Mitotic-cycle time and the development of embryo and endosperm in compatible and incompatible crosses in tuber-bearing Solanum species

Genome ◽  
2001 ◽  
Vol 44 (3) ◽  
pp. 426-431 ◽  
Author(s):  
R W Masuelli
Keyword(s):  
Growth Rates ◽  
Doubling Time ◽  
Mitotic Cycle ◽  
Solanum Species ◽  
Endosperm Balance Number ◽  
Solanum Commersonii ◽  
Cell Doubling Time ◽  
The Mean ◽  
The Relationship ◽  
Solanum Spp

To understand the relationship between early seed development and the EBN (endosperm balance number) hypothesis, the embryo and endosperm growth rates in crosses among Solanum spp. with the same and different EBNs were analyzed. For the embryo, the differences in the mean cell-doubling time (MCDT) between the compatible species 2x Solanum gourlayi and Solanum acaule was 3.9 h, whereas the incompatible species Solanum commersonii had MCDT differences of 10 and 13.9 h with 2x S. gourlayi and S. acaule, respectively. The embryo growth rates of the 2EBN species S. acaule and S. gourlayi were almost twice as fast as that of the 1EBN species S. commersonii. Nuclei of variable sizes were observed in the endosperms resulting from incompatible crosses. The author discusses the possibility that the collapse of the endosperm in inter-EBN crosses could be caused by differences in the MCDT between the parents that produce hybrid endosperms with high levels of DNA synthesis and transcription activity, resulting in increased nuclear size. A model is proposed to explain the formation of enlarged endosperm nuclei in incompatible crosses in the genus Solanum.Key words: mean cell-doubling time, endosperm balance number, Solanum, endosperm, embryo.

Estimation of Recent Growth of Field-Caught Postlarval American Lobsters, Homarus americanus, from RNA:DNA Ratios

1994 ◽  
Vol 51 (2) ◽  
pp. 286-294 ◽  
Author(s):  
Marie Antonette R. Juinio ◽  
J. Stanley Cobb
Keyword(s):  
Growth Rates ◽  
Food Limitation ◽  
Homarus Americanus ◽  
Zooplankton Biomass ◽  
Individual Growth ◽  
Prolonged Duration ◽  
The Mean ◽  
Temperature And Growth ◽  
Relationship Of ◽  
The Relationship

We developed a growth model for the postlarvae of the American lobster, Homarus americanus, using the relationship of RNA:DNA ratios, temperature, and growth rates during postmolt through early pre-molt of laboratory-reared postlarval lobsters. The model was used to estimate individual growth rates of 385 postlarval lobsters in molt stages C and D0, collected at two sites in Block Island Sound over three years, 1988–90. The mean growth rates of postlarvae collected in June 1989 and 1990 (0.57 ± 0.19 and 0.54 ± 0.18 mg protein∙d−1) were significantly higher than those collected in July (0.39 ± 0.17 and 0.43 ± 0.18 mg protein∙d−1). Changes in sea surface temperatures of zooplankton biomass did not account for the seasonal difference in growth rates, nor was there correlation between the biweekly mean growth rates and postlarval densities. The incidence of poorly nourished postlarval lobsters (individuals with growth rates < 0.22 mg protein∙d−1) was less than 10% of the total samples in each year. We found no evidence that food limitation, resulting in starvation or prolonged duration of the postlarval instar, was a significant factor contributing to the observed interannual variability of postlarval densities.

Migration as a source of bias in the measurement of cephalopod growth

1994 ◽  
Vol 6 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Emma M.C. Hatfield ◽  
Paul G. Rodhouse
Keyword(s):  
Growth Rates ◽  
Time Interval ◽  
Elapsed Time ◽  
The Mean ◽  
Sampling Biases ◽  
June July ◽  
The Relationship ◽  
Modal Group ◽  
Daily Time

Theory predicts that, in a closed exploited population showing no sampling or other bias, the mean age of fish or squid between one sampling date and the next should increase by the time interval between samples. Age data, derived from statoliths, have been used to test the hypothesis that the effect of migration through an area where a population of Loligo gahi is sampled would be apparent as an increase in mean age per modal group of less than one day per daily time interval between samples. The data show that, in both females and males, the relationship between mean statolith increment number and elapsed time between samples is positive in some months and negative in others. The months in which the relationship between mean increment number and elapsed time is negative are similar to those months in which recruitment has previously been demonstrated to occur, in February, April/May and September for both females and males. Cohorts of squid remain available to the fishery from June–September (females) and February–May and June–July (males) thus allowing mean monthly growth rates of 0.4 mm d−1 for females and 0.7 mm d−1 for males to be calculated. The present study shows that putative age data derived from statoliths apparently demonstrate some sampling biases within a fishery and their effects on the measurement of growth. Migration through the sampled population is manifested by an increase in mean increment number of less than one per day between samples, and growth can only be assessed where the increase in mean increment number is not significantly different from the time elapsed between samples.

Plastochrone, cycle cellulaire et teneurs en ADN nucléaire du méristème caulinaire de plants de Chrysanthemum segetum soumis à deux conditions lumineuses différentes, sous une photopériode de 16 heures

1990 ◽  
Vol 68 (11) ◽  
pp. 2389-2397 ◽  
Author(s):  
Arlette Nougarède ◽  
Maria Nicola Di Michele ◽  
Pierre Rondet ◽  
Robert Saint-Côme
Keyword(s):  
Cell Cycle ◽  
Doubling Time ◽  
Nuclear Dna ◽  
Cycle Duration ◽  
Axial Zone ◽  
Lateral Zone ◽  
Cell Doubling Time ◽  
Photon Fluence ◽  
The Mean ◽  
Chrysanthemum Segetum

Chrysanthemum segetum plants were grown from seeds under a 16-h photoperiod, at two different photon fluence rates (70 or 200 μmol m−2 s−1. At 200 μmol m−2 s−1, by comparison with 70 μmol m−2 s−1, phyllotaxy was not modified, but the plastochron decreased and the apical diameter increased by extension of the axial zone. The mean cell doubling time decreased 36.2% in the lateral zone, 29% in the axial zone, and only 13% in the rib meristem. In contrast, mitosis duration was constant. Under both light conditions, nuclei with a DNA content within the limits of the 2C range were always predominant, which means that the G1 phase of the cell cycle was the longest. At 200 μmol m−2 s−1, the shortening of the mean cell doubling time is accompanied by a reduction of the percentage of nuclei with DNA levels within the limits of the 2C range. The decrease of the latter was the most important in the axial zone and the least important in the rib meristem, showing that control of cell proliferation was obtained by means of the G1 phase of the cell cycle. Key words: Chrysanthemum segetum, cell cycle, duration of mitosis, plastochron, nuclear DNA levels, zonation.

Among-Population Variability of Fish Growth: II. Influence of Prey Type.

1989 ◽  
Vol 46 (3) ◽  
pp. 468-482 ◽  
Author(s):  
D. Boisclair ◽  
W. C. Leggett
Keyword(s):  
Growth Rates ◽  
Prey Size ◽  
Prey Type ◽  
Growth Efficiency ◽  
Population Variability ◽  
Fish Growth ◽  
Percent Contribution ◽  
The Mean ◽  
Taxonomic Groups ◽  
The Relationship

We tested the significance of the relationship between in situ growth and several diet descriptors using 12 yellow perch (Perca flavescens) populations that varied widely in growth rates. In addition, we tested the assumption of optimal foraging theory that mean prey size is an important regulator of fish growth. The percent contribution of four prey taxonomic groups and six prey size–classes (alone or combined with food consumption estimates) explained between 41 and 95% of among-population variability in growth rates or growth efficiency. We found no significant relationship between growth rates or growth efficiency and mean prey weight. We observed a pattern suggesting the existence of an optimal prey size for (1 mg dry weight) age I + and age II + fish, when the percent contribution of specific prey taxonomic groups or size–classes to the diet was assessed. This pattern was not apparent in the relationship between growth and the mean weight of prey consumed. The energetic advantage of feeding on a given prey type is believed to be related to its low cost/benefit ratio while foraging. Our data indicate that interactions between prey availability (index of searching component of foraging cost) and prey size (index of handling component of foraging cost) are more effectively represented by the percent contribution of a given prey type to the diet than by the mean weight of prey consumed. Our analyses lead us to conclude that the probability of deriving broadly applicable models explaining among-population variability in fish growth rates based on mean prey weight is very low.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

Evaluation of the Efficacy of ST2 and NT-proBNP in the Diagnosis and Prediction of Short- Term Prognosis in Heart Failure with Reduced Ejection Fraction

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Biomarkers ◽  
Double Blind Study ◽  
Short Term ◽  
Double Blind ◽  
Reduced Ejection Fraction ◽  
The Mean ◽  
Design And Methods ◽  
The Relationship

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.

scholarly journals Correlation between fundus autofluorescence and visual function in patients with cone-rod dystrophy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoru Kanda ◽  
Takumi Hara ◽  
Ryosuke Fujino ◽  
Keiko Azuma ◽  
Hirotsugu Soga ◽  
...  
Keyword(s):  
Visual Field ◽  
Significant Relationship ◽  
Fundus Autofluorescence ◽  
Univariate Analysis ◽  
Retrospective Chart Review ◽  
Mean Deviation ◽  
Wide Field ◽  
The Mean ◽  
The Relationship ◽  
Field Imaging

AbstractThis study aimed to investigate the relationship between autofluorescence (AF) signal measured with ultra-wide field imaging and visual functions in patients with cone-rod dystrophy (CORD). A retrospective chart review was performed for CORD patients. We performed the visual field test and fundus autofluorescence (FAF) measurement and visualized retinal structures with optical coherence tomography (OCT) on the same day. Using binarised FAF images, we identified a low FAF area ratio (LFAR: low FAF/30°). Relationships between age and logMAR visual acuity (VA), central retinal thickness (CRT), central choroidal thickness (CCT), mean deviation (MD) value, and LFAR were investigated. Thirty-seven eyes of 21 CORD patients (8 men and 13 women) were enrolled. The mean patient age was 49.8 years. LogMAR VA and MD were 0.52 ± 0.47 and − 17.91 ± 10.59 dB, respectively. There was a significant relationship between logMAR VA and MD (p = 0.001). LogMAR VA significantly correlated with CRT (p = 0.006) but not with other parameters. Conversely, univariate analysis suggested a significant relationship between MD and LFAR (p = 0.001). In the multivariate analysis, LFAR was significantly associated with MD (p = 0.002). In conclusion, it is useful to measure the low FAF area in patients with CORD. The AF measurement reflects the visual field deterioration but not VA in CORD.

Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management

2020 ◽  
pp. 088506662098250
Author(s):  
Chad M. Conner ◽  
William H. Perucki ◽  
Andre Gabriel ◽  
David M. O’Sullivan ◽  
Antonio B. Fernandez
Keyword(s):  
Heart Rate ◽  
Positive Association ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Neurological Outcomes ◽  
Neurologic Outcomes ◽  
Resuscitation Guidelines ◽  
The Mean ◽  
The Impact ◽  
The Relationship

Introduction: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. Methods: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student’s t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. Results: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR’s < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR’s in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. Conclusion: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

scholarly journals Relationship between 24-h venous blood glucose variation and mortality among patients with acute respiratory failure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoling Zhang ◽  
Jingjing Zhang ◽  
Jiamei Li ◽  
Ya Gao ◽  
Ruohan Li ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Respiratory Failure ◽  
Hospital Mortality ◽  
Acute Respiratory Failure ◽  
Venous Blood ◽  
Sensitivity Analyses ◽  
Icu Mortality ◽  
Logistic Regression Models ◽  
The Mean ◽  
The Relationship

AbstractEvidence indicates that glucose variation (GV) plays an important role in mortality of critically ill patients. We aimed to investigate the relationship between the coefficient of variation of 24-h venous blood glucose (24-hVBGCV) and mortality among patients with acute respiratory failure. The records of 1625 patients in the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II) database were extracted. The 24-hVBGCV was calculated as the ratio of the standard deviation (SD) to the mean venous blood glucose level, expressed as a percentage. The outcomes included ICU mortality and in-hospital mortality. Participants were divided into three subgroups based on tertiles of 24-hVBGCV. Multivariable logistic regression models were used to evaluate the relationship between 24-hVBGCV and mortality. Sensitivity analyses were also performed in groups of patients with and without diabetes mellitus. Taking the lowest tertile as a reference, after adjustment for all the covariates, the highest tertile was significantly associated with ICU mortality [odds ratio (OR), 1.353; 95% confidence interval (CI), 1.018–1.797] and in-hospital mortality (OR, 1.319; 95% CI, 1.003–1.735), especially in the population without diabetes. The 24-hVBGCV may be associated with ICU and in-hospital mortality in patients with acute respiratory failure in the ICU, especially in those without diabetes.

Association between obstructive sleep apnea and persistent-postural perceptual dizziness

2021 ◽  
pp. 1-6
Author(s):  
Anand K. Bery ◽  
Jayson Lee Azzi ◽  
Andre Le ◽  
Naomi S. Spitale ◽  
Judith Leech ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Sensitivity And Specificity ◽  
Berlin Questionnaire ◽  
Future Studies ◽  
Obstructive Sleep ◽  
Chronic Dizziness ◽  
Patients At Risk ◽  
The Mean ◽  
The Relationship

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to vestibular dysfunction, but no prior studies have investigated the relationship between Persistent Postural Perceptual Dizziness (PPPD), a common cause of chronic dizziness, and OSA. OBJECTIVE AND METHODS: We determined the frequency of OSA in an uncontrolled group of PPPD patients from a tertiary dizziness clinic based on polysomnogram (PSG). We then assessed the sensitivity and specificity of common OSA questionnaires in this population. RESULTS: Twenty-five patients with PPPD underwent PSG (mean age 47, 60% female, mean BMI 29.5). A majority, or 56%, of patients were diagnosed with OSA, and in most, the OSA was severe. OSA patients were older (56 years versus 40 years, p = 0.0006) and had higher BMI (32 versus 26, p = 0.0078), but there was no clear gender bias (56% versus 64% female, p = 1.00). The mean sensitivity and specificity of the STOP BANG questionnaire for detecting OSA was 86% and 55%, respectively. Sensitivity and specificity of the Berlin Questionnaire was 79% and 45%, respectively. CONCLUSIONS: The prevalence of OSA was much higher in our small PPPD group than in the general population. Screening questionnaires appear to demonstrate good sensitivity to detect PPPD patients at risk of OSA in this small study. Future studies should confirm these findings and determine whether treatment of OSA improves symptoms in PPPD.

Sign in / Sign up

Export Citation Format

Share Document