scholarly journals Dill seed germ development after short-term temperature stress.

Author(s):  
A. F. Bukharov ◽  
D. N. Baleev ◽  
N. A. Eremina

NNew data on germ growth processes of dill seeds formed at the first and second branching orders after exposure to short-term heat stress (40 °C) are presented. Morphometric method and analysis of dill seed embryo growth in dynamics were used. The studies were carried out in 20152017 at the All-Russian Research Institute of Vegetable Growing, a branch of FSBSI FSCVG. Seeds of dill (Anethum graveolens L.) of the variety Centaurus from the first and second branching orders were the object of research. First, seeds were germinated in a thermostat. Then, swollen roots were exposed to a temperature of 40 °C according to the experiment scheme: 0 (control); 1; 2; 3; 4 and 5 days. After incubation, the seeds were transferred to standard conditions (temperature 20 °C) and germinated in Petri dishes on filter paper without light for 21 days. Germ size was measured using image analysis software. Critical embryo length and degree of underdevelopment were determined, and the ratio of embryo length to endosperm length (I Z/E) was calculated. Logistic regression with four parameters: b, c, d, e., was used to construct a germ growth curve. The relationship between the parameters was assessed using Pearson correlation analysis. The differences were considered statistically significant at P≤0.05. The duration of temperature action, which has an inhibitory effect on embryo growth, germination rate, the number of germinated seeds, were revealed. It was found that the embryos of seeds obtained from different branching orders have different sizes and have different intensity of growth under stress and standard conditions. It was shown that the effect of brief temperature (40 °C) on embryo growth depends on branching order and that embryos of seeds of the second branching order are more sensitive to high temperature. Morphometric parameters of the source were shown to play a critical role in the ability of dill seeds to resist the effect of temperature stressor during germination.

1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.


2019 ◽  
Author(s):  
Majid Manoochehri

Memory span in humans has been intensely studied for more than a century. In spite of the critical role of memory span in our cognitive system, which intensifies the importance of fundamental determinants of its evolution, few studies have investigated it by taking an evolutionary approach. Overall, we know hardly anything about the evolution of memory components. In the present study, I briefly review the experimental studies of memory span in humans and non-human animals and shortly discuss some of the relevant evolutionary hypotheses.


2021 ◽  
Vol 11 (6) ◽  
pp. 2742
Author(s):  
Fatih Ünal ◽  
Abdulaziz Almalaq ◽  
Sami Ekici

Short-term load forecasting models play a critical role in distribution companies in making effective decisions in their planning and scheduling for production and load balancing. Unlike aggregated load forecasting at the distribution level or substations, forecasting load profiles of many end-users at the customer-level, thanks to smart meters, is a complicated problem due to the high variability and uncertainty of load consumptions as well as customer privacy issues. In terms of customers’ short-term load forecasting, these models include a high level of nonlinearity between input data and output predictions, demanding more robustness, higher prediction accuracy, and generalizability. In this paper, we develop an advanced preprocessing technique coupled with a hybrid sequential learning-based energy forecasting model that employs a convolution neural network (CNN) and bidirectional long short-term memory (BLSTM) within a unified framework for accurate energy consumption prediction. The energy consumption outliers and feature clustering are extracted at the advanced preprocessing stage. The novel hybrid deep learning approach based on data features coding and decoding is implemented in the prediction stage. The proposed approach is tested and validated using real-world datasets in Turkey, and the results outperformed the traditional prediction models compared in this paper.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhu ◽  
Anchi Wu ◽  
Guoyi Zhou

AbstractPhosphorus (P) is an important element in terrestrial ecosystems and plays a critical role in soil quality and ecosystem productivity. Soil total P distributions have undergone large spatial changes as a result of centuries of climate change. It is necessary to study the characteristics of the horizontal and vertical distributions of soil total P and its influencing factors. In particular, the influence of climatic factors on the spatial distribution of soil total P in China’s forest ecosystems remain relatively unknown. Here, we conducted an intensive field investigation in different forest ecosystems in China to assess the effect of climatic factors on soil total P concentration and distribution. The results showed that soil total P concentration significantly decreased with increasing soil depth. The spatial distribution of soil total P increased with increasing latitude and elevation gradient but decreased with increasing longitude gradient. Random forest models and linear regression analyses showed that the explanation rate of bioclimatic factors and their relationship with soil total P concentration gradually decreased with increasing soil depths. Variance partitioning analysis demonstrated that the most important factor affecting soil total P distribution was the combined effect of temperature and precipitation factor, and the single effect of temperature factors had a higher explanation rate compare with the single effect of precipitation factors. This work provides a new farmework for the geographic distribution pattern of soil total P and the impact of climate variability on P distribution in forest ecosystems.


2011 ◽  
Vol 49 (3) ◽  
pp. 368-381 ◽  
Author(s):  
Paul Hoffman ◽  
Elizabeth Jefferies ◽  
Matthew A. Lambon Ralph

2008 ◽  
Vol 294 (3) ◽  
pp. R811-R818 ◽  
Author(s):  
Chao-Hung Wang ◽  
Wen-Jin Cherng ◽  
Ning-I Yang ◽  
Chia-Ming Hsu ◽  
Chi-Hsiao Yeh ◽  
...  

Cyclosporin A (CsA) improves the success rate of transplantation. The CD26/dipeptidylpeptidase IV (DPP IV) system plays a critical role in mobilizing endothelial progenitor cells (EPCs) from bone marrow. This study investigated whether CsA manipulates CD26/DPP IV activity and increases EPC mobilization. C57BL/6 mice were divided into control and CsA-treated groups. Before and after hindlimb ischemia was induced, circulating EPC number and serum levels of different cytokines were measured. Compared with the controls, CsA treatment significantly increased the blood levels of stroma-derived factor-1α and stem cell factor after ischemic stress ( P < 0.001). The CsA group displayed a significant increase in the number of circulating EPCs (sca-1+KDR+ and c-kit+CD31+ EPCs, both P < 0.05). In vivo, CsA caused a significant increase in the numbers of EPCs incorporated into the Matrigel and ischemic limbs ( P < 0.05). In the peripheral blood, CsA significantly decreased CD26+ cell numbers and attenuated the plasma CD26/DPP IV activity ( P < 0.001). Furthermore, short-term CsA treatment significantly improved the perfusion of ischemic limbs and decreased the spontaneous digital amputation rate. In summary, CsA manipulates the mobilization of EPCs into the circulation via the CD26/DPP IV system. Short-term CsA treatment has beneficial effects on angiogenesis of ischemic tissues.


2008 ◽  
Vol 295 (5) ◽  
pp. H1905-H1916 ◽  
Author(s):  
Andrianos Kontogeorgis ◽  
Xiaodong Li ◽  
Eunice Y. Kang ◽  
Jonathan E. Feig ◽  
Marc Ponzio ◽  
...  

Gap junction redistribution and reduced expression, a phenomenon termed gap junction remodeling (GJR), is often seen in diseased hearts and may predispose toward arrhythmias. We have recently shown that short-term pacing in the mouse is associated with changes in connexin43 (Cx43) expression and localization but not with increased inducibility into sustained arrhythmias. We hypothesized that short-term pacing, if imposed on murine hearts with decreased Cx43 abundance, could serve as a model for evaluating the electrophysiological effects of GJR. We paced wild-type (normal Cx43 abundance) and heterozygous Cx43 knockout (Cx43+/−; 66% mean reduction in Cx43) mice for 6 h at 10–15% above their average sinus rate. We investigated the electrophysiological effects of pacing on the whole animal using programmed electrical stimulation and in isolated ventricular myocytes with patch-clamp studies. Cx43+/− myocytes had significantly shorter action potential durations (APD) and increased steady-state ( Iss) and inward rectifier ( IK1) potassium currents compared with those of wild-type littermate cells. In Cx43+/− hearts, pacing resulted in a significant prolongation of ventricular effective refractory period and APD and significant diminution of Iss compared with unpaced Cx43+/− hearts. However, these changes were not seen in paced wild-type mice. These data suggest that Cx43 abundance plays a critical role in regulating currents involved in myocardial repolarization and their response to pacing. Our study may aid in understanding how dyssynchronous activation of diseased, Cx43-deficient myocardial tissue can lead to electrophysiological changes, which may contribute to the worsened prognosis often associated with pacing in the failing heart.


2021 ◽  
pp. 164-168
Author(s):  
Sruthi B ◽  
Rashmi R

Working capital management is important for every organization as it refers to the effective management of current assets and current liabilities. The aim is to make sure that the firm is capable to continue its operations and it has sufficient cash flow to satisfy both maturing short-term debt and upcoming operational expenses. In this paper, an attempt has been made to study the management of working capital in Hindustan Petroleum Corporation Limited, a leading public sector enterprise in India over a period of 10 years (That is from 2009-10 to 2018-19). The paper also attempts to study the components of working capital and analyze the relationship between liquidity and profitability of HPCL. The study is based on secondary data collected from annual report of HPCL for the past 10 years, Pearson correlation and regression model are used for this purpose. From the study it is found that there is a significant relationship between liquidity and profitability.


2021 ◽  
Author(s):  
Yuanzhi Liu ◽  
Jie Zhang

Abstract Vehicle velocity forecasting plays a critical role in scheduling the operations of varying systems and devices in a passenger vehicle. This paper first generates a repeated urban driving cycle dataset at a fixed route in the Dallas area, aiming to contribute to the improvement of vehicle energy efficiency for commuting routes. The generated driving cycles are divided into cycle segments based on intersection/stop identification, deceleration and reacceleration identification, and waiting time estimation, which could be used for better evaluating the effectiveness of model localization. Then, a segment-based vehicle velocity forecasting model is developed, where a machine learning model is trained/developed at each segment, using the hidden Markov chain (HMM) model and long short-term memory network (LSTM). To further improve the forecasting accuracy, a localized model selection framework is developed, which can dynamically choose a forecasting model (i.e., HMM or LSTM) for each segment. Results show that (i) the segment-based forecast could improve the forecasting accuracy by up to 24%, compared the whole cycle-based forecast; and (ii) the localized model selection framework could further improve the forecasting accuracy by 6.8%, compared to the segment-based LSTM model. Moreover, the potential of leveraging the stopping location at an intersection to estimate the waiting time is also evaluated in this study.


2017 ◽  
Vol 31 (10) ◽  
pp. 1374-1376
Author(s):  
Jack H Wilson ◽  
Amy H Criss ◽  
Sean A Spangler ◽  
Katherine Walukevich ◽  
Sandra Hewett

Nonsteroidal anti-inflammatory drugs work by non-selectively inhibiting cyclooxygenase enzymes. Evidence indicates that metabolites of the cyclooxygenase pathway play a critical role in the process of learning and memory. We evaluated whether acute naproxen treatment impairs short-term working memory, episodic memory, or semantic memory in a young, healthy adult population. Participants received a single dose of placebo or naproxen (750 mg) in random order separated by 7–10 days. Two hours following administration, participants completed five memory tasks. The administration of acute high-dose naproxen had no effect on memory in healthy young adults.


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