes in a sedimentary basin: A case study around a shallow drilling site in the Mizunami area, eastern part of southwest Japan
Authors: Itoh Yasuto , Amano Kenji , Kumazaki Naoki
Published: March 2006

Abstract  Tectonic episodes in a sedimentary basin are described on the basis of an integrated study combining reflection seismic interpretation, drilling survey and paleomagnetism. A shallow inclined borehole penetrated a fault shown by reflection seismic and geological surveys in the Mizunami area, in the eastern part of southwest Japan. Paleomagnetic measurements were carried out on core samples successfully oriented using side‐wall image logging of structural attitude. At six horizons, stable characteristic remanent magnetization (ChRM) was confirmed through thermal and alternating field demagnetization tests, which were carried by magnetite with minor amounts of high coercivity minerals, as revealed by experiments of stepwise acquisition of isothermal remanent magnetization. After correction of multiphase deformation inferred from borehole structural analysis, ChRM directions were combined with previous data and confirmed an easterly deflection reflecting the coherent clockwise rotation of the arc before the Middle Miocene. Compilation of reliable paleomagnetic data described differential rotation of the eastern part of southwest Japan raised by collision of the Izu–Bonin Arc since the Middle Miocene. The present study suggests that (i) the Mizunami area is adjacent to a highly deformed zone bounded by the Akaishi Tectonic Line (ATL), and (ii) forearc deformation of southwest Japan is localized around the ATL, which is quite different from gradual bending on the back‐arc side without remarkable crustal break related to the collision event.
40Ar/39Ar ages of blueschist facies pelitic schists from Qingshuigou in the Northern Qilian Mountains, western China
Authors: Liu Yong‐Jiang , Neubauer Franz , Genser Johann , Takasu Akira , Ge Xiao‐Hong , Handler Robert
Published: March 2006

Abstract  Pelitic schists from Qingshuigou in the Northern Qilian Mountains of China contain mainly glaucophane, garnet, white mica, clinozoisite, chlorite and piemontite. Isotopic age dating of these schists provides new constraints on the formation of the high‐grade blueschists at Qingshuigou. White mica 40Ar/39Ar ages range from 442.1 to 447.5 Ma (total fusion age of single grain) and from 445.7 to 453.9 Ma (integrated age of white mica concentrates). These ages (442.1–453.9 Ma) represent the peak metamorphic ages or cooling ages of the blueschists during exhumation shortly after peak metamorphism. The 40Ar/39Ar dates in the present study are similar to ages previously reported for eclogites and blueschists in the area; this suggests that both the eclogites and pelitic sediments underwent high‐grade metamorphism during the same subduction event. From this chronological evidence and the presence of well‐developed Silurian remnant‐sea flysch and Devonian molasse, it is concluded that the Northern Qilian Ocean had closed by the end of the Ordovician, and rapid orogenic uplift followed in the Devonian.
Geochemistry of geopressured hydrothermal waters in the Niigata Sedimentary Basin, Japan
Authors: Xu Hui‐Long , Shen Jian‐Wei , Zhou Xue‐Wu
Published: March 2006

Abstract  Geothermal waters in the Niigata Sedimentary Basin, central Japan, are divided into four groups based on their chemical composition (i.e. Na‐SO4‐type, Na‐SO4‐Cl‐type, Na‐Cl‐type and Na‐Cl‐HCO3‐type). The Na‐SO4‐type geothermal water forms as a consequence of water–rock interaction and generally occurs in the outer part of the basin. The Na‐Cl‐type geothermal water is further subdivided into the original Na‐Cl‐type geopressured thermal water and the mixed Na‐Cl‐type geothermal water, in terms of its geochemical and isotopic composition. The original Na‐Cl‐type geopressured thermal water originates from a geopressured hydrothermal system containing the altered fossil formation waters that are sealed at depth. It moves up to the upper part of the depositional succession or the ground, and generally does not mix with groundwater that is of meteoric origin. This type of water is cooled by heat conduction. The concentration of Cl– in this type of thermal water is very similar to that in seawater. The δD and δ18O values are approximately constant and independent of temperature. The original Na‐Cl‐type geopressured thermal water is distributed mainly along anticlinal axes in folded Neogene formations. The mixed Na‐Cl‐type geothermal water is related to the expulsion activity of the geopressured hydrothermal system and occurs mostly along active faults. It is formed by shallow groundwater of meteoric origin being mixed with geopressured hydrothermal water when the geopressured hydrothermal system was expulsed along active faults by paroxysmal tectonic events.
Dredge petrology of the boninite‐ and adakite‐bearing Hahajima Seamount of the Ogasawara (Bonin) forearc: An ophiolite or a serpentinite seamount?§
Authors: Ishiwatari Akira , Yanagida Yuki , Li Yi‐Bing , Ishii Teruaki , Haraguchi Satoru , Koizumi Kazuto , Ichiyama Yuji , Umeka Masaru
Published: March 2006

Abstract  During the Hakuho‐Maru KH03‐3 cruise and the Tansei‐Maru KT04‐28 cruise, more than 1000 rock samples were dredged from several localities over the Hahajima Seamount, a northwest–southeast elongated, rectangular massif, 60 km × 30 km in size, with a flat top approximately 1100 m deep. The rocks included almost every lithology commonly observed among the on‐land ophiolite outcrops. Volcanic rocks included mid‐oceanic ridge basalt (MORB)‐like tholeiitic basalt and dolerite, calc‐alkaline basalt and andesite, boninite, high‐Mg adakitic andesite, dacite, and minor rhyolite. Gabbroic rocks included troctolite, olivine gabbro, olivine gabbronorite (with inverted pigeonite), gabbro, gabbronorite, norite, and hornblende gabbro, and showed both MORB‐type and island arc‐type mineralogies. Ultramafic rocks were mainly depleted mantle harzburgite (spinel Cr♯ 50–80) and its serpentinized varieties, with some cumulate dunite, wehrlite and pyroxenites. This rock assemblage suggests a supra‐subduction zone origin for the Hahajima Seamount. Compilation of the available dredge data indicated that the ultramafic rocks occur in the two northeast–southwest‐oriented belts on the seamount, where serpentinite breccia and gabbro breccia have also developed, but the other areas are free from ultramafic rocks. Although many conical serpentinite seamounts 10 km in size are aligned along the Izu–Ogasawara (Bonin)–Mariana forearc, the Hahajima Seamount may be better interpreted as a fault‐bounded, uplifted massif composed of ophiolitic thrust sheets, resembling the Izki block of the Oman ophiolite in its shape and size. The ubiquitous roundness of the dredged rocks and their thin Mn coating (<2 mm) suggest that the Hahajima Seamount was uplifted above sealevel and wave‐eroded, like the present Macquarie Is., a rare example of ophiolite exposure in an oceanic setting. The Ogasawara Plateau on the Pacific Plate is adjacent to the east of the Hahajima Seamount, and collision and subduction of the plateau may have caused uplift of the forearc ophiolite body.
Zircon sensitive high mass‐resolution ion microprobe U–Pb and fission‐track ages for gabbros and sheeted dykes of the Taitao ophiolite, Southern Chile, and their tectonic implications
Authors: Anma Ryo , Armstrong Richard , Danhara Toru , Orihashi Yuji , Iwano Hideki
Published: March 2006

Abstract  The Late Miocene–Pliocene Taitao ophiolite is composed of a complete sequence of classic oceanic lithosphere and is exposed approximately 50 km southeast of the Chile triple junction, where the Chile Ridge subducts beneath the South American Plate. Gabbros and ultramafic rocks are folded into a complex pattern, but only evidence for block rotation has been reported in the overriding sheeted dyke complex. In the present study, sensitive high mass‐resolution ion microprobe U–Pb and fission‐track dating methods were applied to zircon crystals separated from gabbros and sheeted dykes. Two sets of radiometric ages of gabbros range between 5.9 ± 0.4 and 5.6 ± 0.1 Ma. These ages coincide within their error ranges and imply rapid intrusion and cooling of gabbros. The U–Pb age of a dacite dyke intruded into the sheeted dyke complex was determined to be 5.2 ± 0.2 Ma. These data indicate that the magmas of the Taitao ophiolite were formed during the 6 Ma Chile Ridge collision event and emplaced in a shorter period than previously thought. A short segment of the Chile Mid‐oceanic Ridge must have been emplaced during the 6 Ma event.
Initiation and evolution of intra‐oceanic subduction in the Uralides: Geochemical and isotopic constraints from Devonian oceanic rocks of the Southern Urals, Russia
Authors: Spadea Piera , D’Antonio Massimo
Published: March 2006

Abstract  The Southern Uralides are a collisional orogen generated in the Late Devonian–Early Carboniferous by the collision of the Magnitogorsk island arc (MA) generated in the Early to Middle Devonian by intra‐oceanic convergence opposite to the continental margin, and the continental margin of the East European craton. A suture zone of the arc to the continental margin, the Main Uralian Fault (MUF), is marked by ophiolites and exhumed high‐pressure–low‐temperature metamorphic rocks of continental origin. The pre‐orogenic events of the Southern Urals and their geodynamic setting are traced by means of fluid‐immobile incompatible trace elements (rare earth elements and high field strength elements) and Sr–Nd–Pb isotope geochemistry of the MA suites, in particular the protoarc suite with boninites and probably ankaramites, and the mature arc comprised of island arc tholeiitic (IAT) suites, transitional IAT to calc‐alkaline (CA), and CA suites. The MA volcanics result in genetically distinct magmatic source components. In particular, depleted normal‐mid‐oceanic ridge basalt‐type mantle sources with various enrichments in a slab‐derived aqueous fluid component are evident. The enriched component is not involved in significant amounts, as testified by the rather radiogenic Nd isotopes and unradiogenic Pb isotopes. Further information on the pre‐orogenic events is provided by the Mindyak Massif metagabbros derived from diverse gabbroic protoliths that were affected by oceanic rodingitization, and subsequently by a high‐temperature (HT) metamorphism related to the development of a metamorphic sole. The HT metamorphism has the same age as the protoarc volcanism, and constrains the initiation of subduction at approximately 410 Ma. Consequently, the maximum timespan between initial intra‐oceanic convergence and final collision is approximately 31 my, a duration consistent with that of present‐day ongoing collisions in the western Pacific. The characteristics of early volcanism and the traces of a metamorphic sole provide useful criteria to attribute most MUF ophiolites to the Tethyan type with a complex pre‐orogenic evolution.
Mantle process beneath Philippine Sea back‐arc spreading ridges: A synthesis of peridotite petrology and tectonics
Authors: Ohara Yasuhiko
Published: March 2006

Abstract  In order to obtain a general view of the mantle process beneath a back‐arc basin spreading ridge, the diversity of peridotite petrology and tectonic occurrences in two back‐arc basin spreading ridges from the Philippine Sea were examined: the Parece Vela Rift and the Mariana Trough. The Parece Vela Basin spreading ridge (Parece Vela Rift) was a physically fast/intermediate‐spreading ridge, although many tectono‐magmatic features resemble those of slow‐ to ultraslow‐spreading ridges. Two unusual features of the Parece Vela Rift further demonstrate the uniqueness of the ridge: full‐axial development of oceanic core complexes and exposure of mantle peridotite at segment midpoints. The Parece Vela Rift yields a lithological assemblage of residual but still fertile lherzolite/harzburgite, plagioclase‐bearing harzburgite and dunite; similar assemblages are reported from the equatorial Mid‐Atlantic Ridge at the Romanche Fracture Zone and the ultraslow‐spreading ridges from the Indian and Arctic Oceans. The tectono‐magmatic characteristics of the Parece Vela Rift suggest that diffuse porous melt flow and pervasive melt–mantle interaction were the important mantle processes there. Globally, this ‘porous melt flow‐type’ mantle process is likely to occur beneath a segment midpoint of the ridge having a thick lithosphere, typically an ultraslow‐spreading ridge. In contrast, the Mariana Trough is a typical slow‐spreading ridge, exposing mantle peridotite at segment ends. The Mariana Trough yields a lithological assemblage of residual harzburgite and veined harzburgite, a common assemblage among the global abyssal peridotite suite. The tectono‐magmatic characteristics of the Mariana Trough suggest that channeled melt/fluid flow and limited melt–mantle interaction are the important mantle processes there, because of the colder wall‐rock peridotite in the segment end. This ‘channeled melt flow‐type’ mantle process is likely to occur in the shallow lithospheric mantle at the segment ends of any spreading ridges.
Tectonic control of bioalteration in modern and ancient oceanic crust as evidenced by carbon isotopes
Authors: Furnes Harald , Dilek Yildirim , Muehlenbachs Karlis , Banerjee Neil R.
Published: March 2006

Abstract  We review the carbon‐isotope data for finely disseminated carbonates from bioaltered, glassy pillow rims of basaltic lava flows from in situ slow‐ and intermediate‐spreading oceanic crust of the central Atlantic Ocean (CAO) and the Costa Rica Rift (CRR). The δ13C values of the bioaltered glassy samples from the CAO show a large range, between −17 and +3‰ (Vienna Peedee belemnite standard), whereas those from the CRR define a much narrower range, between −17‰ and −7‰. This variation can be interpreted as the product of different microbial metabolisms during microbial alteration of the glass. In the present study, the generally low δ13C values (less than −7‰) are attributed to carbonate precipitated from microbially produced CO2 during oxidation of organic matter. Positive δ13C values >0‰ likely result from lithotrophic utilization of CO2 by methanogenic Archaea that produce CH4 from H2 and CO2. High production of H2 at the slow‐spreading CAO crust may be a consequence of fault‐bounded, high‐level serpentinized peridotites near or on the sea floor, in contrast to the CRR crust, which exhibits a layer‐cake pseudostratigraphy with much less faulting and supposedly less H2 production. A comparison of the δ13C data from glassy pillow margins in two ophiolites interpreted to have formed at different spreading rates supports this interpretation. The Jurassic Mirdita ophiolite complex in Albania shows a structural architecture similar to that of the slow‐spreading CAO crust, with a similar range in δ13C values of biogenic carbonates. The Late Ordvician Solund–Stavfjord ophiolite complex in western Norway exhibits structural and geochemical evidence for evolution at an intermediate‐spreading mid‐ocean ridge and displays δ13C signatures in biogenic carbonates similar to those of the CRR. Based on the results of this comparative study, it is tentatively concluded that the spreading rate‐dependent tectonic evolution of oceanic lithosphere has a significant control on the evolution of microbial life and hence on the δ13C biosignatures preserved in disseminated biogenic carbonates in glassy, bioaltered lavas.
Oceanic plateau accretion inferred from Late Paleozoic greenstones in the Jurassic Tamba accretionary complex, southwest Japan
Authors: Koizumi Kazuto , Ishiwatari Akira
Published: March 2006

Abstract  The Jurassic Tamba accretionary complex is divided into two tectono‐stratigraphic suites (Type I and II nappe groups), which are further divided into six complexes (nappes) each of which is characterized by a rock sequence of Late Paleozoic greenstone/limestone, Permian to Jurassic chert and Jurassic terrigenous clastic rocks. The mode of occurrence of the greenstone is divided into two types. The major basal type occurs as a large coherent slab associated with Permian chert and limestone, constituting the basal part of each complex, and the minor mixed type occurs as fragmented allochthonous greenstone blocks and lenses mixed with chert, limestone and sandstone in the Jurassic mudstone matrix. Most of the basal greenstones have uniform geochemical characteristics, which indicate enriched‐mid‐oceanic ridge basalt (MORB) affinity. Their geochemical compositions are akin to the reported Permo‐Carboniferous and Triassic oceanic plateau basalts. Mixed greenstones are divided into two petrochemical types: (i) tholeiitic basalt with normal‐MORB affinity, which is predominant in the uppermost complex of the Type II suite (upper nappe group); and (ii) tholeiitic and alkalic basalts of oceanic island or seamount origin, which are common in all complexes of the Tamba Belt. Geochemical characteristics of the greenstones thus vary in accordance with their occurrences and the structural units to which they belong. This relationship reflects the difference in topographic relief and crustal thickness of the accreted oceanic edifices – the remnants of thick oceanic plateau crust tended to accrete to the continental margin as a large basal greenstone body, whereas thin normal oceanic crust with small seamounts or oceanic islands accreted as mixed greenstones because of their mechanical weakness. The Type II suite (upper nappe group) contains the basal and mixed greenstones, whereas the Type I suite (lower nappe group) includes only mixed greenstones. This distinction may reflect the temporal change of subducting edifices from a thick oceanic plateau to a thin normal oceanic crust, and suggests that the accretion of a large oceanic plateau may be responsible for building accretionary complexes with thick basal greenstones slabs.