scholarly journals A simplified method for differential staining of aborted and non-aborted pollen grains

2010 ◽  
Vol 1 (2) ◽  
pp. 13 ◽  
Author(s):  
Ross Peterson ◽  
Janet P. Slovin ◽  
Changbin Chen
Keyword(s):  
Mercuric Chloride ◽  
Chloral Hydrate ◽  
Pollen Grains ◽  
Staining Technique ◽  
Field Studies ◽  
Differential Staining ◽  
Practical Applications ◽  
Time Period ◽  
Simplified Method ◽  
Pollen Vitality

The ability to use chemical staining to discriminate aborted from non-aborted pollen grains has well-known practical applications in agriculture. A commonly used technique for assessing pollen vitality, Alexander’s stain, uses chloral hydrate, phenol and mercuric chloride, all of which are highly toxic. We describe here an improved pollen staining technique that avoids the use of a regulated chemical chloral hydrate and two extremely toxic chemicals mercuric chloride and phenol, and requires a much shorter time period for sample preparation and staining. This simplified method is very useful for field studies without high-end equipments such as fluorescence microscopes. Samples can be collected and fixed in the fields and examined in a simple laboratory that has light microscopes.

The preimplantation pig embryo: cell number and allocation to trophectoderm and inner cell mass of the blastocyst in vivo and in vitro

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 793-803 ◽  
Author(s):  
V.E. Papaioannou ◽  
K.M. Ebert
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Staining Technique ◽  
Cell Number ◽  
Total Cell ◽  
Differential Staining ◽  
Morphological Development ◽  
Total Cell Number

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from different females. Inner cells could be detected in some but not all embryos of 12–16 cells. The proportion of inner cells was low in morulae but increased during differentiation of ICM and trophectoderm in early blastocysts. The proportion of ICM cells then decreased as blastocysts expanded and hatched. Some embryos were cultured in vitro and others were transferred to the oviducts of immature mice as a surrogate in vivo environment and assessed for morphology and cell number after several days. Although total cell number did not reach in vivo levels, morphological development and cell number increase was sustained better in the immature mice than in vitro. The proportion of ICM cells in blastocysts formed in vitro was in the normal range.

scholarly journals Distribution trends of some species of the Brassicaceae family in Latvia

Botanica ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 124-131
Author(s):  
Ieva Rūrāne ◽  
Pēteris Evarts-Bunders ◽  
Māris Nitcis
Keyword(s):  
Agricultural Land ◽  
Field Studies ◽  
Agricultural Crops ◽  
Bunias Orientalis ◽  
Time Period ◽  
Brassicaceae Species ◽  
Time Periods ◽  
Agricultural Land Management ◽  
Brassicaceae Family ◽  
Distribution Trends

Abstract Rūrāne I., Evarts-Bunders P., Nitcis M., 2018: Distribution trends of some species of the Brassicaceae family in Latvia. - Botanica, 24(2): 124-131. The aim of this paper was to clarify and analyse the distribution trends of some Brassicaceae species (Bunias orientalis, Sisymbrium volgense, Barbarea arcuata, Draba nemorosa and Camelina alyssum) in Latvia. Field studies and the herbarium material analyses were carried out. The distribution trends were analysed by comparing all selected species in three time periods: by 1940, from 1941 to 1990, and from 1991 to the present. The study shows that the distribution of Brassicaceae species such as Bunias orientalis, Sisymbrium volgense, Barbarea arcuata and Draba nemorosa has increased significantly in Latvia during the time period from 1991 to the present, and these species are mostly found on railway, ruderal areas and roadsides, which are important habitats for species distribution. The occurrence of Camelina alyssum has considerably declined or perhaps the species has even disappeared from the flora of Latvia, which has been affected greatly by changes in the cultivation of agricultural crops as well as in agricultural land management.

Exploring the Role of Project Management in the Development of the Academic Agile Software Discourse: A Bibliometric Analysis

2017 ◽  
Vol 48 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Thomas G. Lechler ◽  
Siwen Yang
Keyword(s):  
Project Management ◽  
Software Development ◽  
Bibliometric Analysis ◽  
Agile Methods ◽  
Management Research ◽  
Practical Applications ◽  
Time Period ◽  
Time Periods ◽  
Agile Software

The practical applications of agile methods and their impact on the productivity and efficiency of software development dominate the agile literature. We analyzed 827 academic articles with bibliometric techniques to explore the role project management research played in the development of the academic agile discourse. Bibliometric analyses over two time periods reveal that project management–related topics form a distinct stream of research in the second time period but not in the first. Furthermore, our results reveal that the academic agile discussion has been mainly unidirectional. This situation offers many opportunities for project management researchers to contribute to the agile discourse.

scholarly journals Survey of entomopathogenic nematodes and fungi in agricultural areas

2020 ◽  
Vol 56 (No. 3) ◽  
pp. 214-225
Author(s):  
Magdalena Dzięgielewska ◽  
Iwona Adamska
Keyword(s):  
Entomopathogenic Nematodes ◽  
Plant Protection ◽  
Abiotic Factors ◽  
Field Studies ◽  
Natural Resistance ◽  
Steinernema Feltiae ◽  
Practical Applications ◽  
Taxonomic Groups ◽  
The Right ◽  
Biological Methods

In 2016-2018, in north-western Poland, field studies were carried out on the coexistence of various taxonomic groups, such as soil nematodes and fungi, including beneficial species that comprise the environment’s natural resistance to pests in agrocenoses. The research aimed to find a connection between select biotic and abiotic factors in the chosen crops which could have practical applications in plant protection. Entomopathogenic nematodes Steinernema feltiae Filipiev, 1934 and entomopathogenic fungi Cordyceps fumosorosea and Metarhizium anisopliae (Metschn.) Sorokin were found to be present in all studied agrocenoses; however, they showed clear preferences for some types of crops or soil. The research shows that the effectiveness of the biological methods of plant protection depends on the selection of the right biopreparations, which strengthen the local populations of the beneficial organisms present in specific agriculture areas.

Implementation of FCAUP – a framework for conformity assessment inspired by the uncertainty principle

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Celso Francisco de Moraes ◽  
Messias Borges Silva ◽  
Rapinder Sawhney
Keyword(s):  
Uncertainty Principle ◽  
Quality Management System ◽  
Internal Audit ◽  
Field Studies ◽  
Manufacturing Industries ◽  
Conformity Assessment ◽  
Practical Application ◽  
Content Type ◽  
Practical Applications ◽  
Pilot Implementation

PurposeThe purpose of this paper is to report the first practical applications of FCAUP (Framework for Conformity Assessment inspired by the Uncertainty Principle) carried out using a pilot implementation in a boat trailer manufacturer company in Maryville, Tennessee, USA and a practical application in a metrology company in São José dos Campos, São Paulo, Brazil.Design/methodology/approachField studies have been conducted in two different companies: a pilot implementation during the preparation activities of the acceptance inspection of finished products and a practical application during the internal audit related to the quality management system.Findings(1) partial double inspection is advantageous in conformity assessment; (2) a structured procedure tends to reduce the risks arising from the use of partial double inspection; (3) the recommended amount of double inspections is directly proportional to the uncertainty involved in the process and it is inversely proportional to the degree of trust in a presumed conformity status.Research limitations/implicationsThis novel framework is for practitioners in manufacturing industries and test laboratories.Practical implicationsThe results of these practical applications suggest that FCAUP is a consistent approach to be used in several categories of conformity assessment in manufacturing industries and test laboratories due to the balance between result and time (cost).Originality/valueThis new framework, named FCAUP, for planning and executing conformity assessment activities has been introduced in a theoretical study published by Moraes and Silva (2018) and it is based on an analogy with the Uncertainty Principle of Quantum Mechanics.

scholarly journals Cytokinetic analysis of the impaired proliferative response of peripheral lymphocytes from aged humans to phytohemagglutinin.

1979 ◽  
Vol 149 (5) ◽  
pp. 1029-1041 ◽  
Author(s):  
R R Tice ◽  
E L Schneider ◽  
D Kram ◽  
P Thorne
Keyword(s):  
Cell Cycle ◽  
Staining Technique ◽  
Cell Entry ◽  
Differential Staining ◽  
Cycle Duration ◽  
Computer Simulation Model ◽  
Peripheral Lymphocytes ◽  
Lymphocyte Cultures ◽  
Aged Individual ◽  
Successive Generations

The effect of donor age on the rate of cell entry into the proliferating pool and subsequent cell cycle duration for peripheral lymphocytes stimulated by phytohemagglutinin (PHA) were examined by using the bromodeoxyuridine incorporation-differential staining technique. Distribution curves for the appearance of metaphase cells in successive generations as a function of culture time were obtained and analyzed both graphically and by a computer simulation model. Peripheral lymphocytes from aged individuals (approximately 75 yr) were stimulated by PHA at approximately one-half of the rate of peripheral lymphocytes from young individuals (approximately 21 yr). Subsequent cell-cycle durations were estimated to range from 10.0 to 25.0 h for aged individual lymphocyte cultures and 10.6-15.6 h for young individual lymphocyte cultures. The possible significance of these findings to aging in general is discussed.

Simplified filter paper method for determining the 15-atmosphere percentage of soils

1965 ◽  
Vol 5 (18) ◽  
pp. 201 ◽  
Author(s):  
OB Williams ◽  
RH Sedgley
Keyword(s):  
Filter Paper ◽  
Field Studies ◽  
Filter Paper Method ◽  
Simplified Method ◽  
Paper Method

A simplified filter paper method of determining the 15-atmosphere percentage in soils has been tested over a range of soil textures from sands to heavy clays. The regression of filter paper determinations against pressure membrane determinations of the 15-atmosphere percentage for the 34 soils gave the equation- y = 1.03x + 3.0 (r = 0.99 and P<0.001) where y = 15-atmosphere percentage (filter paper) x = 15-atmosphere percentage (pressure membrane). The results given by this simplified method indicate that it should be acceptable to agronomists and ecologists for field studies where facilities are limited.

scholarly journals Heat Stress After Pollination Reduces Kernel Number in Maize by Insufficient Assimilates

2021 ◽  
Vol 12 ◽  
Author(s):  
Shiduo Niu ◽  
Xiong Du ◽  
Dejie Wei ◽  
Shanshan Liu ◽  
Qian Tang ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Soluble Sugar ◽  
Pollen Grains ◽  
Field Studies ◽  
High Temperature Stress ◽  
Sequencing Analysis ◽  
Grain Number ◽  
Heat Resistant ◽  
Grain Starch

Global warming has increased the occurrence of high temperature stress in plants, including maize, resulting in decreased the grain number and yield. Previous studies indicate that heat stress mainly damages the pollen grains and thus lowered maize grain number. Other field studies have shown that heat stress after pollination results in kernel abortion. However, the mechanism by which high temperature affect grain abortion following pollination remains unclear. Hence, this study investigated the field grown heat-resistant maize variety “Zhengdan 958” (ZD958) and heat-sensitive variety “Xianyu 335” (XY335) under a seven-day heat stress treatment (HT) after pollination. Under HT, the grain numbers of XY335 and ZD958 were reduced by 10.9% (p = 0.006) and 5.3% (p = 0.129), respectively. The RNA sequencing analysis showed a higher number of differentially expressed genes (DEGs) between HT and the control in XY335 compared to ZD958. Ribulose diphosphate carboxylase (RuBPCase) genes were downregulated by heat stress, and RuBPCase activity was significantly lowered by 14.1% (p = 0.020) in XY335 and 5.3% (p = 0.436) in ZD958 in comparison to CK. The soluble sugar and starch contents in the grains of XY335 were obviously reduced by 26.1 and 58.5%, respectively, with no distinct change observed in ZD958. Heat stress also inhibited the synthesis of grain starch, as shown by the low activities of metabolism-related enzymes. Under HT, the expression of trehalose metabolism genes in XY335 were upregulated, and these genes may be involved in kernel abortion at high temperature. In conclusion, this study revealed that post-pollination heat stress in maize mainly resulted in reduced carbohydrate availability for grain development, though the heat-resistant ZD958 was nevertheless able to maintain growth.

scholarly journals Ecology of flowers and morphology of pollen grains of selected Narcissus varieties (Narcissus pseudonarcissus x Narcissus poëticus)

2012 ◽  
Vol 59 (1) ◽  
pp. 107-122 ◽  
Author(s):  
Mirosława Chwil
Keyword(s):  
Pollen Grains ◽  
Polar View ◽  
The Sun ◽  
Flowering Period ◽  
Large Fire ◽  
Anatomic Structure ◽  
Narcissus Poeticus ◽  
Narcissus Pseudonarcissus ◽  
Pollen Vitality ◽  
Scanning Electron

The investigations carried out in the years 2004-2005 covered five varieties of Narcissus (<i>Narcissus pseudonarcissus</i> L. x <i>Narcissus poëticus</i> L.): 'Fire Bird', 'Hardy', 'Ivory Yellow', 'Pomona' and 'The Sun'. Longevity of a flower and the flowering period of the studied Narcissus varieties determined, flower elements were compared, as well as the anatomic structure of ovary and nectary and the morphology of pollen grains. Pollen grains of 'Hardy' and 'The Sun' var. were observed in a scanning electron microscope. The flowering period of 'The Sun' plants appeared to be the longest, while the shortest in the case of 'Fire Bird' and 'Ivory Yellow'. Each perianth of the studied taxons was characterized by a different corolla appendage, from slightly corrugated ('Pomona') to greatly curled, with the notches getting inside and giving impression of a few whort in this part of the perianth ('Ivory Yellow', 'Hardy'). Monosulcate pollen grains with regards to 9 size was numbered among medium ('Pomona', 'The Sun') and large ('Fire Bird', 'Hardy', 'Ivory Yellow'). Their shape was assumed as circular elongated (<i>prolato-spheroides</i>) in polar view and flattened (<i>oblatum</i>) and slightly flat (<i>suboboblatum</i>) in equatorial view. The highest pollen vitality was shown by 'Hardy' variety (92%), whereas for 'The Sun' it proved to be the lowest (22%). In the narcissus flowers, septal nectaries are situated in the upper part of the ovary.

Virtual Reality Stereoscopic 180-Degree Video-Based Immersive Environments

2020 ◽  
pp. 92-119
Author(s):  
Maxime Ros ◽  
Lorraine Weaver ◽  
Lorenz S. Neuwirth
Keyword(s):  
Skill Acquisition ◽  
Mirror Neurons ◽  
Professional Training ◽  
Knowledge Retention ◽  
Medical Professional ◽  
Point Of View ◽  
Modern World ◽  
Academic Achievement Gap ◽  
Practical Applications ◽  
Time Period

The theoretical and practical applications of immersive VR, although relatively new, have accomplished much in the area of pedagogical learner applications. This chapter describes the conceptual framework and Revinax® 180-degree stereoscopic video-based approach in addressing the academic achievement gap through conventional surgical students and nurses shadowing and how immersive VR environments may best address leveraging the learner's capability of increasing their skill acquisition, learning, and knowledge retention in a more efficient time-period, circumventing the inherent issues with conventional shadowing. Further, these VR experiences through first-person Point of View (POV), although simulated and artificial, evoke mirror neurons, and can recruit neurocircuitry that are imperative for skill acquisition and later skill application. As such, the Revinax® instructional design model may provide a unique insight in how to use immersive VR environments to teach any learner that seeks to acquire surgical/medical professional training more efficiently and practically in a modern world of technology.

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