Propanediol alters intracellular pH and developmental potential of mouse zygotes independently of volume change

1990 ◽  
Vol 5 (2) ◽  
pp. 212-216 ◽  
Author(s):  
M. Damien ◽  
A.A. Luciano ◽  
J.J. Peluso
Author(s):  
Hilton H. Mollenhauer

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.


2008 ◽  
Vol 45 ◽  
pp. 147-160 ◽  
Author(s):  
Jörg Schaber ◽  
Edda Klipp

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.


Author(s):  
Matthew L. Hall ◽  
Stephanie De Anda

Purpose The purposes of this study were (a) to introduce “language access profiles” as a viable alternative construct to “communication mode” for describing experience with language input during early childhood for deaf and hard-of-hearing (DHH) children; (b) to describe the development of a new tool for measuring DHH children's language access profiles during infancy and toddlerhood; and (c) to evaluate the novelty, reliability, and validity of this tool. Method We adapted an existing retrospective parent report measure of early language experience (the Language Exposure Assessment Tool) to make it suitable for use with DHH populations. We administered the adapted instrument (DHH Language Exposure Assessment Tool [D-LEAT]) to the caregivers of 105 DHH children aged 12 years and younger. To measure convergent validity, we also administered another novel instrument: the Language Access Profile Tool. To measure test–retest reliability, half of the participants were interviewed again after 1 month. We identified groups of children with similar language access profiles by using hierarchical cluster analysis. Results The D-LEAT revealed DHH children's diverse experiences with access to language during infancy and toddlerhood. Cluster analysis groupings were markedly different from those derived from more traditional grouping rules (e.g., communication modes). Test–retest reliability was good, especially for the same-interviewer condition. Content, convergent, and face validity were strong. Conclusions To optimize DHH children's developmental potential, stakeholders who work at the individual and population levels would benefit from replacing communication mode with language access profiles. The D-LEAT is the first tool that aims to measure this novel construct. Despite limitations that future work aims to address, the present results demonstrate that the D-LEAT represents progress over the status quo.


1980 ◽  
Vol 41 (C8) ◽  
pp. C8-875-C8-877
Author(s):  
E. Girt ◽  
P. Tomić ◽  
A. Kuršumović ◽  
T. Mihać-Kosanović

1970 ◽  
Vol 8 (1) ◽  
pp. 103-109
Author(s):  
Галина Радчук

Статтю  присвячено  проблемі  теоретичного  обґрунтування  діалогу  як  механізму  аксіогенезу  особистості в освітньому процесі та виокремлення сутнісних аспектів діалогізації освітнього середовища  вищої школи. Обґрунтовано, що провідними цілями сучасної вищої освіти в контексті її гуманітаризації є  загальнокультурні орієнтири, які дозволяють замінити власне  когнітивний  підхід на смислотворчий, де і  викладач, і студент є активними суб’єктами освітнього діалогу. Показано, що освітній діалог виступає  зовнішньою   спонукою   внутрішнього   ініціювання   особистісно-професійного   становлення   майбутнього  фахівця,  становлення  його  ціннісно-смислової  сфери,  а  рівень  діалогізації  освітнього  середовища  може  слугувати  мірилом  реалізації  особистісно-розвивального  потенціалу  освіти.  На  підставі  емпіричного  дослідження   визначено,  що  у   реальному   освітньому   процесі  найбільшою   перешкодою  у   діалогізації  освітнього   середовища   є      догматичність,   формалізованість   освітнього   процесу   та   закритість,  стереотипність рольової поведінки викладачів та студентів.  The  article  is  focused  on  theoretical  argumentation  of the  dialogue  as  a  mechanism  for  personality  axiogenesis in  educational process and separation of essential dialogue aspects in higher educational environment.  The author argues that general cultural orientations are main goals of modern higher education in the context of its  humanization. This allows to replace the actual cognitive approach with sense creation one, where both teacher and  student are active subjects of educational dialogue. It is shown that educational dialogue is an external stimulus of  internal initiation of personal and professional formation in future specialists, as well as formation of their value- semantic sphere. The level of dialogue in educational environment can serve as a measure of implementation of  personality and developmental potential in education. On the basis of empirical research it is determined that  dogmatism,  formalization  of  educational  process,  and  closeness,  stereotyped  role  of  teachers’  and  students’  behavior  are  the  greatest  obstacles  for  educational  environment  becoming  more  dialogue  driven  in  real-life  educational process.


PCI Journal ◽  
2009 ◽  
Vol 54 (4) ◽  
pp. 112-131 ◽  
Author(s):  
Gary J. Klein ◽  
Richard E. Lindenberg

Diabetes ◽  
1995 ◽  
Vol 44 (2) ◽  
pp. 196-202 ◽  
Author(s):  
N. Khandoudi ◽  
M. Bernard ◽  
P. Cozzone ◽  
D. Feuvray

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