bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and characterization of new microsatellite loci in the Pacific white shrimp Litopenaeus vannamei and cross‐species amplification in other penaeid species
Authors: FREITAS PATRÍCIA D. , JESUS CELIA M. , GALETTI PEDRO M. 
Published: November 2006

AbstractThe goal of the present study was to obtain valuable microsatellite markers useful in genetic approaches of the shrimp Litopenaeus vannamei, an important aquaculture species of the world. Eight loci produced suitable polymorphic patterns with allele number ranging from two to 12 and expected heterozygosity from 0.18 to 0.89. Cross‐species amplification was successfully performed in five other penaeid species (Litopenaeus schmitti, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis, Xiphopenaeus kroyeri and Rimapenaeus constrictus), indicating that some these loci can be useful in studies of other related species.
Prevalence of myopia and hyperopia in a population of Polish schoolchildren
Authors: Czepita Damian , Żejmo Maria , Mojsa Artur 
Published: November 2006

AbstractPurpose:  The aim of this study was to determine the prevalence of myopia and hyperopia in a population of Polish schoolchildren.Methods:  A total of 4422 students were examined (2107 boys and 2315 girls, aged 6–18 years, mean age 11.1, S.D. 3.5). The examination included retinoscopy under cycloplegia induced with 1% tropicamide. Myopia was defined as a spherical equivalent (SE) of at least −0.5 dioptres (D), and hyperopia as a SE of at least +1.0 D. Data analysis was performed using Spearman's rank correlation coefficients and chi‐squared test; p‐values of <0.05 were considered statistically significant.Results:  It was observed that 13.3% of Polish students in the age group ranging from 6 to 18 years were myopic while 13.1% of students were hyperopic. Furthermore, a positive correlation was found between the prevalence of myopia and age (p < 0.001) and a negative correlation between prevalence of hyperopia and age (p < 0.001). It was observed that the prevalence of myopia increases substantially between 7 and 8 years of age (p < 0.01). Moreover, it was determined that with age the average refractive error among schoolchildren becomes more myopic (p < 0.001).Conclusions:  The occurrence, degree and progress of myopia and hyperopia in Poland is similar to that in other European countries with a predominantly Caucasian population.
LibertyandDeath: The French Revolution
Authors: Heuer Jennifer 
Published: November 2006

AbstractThis article explores recent developments in scholarship on the French Revolution and new strategies for teaching about it as a cauldron of both rights and violence. Historians have increasingly moved beyond the schools of Marxism, “revisionism,” and “political culture” that dominated earlier interpretations. Although individual approaches differ radically, they reveal several general trends. Scholars are rethinking the narrative of the Revolution, emphasizing unexpected turning points and previously neglected periods. Many insist that revolutionary politics and culture were always multi‐vocal, even during the most repressive moments. Historians have also turned towards apparently marginal groups and actors, attempting to assess not only how the Revolution affected them, but also how their stories affect our understanding of the dynamics of historical change. These trends are intensified, and to some extent, challenged, by attempts to situate the French Revolution within comparative history.
ADDITIONAL EVIDENCE FOR ECOLOGICAL DIFFERENCES AMONG ISOMORPHIC REPRODUCTIVE PHASES OF IRIDAEA LAMINARIOIDES (RHODOPHYTA: GIGARTINALES)1
Authors: Luxoro Carolina , Santelices Bernabe 
Published: November 2006

ABSTRACTGametophytes are more abundant thou sporophytes in wave exposed rocky intertidal populations of Iridaea laminarioides Bory in Central Chile. In this study we experimental tested the differential effects of selected ecological factors on karyologically different life history phases. In the field, gametophytes dominated at higher elevation and during summer; tetrasporophytes were most abundant low in the intertidal and during the fall. Laboratory responses correlated with these patterns. Gametophytes exhibited greater desiccation tolerance than tetrasporophytes. Optimum growth of gametophytes occurred at higher temperatures (20°C) and longer photoperiods (16:8 h LD) than sporophytes (15°C and 12:12 h LD). Grazing preferences changed with the developmental stage of the alga, but all herbivores tested had increased preference for diploid tissues as compared to haploid. Number of spores produced with respect to total plant surface, or total rocky surface, or settlement of spores and their germination rate did not show significant differences between phases but showed great variability in space and time. Spontaneous spore release, however, was always higher in cystocarpic than in tetrasporangial thalli. Such a combination of results suggests that some real ecological differences exist between the two life history phases of I. laminarioides. Such ecological differences permit a prediction of vertical and temporal patterns of distribution for both phases. Horizontal patterns of distribution cannot be explained because the several selection factors probably interact differently in various habitats.
STIMULATION OF LIGHT‐SATURATED PHOTOSYNTHESIS IN LAMINARIA (PHAEOPHYTA) BY BLUE LIGHT1
Authors: Dring Matthew J. 
Published: November 2006

ABSTRACTThe light‐saturated rate of photosynthesis in blue light was 50‐100% higher than that in red light for young sporophytes of Laminaria digitata (Huds.) Lamour., although photosynthetic rates were slightly higher in red than in blue light at low irradiances. Short exposures to low irradiances (e.g. 2 min at 20 μmol · m−2· s−1) of blue light also stimulated the subsequent photosynthesis of Laminaria sporophytes in saturating irradiances of red light but had little effect on photosynthesis in low irradiances of red light. The full stimulatory effect of short exposures to blue light was observed within 5 min of the blue treatment and persisted for at least 15 min in red light or in darkness. Thereafter, the effect began to decline, but some stimulation was still detectable 45 min after the blue treatment. The degree of stimulation was proportional to the logarithm of the photon exposure to blue light over the range 0.15‐2.4 mmol · m−2, and the effectiveness of an exposure to 0.6 mmol · m−2at different wavelengths was high at 402‐475 nm (with a peak at 460‐475 nm) but declined sharply at 475‐497 nm and was minimal at 544‐701 nm. Blue light appears, therefore, to exert a direct effect on the dark reaction of photosynthesis in brown algae, possibly by activating carbon‐fixing enzymes or by stimulating the uptake or transport of inorganic carbon in the plants.
NITROGEN LIMITATION IN ISOCHRYSIS GALBANA (HAPTOPHYCEAE). I. PHOTOSYNTHETIC ENERGY CONVERSION AND GROWTH EFFICIENCIES1
Authors: Herrig Ronny , Falkowski Paul G. 
Published: November 2006

ABSTRACTThe effect of steady‐state nitrogen limitation on photo‐synthetic characteristics and growth efficiency was examined in the marine haptophyte Isochrysis galbana Green. Nitrate limited chemostats were maintained at nine dilution rates, ranging from 0.18‐0.96 d−1, under continuous irradiance levels of 175 μmole quanta·m−2·s−1, an irradiance level which saturated photosynthesis at all growth rates. Nitrogen limitation led to an overall reduction in pigmentation and a decrease in the cellular concentration of reaction centers; however, the optical absorption cross section, normalized to Chl a, increased. Moreover, Chl c/a ratios were higher in nitrogen‐limited cells: the change in Chl c/a ratios were correlated with an increase in the functional size of Photosystem II. Both light saturated photosynthetic rates normalized per cell and specific respiratory losses were positively linearly correlated with growth rate. Light saturated photosynthetic rates normalized to Chl a remained relatively insensitive to the rate of nitrogen supply. The minimum quantum requirement for gross photosynthetic oxygen evolution increased from 12.4 to 17.0 quanta/O2. At the growth irradiance, the quantum requirement increased 88%, from 19.9 to 37.5 quauta/O2 Photosynthesis/respiration ratios remained relatively constant at dilution rates greater than 35% of the maximum relative growth rate. Consequently, net growth efficiency, defined as the ratio of the specific growth rate, μ, to specific gross photosynthesis, P, also remained relatively constant over this range of growth rates averaging 85 ± 3%.
EXTRACTION, PARTIAL PURIFICATION AND CHARACTERIZATION OF PHOSPHOENOLPYRUVATE CARBOXYKINASE FROM ASCOPHYLLIUM NODOSUM (PHAEOPHYCEAE)1
Authors: Johnston Andrew M. , Raven John A. 
Published: November 2006

ABSTRACTPhosphoenolpyruvate carboxykinase (PEPCK) from Ascophyllum nodosum (L.) Le Jolis was partially purified and characterized to investigate its role in inorganic carbon assimilation in macroalgae. Inorganic carbon isotopic disequilibrium studies showed that the carboxylation of phosphoenolpyruvate utilized CO2 rather than HCO3−as its source of inorganic carbon. This is consistent with the enzyme being a phosphoenolpyruvate carboxykinase rather than a phosphoenolpyruvate carboxylase. Pre‐incubation with Mn2+alone activated PEPCK more effectively than when combinations of Mn2+, ADP and HCO3−were used as activators. Activation of PEPCK during catalysis was found not to occur. Although the activation of PEPCK reduced the Km for CO2 by a factor of 2.25, the value reported here of 1.084 mM CO2 for the activated enzyme at pH 7.0 is at the top of the range of previously reported values for brown algal PEPCK. The specific activity of PEPCK was increased from 0.268 μmol·min−1·mg−1in the crude extract to 33.03 μmol·min−1·mg−1in the partially purified preparations. Whether PEPCK can act as an initial carboxylating enzyme is discussed.Triton X‐100 at 0.57% (v/v) was found to be the optimum detergent and concentration for the extraction of enzymes from A. nodosum. When high concentrations of detergents ‐were used, a low (NH4)2SO4 cut was required to remove the free detergent from solution, which was extracted by centrifugation. Q Sepharose was used to partially purify PEPCK and separate it from pyruvate kinase. Good protein separations were consistently obtained.
VEGETATIVE REPRODUCTION AND SEXUAL LIFE CYCLE OF THE TOXIC DINOFLAGELLATEGYMNODINIUM CATENATUMFROM TASMANIA, AUSTRALIA1
Authors: Blackburn Susan I. , Hallegraeff Gustaaf M. , Bolch Christopher J. 
Published: November 2006

ABSTRACTThe toxic, chain‐forming dinoflagellateGymnodinium catenatumGraham was cultured from vegetative cells and benthic resting cysts isolated from estuarine waters in Tasmania, Australia. Rapidly dividing, log phase cultures formed long chains of up to 64 cells whereas stationary phase cultures were composed primarily of single cells (23‐41 pm long, 27‐36 pm wide). Vegetative growth (mean doubling time 3‐4 days) was optimal at temperatures from 14.5‐20° C, salinities of 23‐34% and light irradiances of 50‐300 μE·m−2·s−1.The sexual life cycle ofG. catenatumwas easily induced in a nutrient‐deficient medium, provided compatible opposite mating types were combined (heterothallism). Gamete fusion produced a large (59‐73 μm long, 50‐59 μm wide) biconical, posteriorly biflagellate planozygote (double longitudinal flagellum) which after several days lost one longitudinal flagellum and gradually became subspherical in shape. This older planozygote stage persisted for up to two weeks before encysting into a round, brown resting cyst (42‐52 μm diam; hypnozygote) with microreticulate surface ornamentation. Resting cysts germinated after a dormancy period as short as two weeks under our culture conditions, resulting in a single, posteriorly biflagellate germling cell (planomeiocyte). This divided to form a chain of two cells, which subsequently re‐established a vegetative population. Implications for the bloom dynamics of this toxic dinoflagellate, a causative organism of paralytic shellfish poisoning, are discussed.
Regulating MHC expression for cellular therapeutics
Authors: Figueiredo Constança , Horn Peter A. , Blasczyk Rainer , Seltsam Axel 
Published: November 2006

BACKGROUND: In the past decade, regenerative medicine and cell‐based therapies have emerged as new science and technology, with the main goal of repairing, replacing, or regenerating new tissues. A critical issue in this field is the high polymorphism of HLA, which compromises immune acceptance. The lentivirus‐mediated delivery of short‐hairpin RNAs (shRNAs) has proved to be an efficient method to inhibit the translation of a specific gene.STUDY DESIGN AND METHODS: A lentiviral‐based vector system was used for drug‐inducible expression of shRNA sequences that target either β2‐microglobulin (β2m) or HLA heavy‐chain transcripts.RESULTS: The transduction of inducible RNA interference cassettes containing the sequences for shRNAs targeting β2m or HLA heavy chain suppressed HLA class I expression by up to 90 percent in HeLa and B‐lymphocyte cell lines as well as in peripheral blood monocytes. The expression of HLA class I antigens was fully restored in these cells after the drug had been discontinued. It was demonstrated that HLA class I knockdown was effective in preventing antibody‐mediated cell lysis and CD8+ T‐cell response. The residual HLA expression in HLA‐silenced cells may provide sufficient protection against natural killer cell–mediated lysis.CONCLUSIONS: These data demonstrate the feasibility of controlling HLA expression by genetically modifying cell‐based therapeutics to overcome the limitations of immune rejection, bringing cellular therapies closer to reality.
Duffy and Kidd blood group antigens: minor histocompatibility antigens involved in renal allograft rejection?
Authors: Lerut Evelyne , Van Damme Boudewijn , Noizat‐Pirenne France , Emonds Marie‐Paule , Rouger Philippe , Vanrenterghem Yves , Pirenne Jacques , Ansart‐Pirenne Hélène 
Published: November 2006

BACKGROUND: Minor histocompatibility antigens have been poorly defined. Whether Duffy (FY) and Kidd (JK), polymorphic and immunogenic blood group antigens, widely distributed in human organs, expressed and functional in the kidney, could function as minor histocompatibility antigens and be implicated in renal allograft rejection was questioned.STUDY DESIGN AND METHODS: A retrospective, homogeneous, single‐center cohort of 370 renal transplants was analyzed. In all donor/recipient pairs, FY and JK polymorphisms were identified by real‐time polymerase chain reaction. In all donor/recipient pairs the matching (m) or mismatching (mm) status was defined for both systems. All biopsies were reviewed, and historical screening results for FY and JK alloantibodies and graft survival were retrospectively analyzed.RESULTS: Although graft survival was not different between the groups, it was observed that FY mm grafts had significantly more chronic lesions compared to FY m grafts. HLA‐DR11 was more frequent in both recipients (p = 0.0081) and donors (p = 0.0104) of FY mm couples without chronic allograft nephropathy, suggesting a protective effect for this molecule. JK mm grafts had more interstitial inflammation than JK m grafts (p = 0.0369).CONCLUSION: This renal model unmasks for the first time the role of FY and—to a lesser extent—JK antigens as minor histocompatibility antigens and suggests their potential role for other clinical transplant settings.
False‐reactive microbiologic screening test results in Swedish blood donors—how big is the problem? A survey among blood centers and deferred donors
Authors: Tynell Elsa , Norda Rut , Ekermo Bengt , Sanner Margareta , Andersson Sören , Björkman Anders 
Published: November 2006

BACKGROUND: Screening of blood donors for markers of transfusion‐transmissible infectious agents leads to a varying number of false‐reactive test results and sometimes thereby temporary or permanent deferral of donors and also to loss of collected units.STUDY DESIGN AND METHODS: Data on false‐reactive screening test results in 2002 and 2003 were collected from 19 blood centers in Sweden. A questionnaire was sent to donors deferred because of false‐reactive screening test results to investigate their perception of the information and their reaction to the deferral.RESULTS: Testing of 21,189 samples from new donors and 423,543 donations from regular and/or repeat donors produced 1,059 false‐reactive test results, mostly from hepatitis C virus antibody testing, and 299 deferrals. Six different human immunodeficiency virus tests led to between 0.02 and 0.2 percent false‐reactive results. The deferral rate varied considerably between different counties. Of 204 deferred donors contacted, 180 (88%) answered the questionnaire. More than 80 percent were worried about their test results and worry was more common among those who did not feel sufficiently informed.CONCLUSION: The results imply that there is a need for a more standardized approach to the screening of blood donors and donations with the aim of minimizing the number of false‐reactive screening test results. They also emphasize the importance of appropriate information and support to deferred donors.
Male‐to‐male differences in post‐thaw motility of rhesus spermatozoa after cryopreservation of replicate ejaculates
Authors: Leibo S.P. , Michael Kubisch H. , Dee Schramm R. , Harrison Richard M. , VandeVoort Catherine A. 
Published: November 2006

AbstractBackground The efficiency of controlled propagation to produce rhesus monkeys of particular genotypes can be maximized by use of cryopreserved spermatozoa collected from specific males to inseminate appropriate females. But this assumes that semen from males with different genotypes can be cryopreserved with equal effectiveness.Methods To investigate whether spermatozoa from differentMacaca mulattamales can be effectively cryopreserved when frozen under identical conditions, we collected and froze semen specimens from 13 adult, fertile males maintained at three primate research centers.Results Survival, based on post‐thaw motility normalized to the pre‐freeze value, was assayed within 30 minutes after thawing; it varied from 50% to 70% but declined thereafter. To examine the response of semen from individual males, we collected and froze three to six ejaculates per male from each of seven males.Conclusions In general, semen from a given male responded reproducibly to freezing, but there were significant differences among males. The cause of these differences amongM. mulattamales in post‐thaw sperm survival remains unidentified.
Regulation of calprotectin expression by interleukin‐1α and transforming growth factor‐β in human gingival keratinocytes
Authors: Hayashi N. , Kido J. , Suryono  , Kido R. , Wada C. , Kataoka M. , Shinohara Y. , Nagata T. 
Published: November 2006

Background and Objective:  Calprotectin, a heterodimer of S100A8 and S100A9 with antimicrobial properties, is expressed in gingival keratinocytes and plays an important role in innate immunity. Because calprotectin expression is localized in the spinous cell layer of the gingival epithelium, we hypothesized that the expression of calprotectin in keratinocytes is related to the differentiation stage. The aim of the present study was to investigate the relationship between calprotectin expression and keratinocyte differentiation using some factors that regulated its differentiation.Material and Methods:  Normal human gingival keratinocytes were isolated from gingival tissues obtained at the extraction of wisdom teeth, and were cultured in serum‐free keratinocyte medium supplemented with interleukin‐1α or calcium, which promote keratinocyte differentiation, and transforming frowth factor‐β (TGF‐β) or retinoic acid, which suppress its differentiation. The expression of S100A8/A9 mRNA and the production of calprotectin in normal human gingival keratinocytes were examined by northern blotting and enzyme‐linked immunosorbent assay, respectively. The expression of cytokeratin 14, involucrin and filaggrin (marker proteins of keratinocyte differentiation) was investigated by immunohistochemical staining, and the DNA‐binding activity of CCAAT/enhancer binding protein α (C/EBPα), a transcription factor, was examined by electrophoretic mobility shift assay.Results:  The expression of S100A8/A9 mRNA and the production of calprotectin were increased by interleukin‐1α and calcium, but decreased by TGF‐β. RA inhibited the expression of S100A8/A9 and keratinocyte differentiation, which were induced by interleukin‐1α. C/EBPα DNA‐binding activity in normal human gingival keratinocytes was enhanced by interleukin‐1α and calcium, but suppressed by TGF‐β.Conclusion:  The present study suggests that calprotectin expression is related to keratinocyte differentiation and that C/EBPα is a regulator of calprotectin expression in keratinocytes.
Lip piercing: prevalence of associated gingival recession and contributing factors. A cross‐sectional study
Authors: Kapferer I. , Benesch T. , Gregoric N. , Ulm C. , Hienz S. A. 
Published: November 2006

Background and Objective:  Body piercings have increased tremendously in popularity in recent years. For oral piercing, late complications include gingival trauma and localized periodontitis. The purpose of this cross‐sectional study was to investigate the prevalence and contributing factors of gingival recession associated with labial piercing.Material and Methods:  The test group included 50 subjects with lower‐lip studs. Nonpierced controls were matched according to gender, age and smoking status. Clinical examination included plaque and bleeding indices, probing depth, recession, clinical attachment level, width of keratinized gingiva, periodontal biotype, insertion of frenula, evaluation of hard tissues, trauma of occlusion, characteristics of the stud, radiographs and photographs.Results:  Gingival recessions were noted on teeth opposite the stud in 68% of the test group compared with 4% of the controls. Localized periodontitis was recorded in 4% of test subjects. Time since piercing and the position of the stud in relation to the cemento–enamel junction were significantly associated with the prevalence of buccal recessions. There were no significant associations between piercing and abnormal tooth wear.Conclusion:  The prevalence of gingival recessions is associated with labial piercing. The position of the intra‐oral disc and time since piercing are associated with a greater prevalence of gingival recession. A narrow width of keratinized gingiva is associated with increased buccal recessions.
Effects of successive seasons of genetically modified herbicide‐tolerant maize cropping on weeds and invertebrates
Authors: Heard M.S. , Clark S.J. , Rothery P. , Perry J.N. , Bohan D.A. , Brooks D.R. , Champion G.T. , Dewar A.M. , Hawes C. , Haughton A.J. , May M.J. , Scott R.J. , Stuart R.S. , Squire G.R. , Firbank L.G. 
Published: November 2006

AbstractThe use of genetically modified herbicide‐tolerant (GMHT) crops influences the abundance of weeds and some invertebrate groups because the associated herbicide regime contrasts with that of conventional systems. However, it is not clear to what extent these effects might be cumulative; should GMHT crops be grown continuously. In northern Europe, in the near future, this situation is most likely to apply to maize crops. Here, we consider the effects of continuous GMHT maize cropping on plant and invertebrate taxa using a split‐field experiment. Half of each field was managed using GMHT and the other half with a conventional variety, with the treatments retained for two seasons. The treatment effects were broadly consistent with those found in the larger sample of non‐continuous maize sites within the Farm Scale Evaluations. There was little evidence of effects being significantly more pronounced in the second year; any cumulative differences in above‐ground biodiversity between GMHT and conventional cropping were too variable to be readily detected.