bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual rest and post‐meiotic sperm ageing in house mice
Authors: Firman R. C. , Young F. J. , Rowe D. C. , Duong H. T. , Gasparini C. 
Published: May 2015

AbstractFertilization by aged sperm can result in adverse fitness consequences for both males and females. Sperm storage during male sexual rest could provide an environment for post‐meiotic sperm senescence causing a deterioration in the quality of stored sperm, possibly impacting on both sperm performance (e.g. swimming ability) and DNA quality. Here, we compared the proportion of sperm with fragmented DNA, an indicator of structural damage of DNA within the sperm cell, among males that had been sexually rested for approximately 2 months, to that of males that had mated recently. We found no evidence of intra‐epididymal sperm DNA damage or any impairment in sperm performance, and consequently no evidence of post‐meiotic sperm senescence. Our results suggest that male house mice are likely to possess mechanisms that function to ensure that their sperm reserves remain stocked with ‘young’, viable sperm during periods of sexual inactivity. We also discuss the possibility that our experimental design leads to no difference in the age of sperm among males from the two mating treatments. Post‐meiotic sperm senescence is especially relevant under sperm competition. Thus, we sourced mice from populations that differed in their levels of post‐copulatory sexual selection, enabling us to gain insight into how selection for higher sperm production influences the rate of sperm ageing and levels of DNA fragmentation. We found that males from the population that produced the highest number of sperm also had the smallest proportion of DNA‐fragmented sperm and discuss this outcome in relation to selection acting upon males to ensure that they produce ejaculates with high‐quality sperm that are successful in achieving fertilizations under competitive conditions.
Agreement on intrapartum cardiotocogram recordings between expert obstetricians
Authors: Hruban Lukáš , Spilka Jiří , Chudáček Václav , Janků Petr , Huptych Michal , Burša Miroslav , Hudec Adam , Kacerovský Marian , Koucký Michal , Procházka Martin , Korečko Vladimír , Seget'a Jan , Šimetka Ondřej , Měchurová Alena , Lhotská Lenka 
Published: May 2015

AbstractRationale, aims and objectivesTo evaluate obstetricians' inter‐ and intra‐observer agreement on intrapartum cardiotocogram (CTG) recordings and to examine obstetricians' evaluations with respect to umbilical artery pH and base deficit.MethodsNine experienced obstetricians annotated 634 intrapartum CTG recordings. The evaluation of each recording was divided into four steps: evaluation of two 30‐minute windows in the first stage of labour, evaluation of one window in the second stage of labour and labour outcome prediction. The complete set of evaluations used for this experiment is available online. The inter‐ and intra‐observer agreement was evaluated using proportion of agreement and kappa coefficient. Clinicians' sensitivity and specificity was computed with respect to umbilical artery pH, base deficit and to Apgar score at the fifth minute.ResultsThe overall proportion of agreement between clinicians reached 48% with 95% confidence intervals (CI) (CI: 47–50). Regarding the different classes, proportion of agreement ranged from 57% (CI: 54–60) for normal to 41% (CI: 36–46) for pathological class. The sensitivity of clinicians' majority vote to objective outcome was 39% (CI: 16–63) for the umbilical artery base deficit and 27% (CI: 16–42) for pH. The specificity was 89% (CI: 86–92) for both types of objective outcome.ConclusionsThe reported inter‐/intra‐observer variability is large and this holds irrespective of clinicians' experience or work place. The results support the need of modernized guidelines for CTG evaluation and/or objectivization and repeatability by introduction of a computerized approach that could standardize the process of CTG evaluation within the delivery ward.
Relationship between Baked‐Cheese Sensory Properties and Melted‐Cheese Physical Characteristics
Authors: Banville Vincent , Power Nelson , Pouliot Yves , Britten Michel 
Published: May 2015

AbstractManufacturing conditions affect the sensory properties of baked Mozzarella cheese. However, instrumental analysis of cheese at room temperature does not fully correlate with the sensory properties of cheese after baking on a cooking dish. In this study, regular and stabilized pizza cheese were aged for 10, 25, 40 or 55 days before testing. A descriptive sensory analysis was performed on cheese baked on a pizza model and was related to the rheological properties of melted cheese. The sensory firmness, breakdown resistance, rubberiness and liquid release varied among cheese types and ages. Differences among cheese types and ages were also observed in small‐strain oscillatory shear moduli measured on melted cheese cooled at different temperatures. The multiple stress creep recovery test proved to provide the best correlation with baked‐cheese sensory terms. Partial dehydration of cheese before melting, to mimic the water loss during the baking process, was shown to increase correlations.Practical ApplicationsIngredient cheese that are baked on pizzas are required to have specific behaviors in order to meet consumer acceptance. Hence, understanding the effect of baking on cheese sensory properties and their relationship to mechanical properties should facilitate the development of new cheese functionalities. This study proposes a descriptive sensory evaluation of pizza cheese baked on a standardized pizza model. This approach increases the robustness of the quality evaluation of cheese properties. A novel method was also tested to probe the linear and nonlinear behavior of melted cheese in an effort to reduce the gap between standard rheological procedures and the sensations experienced during the rather complex action of oral processing.
The role of Rhipicephalus sanguineus sensu lato saliva in the dissemination of Rickettsia conorii in C3H/HeJ mice
Authors: MILHANO N. , SAITO T. B. , BECHELLI J. , FANG R. , VILHENA M. , DE SOUSA R. , WALKER D. H. 
Published: May 2015

AbstractAnimal models have been developed for the study of rickettsial pathogenesis. However, to understand what occurs during the natural route of rickettsial transmission via the tick bite, the role of tick saliva should be considered in these models. To address this, we analysed the role of tick saliva in the transmission of Rickettsia conorii (Rickettsiales: Rickettsiaceae) in a murine host by intradermally (i.d.) inoculating two groups of susceptible C3H/HeJ mice with this Rickettsia, and infesting one group with nymphal Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae) ticks. Quantification of bacterial loads and mRNA levels of interleukin‐1β (IL‐1β), IL‐10 and NF‐κB was performed in C3H/HeJ lung samples by real‐time quantitative polymerase chain reaction (PCR) and real‐time reverse transcriptase PCR, respectively. Lung histology was examined to evaluate the pathological manifestations of infection. No statistically significant difference in bacterial load in the lungs of mice was observed between these two groups; however, a statistically significant difference was observed in levels of IL‐1β and NF‐κB, both of which were higher in the group inoculated with rickettsiae but not infected with ticks. Lung histology in both groups of animals revealed infiltration of inflammatory cells. Overall, this study showed that i.d. inoculation of R. conorii caused infection in the lungs of C3H/HeJ mice and tick saliva inhibited proinflammatory effects.
A New Method for Sham‐Controlled Acupuncture in Experimental Visceral Pain – a Randomized, Single‐Blinded Study
Authors: Juel Jacob , Liguori Stefano , Liguori Aldo , Valeriani Massimiliano , Graversen Carina , Olesen Søren S. , Drewes Asbjørn M. 
Published: May 2015

AbstractObjectiveAcupuncture is increasingly used as an alternative to medical therapy for various pain conditions. To study the effect of acupuncture in experimental and clinical studies, a control condition with sham acupuncture is needed. However, as such models have not been established in assessment of acupunctures effect against visceral pain, this study aimed to validate a new method for blinded sham acupuncture in experimental rectal pain.MethodsFifteen subjects underwent a sequence of either sham or real acupuncture in randomized order. In the sham arm, a hollow inner tube with a sharp tip was fitted into an outer tube and subjects were blinded to the stimulations. Before and after the intervention, pain was induced by rectal stimulation with an inflatable balloon distended until the subjects' pain threshold was reached. The resting electroencephalogram (EEG) was quantified by spectral power analysis to explore the central nervous system effects objectively. Additionally, after the second study day, the subject was asked to indicate the sequence of interventions.ResultsA significant increase in rectal balloon volume was observed after sham 12 ± 21 mL (P = 0.049) and acupuncture 17 ± 30 mL (P = 0.046). However, the change in volume was not different between groups (P = 0.6). No differences in EEG spectral power distributions between sham and acupuncture were seen (all P > 0.6). The correct sequence of sham and acupuncture was indicated by 36% of the subjects (P = 0.4).ConclusionsThe presented sham procedure provides a valid method for blinding of “sham acupuncture” and may be used in future blinded controlled trials of acupuncture for visceral pain.
Engineering high α‐amylase levels in wheat grain lowers Falling Number but improves baking properties
Authors: Ral Jean‐Philippe , Whan Alex , Larroque Oscar , Leyne Emmett , Pritchard Jeni , Dielen Anne‐Sophie , Howitt Crispin A. , Morell Matthew K. , Newberry Marcus 
Published: May 2015

SummaryLate maturity α‐amylase (LMA) and preharvest sprouting (PHS) are genetic defects in wheat. They are both characterized by the expression of specific isoforms of α‐amylase in particular genotypes in the grain prior to harvest. The enhanced expression of α‐amylase in both LMA and PHS results in a reduction in Falling Number (FN), a test of gel viscosity, and subsequent downgrading of the grain, along with a reduced price for growers. The FN test is unable to distinguish between LMA and PHS; thus, both defects are treated similarly when grain is traded. However, in PHS‐affected grains, proteases and other degradative process are activated, and this has been shown to have a negative impact on end product quality. No studies have been conducted to determine whether LMA is detrimental to end product quality. This work demonstrated that wheat in which an isoform α‐amylase (TaAmy3) was overexpressed in the endosperm of developing grain to levels of up to 100‐fold higher than the wild‐type resulted in low FN similar to those seen in LMA‐ or PHS‐affected grains. This increase had no detrimental effect on starch structure, flour composition and enhanced baking quality, in small‐scale 10‐g baking tests. In these small‐scale tests, overexpression of TaAmy3 led to increased loaf volume and Maillard‐related browning to levels higher than those in control flours when baking improver was added. These findings raise questions as to the validity of the assumption that (i) LMA is detrimental to end product quality and (ii) a low FN is always indicative of a reduction in quality. This work suggests the need for a better understanding of the impact of elevated expression of specific α‐amylase on end product quality.
A myo‐inositol‐1‐phosphate synthase gene, IbMIPS1, enhances salt and drought tolerance and stem nematode resistance in transgenic sweet potato
Authors: Zhai Hong , Wang Feibing , Si Zengzhi , Huo Jinxi , Xing Lei , An Yanyan , He Shaozhen , Liu Qingchang 
Published: May 2015

SummaryMyo‐inositol‐1‐phosphate synthase (MIPS) is a key rate limiting enzyme in myo‐inositol biosynthesis. The MIPS gene has been shown to improve tolerance to abiotic stresses in several plant species. However, its role in resistance to biotic stresses has not been reported. In this study, we found that expression of the sweet potato IbMIPS1 gene was induced by NaCl, polyethylene glycol (PEG), abscisic acid (ABA) and stem nematodes. Its overexpression significantly enhanced stem nematode resistance as well as salt and drought tolerance in transgenic sweet potato under field conditions. Transcriptome and real‐time quantitative PCR analyses showed that overexpression of IbMIPS1 up‐regulated the genes involved in inositol biosynthesis, phosphatidylinositol (PI) and ABA signalling pathways, stress responses, photosynthesis and ROS‐scavenging system under salt, drought and stem nematode stresses. Inositol, inositol‐1,4,5‐trisphosphate (IP3), phosphatidic acid (PA), Ca2+, ABA, K+, proline and trehalose content was significantly increased, whereas malonaldehyde (MDA), Na+ and H2O2 content was significantly decreased in the transgenic plants under salt and drought stresses. After stem nematode infection, the significant increase of inositol, IP3, PA, Ca2+, ABA, callose and lignin content and significant reduction of MDA content were found, and a rapid increase of H2O2 levels was observed, peaked at 1 to 2 days and thereafter declined in the transgenic plants. This study indicates that the IbMIPS1 gene has the potential to be used to improve the resistance to biotic and abiotic stresses in plants.
Estimation of the Spectral Density with Assigned Risk
Authors: Efromovich Sam 
Published: May 2015

AbstractIt is well known that adaptive sequential nonparametric estimation of differentiable functions with assigned mean integrated squared error and minimax expected stopping time is impossible. In other words, no sequential estimator can compete with an oracle estimator that knows how many derivatives an estimated curve has. Differentiable functions are typical in probability density and regression models but not in spectral density models, where considered functions are typically smoother. This paper shows that for a large class of spectral densities, which includes spectral densities of classical autoregressive moving average processes, an adaptive minimax sequential estimation with assigned mean integrated squared error is possible. Furthermore, a two‐stage sequential procedure is proposed, which is minimax and adaptive to smoothness of an underlying spectral density.
Mutator
and
MULE
Transposons
Authors: Lisch Damon 
Published: May 2015

ABSTRACT

The
Mutator
system of transposable elements (TEs) is a highly mutagenic family of transposons in maize. Because they transpose at high rates and target genic regions, these transposons can rapidly generate large numbers of new mutants, which has made the
Mutator
system a favored tool for both forward and reverse mutagenesis in maize. Low copy number versions of this system have also proved to be excellent models for understanding the regulation and behavior of Class II transposons in plants. Notably, the availability of a naturally occurring locus that can heritably silence autonomous
Mutator
elements has provided insights into the means by which otherwise active transposons are recognized and silenced. This chapter will provide a review of the biology, regulation, evolution and uses of this remarkable transposon system, with an emphasis on recent developments in our understanding of the ways in which this TE system is recognized and epigenetically silenced as well as recent evidence that
Mu
-like elements (
MULE
s) have had a significant impact on the evolution of plant genomes.
Mariner and the ITm Superfamily of Transposons
Authors: Tellier Michael , Bouuaert Corentin Claeys , Chalmers Ronald 
Published: May 2015

ABSTRACT

The IS630-Tc1-mariner (ITm) family of transposons is one of the most widespread in nature. The phylogenetic distribution of its members shows that they do not persist for long in a given lineage, but rely on frequent horizontal transfer to new hosts. Although they are primarily selfish genomic-parasites, ITm transposons contribute to the evolution of their hosts because they generate variation and contribute protein domains and regulatory regions. Here we review the molecular mechanism of ITm transposition and its regulation. We focus mostly on the mariner elements, which are understood in the greatest detail owing to
in vitro
reconstitution and structural analysis. Nevertheless, the most important characteristics are probably shared across the grouping. Members of the ITm family are mobilized by a cut-and-paste mechanism and integrate at 5′-TA dinucleotide target sites. The elements encode a single transposase protein with an N-terminal DNA-binding domain and a C-terminal catalytic domain. The phosphoryl-transferase reactions during the DNA-strand breaking and joining reactions are performed by the two metal-ion mechanism. The metal ions are coordinated by three or four acidic amino acid residues located within an RNase H-like structural fold. Although all of the strand breaking and joining events at a given transposon end are performed by a single molecule of transposase, the reaction is coordinated by close communication between transpososome components. During transpososome assembly, transposase dimers compete for free transposon ends. This helps to protect the host by dampening an otherwise exponential increase in the rate of transposition as the copy number increases.
The Influence of LINE-1 and SINE Retrotransposons on Mammalian Genomes
Authors: Richardson Sandra R. , Doucet Aurélien J. , Kopera Huira C. , Moldovan John B. , Garcia-Perez José Luis , Moran John V. 
Published: May 2015

ABSTRACT

Transposable elements have had a profound impact on the structure and function of mammalian genomes. The retrotransposon Long INterspersed Element-1 (LINE-1 or L1), by virtue of its replicative mobilization mechanism, comprises ∼17% of the human genome. Although the vast majority of human LINE-1 sequences are inactive molecular fossils, an estimated 80–100 copies per individual retain the ability to mobilize by a process termed retrotransposition. Indeed, LINE-1 is the only active, autonomous retrotransposon in humans and its retrotransposition continues to generate both intra-individual and inter-individual genetic diversity. Here, we briefly review the types of transposable elements that reside in mammalian genomes. We will focus our discussion on LINE-1 retrotransposons and the non-autonomous Short INterspersed Elements (SINEs) that rely on the proteins encoded by LINE-1 for their mobilization. We review cases where LINE-1-mediated retrotransposition events have resulted in genetic disease and discuss how the characterization of these mutagenic insertions led to the identification of retrotransposition-competent LINE-1s in the human and mouse genomes. We then discuss how the integration of molecular genetic, biochemical, and modern genomic technologies have yielded insight into the mechanism of LINE-1 retrotransposition, the impact of LINE-1-mediated retrotransposition events on mammalian genomes, and the host cellular mechanisms that protect the genome from unabated LINE-1-mediated retrotransposition events. Throughout this review, we highlight unanswered questions in LINE-1 biology that provide exciting opportunities for future research. Clearly, much has been learned about LINE-1 and SINE biology since the publication of
Mobile DNA II
thirteen years ago. Future studies should continue to yield exciting discoveries about how these retrotransposons contribute to genetic diversity in mammalian genomes.
Mechanisms of Theta Plasmid Replication
Authors: Lilly Joshua , Camps Manel 
Published: May 2015

ABSTRACT

Plasmids are autonomously replicating pieces of DNA. This article discusses theta plasmid replication, which is a class of circular plasmid replication that includes ColE1-like origins of replication popular with expression vectors. All modalities of theta plasmid replication initiate synthesis with the leading strand at a predetermined site and complete replication through recruitment of the host's replisome, which extends the leading strand continuously while synthesizing the lagging strand discontinuously. There are clear differences between different modalities of theta plasmid replication in mechanisms of DNA duplex melting and in priming of leading- and lagging-strand synthesis. In some replicons duplex melting depends on transcription, while other replicons rely on plasmid-encoded
trans
-acting proteins (Reps); primers for leading-strand synthesis can be generated through processing of a transcript or in other replicons by the action of host- or plasmid-encoded primases. None of these processes require DNA breaks. The frequency of replication initiation is tightly regulated to facilitate establishment in permissive hosts and to achieve a steady state. The last section of the article reviews how plasmid copy number is sensed and how this feedback modulates the frequency of replication.
Plasmid Rolling-Circle Replication
Authors: Ruiz-Masó J. A. , MachóN C. , Bordanaba-Ruiseco L. , Espinosa M. , Coll M. , Del Solar G. 
Published: May 2015

ABSTRACTPlasmids are DNA entities that undergo controlled replication independent of the chromosomal DNA, a crucial step that guarantees the prevalence of the plasmid in its host. DNA replication has to cope with the incapacity of the DNA polymerases to startde novoDNA synthesis, and different replication mechanisms offer diverse solutions to this problem. Rolling-circle replication (RCR) is a mechanism adopted by certain plasmids, among other genetic elements, that represents one of the simplest initiation strategies, that is, the nicking by a replication initiator protein on one parental strand to generate the primer for leading-strand initiation and a single priming site for lagging-strand synthesis. All RCR plasmid genomes consist of a number of basic elements: leading strand initiation and control, lagging strand origin, phenotypic determinants, and mobilization, generally in that order of frequency. RCR has been mainly characterized in Gram-positive bacterial plasmids, although it has also been described in Gram-negative bacterial or archaeal plasmids. Here we aim to provide an overview of the RCR plasmids' lifestyle, with emphasis on their characteristic traits, promiscuity, stability, utility as vectors, etc. While RCR is one of the best-characterized plasmid replication mechanisms, there are still many questions left unanswered, which will be pointed out along the way in this review.