Responses of wheat to vernalization and photoperiod

1985 ◽  
Vol 36 (3) ◽  
pp. 347 ◽  
Author(s):  
JL Davidson ◽  
KR Christian ◽  
DB Jones ◽  
PM Bremner

The effects of vernalization and photoperiod on times from planting of seedlings to ear emergence were measured in 68 Australian and 49 overseas varieties of wheat, comprising a broad spectrum of genetic material, in a glasshouse in Canberra (latitude 35�S). Vernalization was carried out by growing germinated seedlings in the dark at 1-2�C for 6 weeks. Long photoperiods (16 h) separated unvernalized plants into two distinct groups, corresponding to commonly recognized spring and winter types. Responses to vernalization were generally small under natural photoperiods (11-15 h), but much more pronounced in long photoperiods, particularly with winter wheats. In a second experiment, 24 varieties of wheat gave widely different responses to vernalization treatments. With 8 weeks' vernalization and long photoperiods, all varieties reached ear emergence within 66 days, but in some winter wheats 4 weeks treatment had little effect and 6 weeks gave incomplete vernalization. Under the conditions of these experiments, Australian wheats showed a wide range of responses to photoperiod and a narrow range of responses to vernalization compared with overseas varieties. The need to investigate the control of flowering time in obtaining varieties suited to the high-rainfall zone of Australia is discussed.

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.


Author(s):  
G. Rossini ◽  
A. Caimi ◽  
A. Redaelli ◽  
E. Votta

AbstractA Finite Element workflow for the multiscale analysis of the aortic valve biomechanics was developed and applied to three physiological anatomies with the aim of describing the aortic valve interstitial cells biomechanical milieu in physiological conditions, capturing the effect of subject-specific and leaflet-specific anatomical features from the organ down to the cell scale. A mixed approach was used to transfer organ-scale information down to the cell-scale. Displacement data from the organ model were used to impose kinematic boundary conditions to the tissue model, while stress data from the latter were used to impose loading boundary conditions to the cell level. Peak of radial leaflet strains was correlated with leaflet extent variability at the organ scale, while circumferential leaflet strains varied over a narrow range of values regardless of leaflet extent. The dependency of leaflet biomechanics on the leaflet-specific anatomy observed at the organ length-scale is reflected, and to some extent emphasized, into the results obtained at the lower length-scales. At the tissue length-scale, the peak diastolic circumferential and radial stresses computed in the fibrosa correlated with the leaflet surface area. At the cell length-scale, the difference between the strains in two main directions, and between the respective relationships with the specific leaflet anatomy, was even more evident; cell strains in the radial direction varied over a relatively wide range ($$0.36-0.87$$ 0.36 - 0.87 ) with a strong correlation with the organ length-scale radial strain ($$R^{2}= 0.95$$ R 2 = 0.95 ); conversely, circumferential cell strains spanned a very narrow range ($$0.75-0.88$$ 0.75 - 0.88 ) showing no correlation with the circumferential strain at the organ level ($$R^{2}= 0.02$$ R 2 = 0.02 ). Within the proposed simulation framework, being able to account for the actual anatomical features of the aortic valve leaflets allowed to gain insight into their effect on the structural mechanics of the leaflets at all length-scales, down to the cell scale.


Metrologia ◽  
2021 ◽  
Author(s):  
Ralf D Geckeler ◽  
Matthias Schumann ◽  
Andreas Just ◽  
Michael Krause ◽  
Antti Lassila ◽  
...  

Abstract Autocollimators are versatile devices for angle metrology used in a wide range of applications in engineering and manufacturing. A modern electronic autocollimator generally features two measuring axes and can thus fully determine the surface normal of an optical surface relative to it in space. Until recently, however, the calibration capabilities of the national metrology institutes were limited to plane angles. Although it was possible to calibrate both measuring axes independently of each other, it was not feasible to determine their crosstalk if angular deflections were present in both axes simultaneously. To expand autocollimator calibrations from plane angles to spatial angles, PTB and VTT MIKES have created dedicated calibration devices which are based on different measurement principles and accomplish the task of measurand traceability in different ways. Comparing calibrations of a transfer standard makes it possible to detect systematic measurement errors of the two devices and to evaluate the validity of their uncertainty budgets. The importance of measurand traceability via calibration for a broad spectrum of autocollimator applications is one of the motivating factors behind the creation of both devices and for this comparison of the calibration capabilities of the two national metrology institutes. The latter is the focus of the work presented here.


1996 ◽  
Vol 82 (3_suppl) ◽  
pp. 1371-1376 ◽  
Author(s):  
Kimihiko Yamagishi

Frequency estimation of social facts was compared between two methods of response elicitation. In the “narrow range” method, respondents answered questions like: “Out of 100 instances, how many instances belong to category X?”. In the “wide range” method, the same question was asked regarding “Out of 10,000.” A previous study in 1994 showed that judged frequencies were proportionally greater in the narrow condition than in the wide condition when subjects estimated the occurrence of low-frequency events. These results were interpreted to reflect cognitive processes of anchoring, wherein judged frequencies he close to small numbers within particular response ranges. The current work extends this argument to high-frequency events. In such cases, judgments about high-frequency events would be reached by similar cognitive processes operating toward the opposite direction. Hence, I predicted that judged frequencies for high-frequency events would be proportionally greater in the wide than in the narrow condition. Results were mostly consistent with these predictions. The relation to previous research is discussed.


2020 ◽  
Vol 12 (10) ◽  
pp. 949-959
Author(s):  
Ranju Bansal ◽  
Ranjit Singh

Steroidal pyrazolines constitute an interesting and promising scaffold for drug discovery as they display diverse chemical reactivity and a wide range of biological activities. Literature reports indicate potent anticancer potential of steroidal pyrazolines along with broad-spectrum antimicrobial activities. Strong neuroprotective effects with steroids possessing pyrazoline moiety have also been observed. Among all the therapeutically active steroidal pyrazolines, D-ring-substituted derivatives are highly potent and the least toxic. The current and futuristic research approaches in this area are focused towards the exploration of this promising scaffold to develop molecules with widespread pharmacological activities. This review article mainly covers the synthetic and pharmacological aspects of steroidal pyrazolines, which will assist the medicinal chemists working in this area in their scientific endeavors.


2020 ◽  
Vol 40 (9/10) ◽  
pp. 1021-1039
Author(s):  
Kaz Stuart ◽  
Mark A. Faghy ◽  
Elaine Bidmead ◽  
Ruth Browning ◽  
Catriona Roberts ◽  
...  

PurposeThis paper proposes a biopsychosocial (BPS) analysis of COVID-19 experiences which enhances understanding of complex and interrelated factors and leads to the proposition of a BPS recovery framework.Design/methodology/approachOnline narrative research was used to explore people's experiences of COVID-19 and was conducted over a four-month period. The call was distributed via a short open-ended qualitative online survey advertised on social media platforms and 305 responses came from across England.FindingsThe findings illustrate people with a narrow range of BPS characteristics experienced over a wide range of BPS impacts which are nuanced, complex and dynamic. Left unaddressed these may create future adverse BPS characteristics. An integrated BPS framework for recovery is proposed to avoid such further negative outcomes from the pandemic.Research limitations/implicationsThe sample contained a bias in age, gender and living arrangements.Practical implicationsThe paper offers a clear framework to enable integrated holistic recovery/regrowth planning.Social implicationsUsing the framework would reduce social and health inequities which have been recently deepened by COVID-19 in the long-term.Originality/valueThe paper is original in its use of a BPS analytical framework.


2013 ◽  
Vol 25 (1) ◽  
pp. 179 ◽  
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
M. C. Gómez ◽  
C. Dumas ◽  
S. P. Leibo

The cryopreservation of ovarian tissue is linked to a wide range of possible applications, from oocyte harvesting to allo- and xenotransplantation. These procedures have significant potential for the preservation of valuable genetic material and endangered-species conservation. The objectives of the present study were to (1) compare viability of preantral follicles obtained from fresh v. vitrified feline ovarian cortex, (2) evaluate the effect of apoptotic inhibitors (ROCK inhibitor v. glutathione) on viability of follicles from vitrified samples, and (3) determine the optimal inhibitor concentration for follicle viability. In Experiment 1, 5 × 5 × 1 mm cortical tissue samples were obtained from excised cat ovaries and assigned to either the fresh control or vitrification group. Fresh samples were processed through a 230-micron-pore dissection strainer to collect preantral follicles. Follicles were then stained in Trypan blue to determine membrane integrity and survival rates. Vitrification samples were first equilibrated in 7.5% dimethyl sulfoxide and 7.5% ethylene glycol at ~22°C and then in vitrification solution consisting of 20% dimethyl sulfoxide, 20% ethylene glycol, and 0.5 M sucrose. They were then vitrified on a thin, perforated, metal strip (Cryotissue, Kitazato Biopharma, Fujinomiya, Japan). Samples were later warmed in 1.0 M sucrose at 38°C. Follicles were then collected and assessed for survival. In Experiment 2, follicles were collected from samples vitrified/warmed in cryo-media supplemented with either 3 × 104 nM ROCK inhibitor or 6 nM glutathione. Follicles from samples vitrified/warmed without inhibitor treatment were used as controls. In Experiment 3, tissue samples were vitrified/warmed in cryo-media supplemented with 0, 2, 6, or 10 nM glutathione before follicle viability was determined. Data were evaluated by chi square analysis. In Experiment 1, 637 and 340 follicles were collected from fresh and vitrified samples, respectively. Overall, survival was higher in freshly collected follicles when compared to those from the vitrified group (67 v. 18%, respectively; P < 0.05). Evaluation of apoptotic inhibitors was determined through collection of 314, 354, and 506 follicles from inhibitor-free, ROCK inhibitor, and glutathione-treated media, respectively. Follicles from samples vitrified in inhibitor-free media and in ROCK inhibitor survived at a lower rate than those from glutathione-treated samples (10 and 13% v. 18%, respectively; P < 0.05). In Experiment 3, a total of 539, 641, 625, and 632 follicles were collected from samples treated in 0, 2, 6, and 10 nM glutathione, respectively. There were no statistical differences in follicle survival among the 0, 2, and 6 nM groups. However, follicles treated in 10 nM glutathione survived at a higher rate than those vitrified/warmed in the absence of glutathione (20 v. 14%; P < 0.05). In summary, viability of preantral follicles from ovarian cortical tissue was significantly reduced by vitrification. Despite this, tolerance of such follicles to cryopreservation was improved by vitrifying and warming in cryo-media containing 10 nM glutathione. Partially funded by the LSU/ACRES Collaborative Project.


2019 ◽  
Vol 117 (2) ◽  
pp. 1191-1200 ◽  
Author(s):  
Thierri Callier ◽  
Nathan W. Brantly ◽  
Attilio Caravelli ◽  
Sliman J. Bensmaia

Intracortical microstimulation (ICMS) of the somatosensory cortex evokes vivid tactile sensations and can be used to convey sensory feedback from brain-controlled bionic hands. Changes in ICMS frequency lead to changes in the resulting sensation, but the discriminability of frequency has only been investigated over a narrow range of low frequencies. Furthermore, the sensory correlates of changes in ICMS frequency remain poorly understood. Specifically, it remains to be elucidated whether changes in frequency only modulate sensation magnitude—as do changes in amplitude—or whether they also modulate the quality of the sensation. To fill these gaps, we trained monkeys to discriminate the frequency of ICMS pulse trains over a wide range of frequencies (from 10 to 400 Hz). ICMS amplitude also varied across stimuli to dissociate sensation magnitude from ICMS frequency and ensure that animals could not make frequency judgments based on magnitude. We found that animals could consistently discriminate ICMS frequency up to ∼200 Hz but that the sensory correlates of frequency were highly electrode dependent: On some electrodes, changes in frequency were perceptually distinguishable from changes in amplitude—seemingly giving rise to a change in sensory quality; on others, they were not. We discuss the implications of our findings for neural coding and for brain-controlled bionic hands.


1959 ◽  
Vol 14 (6) ◽  
pp. 905-908 ◽  
Author(s):  
N. R. Frank

The effects of acute reversible pulmonary vascular congestion on the elastic behavior of excised cats' lungs were studied in 10 preparations. Measurements were made of changes in airway pressure at constantly held lung volumes over a wide range of deflation. To achieve vascular congestion left atrial pressure was raised to 20 and 30 cm H2O. Two effects were noted; one was that the slope of the volume-pressure relations of the lungs was slightly reduced at all levels of deflation, the other, the effect of vascular congestion on the recoiling force of the lungs was a function of the volume of the lungs at which congestion was induced. At large volumes (airway pressures of 5 cm H2O or more) recoiling force was increased; at intermediate volumes (airway pressures of 2.5 and 3 cm H2O) the change was negligible and, at smaller volumes, it was reduced in a manner consistent with the early work of von Basch. The findings suggest that there is a volume of the lungs, or perhaps a narrow range of volume, at which the lungs and blood vessels exert least mechanical stress on each other. This volume is believed to lie close to that in which tidal breathing occurs. Note: (With the Technical Assistance of Elcanor Gotz) Submitted on April 17, 1959


Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 380-387 ◽  
Author(s):  
Gerbert Sylvestre Dossa ◽  
Ricardo Oliva ◽  
Edgar Maiss ◽  
Casiana Vera Cruz ◽  
Kerstin Wydra

Rice bacterial blight (BB) is caused by Xanthomonas oryzae pv. oryzae and is responsible for substantial yield loss worldwide. Host resistance remains the most feasible control measure. However, pathogen variability leads to the failure of certain resistance genes to control the disease, and climate change with high amplitudes of heat predisposes the host plant to pathogen invasion. Due to pressure in natural selection, landrace species often carry a wide range of unique traits conferring tolerance of stress. Therefore, exploring their genetic background for host resistance could enable the identification of broad-spectrum resistance to combined abiotic and biotic stresses. Nineteen Oryza glaberrima accessions and O. sativa rice variety SUPA were evaluated for BB resistance under high temperature (35 and 31°C day and night, respectively) using 14 X. oryzae pv. oryzae strains originated from the Philippines. Under normal temperature, most of the accessions showed resistance to 9 strains (64.3%) and accession TOG6007 showed broad-spectrum resistance to 12 strains (85.7%). Under high temperature, most accessions showed a reduction in BB disease, whereas, accession TOG5620 showed disease reduction from all the X. oryzae pv. oryzae strains under high temperature. Molecular characterization using gene-based and linked markers for BB resistance genes Xa4, xa5, Xa7, xa13, and Xa21 revealed the susceptible alleles of Xa4, xa5, xa13, and Xa21 in O. glaberrima. However, no allele of Xa7 was detected among O. glaberrima accessions. Our results suggest that O. glaberrima accessions contain a BB resistance different from the Xa gene type. Genome-wide association mapping could be used to identify quantitative trait loci that are associated with BB resistance or combined BB resistance and high-temperature tolerance.


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