bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lectin uptake and incorporation into the calcitic spicule of sea urchin embryos
Authors: Mozingo Nancy M. 
Published: April 2014

SummaryPrimary mesenchyme cells (PMCs) are skeletogenenic cells that produce a calcareous endoskeleton in developing sea urchin larvae. The PMCs fuse to form a cavity in which spicule matrix proteins and calcium are secreted forming the mineralized spicule. In this study, living sea urchin embryos were stained with fluorescently conjugated wheat germ agglutinin, a lectin that preferentially binds to PMCs, and the redistribution of this fluorescent tag was examined during sea urchin development. Initially, fluorescence was associated primarily with the surface of PMCs. Subsequently, the fluorescent label redistributed to intracellular vesicles in the PMCs. As the larval skeleton developed, intracellular granular staining diminished and fluorescence appeared in the spicules. Spicules that were cleaned to remove membranous material associated with the surface exhibited bright fluorescence, which indicated that fluorescently labelled lectin had been incorporated into the spicule matrix. The results provide evidence for a cellular pathway in which material is taken up at the cell surface, sequestered in intracellular vesicles and then incorporated into the developing spicule.
Effect of different superovulation stimulation protocols on adenosine triphosphate concentration in rabbit oocytes
Authors: Cortell Carmela , Salvetti Pascal , Joly Thierry , Viudes-de-Castro Maria Pilar 
Published: April 2014

SummaryOvarian stimulation protocols are used usually to increase the number of oocytes collected. The determination of how oocyte quality may be affected by these superovulation procedures, therefore, would be very useful. There is a high correlation between oocyte ATP concentration and developmental competence of the resulting embryo. The aim of this study was to evaluate the effect of follicle stimulating hormone (FSH) origin and administration protocols on oocyte ATP content. Rabbit does were distributed randomly into four groups: (i) a control group; (ii) the rhFSH3 group: females were injected, every 24 h over 3 days, with 0.6 μl of rhFSH diluted in polyvinylpyrrolidone (PVP); (iii) the pFSH3 group: females were injected every 24 h over 3 days with 11.4 μg of pFSH diluted in PVP; and (iv) the pFSH5 group: females were injected twice a day for 5 days with 11.4 μg of pFSH diluted in saline serum. Secondly, the effect of pFSH5 protocol on developmental potential was evaluated. Developmental competence of oocytes from the control and pFSH5 groups was examined. Differences in superovulation treatments were found for ATP levels. In the pFSH5 group, the ATP level was significantly lower than that of the other groups (5.63 ± 0.14 for pFSH group versus 6.42 ± 0.13 and 6.19 ± 0.15 for rhFSH3 and pFSH3, respectively; P < 0.05). In a second phase, only 24.28% of pFSH5 ova developed into hatched blastocysts compared with 80.39% for the control group. A negative effect on oocyte quality was observed in the pFSH5 group in ATP production, it is possible that, after this superovulation treatment, oocyte metabolism would be affected.
Raman Microspectroscopy Imaging Study on Topochemical Correlation Between Lignin and Hydroxycinnamic Acids in Miscanthus sinensis
Authors: Ma Jianfeng , Zhou Xia , Ma Jing , Ji Zhe , Zhang Xun , Xu Feng 
Published: April 2014

AbstractConfocal Raman microspectroscopy (CRM) has emerged as a powerful approach to visualize the compositional distribution in lignocellulosic biomass of cell walls. In this work, the applicability of CRM for imaging the topochemical correlation between lignin and hydroxycinnamic acids (HCA) in the Miscanthus sinensis internode was explored. Model compound [p-coumaric acid (PCA) and ferulic acid (FA)] analysis indicated that the band region from 1,152 to 1,197 cm−1 can be used to characterize the distribution of HCA. Raman images calculated by integrating over the area intensity of characteristic spectral regions showed heterogeneous distribution of lignin and HCA at cellular and sub-cellular level. When overlaying the Raman image of lignin and HCA distribution, it was found that these two polymers were co-located in the middle lamella and secondary wall of corresponding cells. Raman images for the band intensity ratio (1,173 cm−1/1,603 cm−1) indicated a clear association between lignin and HCA distribution within morphologically distinct cell wall layers of sclerenchyma fibers and the parenchyma. This is the first time that the spatial correlation between lignin and HCA concentration has been illustrated by a microspectroscopy imaging approach. The results are of importance in extending the current understanding of lignin and aromatics topochemistry in herbaceous biomass.
Histological and Histometrical Study of the Protective Role ofα-Tocopherol against Sodium Arsenite Toxicity in Rat Ovaries
Authors: Dezfouli Maryam Ghandi Zadeh , Eissazadeh Samira , Zade Sayed Mohammad Ali Shariat 
Published: April 2014

AbstractThis study examines histometrical changes induced by sodium arsenite (SA), as an environmental pollutant, and investigates the protective effect ofα-tocopherol on ovaries of SA-treated rats during the prenatal stage until sexual maturity. Rats were classified into groups: control, SA (8 ppm/day),α-tocopherol (100 ppm/day), and SA+α-tocopherol. Treatment was performed from pregnancy until maturation when the rats and ovaries were weighed. The Cavalieri method was used to estimate volume of the ovaries, cortex, medulla, and corpus luteum. The mean diameter of oocytes, granulosa cells, and nuclei were measured and volume was estimated using the Nucleator method. The number of oocytes and thickness of the zona pellucida (ZP) were determined using an optical dissector and orthogonal intercept method, respectively. SA reduced the body and ovary weight, the number of secondary, antral and Graafian oocytes, volume of the ovaries, cortex, medulla and corpus luteum, mean diameter and volume of oocytes in primordial and primary follicles, mean diameter and volume of oocyte nuclei in all types of follicles, and mean thickness of the ZP in secondary and antral follicles. Also, the mean diameter and volume of granulosa cells and their nuclei in antral and Graafian follicles decreased significantly. Vacuolization and vascular congestion in the corpus luteum and an increase in the number of atretic oocytes were seen in the SA group. Most of these parameters were unchanged from the control level in the SA+α-tocopherol group. It was concluded thatα-tocopherol supplementation reduced the toxic effects of SA exposure on ovarian tissue in rats.
Inference and learning in probabilistic logic programs using weighted Boolean formulas
Authors: FIERENS DAAN , VAN DEN BROECK GUY , RENKENS JORIS , SHTERIONOV DIMITAR , GUTMANN BERND , THON INGO , JANSSENS GERDA , DE RAEDT LUC 
Published: April 2014

AbstractProbabilistic logic programs are logic programs in which some of the facts are annotated with probabilities. This paper investigates how classical inference and learning tasks known from the graphical model community can be tackled for probabilistic logic programs. Several such tasks, such as computing the marginals, given evidence and learning from (partial) interpretations, have not really been addressed for probabilistic logic programs before. The first contribution of this paper is a suite of efficient algorithms for various inference tasks. It is based on the conversion of the program and the queries and evidence to a weighted Boolean formula. This allows us to reduce inference tasks to well-studied tasks, such as weighted model counting, which can be solved using state-of-the-art methods known from the graphical model and knowledge compilation literature. The second contribution is an algorithm for parameter estimation in the learning from interpretations setting. The algorithm employs expectation-maximization, and is built on top of the developed inference algorithms. The proposed approach is experimentally evaluated. The results show that the inference algorithms improve upon the state of the art in probabilistic logic programming, and that it is indeed possible to learn the parameters of a probabilistic logic program from interpretations.
The Role of Psychological Maturity in Direct and Indirect Aggressiveness in Spanish Adolescents
Authors: Morales-Vives Fabia , Camps Elisa , Lorenzo-Seva Urbano , Vigil-Colet Andreu 
Published: April 2014

AbstractUnderstanding which factors are related to different kinds of aggressive behaviors in adolescents might help to improve violence-prevention programs for schools and families. Although some studies show that adolescents who are less psychologically mature tend to display more behavioral problems, few studies have been performed on the relationship between aggressive behavior and psychological maturity in adolescence, and no studies have focused specifically on indirect aggression. For this reason, the current research tests the role of psychological maturity in direct and indirect aggressiveness in a sample of 193 Spanish adolescents (49% boys and 51% girls) between 14 and 18 years old (M = 16.1, SD = 1.18). The results show that psychological maturity is related to both kinds of aggressiveness. In fact, less mature adolescents tend to show higher levels of direct aggression (r = –.22, p < .01) and indirect aggression (r = –.44, p < .01). More specifically, the dimensions of psychological maturity most related to aggressiveness are self-reliance and identity: self-reliance is the main predictor of indirect aggression (p < .01) and identity is the main predictor of direct aggression (p < .01). Moreover, overall psychological maturity is more related to indirect aggression in men than in women (p < .05), so the increase in psychological maturity implies a greater decrease of indirect aggression in men.
Strain-induced enhancement of plasma dispersion effect and free-carrier absorption in SiGe optical modulators
Authors: Kim Younghyun , Takenaka Mitsuru , Osada Takenori , Hata Masahiko , Takagi Shinichi 
Published: April 2014

AbstractThe plasma dispersion effect and free-carrier absorption are widely used to change refractive index and absorption coefficient in Si-based optical modulators. However, the weak free-carrier effects in Si cause low modulation efficiency, resulting in large device footprint and power consumption. Here, we theoretically and experimentally investigate the enhancement of the free-carrier effects by strain-induced mass modulation in silicon-germanium (SiGe). The application of compressive strain to SiGe reduces the conductivity effective mass of holes, resulting in the enhanced free-carrier effects. Thus, the strained SiGe-based optical modulator exhibits more than twice modulation efficiency as large as that of the Si modulator. To the best of our knowledge, this is the first demonstration of the enhanced free-carrier effects in strained SiGe at the near-infrared telecommunication wavelength. The strain-induced enhancement technology for the free-carrier effects is expected to boost modulation efficiency of the most Si-based optical modulators thanks to high complementary metal-oxide-semiconductor (CMOS) compatibility.
8-oxoguanine causes spontaneous de novo germline mutations in mice
Authors: Ohno Mizuki , Sakumi Kunihiko , Fukumura Ryutaro , Furuichi Masato , Iwasaki Yuki , Hokama Masaaki , Ikemura Toshimichi , Tsuzuki Teruhisa , Gondo Yoichi , Nakabeppu Yusaku 
Published: April 2014

AbstractSpontaneous germline mutations generate genetic diversity in populations of sexually reproductive organisms and are thus regarded as a driving force of evolution. However, the cause and mechanism remain unclear. 8-oxoguanine (8-oxoG) is a candidate molecule that causes germline mutations, because it makes DNA more prone to mutation and is constantly generated by reactive oxygen species in vivo. We show here that endogenous 8-oxoG caused de novo spontaneous and heritable G to T mutations in mice, which occurred at different stages in the germ cell lineage and were distributed throughout the chromosomes. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations at a rate of 2 × 10−7 mutations/base/generation in offspring of Mth1/Ogg1/Mutyh triple knockout (TOY-KO) mice, which accumulate 8-oxoG in the nuclear DNA of gonadal cells. The roles of MTH1, OGG1 and MUTYH are specific for the prevention of 8-oxoG-induced mutation and 99% of the mutations observed in TOY-KO mice were G to T transversions caused by 8-oxoG; therefore, we concluded that 8-oxoG is a causative molecule for spontaneous and inheritable mutations of the germ lineage cells.
Differential bradykinin B1 and B2 receptor regulation in cell death induced by hepatic ischaemia/reperfusion injury
Authors: Paio Mayra A. , Kouyoumdjian Maria , Borges Durval R. , Nagaoka Marcia R. 
Published: April 2014

The biological and pharmacological effects of BK (bradykinin) are mediated by two receptors: the constitutive B2R (B2 receptor) and the inducible B1R (B1 receptor). BK plays a role in the hepatic microcirculation by inducing the PHR (portal hypertensive response) via B2R, whereas DABK (des-Arg9-BK), a B1R agonist, does not elicit the response. During IRI (ischaemia/reperfusion injury), important changes occur in the microcirculation, and cell death by necrosis and apoptosis is involved in poor graft function. The aim of the present study was to analyse the role of B1R and B2R in liver cell death induced by IRI. Livers from Wistar rats were submitted to ischaemia (4°C) for 4 or 24 h. After this period, livers were reperfused ex vivo with Krebs–Henseleit solution (37°C). BK or DABK was then injected as a bolus during reperfusion in the absence or presence of HOE-140 (a B2R antagonist) or DALBK (des-Arg9-Leu8-BK) (a B1R antagonist) respectively. Liver viability was analysed by glucose release and bile secretion. The PHR to kinins did not change. Cell death was higher in the DABK group and its antagonist significantly decreased cell death. Interestingly, the B1R antagonist did not alter the number of necrotic cells, but it decreased the number of apoptotic cells. On the other hand, the B2R antagonist decreased the number of necrotic cells, but did not alter the number of apoptotic cells. Therefore B1R may participate in apoptotic cell death signalling, and B2R may be involved in necrotic cell death.
Passive frequency compensation for high gain‐bandwidth and high slew‐rate two‐stage OTA
Authors: Mirvakili A. , Koomson V.J. 
Published: April 2014

A passive frequency compensation method is presented for the first time, which can be applied to two/multi‐stage operational transconductance amplifier (OTA) designs, to achieve high gain‐bandwidth (GBW) and high slew‐rate with no increase in the overall power consumption. A nulling resistor with series compensating capacitor is applied in the first stage and extends the GBW by introducing a left‐hand‐plane (LHP) zero. This design is implemented in a 0.18 μm CMOS process and the measured results show a GBW of 100 MHz and average SR of 60 V/μs with a power consumption of 1.7 mW. A high figure of merit (FoM) of 94.7 GHz pF V/μs/mA is achieved.
Development of multi‐band ultra‐high‐frequency sensor for partial discharge monitoring based on the meandering technique
Authors: Hai‐feng Ye , Yong Qian , Yue Dong , Ge‐hao Sheng , Xiu‐chen Jiang 
Published: April 2014

To design high‐sensitivity sensors is one of the critical issues to be solved for ultra‐high‐frequency (UHF) partial discharge (PD) detection in substations. Commonly‐used UHF sensors usually use ultra‐wideband antennas for the frequency bands ranging from 300 MHz to 1.5 GHz. To avoid interference in the frequency bands, such as signals generated from mobile phones, a new multi‐band UHF sensor is proposed based on the loop antenna theory and meandering technique, which reduces the sensor size, provides high sensitivity and exhibits omnidirectional performance. The sensor works in the bandwidth ranges of 480–520, 800–850 and 1100–1200 MHz, and has sensitivity of more than 10 mm. The PD detection platform was set up, three typical insulation defects, such as corona discharge, surface discharge and free metal particle discharge, were designed, and then the tests were performed to compare the performance of the multi‐band sensor and broadband sensor. The results show that the multi‐band sensor's bandwidth covers the main spectra of PD signals, thereby can be used for detecting most kinds of PD signals. The sensor's sensitivity is higher than that of the broadband sensor with its size occupying only 5% of the latter, meeting the requirements for detection of PD sources in substations.
Hepatitis C virus triggers mitochondrial fission and attenuates apoptosis to promote viral persistence
Authors: Kim Seong-Jun , Syed Gulam H. , Khan Mohsin , Chiu Wei-Wei , Sohail Muhammad A. , Gish Robert G. , Siddiqui Aleem 
Published: April 2014

Significance
Persistent hepatitis C virus (HCV) infection is associated with mitochondrial liver injury. Mitochondrial quality control is established as a physiological adaptation to mitochondrial injury. This study provides a new insight into how HCV disrupts mitochondrial dynamics and evades apoptosis and innate immunity to sustain persistent viral infection. HCV promoted dynamin-related protein 1-mediated mitochondrial fission, followed by mitophagy. Interference of HCV-induced mitochondrial fission and mitophagy led to the suppression of virus secretion, a decrease in glycolysis and ATP generation, an increase in interferon synthesis, and an increase in apoptotic death of infected cells via enhanced apoptotic signaling. These observations implicate the functional relevance of altered mitochondrial dynamics in the pathogenesis of chronic liver disease associated with HCV infection.
Younger Dryas deglaciation of Scotland driven by warming summers
Authors: Bromley Gordon R. M. , Putnam Aaron E. , Rademaker Kurt M. , Lowell Thomas V. , Schaefer Joerg M. , Hall Brenda , Winckler Gisela , Birkel Sean D. , Borns Harold W. 
Published: April 2014

Significance
Resolving the full manifestation of past abrupt climate change is key to understanding the processes driving and propagating these events. As a principal component of global heat transport, the North Atlantic Ocean also is susceptible to rapid disruptions of meridional overturning circulation and thus widely invoked as a cause of abrupt climate variability in the Northern Hemisphere. We assess the impact of one such North Atlantic cold event—the Younger Dryas Stadial—on an adjacent ice mass and show that, rather than instigating a return to glacial conditions, this abrupt climate event was characterized by deglaciation. We suggest this pattern indicates summertime warming during the Younger Dryas, potentially as a function of enhanced seasonality in the North Atlantic.
Tetherin antagonism by Vpu protects HIV-infected cells from antibody-dependent cell-mediated cytotoxicity
Authors: Arias Juan F. , Heyer Lisa N. , von Bredow Benjamin , Weisgrau Kim L. , Moldt Brian , Burton Dennis R. , Rakasz Eva G. , Evans David T. 
Published: April 2014

Significance
HIV-1 viral protein U (Vpu) facilitates virus release from infected cells by down-regulating and degrading tetherin, a transmembrane protein upregulated by IFN that impedes the detachment of enveloped viruses from infected cells. Here we show that this activity of Vpu protects HIV-infected cells from antibodies that are capable of directing their elimination by antibody-dependent cell-mediated cytotoxicity. A direct implication of these observations is that tetherin serves as a link between innate and adaptive immunity to enhance the susceptibility of virus-infected cells to antibodies. Thus, the antiviral activity of tetherin may be much greater than previously appreciated based on its ability to inhibit virus release in cell culture assays.
Stretched cell cycle model for proliferating lymphocytes
Authors: Dowling Mark R. , Kan Andrey , Heinzel Susanne , Zhou Jie H. S. , Marchingo Julia M. , Wellard Cameron J. , Markham John F. , Hodgkin Philip D. 
Published: April 2014

Significance
Cell division is essential for an effective immune response. Estimates of rates of division are often based on DNA measurements interpreted with an appropriate model for internal cell cycle steps. Here we use time-lapse microscopy and single cell tracking of T and B lymphocytes from reporter mice to measure times spent in cell cycle phases. These data led us to a stretched cell cycle model, a novel and improved mathematical description of cell cycle progression for proliferating lymphocytes. Our model can be used to deduce cell cycle parameters for lymphocytes from DNA and BrdU labeling and will be useful when comparing the effects of different stimuli, or therapeutic treatments on immune responses, or to understand molecular pathways controlling cell division.
Discovery of LPMO activity on hemicelluloses shows the importance of oxidative processes in plant cell wall degradation
Authors: Agger Jane W. , Isaksen Trine , Várnai Anikó , Vidal-Melgosa Silvia , Willats William G. T. , Ludwig Roland , Horn Svein J. , Eijsink Vincent G. H. , Westereng Bjørge 
Published: April 2014

Significance
Plant cell walls are recalcitrant copolymeric structures mainly comprising polysaccharides and lignin. Enzymatic degradation of the polysaccharides is a crucial step in biorefining of biomass. Recently, it was discovered that nature employs copper-dependent redox enzymes called lytic polysaccharide monoxoygenases (LPMOs) to promote degradation of the most recalcitrant and crystalline of these polysaccharides, cellulose. By carrying out oxidative cleavage of otherwise inaccessible cellulose chains, LPMOs create access points for classical hydrolytic enzymes such as cellulases. Intriguingly, the genomes of biomass degrading microorganisms encode a plethora of LPMOs (up to over 40). To our knowledge, we demonstrate for the first time that LPMOs act on hemicelluloses. This finding dramatically widens the scope of LPMOs and oxidative processes in plant cell wall degradation and biorefining.
Sea star tenacity mediated by a protein that fragments, then aggregates
Authors: Hennebert Elise , Wattiez Ruddy , Demeuldre Mélanie , Ladurner Peter , Hwang Dong Soo , Waite J. Herbert , Flammang Patrick 
Published: April 2014

Significance
Sea stars are emblematic of the seashore. Despite this, their ability to pry open mussels and attach strongly but temporarily to rocks in their environments are poorly understood. Here we report, to our knowledge, the first sequence of a protein, Sea star footprint protein 1 (Sfp1), a primary constituent of the adhesive footprints secreted by sea star tube feet. Sfp1 is unusually large and complex compared with other marine adhesive proteins such as those of mussels. It is translated from a single mRNA and then fragmented into four subunits, which display specific domains that mediate interactions with other proteins present in the adhesive material and on the tube foot surface. After secretion, Sfp1 forms a structural scaffold and appears to provide footprints with cohesion.