bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of plant species composition, biomass production and biomass chemical properties to high N, P and K application rates in Dactylis glomerata‐ and Festuca arundinacea‐dominated grassland
Authors: Hejcman M. , Strnad L. , Hejcmanová P. , Pavlů V.
Published: March 2012

Little is known about the immediate effect of high nitrogen (N), phosphorus (P) and potassium (K) application rates on sown grasslands cut twice per year. We asked how quickly plant species composition, biomass yield, biomass chemical properties and nutrient balance respond to N, P and K application. An experiment using unfertilized control, P, N, NP and NPK treatments was established on seven‐year‐old cut grassland in the Czech Republic in 2007 and monitored over four years. Annual application rates were 300 kg N ha−1, 80 kg P ha−1 and 200 kg K ha−1. The immediate response of plant species composition to N application was recorded and was found to be different to the response over the four years of the study period. Highly productive grasses (Dactylis glomerata, Festuca arundinacea and Phleum pratense) were promoted by N application in 2008 and then retreated together with legumes (Medicago sativa, Trifolium pratense and Trifolium repens) in all N treatments where the expansion of perennial forbs (Urtica dioica and Rumex obtusifolius) and annual weeds (Galinsoga quadriradiata, Impatiens parviflora, Lamium purpureum and Stellaria media) was recorded. At the end of the experiment, Festuca rubra was the dominant grass in the control and P treatment, and species richness was lowest in all treatments with N application. Mean annual dry‐matter yield over all years was 3.5, 3.9, 5.8, 5.6 and 6.8 t ha−1 in the control, P, N, NP and NPK treatments, respectively. Concentrations of N in the biomass ranged from 20.0 to 28.7 g kg−1 in the P and N treatments; concentrations of P ranged from 3.2 to 3.7 g kg−1 in the N and P treatments; and concentrations of K ranged from 24.1 to 34.0 g kg−1 in the NP and NPK treatments. The N:P, N:K and K:P ratios did not correctly indicate the nutrient limitation of biomass production, which was primarily N‐limited, and K‐limitation was only recorded for high production levels in treatments with N applications. On the basis of the nutrient‐balance approach, the balanced annual application rates were estimated as 140 kg N ha−1, 30 kg P ha−1 and 100 kg K ha−1. We concluded that high N, P and K application rates can very quickly and dramatically change species composition, biomass production and its chemical properties in sown cut grasslands. High N application rates can be detrimental for tall forage grasses and can support the spread of weedy species.
Ontogenetic and evolutionary effects of predation and competition on nine‐spined stickleback (Pungitius pungitius) body size
Authors: Välimäki Kaisa , Herczeg Gábor
Published: March 2012

1. Individual‐ and population‐level variation in body size and growth often correlates with many fitness traits. Predation and food availability are expected to affect body size and growth as important agents of both natural selection and phenotypic plasticity. How differences in predation and food availability affect body size/growth during ontogeny in populations adapted to different predation and competition regimes is rarely studied.

2. Nine‐spined stickleback (Pungitius pungitius) populations originating from habitats with varying levels of predation and competition are known to be locally adapted to their respective habitats in terms of body size and growth. Here, we studied how different levels of perceived predation risk and competition during ontogeny affect the reaction norms of body size and growth in (i) marine and pond populations adapted to different levels of predation and competition and (ii) different sexes. We reared nine‐spined stickleback in a factorial experiment under two levels of perceived predation risk (present/absent) and competition (high/low food supply).

3. We found divergence in the reaction norms at two levels: (i) predation‐adapted marine stickleback had stronger reactions to predatory cues than intraspecific competition‐adapted pond stickleback, the latter being more sensitive to available food than the marine fish and (ii) females reacting more strongly to the treatments than males.

4. The repeated, habitat‐dependent nature of the differences suggests that natural selection is the agent behind the observed patterns. Our results suggest that genetic adaptation to certain environmental factors also involves an increase in the range of expressible phenotypic plasticity. We found support for this phenomenon at two levels: (i) across populations driven by habitat type and (ii) within populations driven by sex.
Excessively high soluble Klotho in patients with acromegaly
Authors: Sze L. , Bernays R. L. , Zwimpfer C. , Wiesli P. , Brändle M. , Schmid C.
Published: March 2012

Abstract.  Sze L, Bernays RL, Zwimpfer C, Wiesli P, Brändle M, Schmid C (Division of Endocrinology and Diabetes, University Hospital, Zurich; Division of Endocrinology and Diabetes, Kantonsspital, Gallen; Department of Neurosurgery, University Hospital, Zurich; and Department of Internal Medicine, Kantonsspital Frauenfeld, Frauenfeld, Switzerland). Excessively high soluble Klotho in patients with acromegaly. J Intern Med 2012; 272: 93–97.

Objectives.  Klotho‐deficient mice develop a syndrome resembling accelerated ageing, and genetic variants of Klotho have been associated with human ageing. In humans, serum levels of soluble Klotho decrease with age and with chronic renal failure. The aim of our study was to examine the relationship between excess growth hormone (GH) and serum levels of Klotho in patients with acromegaly, a disease usually caused by a pituitary adenoma, which is associated with high phosphate levels and reduced life expectancy.

Patients and design.  We determined the levels of soluble Klotho, GH and insulin‐like growth factor 1 (IGF‐1) in serum samples from 24 consecutive patients with acromegaly (nine women/15 men, age 28–76 years) before and after transsphenoidal surgery.

Results.  Soluble Klotho levels were excessively high at baseline (mean ± SEM, 4.2 ± 0.7 ng mL−1) and correlated with GH (r = 0.64), IGF‐1 (r = 0.57) and tumour size (r = 0.5). In multiple regression analysis, soluble Klotho was associated with GH after correction for age, gender and levels of creatinine and phosphate (P = 0.029). After surgery, GH and IGF‐1 levels decreased in all patients (from 26.3 ± 5.2 to 2.6 ± 0.6 μg L−1, P <0.0001, and from 588 ± 35 to 193 ± 12 μg L−1, P < 0.001, 0.0001, respectively). Creatinine increased from 71 ± 3 to 80 ± 3 μmol L−1 (P < 0.001), and phosphate decreased from 1.37 ± 0.04 to 1.06 ± 0.02 mmol L−1 (P < 0.001). The markedly increased preoperative levels of soluble Klotho returned towards normal after surgery (0.7 ± 0.1 ng mL−1, P < 0.0001).

Conclusions.  This is the first study to show dramatically increased soluble Klotho levels in an acquired disease in humans. Reversal following tumour removal suggests a causal relation between the GH‐producing adenoma and high serum Klotho concentration in acromegaly.
Interobserver discrepancy in liver fibrosis using transient elastography
Authors: Roca B. , Resino E. , Torres V. , Herrero E. , Penades M.
Published: March 2012

Summary.  Transient elastography is a useful method to assess liver fibrosis, but uncertainties still exist regarding reliability and reproducibility of the technique. We aimed to improve knowledge on interobserver variability with the procedure and tried to find factors associated with such variability. This was a cross‐sectional study to compare the results of transient elastography performed by two different operators, one test made just after the other. We assessed both results with correlation tests and with repeated parametric or nonparametric tests, as needed. We also carried out a multivariate analysis to find factors associated with discrepancy in the results obtained by the two operators. We included a total of 333 pairs of transient elastography tests, belonging to 274 different patients. A total of 325 pairs of tests (97.6%) were valid. Results of the first and the second tests were, respectively, median (and interquartile range) of direct measurement 6.2 (4.6–10.6) and 6.0 (4.4–10.1) kPa (P = 0.012), and mean ± standard deviation of log10 of direct measurement 0.892 ± 0.316 and 0.871 ± 0.324 (P = 0.001). In 87 pairs of tests (26.7%), a discrepancy of at least 2 kPa between both results was found, and in 15 pairs of tests (4.6%), a discrepancy of at least 10 kPa was found. Discordance of at least one stage between both measurements was noted in 74 pairs of tests (22.8%). An association was found between higher stiffness and discrepancy between both operators (P < 0.001). Although transient elastography is a very convenient test to assess liver fibrosis in clinical practice, interobserver discrepancy in results is common and represents a significant problem with the technique. Discrepant results are more common in patients with higher values of stiffness.
Measuring the interaction of meal and gastric secretion: a combined quantitative magnetic resonance imaging and pharmacokinetic modeling approach
Authors: Sauter M. , Curcic J. , Menne D. , Goetze O. , Fried M. , Schwizer W. , Steingoetter A.
Published: March 2012

Background  The stimulation and intragastric accumulation of gastric secretion has been recognized as an important factor in gastroesophageal reflux disease. However, the interaction of gastric secretion and meal emptying has not been fully understood. Current methods to assess gastric secretion are either invasive or unable to provide information on its volume, distribution and dynamics. The aim of this study was to quantify the interaction between meal emptying and meal induced gastric secretion by using quantitative magnetic resonance imaging (MRI) and pharmacokinetic analysis.

Methods  A chocolate test meal was developed which is secretion stimulating and MRI compatible. Meal emptying and gastric secretion were assessed in fourteen healthy volunteers using a validated quantitative MRI technique. A population based pharmacokinetic model was developed and applied to the extracted volume data, assessing the meal emptying rate, rate of secretion and their interaction.

Key Results  The test meal continuously induced gastric secretion in all subjects, which partly accumulated at the meal–air interface, forming a ‘secretion layer’ in the proximal stomach. Traditional fitting detected a significant correlation between meal emptying rate and rate of secretion. The pharmacokinetic model quantified this interaction and estimated a 2.3 ± 1 fold higher effect of meal on secretion than vice versa. The efficacy of the emptied meal to produce gastric secretion was 61%.

Conclusions & Inferences  The combined quantitative MRI and pharmacokinetic model approach allows for the quantification of gastric secretion volume and its interaction on meal emptying. The observed secretion layer might explain previous findings postulating the presence of an intragastric ‘acid pocket’.
Dolomite‐mediating bacterium isolated from the sabkha of Abu Dhabi (UAE)
Authors: Bontognali Tomaso R. R. , Vasconcelos Crisógono , Warthmann Rolf J. , Lundberg Rebecca , McKenzie Judith A.
Published: March 2012

Terra Nova, 24, 248–254, 2012

The study of microbe‐mineral interactions and the identification of biominerals in sedimentary rocks provide crucial information on the coevolution of life and Earth surface environments. Desulfovibrio brasiliensis, a sulfate‐reducing bacterium isolated from Lagoa Vermelha (Brazil), is known for its ability to precipitate dolomite, a mineral that is common in the geological record, but difficult to obtain in laboratory experiments simulating Earth's surface conditions. Here, we report on a new bacterial strain capable of precipitating Mg‐calcite and Ca‐dolomite, isolated from a microbial mat in the sabkha of Abu Dhabi (UAE). The 16S rRNA gene sequence of the isolate revealed a 99.6% identity (i.e. same species) with Desulfovibrio brasiliensis. The presence of the same microbial species at two geographically distant dolomite‐forming locations is difficult to explain in terms of pure coincidence. Rather, it suggests that the ability of precipitating dolomite may be a unique characteristic associated with specific strains.
Composition, architecture and dynamics of the photosynthetic apparatus in higher plants
Authors: Nevo Reinat , Charuvi Dana , Tsabari Onie , Reich Ziv
Published: March 2012

The process of oxygenic photosynthesis enabled and still sustains aerobic life on Earth. The most elaborate form of the apparatus that carries out the primary steps of this vital process is the one present in higher plants. Here, we review the overall composition and supramolecular organization of this apparatus, as well as the complex architecture of the lamellar system within which it is harbored. Along the way, we refer to the genetic, biochemical, spectroscopic and, in particular, microscopic studies that have been employed to elucidate the structure and working of this remarkable molecular energy conversion device. As an example of the highly dynamic nature of the apparatus, we discuss the molecular and structural events that enable it to maintain high photosynthetic yields under fluctuating light conditions. We conclude the review with a summary of the hypotheses made over the years about the driving forces that underlie the partition of the lamellar system of higher plants and certain green algae into appressed and non‐appressed membrane domains and the segregation of the photosynthetic protein complexes within these domains.
Advances in plant genome sequencing
Authors: Hamilton John P. , Robin Buell C.
Published: March 2012

The study of plant biology in the 21st century is, and will continue to be, vastly different from that in the 20th century. One driver for this has been the use of genomics methods to reveal the genetic blueprints for not one but dozens of plant species, as well as resolving genome differences in thousands of individuals at the population level. Genomics technology has advanced substantially since publication of the first plant genome sequence, that of Arabidopsis thaliana, in 2000. Plant genomics researchers have readily embraced new algorithms, technologies and approaches to generate genome, transcriptome and epigenome datasets for model and crop species that have permitted deep inferences into plant biology. Challenges in sequencing any genome include ploidy, heterozygosity and paralogy, all which are amplified in plant genomes compared to animal genomes due to the large genome sizes, high repetitive sequence content, and rampant whole‐ or segmental genome duplication. The ability to generate de novo transcriptome assemblies provides an alternative approach to bypass these complex genomes and access the gene space of these recalcitrant species. The field of genomics is driven by technological improvements in sequencing platforms; however, software and algorithm development has lagged behind reductions in sequencing costs, improved throughput, and quality improvements. It is anticipated that sequencing platforms will continue to improve the length and quality of output, and that the complementary algorithms and bioinformatic software needed to handle large, repetitive genomes will improve. The future is bright for an exponential improvement in our understanding of plant biology.
Analysis of plant germline development by high‐throughput RNA profiling: technical advances and new insights
Authors: Schmidt Anja , Schmid Marc W. , Grossniklaus Ueli
Published: March 2012

Reproduction is a crucial step in the life cycle of plants. The male and female germline lineages develop in the reproductive organs of the flower, which in higher plants are the anthers and ovules, respectively. Development of the germline lineage initiates from a dedicated sporophytic cell that undergoes meiosis to form spores that subsequently give rise to the gametophytes through mitotic cell divisions. The mature male and female gametophytes harbour the male (sperm cells) and female gametes (egg and central cell), respectively. Those unite during double fertilization to initiate embryo and endosperm development in sexually reproducing higher plants. While cytological changes involved in development of the germline lineages have been well characterized in a number of species, investigation of the transcriptional basis underlying their development and the specification of the gametes proved challenging. This is largely due to the inaccessibility of the cells constituting the germline lineages, which are enclosed by sporophytic tissues. Only recently, these technical limitations could be overcome by combining new methods to isolate the relevant cells with powerful transcriptional profiling methods, such as microarrays or high‐throughput sequencing of RNA. This review focuses on these technical advances and the new insights gained from them concerning the transcriptional basis and molecular mechanisms underlying germline development.
Glandular trichomes: what comes after expressed sequence tags?
Authors: Tissier Alain
Published: March 2012

Glandular trichomes cover the surface of many plant species. They exhibit tremendous diversity, be it in their shape or the compounds they secrete. This diversity is expressed between species but also within species or even individual plants. The industrial uses of some trichome secretions and their potential as a defense barrier, for example against arthropod pests, has spurred research into the biosynthesis pathways that lead to these specialized metabolites. Because complete biosynthesis pathways take place in the secretory cells, the establishment of trichome‐specific expressed sequence tag libraries has greatly accelerated their elucidation. Glandular trichomes also have an important metabolic capacity and may be considered as true cell factories. To fully exploit the potential of glandular trichomes as breeding or engineering objects, several research areas will have to be further investigated, such as development, patterning, metabolic fluxes and transcription regulation. The purpose of this review is to provide an update on the methods and technologies which have been used to investigate glandular trichomes and to propose new avenues of research to deepen our understanding of these specialized structures.
High‐resolution imaging of Ca2+, redox status, ROS and pH using GFP biosensors
Authors: Choi Won‐Gyu , Swanson Sarah J. , Gilroy Simon
Published: March 2012

Many plant response systems are linked to complex dynamics in signaling molecules such as Ca2+ and reactive oxygen species (ROS) and to pH. Regulatory changes in these molecules can occur in the timeframe of seconds and are often limited to specific subcellular locales. Thus, to understand how Ca2+, ROS and pH form part of plants’ regulatory networks, it is essential to capture their rapid dynamics with resolutions that span the whole plant to subcellular dimensions. Defining the spatio‐temporal signaling ‘signatures’ of these regulators at high resolution has now been greatly facilitated by the generation of plants expressing a range of GFP‐based bioprobes. For Ca2+ and pH, probes such as the yellow cameleon Ca2+ sensors (principally YC2.1 and 3.6) or the pHluorin and H148D pH sensors provide a robust suite of tools to image changes in these ions. For ROS, the tools are much more limited, with the GFP‐based H2O2 sensor Hyper representing a significant advance for the field. However, with this probe, its marked pH sensitivity provides a key challenge to interpretation without using appropriate controls to test for potentially coupled pH‐dependent changes. Most of these Ca2+‐, ROS‐ and pH‐imaging biosensors are compatible with the standard configurations of confocal microscopes available to many researchers. These probes therefore represent a readily accessible toolkit to monitor cellular signaling. Their use does require appreciation of a minimal set of controls but these are largely related to ensuring that neither the probe itself nor the imaging conditions used perturb the biology of the plant under study.
Surveying the plant’s world by magnetic resonance imaging
Authors: Borisjuk Ljudmilla , Rolletschek Hardy , Neuberger Thomas
Published: March 2012

Understanding the way in which plants develop, grow and interact with their environment requires tools capable of a high degree of both spatial and temporal resolution. Magnetic resonance imaging (MRI), a technique which is able to visualize internal structures and metabolites, has the great virtue that it is non‐invasive and therefore has the potential to monitor physiological processes occurring in vivo. The major aim of this review is to attract plant biologists to MRI by explaining its advantages and wide range of possible applications for solving outstanding issues in plant science. We discuss the challenges and opportunities of MRI in the study of plant physiology and development, plant–environment interactions, biodiversity, gene functions and metabolism. Overall, it is our view that the potential benefit of harnessing MRI for plant research purposes is hard to overrate.
The structure of the phloem – still more questions than answers
Authors: Knoblauch Michael , Oparka Karl
Published: March 2012

Long‐distance assimilate distribution in higher plants takes place in the enucleate sieve‐tube system of the phloem. It is generally accepted that flow of assimilates is driven by an osmotically generated pressure differential, as proposed by Ernst Münch more than 80 years ago. In the period between 1960 and 1980, the pressure flow hypothesis was challenged when electron microscopic images suggested that sieve tubes contain obstructions that would prevent passive flow. This led to the proposal of alternative translocation mechanisms. However, most investigators came to the conclusion that obstructions in the sieve‐tube path were due to preparation artifacts. New developments in bioimaging have vastly enhanced our ability to study the phloem. Unexpectedly, in vivo studies challenge the pressure‐flow hypothesis once again. In this review we summarize current investigations of phloem structure and function and discuss their impact on our understanding of long‐distance transport in the phloem.
Autopolyploidy differentially influences body size in plants, but facilitates enhanced accumulation of secondary metabolites, causing increased cytosine methylation
Authors: Lavania Umesh C. , Srivastava Sarita , Lavania Seshu , Basu Surochita , Misra Nandeesh Kumar , Mukai Yasuhiko
Published: March 2012

Whole genome duplication leads to autopolyploidy and brings about an increase in cell size, concentration of secondary metabolites and enhanced cytosine methylation. The increased cell size offers a positive advantage to polyploids for cell‐surface‐related activities, but there is a differential response to change in body size across species and taxonomic groups. Although polyploidy has been very extensively studied, having genetic, ecological and evolutionary implications, there is no report that underscores the significance of native secondary metabolitesvis‐à‐visbody size with ploidy change. To address this problem we targeted unique diploid–autotetraploid paired sets of eight diverse clones of six species ofCymbopogon– a species complex of aromatic grasses that accumulate qualitatively different monoterpene essential oils (secondary metabolite) in their vegetative biomass. Based on the qualitative composition of essential oils and the plant body size relationship between the diploid versus autotetraploid paired sets, we show that polyploidy brings about enhanced accumulation of secondary metabolites in all cases, but exerts differential effects on body size in various species. It is observed that the accumulation of alcohol‐type metabolites (e.g. geraniol) does not inhibit increase in body size with ploidy change from 2× to 4× (r = 0.854,P < 0.01), but aldehyde‐type metabolites (e.g. citral) appear to drastically impede body development (r = −0.895). Such a differential response may be correlated to the metabolic steps involved in the synthesis of essential oil components. When changed to tetraploidy, the progenitor diploids requiring longer metabolic steps in production of their secondary metabolites are stressed, and those having shorter metabolite routes better utilize their resources for growth and vigour.In situimmunodetection of 5‐methylcytosine sites reveals enhanced DNA methylation in autopolyploids. It is underpinned that the qualitative composition of secondary metabolites found in the vegetative biomass of the progenitor diploid has a decisive bearing on the body size of the derived autotetraploids and brings about an enhancement in genome‐wide cytosine methylation.
Unpredictability of nectar nicotine promotes outcrossing by hummingbirds in Nicotiana attenuata
Authors: Kessler Danny , Bhattacharya Samik , Diezel Celia , Rothe Eva , Gase Klaus , Schöttner Matthias , Baldwin Ian T.
Published: March 2012

Many plants use sophisticated strategies to maximize their reproductive success via outcrossing. Nicotiana attenuata flowers produce nectar with nicotine at concentrations that are repellent to hummingbirds, increasing the number of flowers visited per plant. In choice tests using native hummingbirds, we show that these important pollinators learn to tolerate high‐nicotine nectar but prefer low‐nicotine nectar, and show no signs of nicotine addiction. Nectar nicotine concentrations, unlike those of other vegetative tissues, are unpredictably variable among flowers, not only among populations, but also within populations, and even among flowers within an inflorescence. To evaluate whether variations in nectar nicotine concentrations increase outcrossing, polymorphic microsatellite markers, optimized to evaluate paternity in native N. attenuata populations, were used to compare outcrossing in plants silenced for expression of a biosynthetic gene for nicotine production (Napmt1/2) and in control empty vector plants, which were antherectomized and transplanted into native populations. When only exposed to hummingbird pollinators, seeds produced by flowers with nicotine in their nectar had a greater number of genetically different sires, compared to seeds from nicotine‐free flowers. As the variation in nectar nicotine levels among flowers in an inflorescence decreased in N. attenuata plants silenced in various combinations of three Dicer‐like (DCL) proteins, small RNAs are probably involved in the unpredictable variation in nectar nicotine levels within a plant.
Chestnut blight in south‐western Germany: multiple introductions of Cryphonectria parasitica and slow hypovirus spread
Authors: Peters F. S. , Holweg C. L. , Rigling D. , Metzler B.
Published: March 2012

Cryphonectria parasitica was discovered in the sweet chestnut forests of south‐western Germany in 1992. Two main areas affected by chestnut blight were discerned, one to the east and one to the west of the Rhine valley. The occurrence of the fungal pathogen with respect to vegetative compatibility (vc) type and hypovirulence was analysed by sampling chestnut blight cankers between 1992 and 2010. Among 368 C. parasitica isolates sampled in south‐western Germany, 9 different vc types were found. East of the Rhine valley, EU‐2 is the most widespread vc type. In addition, two isolated forest areas infected with C. parasitica of the vc types EU‐14 and EU‐28 were detected. West of the Rhine valley, C. parasitica of the vc type EU‐65 was repeatedly isolated from an infection focus, the spread of which was successfully suppressed for several years by sanitation measures. Since 2003, additional outbreaks of C. parasitica belonging to the vc types EU‐2 and EU‐5 were detected in the vicinity. Several other vc types (EU‐1, EU‐12, EU‐33 and one vc type incompatible with any of the 74 European testers) were identified on isolated trees mainly in urban areas across the study area and were subsequently eradicated. The spatial and temporal distribution of the different vc types indicates at least nine different introductory events of C. parasitica into south‐western Germany. Natural hypovirulence was only found in the infection area in Baden‐Württemberg. A total of four hypovirulent isolates of the vc type EU‐2 were obtained, one in 1992 and three in recent years. The four hypoviruses were genetically closely related and belonged to the Spanish/German subtype of Cryphonectria hypovirus 1. As the different vc types in south‐western Germany occur mostly in spatially separated, single stands, the introduction of hypovirulence as biological control is expected to be effective.
Oxygen Concentration and Cysteamine Supplementation During In vitro Production of Buffalo (Bubalus bubalis) Embryos Affect mRNA Expression of BCL‐2, BCL‐XL, MCL‐1, BAX and BID
Authors: Elamaran G , Singh KP , Singh MK , Singla SK , Chauhan MS , Manik RS , Palta P
Published: March 2012

Contents

This study examined the effects of O2 concentration (5% vs 20%) during in vitro maturation (IVM), fertilization (IVF) and culture (IVC) or supplementation of IVM and IVC media with cysteamine (50 and 100 μm, respectively; IVM, IVF and IVC carried out in 20% O2), on blastocyst rate and relative mRNA abundance of some apoptosis‐related genes measured by real‐time qPCR in immature and in vitro‐matured buffalo oocytes and in embryos at 2‐, 4‐, 8‐ to 16‐cell, morula and blastocyst stages. The blastocyst rate was significantly higher (p < 0.05) while the percentage of TUNEL‐positive cells was significantly lower (p < 0.05) under 5% O2 than that under 20% O2. The mRNA expression of anti‐apoptotic genes BCL‐2 and MCL‐1 was significantly higher (p < 0.05) and that of pro‐apoptotic genes BAX and BID was lower (p < 0.05) under 5% O2 than that under 20% O2 concentration at many embryonic stages. Following cysteamine supplementation, the blastocyst rate and the relative mRNA abundance of BCL‐XL and MCL‐1 was significantly higher (p < 0.05) and that of BAX but not BID was lower (p < 0.05) at many stages of embryonic development, although it did not affect the percentage of TUNEL positive cells in the blastocysts significantly. The mRNA expression pattern of these genes during embryonic development was different in 5% vs 20% O2 groups and in cysteamine supplemented vs controls. At the 8‐ to 16‐cell stage, where developmental block occurs in buffalo, the relative mRNA abundance of BCL‐2 and MCL‐1 was highest under 5% O2 concentration and that of BAX and BID was highest (p < 0.05) under 20% O2 concentration. These results suggest that one of the mechanisms through which beneficial effects of low O2 concentration and cysteamine supplementation are mediated during in vitro embryo production is through an increase in the expression of anti‐apoptotic and a decrease in the expression of pro‐apoptotic genes.
Bovine OPU‐Derived Oocytes can be Matured In Vitro for 16–28 h with Similar Developmental Capacity
Authors: Merton JS , de Roos APW , Koenen EPC , Roelen BAJ , Vos PLAM , Mullaart E , Knijn HM
Published: March 2012

Contents

The aim of this study was to determine the optimal maturation culture period of ovum pick up (OPU)‐derived cumulus oocytes complexes (COCs) in relation to their developmental capacity. Embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics such as gestation length, birthweight and sex ratio were investigated. This retrospective study covers the analyses of ovum pick up –in vitro production and calving results from a commercial programme that took place between March 1994 and September 2004. Donors were both heifers (of which approximately 90% pregnant) and cows (of which approximately 10% pregnant). Embryo production analyses were based on 7800 OPU sessions conducted from January 1995 until January 1999. Analyses of calving rate were based on 13 468 embryo transfers performed during January 1995 until May 2002. Analyses on calf characteristics were based on 2162 calves born between March 1994 and September 2004. The in vitro maturation culture period ranged from 16 to 28 h. The mean production rate of transferable embryos was 16.5% (1.2 embryos per OPU session). Length of maturation culture period did not affect the production of transferable embryos. Mean calving rate was 40.9% and 38.7% for fresh and frozen/thawed embryos, respectively. Calving rate was not affected by the maturation culture period. Mean birthweight, gestation length and proportion of male calves were 46 kg, 281.9 days and 52.8%, respectively. Maturation culture period did not affect these variables. In conclusion, this study shows that the in vitro maturation culture period within the range of 16–28 h does not affect in vitro embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics, suggesting that all COC batches collected by OPU on the same day, can be fertilized in one IVF session without a significant loss in the production from oocyte to calf.
Comparison of Synthetic Oviductal Fluid and G1/G2 Medium under Low‐1 Oxygen Atmosphere on Embryo Production and Pregnancy Rates in Nelore (Bos indicus) Cattle
Authors: Sanches BV , Pontes JHF , Basso AC , Ferreira CR , Perecin F , Seneda MM
Published: March 2012

Contents

In this work, we evaluated whether embryo development and pregnancy rates would be affected by culturing bovine Bos indicus embryos in Synthetic Oviductal Fluid with amino acids (SOFaa) or G1/G2 sequential medium under a low‐oxygen atmosphere. Using Ovum Pick Up, we obtained 1,538 oocytes, divided into G1/G2 (n = 783) and SOFaa (n = 755). No difference was observed for blastocyst development among the groups (27.8% ± 14.6 and 34.9% ± 20.0 for G1/G2 and SOFaa respectively, p > 0.05). Transferring the embryos (n = 450) from both groups to recipients resulted in similar pregnancy rates for the G1/G2 (38.4% n = 78/203) compared to the SOFaa (39.7% n = 98/247). Our findings confirm that Bos indicus embryos cultured in SOFaa and G1/G2 under low‐oxygen atmosphere have similar in vitro (blastocyst rate) and in vivo (pregnancy rate) developmental capacity. However, embryos cultured in G1/G2 medium have higher cleavage than those cultured in SOFaa medium.
Midkine in the pathology of cancer, neural disease, and inflammation
Authors: Sakamoto Kazuma , Kadomatsu Kenji
Published: March 2012

Midkine (MK) is a heparin‐binding growth factor involved in various cellular processes such as cellular proliferation, survival, and migration. In addition to these typical growth factor activities, MK exhibits several other activities related to fibrinolysis, blood pressure, host defense and other processes. Many cell‐surface receptors have been identified to account for the multiple biological activities of MK. The expression of MK is frequently upregulated in many types of human carcinoma. Moreover, blood MK levels are closely correlated with patient outcome. Knockdown and blockade of MK suppress tumorigenesis and tumor development. Thus, MK serves as a tumor marker and a molecular target for cancer therapy. Furthermore, there is growing evidence that MK plays pivotal roles in neural and inflammatory diseases. Understanding of the mechanisms of action of MK is expected to create new therapeutic options for several human diseases.
Health impact and toxicological effects of nanomaterials in the lung
Authors: KENDALL MICHAELA , HOLGATE STEPHEN
Published: March 2012

The manufacture, use and disposal of nanomaterials will result in increased human exposures to engineered nanoparticles (ENPs), potentially via the lung. ENPs differ physically and chemically from natural‐ or combustion‐derived nanoparticles (NP) in important respects. While there are parallels with ultrafine aerosol particles in the atmosphere and colloids in water, there remain some unique issues and impacts of engineered materials on lung health that require consideration and urgent study.

The study of toxicity of nanomaterials in biological systems—nanotoxicology—emerged from the observed effects of inhaled particulate matter (PM) and NP. Some engineered nanomaterials deserve special toxicological examination because of their unique properties in biological systems; novel toxicological approaches may be required for their assessment. Translocation in biological systems—a key feature of ENPs—is dependent on ENP size and surface interactions with macromolecules at the portal of entry, upstream of cellular interaction. Of particular significance is the agglomeration processes associated with macromolecule adsorption at ENP surfaces, which determine clearance rates and cellular response. ENP toxicity is therefore dominated by three linked physico‐chemical factors: size‐shape, surface and ‘corona’ (formed by adhering macromolecules from the suscipient host). Measuring and predicting ENP translocation and effects following lung entry have proven to be particularly challenging, but understanding ENP behaviour in vivo is fundamental for safe design for effective and targeted drug delivery. Human exposures via medical and dental applications appear important in terms of dose and toxicity, and may need to be assessed for risk on a case‐by‐case basis.
Patchy distributions of Spirogyra arcta do not affect growth of the submerged macrophyte Ceratophyllum demersum
Authors: LIU RUI‐HUA , DONG BI‐CHENG , LI HONG‐LI , ZHANG QIAN , YU FEI‐HAI
Published: March 2012

Spatial heterogeneity is common in aquatic conditions, but few studies have examined the effects of heterogeneous distributions of biological factors on aquatic plants. Spirogyra (Spirogyra arcta) coexists with many submerged macrophytes, such as Ceratophyllum demersum, but no study has examined the effects of heterogeneous distributions of spirogyra on the growth of submerged plants. We grew the submerged plant C. demersum in three homogeneous, aquatic conditions (0, 50 and 100% of the water surface in the container was evenly covered by spirogyra, referred to as ‘control’, ‘50%’ and ‘100%’, respectively) and two patchy conditions (the left half of the water surface in the container was not covered by spirogyra and 50% and 100% of the water surface in the right half of the container was evenly covered by spirogyra, referred to as ‘50%‐patchy’ and ‘100%‐patchy’, respectively). Compared with the control, the 100% treatment greatly decreased the biomass and number of ramets of C. demersum, but the 50% treatment did not. Growth of C. demersum in the left half of the container did not differ significantly between the control and the two heterogeneous treatments (50%‐patchy and 100%‐patchy). In addition, growth of C. demersum in the right half of the container did not differ between the 100% and the 100%‐patchy treatment or between the 50% and the 50%‐patchy treatment. Our results suggest that C. demersum can tolerate shading by spirogyra to a certain extent and that heterogeneous distributions of spirogyra do not affect its growth.
A comparative study of seed morphology in relation to desiccation tolerance and other physiological responses in 71 Eastern Australian rainforest species
Authors: HAMILTON KIM N. , OFFORD CATHERINE A. , CUNEO PETER , DESEO MYRNA A.
Published: March 2012

Seed characteristics were measured in 71 Eastern Australian rainforest species representing 30 families. Sensitivity to desiccation to low moisture contents (< 10%) occurred in 42% of species. We estimate, based on findings from 100 species from this present study and previously published reports, that 49% of Eastern Australian rainforest species have non‐orthodox seeds. Germination level and time to 50% germination were not significantly different between desiccation sensitive (DS) and desiccation tolerant (DT) seeds. The estimation of seed desiccation sensitivity based on predictors is an important tool underpinning ex situ conservation efforts. Seed characteristics differed significantly between DS and DT seeds; that is, DS seeds had: (i) larger fruits (19 949 mg vs 8322 mg); (ii) larger seeds (1663 mg vs 202 mg); (iii) higher seed moisture contents (49.7% vs 35.5% fresh weight); (iv) lower oil content (7.3% vs 24.8% yield); and (v) less investment in seed coats (0.19 vs 0.48 seed coat ratio). Only 25% of DS seeded species had oily seeds compared with 87% of DT seeded species. Most green embryos were DS. Seed coat ratio was the best predictor of seed DS (80% correctly predicted). Seed moisture content at maturity was also related to germination time. Mean seed size was correlated (−0.657, P = 0.01) with mean seed oil content in 46 species. Further research on seed storage physiology of possible oily and/or DS seeded species is crucial to ensure future long‐term security of this biodiversity, particularly for species currently threatened in situ and/or of socioeconomic importance in Eastern Australian rainforests.
Breeding system and thrips (Thysanoptera) pollination in the endangered tree Ocotea porosa (Lauraceae): implications for conservation
Authors: DANIELI‐SILVA ALINE , VARASSIN ISABELA G.
Published: March 2012

Ocotea porosa has been extensively exploited over the past few decades because of the quality of its wood. Today, populations are reduced and the species is now included in the Red List of threatened species by the International Union for Nature Conservation. For conservation and management purposes, it is extremely important that we understand its reproductive ecology. Floral morphology was described based on field and scanning electron microscopic examination. The reproductive system was determined through experimentally controlled pollination along with observations of pollen tube growth. Pollinators were identified through field observations. Flowers of O. porosa are small, shallow, inconspicuous, asynchronous and grouped in inflorescences. This species presented self‐compatibility, but did not reproduce through apomixy and spontaneous self‐pollination was very rare (5%). Despite being monoclinal, flowers were protogynic, and the gynoecium was receptive after the first day of anthesis when the anthers were closed. Spontaneous self‐pollination was avoided by the extrorse position of the anthers of the internal stamens. Frankliniella gardeniae (Thysanoptera) was the only pollinating species observed and, after visiting several asynchronous flowers in the same inflorescence, favors geitonogamy. Together the small distance supposedly achieved by thrips in flight and the small population density of O. porosa can reduce the chances of cross‐pollination in this species. If so, conservation measures must include preservation of the current population and possibly planting to increase population density. This would reduce the distance between individuals and increase genetic variability. Thrips as pollinators must be included in conservation planning for O. porosa.
Conditions for seedling establishment and probable function of seed in the clonal sedge Carex rugulosa Kük. in riverside marshes
Authors: ARAKI SATORU , KUNII HIDENOBU
Published: March 2012

Carex rugulosa Kük. forms large meadows in moist zones along estuarine riversides. These meadows are usually maintained by rhizomatous ramet production (clonal growth), and the appearance of seedlings is uncommon. We studied the conditions required for seedling establishment. In areas in which clonal ramets were dense (906–1050/m2), and the relative light intensity at ground level was low (0.8–3.8%), seed germination was entirely suppressed. In contrast, many seedlings (288–513/m2) were observed in areas in which clonal ramets had been considerably reduced (13–269/m2) by continuous inundation in the previous year. In these areas, the relative light intensity had increased (20.5–79.3%). It was inferred that seeds resisted the prolonged inundation that killed the ramets, and that germination was induced under these open conditions. These results suggest that the main functions of sexual reproduction in C. rugulosa are recovery after severe damage to vegetation using seeds from the seed bank and the dispersal of seeds to areas without dense vegetation. Most seedlings died when the marshy meadow was temporarily inundated by heavy rain. However, transplanted seedlings survived better at artificially elevated sites that were not submerged. This shows that inundation during the seedling stage impedes seedling survival. Therefore, seeds can contribute to recovery after ramet decline or colonization to open area when (i) the rainfall is not heavy to cause seedling submergence or (ii) seeds are dispersed to higher area which is not inundated.
Very rare cause of vaginal mass in pregnancy: Cavernous hemangioma
Authors: Celik Fatih , Arioz Dagistan Tolga , Köken Gülengül N. , Yilmazer Mehmet
Published: March 2012

Vaginal cavernous hemangioma is a considerably rare condition during pregnancy. There has only been one reported case to date. A multiparous, 24‐year‐old woman in the 32nd week of pregnancy was admitted with a mass prolapsed from the vagina, which had suddenly increased in size over the previous few days. A necrotic mass obstructing the vaginal canal and originating from the posterior wall was observed in a pelvic physical examination and carefully excised. The patient had contractions after the intervention and was administered tocolytic treatment with bed‐rest and fluids. Her obstetric clinical status was stable after treatment and she gave birth without complication at 37 weeks and 5 days from the vaginal canal. The main approach to these very rare tumors of pregnancy, especially in the presence of necrosis, infection and/or obstruction, should be excision. But the potential for increased blood loss that may occur due to the hypervascular structure of the tumor should be taken into account.
Fluoroscopic imaging of needle position in the tension‐free vaginal mesh procedure for pelvic organ prolapse: Two case reports
Authors: Kitagawa Yasuhide , Narimoto Kazutaka , Kawaguchi Shohei , Kuribayashi Masato , Takeyama Masami , Namiki Mikio
Published: March 2012

The tension‐free vaginal mesh (TVM) procedure has become one of the commonly used treatments for pelvic organ prolapse (POP) due to good clinical outcome. However, there are several technical difficulties associated with this procedure. We performed fluoroscopy for imaging of the surgical procedure on the TVM to resolve the technical problems regarding needle penetration. Fluoroscopic imaging with rectogram and cystogram demonstrated the positions of the needle, pelvic organs and index finger for needle guidance in the TVM procedure. Fluoroscopic imaging may be useful to understand the movement of surgical devices in the blind space, objectively evaluate the surgeon's skill, avoid injury to the pelvic organs, and detect any such injury immediately should it occur.