scholarly journals Cell cycle-dependent repetitive Ca(2+)waves induced by a cytosolic sperm extract in mature ascidian eggs mimic those observed at fertilization

2000 ◽  
Vol 113 (19) ◽  
pp. 3453-3462 ◽  
Author(s):  
A. McDougall ◽  
M. Levasseur ◽  
A.J. O'Sullivan ◽  
K.T. Jones
Keyword(s):  
Spatial Pattern ◽  
Kinase Activity ◽  
Cyclin B1 ◽  
Egg Activation ◽  
Second Phase ◽  
Protein Factor ◽  
Sperm Extract ◽  
Two Phases ◽  
Cycle Dependent ◽  
Cytosolic Factor

Sperm-triggered Ca(2+) oscillations occur throughout the animal kingdom. The mechanism sperm use to trigger Ca(2+) oscillations at fertilization has not been resolved in any egg. The temporal, spatial and regulatory characteristics of the Ca(2+) oscillations during fertilization in ascidians offer a unique advantage over other systems for determining the mechanism of fertilization. For example, sperm trigger two phases of Ca(2+) oscillations that are all waves in ascidians. The first of these Ca(2+) waves begins at the point of sperm-egg fusion while a second phase of Ca(2+) waves originates at a vegetal protrusion termed the contraction pole. In addition, cyclin B1-dependent kinase activity provides a form of positive feedback, maintaining the second phase of Ca(2+) waves during meiosis and thereby ensuring meiotic exit. We therefore prepared cytosolic ascidian sperm extracts or MonoQ-fractionated ascidian sperm extracts from this urochordate to investigate if a Ca(2+)-releasing sperm-borne factor was responsible for egg activation. Spatially, ascidian sperm extract induced repetitive Ca(2+) waves that mimicked the spatial pattern displayed during fertilization: all the second-phase Ca(2+) waves originated at a vegetal protrusion termed the contraction pole (thus mimicking fertilisation). We also demonstrated that ascidian sperm extract-induced Ca(2+) oscillations were maintained when CDK activity was elevated and MAP kinase activity was low, as found previously for sperm-triggered Ca(2+) oscillations. As would be predicted, large doses of ascidian sperm extract injected into prophase-stage oocytes, lacking CDK activity, failed to induce any Ca(2+) release even though they responded to microinjection of the Ca(2+)-releasing second messenger inositol 1,4,5-trisphosphate. Finally, since the Ca(2+)-releasing activity from Mono-Q fractionated ascidian sperm extract eluted predominantly as one fraction, this may imply that one factor is responsible for the Ca(2+)-releasing activity. These data support a model of egg activation whereby the sperm introduces a Ca(2+)-releasing cytosolic factor into the egg. We demonstrated that ascidian sperm contain a protein factor(s) that is regulated by the egg CDK activity and can trigger all the Ca(2+)waves observed at fertilization with a spatial pattern that mimics those initiated by sperm.

scholarly journals Sil Phosphorylation in a Pin1 Binding Domain Affects the Duration of the Spindle Checkpoint

2005 ◽  
Vol 25 (15) ◽  
pp. 6660-6672 ◽  
Author(s):  
Stefano Campaner ◽  
Philipp Kaldis ◽  
Shai Izraeli ◽  
Ilan R. Kirsch
Keyword(s):  
Kinase Activity ◽  
Phosphorylation Site ◽  
Spindle Checkpoint ◽  
Cyclin B1 ◽  
Early Gene ◽  
Microtubule Inhibitors ◽  
Cycle Dependent ◽  
Mitotic Phosphorylation ◽  
Cdc2 Activity ◽  
In Cells

ABSTRACT SIL is an immediate-early gene that is essential for embryonic development and is implicated in T-cell leukemia-associated translocations. We now show that the Sil protein is hyperphosphorylated during mitosis or in cells blocked at prometaphase by microtubule inhibitors. Cell cycle-dependent phosphorylation of Sil is required for its interaction with Pin1, a regulator of mitosis. Point mutation of the seven (S/T)P sites between amino acids 567 and 760 reduces mitotic phosphorylation of Sil, Pin1 binding, and spindle checkpoint duration. When a phosphorylation site mutant Sil is stably expressed, the duration of the spindle checkpoint is shortened in cells challenged with taxol or nocodazole, and the cells revert to a G2-like state. This event is associated with the downregulation of the kinase activity of the Cdc2/cyclin B1 complex and the dephosphorylation of the threonine 161 on the Cdc2 subunit. Sil downregulation by plasmid-mediated RNA interference limited the ability of cells to activate the spindle checkpoint and correlated with a reduction of Cdc2/cyclin B1 activity and phosphorylation on T161 on the Cdc2 subunit. These data suggest that a critical region of Sil is required to mediate the presentation of Cdc2 activity during spindle checkpoint arrest.

Accurate Detection and Quantization of Leaf- Diseases through Soft Computing

2018 ◽  
Vol 1 (1) ◽  
pp. 236-247
Author(s):  
Divya Srivastava ◽  
Rajitha B. ◽  
Suneeta Agarwal
Keyword(s):  
Machine Learning ◽  
Image Processing ◽  
Agricultural Production ◽  
Bacterial Blight ◽  
Early Stage ◽  
Second Phase ◽  
Computationally Efficient ◽  
Stage Of Disease ◽  
Accurate Detection ◽  
Two Phases

Diseases in leaves can cause the significant reduction in both quality and quantity of agricultural production. If early and accurate detection of disease/diseases in leaves can be automated, then the proper remedy can be taken timely. A simple and computationally efficient approach is presented in this paper for disease/diseases detection on leaves. Only detecting the disease is not beneficial without knowing the stage of disease thus the paper also determine the stage of disease/diseases by quantizing the affected of the leaves by using digital image processing and machine learning. Though there exists a variety of diseases on leaves, but the bacterial and fungal spots (Early Scorch, Late Scorch, and Leaf Spot) are the most prominent diseases found on leaves. Keeping this in mind the paper deals with the detection of Bacterial Blight and Fungal Spot both at an early stage (Early Scorch) and late stage (Late Scorch) on the variety of leaves. The proposed approach is divided into two phases, in the first phase, it identifies one or more disease/diseases existing on leaves. In the second phase, amount of area affected by the disease/diseases is calculated. The experimental results obtained showed 97% accuracy using the proposed approach.

Representação e simbolismo: artes visuais na fronteira Brasil/Bolívia

2020 ◽  
Vol 4 (3) ◽  
pp. 286
Author(s):  
Paulo César Antonini de Souza ◽  
Derick Trindade Bezerra
Keyword(s):  
Visual Arts ◽  
Social Order ◽  
Research Field ◽  
Border Region ◽  
Second Phase ◽  
Two Dimensional ◽  
Santa Cruz ◽  
Cultural Conditions ◽  
Two Phases ◽  
America Latina

ResumoTendo por campo de investigação o Festival da América do Sul Pantanal (FASP) em 2018, na cidade de Corumbá (Brasil), objetiva-se identificar a materialidade e conceitos que permeiam as manifestações artísticas bidimensionais nesta região de fronteira, a partir da percepção de artistas da Bolívia. A pesquisa se organizou em duas fases: na primeira foi realizado um levantamento em plataformas online de produções acadêmicas em artes visuais, com foco no trabalho bidimensional, utilizando os descritores “arte popular” e “estética latina” resultando em três artigos. Na segunda fase foram selecionados dois trabalhos de uma artista da Bolívia, participante da mostra “Conexão Santa Cruz”, realizada durante o FASP 2018, que foram analisados em seus níveis representacional e simbólico. Pela interpretação das imagens foi possível construir uma leitura sobre a perspectiva da artista a respeito de suas condições culturais dentro da ordenação social em que se encontra situada.Palavras-chave: Artes Visuais. Arte Popular. Arte Regional. América Latina. Representation and symbolism: visual arts on the Brazil/Bolivia frontierAbstractHaving as research field the Festival da América do Sul Pantanal (FASP) in 2018, in the city of Corumbá (Brazil), the objective is to identify the materiality and concepts that permeate the two-dimensional artistic manifestations in this border region, from the perception of artists from Bolivia. The research was organized in two phases: in the first, a survey was carried out on online platforms of academic productions in visual arts, focusing on two-dimensional work, using the descriptors “arte popular” and “estética latina” resulting in three articles. In the second phase, two works were selected by an artist from Bolivia, participating in the exhibition “Conexão Santa Cruz”, held during FASP 2018, which were analyzed at their representational and symbolic levels. Through the interpretation of the images, it was possible to construct a reading on the artist’s perspective regarding her cultural conditions within the social order in which she is located.Keywords: Visual Arts. Folk Art. Regional Art. Latin America.Representación y simbolismo: artes visuales en la frontera de Brasil/BoliviaResumenTeniendo como campo de investigación el Festival de Sudamérica Pantanal (FASP) en 2018, en la ciudad de Corumbá (Brasil), el objetivo es identificar la materialidad y conceptos que permean las manifestaciones artísticas bidimensionales en esta región fronteriza, desde la percepción de artistas de Bolivia. La investigación se organizó en dos fases: en la primera, se realizó una encuesta en plataformas online de producciones académicas en artes visuales, con foco en el trabajo bidimensional, utilizando los descriptores “arte popular” y “estética latina” dando como resultado tres artículos. En la segunda fase, dos obras fueron seleccionadas por un artista de Bolivia, participante de la exposición “Conexão Santa Cruz”, realizada durante FASP 2018, que fueron analizadas en sus niveles representativos y simbólicos. A través de la interpretación de las imágenes, fue posible construir una lectura sobre la perspectiva de la artista sobre sus condiciones culturales dentro del orden social en el que se ubica.Palabras clave: Artes Visuales. Arte Popular. Arte Regional. América Latina.

scholarly journals Development and validation of a short version of the Sarcopenia Quality of Life questionnaire: the SF-SarQoL

2021 ◽  
Author(s):  
A. Geerinck ◽  
C. Beaudart ◽  
J.-Y. Reginster ◽  
M. Locquet ◽  
C. Monseur ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Short Form ◽  
Reduction Process ◽  
Community Dwelling ◽  
Short Version ◽  
Second Phase ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
Two Phases

Abstract Purpose To facilitate the measurement of quality of life in sarcopenia, we set out to reduce the number of items in the previously validated Sarcopenia Quality of Life (SarQoL®) questionnaire, and to evaluate the clinimetric properties of this new short form. Methods The item reduction process was carried out in two phases. First, information was gathered through item-impact scores from older people (n = 1950), a Delphi method with sarcopenia experts, and previously published clinimetric data. In the second phase, this information was presented to an expert panel that decided which of the items to include in the short form. The newly created SFSarQoL was then administered to older, community-dwelling participants who previously participated in the SarcoPhAge study. We examined discriminative power, internal consistency, construct validity, test–retest reliability, structural validity and examined item parameters with a graded response model (IRT). Results The questionnaire was reduced from 55 to 14 items, a 75% reduction. A total of 214 older, community-dwelling people were recruited for the validation study. The clinimetric evaluation showed that the SF-SarQoL® can discriminate on sarcopenia status [EWGSOP2 criteria; 34.52 (18.59–43.45) vs. 42.86 (26.56–63.69); p = 0.043], is internally consistent (α = 0.915, ω = 0.917) and reliable [ICC = 0.912 (0.847–0.942)]. A unidimensional model was fitted (CFI = 0.978; TLI = 0.975; RMSEA = 0.108, 90% CI 0.094–0.123; SRMR = 0.055) with no misfitting items and good response category separation. Conclusions A new, 14-item, short form version of the Sarcopenia Quality of Life questionnaire has been developed and shows good clinimetric properties.

scholarly journals SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kui Xu ◽  
Ming Zhang ◽  
Jie Liu ◽  
Nan Sha ◽  
Wei Xie ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Performance Optimization ◽  
Power Transmission ◽  
Base Station ◽  
Second Phase ◽  
Wireless Power ◽  
Half Duplex ◽  
Non Linear ◽  
Two Phases ◽  
And Performance

Abstract In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.

scholarly journals Development and Evaluation of Direct Paddy Seeder in Puddled Field

2021 ◽  
Vol 13 (5) ◽  
pp. 2745
Author(s):  
Manoj Kumar ◽  
Ritu Dogra ◽  
Mahesh Narang ◽  
Manjit Singh ◽  
Sushant Mehan
Keyword(s):  
Laboratory Testing ◽  
Field Evaluation ◽  
Row Spacing ◽  
Second Phase ◽  
Cell Type ◽  
Inclined Plate ◽  
Seed Damage ◽  
Two Phases ◽  
Almost All ◽  
Different Soils

Manual transplanting, a pre-dominant practice in almost all the paddy growing areas in India, is laborious, burdensome, and has many expenses on raising, settling, and transplanting nursery. The transplanting process’s limitations motivated the replacement of conventional paddy transplanting methods. The study was divided into two phases. The first phase included laboratory testing of three levels of metering mechanisms, namely cell type (M1) with 10 cells grooved around a circular plate having a 13 cm diameter, inclined plate (M2) containing 24 U shaped cells provided on an 18 cm diameter plate, and fluted roller (M3) with 10 flutes on a 5 cm diameter shaft. The testing matrix included a missing index, multiple index, and seed damage with forward speeds (2.5, 3.0, and 3.5 km/h), and pre-germination levels of 24 h soaked (P1), 24 h pre-germinated (P2), and 36 h pre-germinated paddy seeds (P3)). The second phase included selecting the best combination obtained from the laboratory study and developing a new efficient planter for the puddled field. The inclined plate metering mechanism operating at 2.5 km/h for 24 h pre-germinated seeds was reported most efficient from the first phase. Therefore, a self-propelled 8-row planter equipped with an inclined plate metering mechanism having a row-to-row spacing of 22.5 cm was developed, fabricated, and evaluated in the puddled field. The designed planter was assessed on two different soils: sandy loom (ST1) and clay loom (ST2) and at two different hopper fill levels as ½ filled hopper (F1) and ¾ filled hopper (F2). The number of plants per square meter and hill-to-hill spacing was measured. The on-field evaluation revealed that the number of plants per square meter was non-significantly affected by the type of soil but was significantly affected by hopper fill.

Activation of bovine oocytes by protein synthesis inhibitors: new findings on the role of MPF/MAPKs†

2021 ◽  
Author(s):  
Cecilia Valencia ◽  
Felipe Alonso Pérez ◽  
Carola Matus ◽  
Ricardo Felmer ◽  
María Elena Arias
Keyword(s):  
Protein Synthesis ◽  
Kinase Activity ◽  
Cyclin B1 ◽  
Protein Synthesis Inhibitors ◽  
Vitro Fertilization ◽  
New Findings ◽  
Bovine Oocytes ◽  
Dependent Pathway

Abstract The present study evaluated the mechanism by which protein synthesis inhibitors activate bovine oocytes. The aim was to analyze the dynamics of MPF and MAPKs. MII oocytes were activated with ionomycin (Io), ionomycin+anisomycin (ANY) and ionomycin+cycloheximide (CHX) and by in vitro fertilization (IVF). The expression of cyclin B1, p-CDK1, p-ERK1/2, p-JNK, and p-P38 were evaluated by immunodetection and the kinase activity of ERK1/2 was measured by enzyme assay. Evaluations at 1, 4, and 15 hours postactivation (hpa) showed that the expression of cyclin B1 was not modified by the treatments. ANY inactivated MPF by p-CDK1Thr14-Tyr15 at 4 hpa (P < 0.05), CHX increased pre-MPF (p-CDK1Thr161 and p-CDK1Thr14-Tyr15) at 1 hpa and IVF increased p-CDK1Thr14-Tyr15 at 17 hours postfertilization (hpf) (P < 0.05). ANY and CHX reduced the levels of p-ERK1/2 at 4 hpa (P < 0.05) and its activity at 4 and 1 hpa, respectively (P < 0.05). Meanwhile, IVF increased p-ERK1/2 at 6 hpf (P < 0.05); however, its kinase activity decreased at 6 hpf (P < 0.05). p-JNK in ANY, CHX, and IVF oocytes decreased at 4 hpa (P < 0.05). p-P38 was only observed at 1 hpa, with no differences between treatments. In conclusion, activation of bovine oocytes by ANY, CHX, and IVF inactivates MPF by CDK1-dependent specific phosphorylation without cyclin B1 degradation. ANY or CHX promoted this inactivation, which seemed to be more delayed in the physiological activation (IVF). Both inhibitors modulated MPF activity via an ERK1/2-independent pathway, whereas IVF activated the bovine oocytes via an ERK1/2-dependent pathway. Finally, ANY does not activate the JNK and P38 kinase pathways.

scholarly journals XCOVNet: Chest X-ray Image Classification for COVID-19 Early Detection Using Convolutional Neural Networks

2021 ◽  
Author(s):  
Vishu Madaan ◽  
Aditya Roy ◽  
Charu Gupta ◽  
Prateek Agrawal ◽  
Anand Sharma ◽  
...  
Keyword(s):  
Image Classification ◽  
Second Phase ◽  
Two Phase ◽  
X Ray ◽  
The Neural Network ◽  
Rapid Spread ◽  
Chest X Ray ◽  
Polymerase Chain ◽  
Two Phases ◽  
Active Patients

AbstractCOVID-19 (also known as SARS-COV-2) pandemic has spread in the entire world. It is a contagious disease that easily spreads from one person in direct contact to another, classified by experts in five categories: asymptomatic, mild, moderate, severe, and critical. Already more than 66 million people got infected worldwide with more than 22 million active patients as of 5 December 2020 and the rate is accelerating. More than 1.5 million patients (approximately 2.5% of total reported cases) across the world lost their life. In many places, the COVID-19 detection takes place through reverse transcription polymerase chain reaction (RT-PCR) tests which may take longer than 48 h. This is one major reason of its severity and rapid spread. We propose in this paper a two-phase X-ray image classification called XCOVNet for early COVID-19 detection using convolutional neural Networks model. XCOVNet detects COVID-19 infections in chest X-ray patient images in two phases. The first phase pre-processes a dataset of 392 chest X-ray images of which half are COVID-19 positive and half are negative. The second phase trains and tunes the neural network model to achieve a 98.44% accuracy in patient classification.

Temporal and Spatial Pattern of a Privet (Ligustrum vulgare) Invasion

2013 ◽  
Vol 6 (2) ◽  
pp. 310-319 ◽  
Author(s):  
Wanying Zhao ◽  
Charles Goebel ◽  
John Cardina
Keyword(s):  
Spatial Pattern ◽  
Spatial Data ◽  
Nearest Neighbor ◽  
Management Strategies ◽  
Age Distribution ◽  
Lag Phase ◽  
Suitable Habitat ◽  
Second Phase ◽  
Invasion History ◽  
Cumulative Number

AbstractPrivet has escaped from cultivation and is invading natural areas throughout eastern North America. Understanding the pattern of invasion over time could help us develop more efficient management strategies. We studied the invasion history and spatial distribution pattern of privet by mapping age and spatial data for established patches in a 132-ha (326 ac) forested natural area in northeast Ohio. We determined the age of 331 geo-referenced patches by counting annual rings, and mapped them with corresponding land habitat. Age distribution and cumulative number of privet patches over about 40 yr showed three phases of invasion. The initial 19-yr lag phase was characterized as a dispersed spatial pattern (based on nearest neighbor analysis), with patches located mostly at edges of different habitats and open places. In a second phase of about 15 yr, an average of 19 patches were initiated yearly, in a pattern that trended towards clustered. The final phase began around 2007, as the rate of new patch establishment declined, possibly because of saturation of the suitable habitat. Establishment of new patches was not associated with specific habitats. Aggregation of patches with similar ages increased after 1998 and became significantly clustered. Mapping of clusters of old and young patches identified invasion hot spots and barriers. Results affirmed that the best time for invasive control is during the lag phase. By monitoring edge habitats associated with early establishment, managers might detect and control early invaders and delay the onset of the expansion phase.

scholarly journals A Separated Reset Waveform Design for Suppressing Oil Backflow in Active Matrix Electrowetting Displays

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 491
Author(s):  
Linwei Liu ◽  
Pengfei Bai ◽  
Zichuan Yi ◽  
Guofu Zhou
Keyword(s):  
Experimental Data ◽  
Dielectric Layer ◽  
Waveform Design ◽  
Second Phase ◽  
Active Matrix ◽  
Two Phases ◽  
Back Stage ◽  
A Charge ◽  
Electric Field Force ◽  
Driving Waveform

The electrowetting display (EWD) is a kind of reflective paper-like display. Flicker and grayscale distortion are caused by oil backflow, which is one of the important factors restricting the wide application of EWDs. The charge embedding caused by the electric field force in the dielectric layer is the cause of oil backflow. To suppress oil backflow, a separated reset waveform based on the study of oil movement is proposed in this paper. The driving waveform is divided into two parts: a reset waveform and a grayscale waveform. The reset waveform generated by a reset circuit can be used to output various voltages. The grayscale waveform is set as a traditional PWM waveform. The reset waveform is composed of a charge-releasing stage and oil-moving back stage. Two phases are contained in the charge releasing stage. The overdriving voltage is used during the first phase to reverse the voltage of all pixels. The trapped charges can then be released from the dielectric layer during the second phase. A higher voltage is used during the oil-moving back stage to drive the oil faster in the pixel. By comparing the experimental data, the oil backflow time is extended 761 times by the reset waveform. The four grayscales can be maintained by the reset waveform after driving for 300 s.

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