Activity-dependent regulation of synaptic clustering in a hippocampal culture system

Currently, there is a limited understanding of the factors that influence the localization and density of individual synapses in the central nervous system. Here we have studied the effects of activity on synapse formation between hippocampal dentate granule cells and CA3 pyramidal neurons in culture, taking advantage of FM1–43 as a fluorescent marker of synaptic boutons. We observed an early tendency for synapses to group together, quickly followed by the appearance of synaptic clusters on dendritic processes. These events were strongly influenced by N-methyl-d-aspartic acid receptor- and cyclic AMP-dependent signaling. The microstructure and localization of the synaptic clusters resembled that found in hippocampus, at mossy fiber synapses of stratum lucidum. Activity-dependent clustering of synapses represents a means for synaptic targeting that might contribute to synaptic organization in the brain.

Amino-terminal Polypeptides of Vimentin Are Responsible for the Changes in Nuclear Architecture Associated with Human Immunodeficiency Virus Type 1 Protease Activity in Tissue Culture Cells

Electron microscopy of human skin fibroblasts syringe-loaded with human immunodeficiency virus type 1 protease (HIV-1 PR) revealed several effects on nuclear architecture. The most dramatic is a change from a spherical nuclear morphology to one with multiple lobes or deep invaginations. The nuclear matrix collapses or remains only as a peripheral rudiment, with individual elements thicker than in control cells. Chromatin organization and distribution is also perturbed. Attempts to identify a major nuclear protein whose cleavage by the protease might be responsible for these alterations were unsuccessful. Similar changes were observed in SW 13 T3 M [vimentin+] cells, whereas no changes were observed in SW 13 [vimentin−] cells after microinjection of protease. Treatment of SW 13 [vimentin−] cells, preinjected with vimentin to establish an intermediate filament network, with HIV-1 PR resulted in alterations in chromatin staining and distribution, but not in nuclear shape. These same changes were produced in SW 13 [vimentin−] cells after the injection of a mixture of vimentin peptides, produced by the cleavage of vimentin to completion by HIV-1 PR in vitro. Similar experiments with 16 purified peptides derived from wild-type or mutant vimentin proteins and five synthetic peptides demonstrated that exclusively N-terminal peptides were capable of altering chromatin distribution. Furthermore, two separate regions of the N-terminal head domain are primarily responsible for perturbing nuclear architecture. The ability of HIV-1 to affect nuclear organization via the liberation of vimentin peptides may play an important role in HIV-1-associated cytopathogenesis and carcinogenesis.

Suppression of apoptosis by basement membrane requires three-dimensional tissue organization and withdrawal from the cell cycle.

The basement membrane (BM) extracellular matrix induces differentiation and suppresses apoptosis in mammary epithelial cells, whereas cells lacking BM lose their differentiated phenotype and undergo apoptosis. Addition of purified BM components, which are known to induce beta-casein expression, did not prevent apoptosis, indicating that a more complex BM was necessary. A comparison of culture conditions where apoptosis would or would not occur allowed us to relate inhibition of apoptosis to a complete withdrawal from the cell cycle, which was observed only when cells acquired a three-dimensional alveolar structure in response to BM. In the absence of this morphology, both the GI cyclin kinase inhibitor p21/WAF-1 and positive proliferative signals including c-myc and cyclin DI were expressed and the retinoblastoma protein (Rb) continued to be hyperphosphorylated. When we overexpressed either c-myc in quiescent cells or p21 when cells were still cycling, apoptosis was induced. In the absence of three-dimensional alveolar structures, mammary epithelial cells secrete a number of factors including transforming growth factor alpha and tenascin, which when added exogenously to quiescent cells induced expression of c-myc and interleukin-beta1-converting enzyme (ICE) mRNA and led to apoptosis. These experiments demonstrate that a correct tissue architecture is crucial for long-range homeostasis, suppression of apoptosis, and maintenance of differentiated phenotype.

Suppression of synapsin II inhibits the formation and maintenance of synapses in hippocampal culture.

Numerous synaptic proteins, including several integral membrane proteins, have been assigned roles in synaptic vesicle fusion with or retrieval from the presynaptic plasma membrane. In contrast, the synapsins, neuron-specific phosphoproteins associated with the cytoplasmic surface of synaptic vesicles, appear to play a much broader role, being involved in the regulation of neurotransmitter release and in the organization of the nerve terminal. Here we have administered antisense synapsin II oligonucleotides to dissociated hippocampal neurons, either before the onset of synaptogenesis or 1 week after the onset of synaptogenesis. In both cases, synapsin II was no longer detectable within 24-48 h of treatment. After 5 days of treatment, cultures were analyzed for the presence of synapses by synapsin I and synaptophysin antibody labeling and by electron microscopy. Cultures in which synapsin II was suppressed after axon elongation, but before synapse formation, did not develop synapses. Cultures in which synapsin II was suppressed after the development of synapses lost most of their synapses. Remarkably, with the removal of the antisense oligonucleotides, neurons and their synaptic connections recovered. These studies lead us to conclude that synapsin II is involved in the formation and maintenance of synapses in hippocampal neurons.

Digital Fabrication and Free Culture. One More Minor Becoming?

Diferentes autores se refieren a la fabricación digital como la Tercera Revolución Digital, después de las revoluciones de la computación y la comunicación. Como ocurriera con las dos revoluciones precedentes, se generaron grandes expectativas en torno a las virtualidades políticas de estas nuevas tecnologías para dar lugar a relaciones de producción más libres e individuos más autónomos. Sin embargo, como también ocurriera con la computación y la comunicación, lo que realmente está ocurriendo demuestra que las supuestas virtualidades no llegarán a hacerse actuales sin una intensa implicación, organización y trabajo por parte de sectores activistas técnicos y sociales. Se discute el caso de la compra corporativa de la empresa pionera de hardware libre Makerbot, como ejemplo de la situación y punto de inflexión en las expectativas de los nuevos tecno-visionarios. Para concluir se propone una serie de posibles estrategias que podrían promover el desarrollo efectivo de un ecosistema libre y open source de fabricación digital.

A treatise containing a plan for the internal organization and government of marine hospitals in the United States: together with a scheme for amending and systematizing the medical department of the navy.

Microfilm. Ann Arbor, Mich., University Microfilms [n.d.] (American culture series, Reel 116.5)

Lessons Learned From Loko I‘a Culture: How Hawaiian Ecological Knowledge Influences Environmental Policies

Thesis (Master's)--University of Washington, 2016-06

Presence of a novel small RNA-containing virus in a laboratory culture of the endoparasitic wasp Venturia canescens (Hymenoptera : Ichneumonidae)

Parasitoid wasps use a variety of mechanisms to alter their host's physiology to the benefit of the developing endoparasite inside the host larva. Association of certain wasps with viruses and virus-like particles (VLPs) that contribute to their success in parasitism is one of the fascinating evolutionary adaptations conferring active or passive protection for the endoparasite from the host immune system. Venturia canescens has been shown to produce VLPs that provide protection for the developing parasitoid egg inside the host, Ephestia kuehniella. Here, we report on the presence of a novel small RNA-containing virus from V. canescens, designated as VcSRV, occurring in the ovaries of the wasp. The virus particles are found together with VcVLPs in the lumen of the calyx region of the ovaries and are injected together with the egg and VcVLPs into E kuehniella larvae where they enter hemocytes. Alignment of the RNA-dependent RNA polymerase gene of VcSRV indicates that the virus most likely belongs to the recently described genus Iflavirus. (c) 2004 Elsevier Ltd. All rights reserved.

The impact of leadership and change management strategy on organizational culture and individual acceptance of change during a merger

This article reports a longitudinal study that examined mergers between three large multi-site public-sector organizations. Both qualitative and quantitative methods of analysis are used to examine the effect of leadership and change management strategies on acceptance of cultural change by individuals. Findings indicate that in many cases the change that occurs as a result of a merger is imposed on the leaders themselves, and it is often the pace of change that inhibits the successful re-engineering of the culture. In this respect, the success or otherwise of any merger hinges on individual perceptions about the manner in which the process is handled and the direction in which the culture is moved. Communication and a transparent change process are important, as this will often determine not only how a leader will be regarded, but who will be regarded as a leader. Leaders need to be competent and trained in the process of transforming organizations to ensure that individuals within the organization accept the changes prompted by a merger.

Through the lenses of organizational culture: A comparison of state-owned enterprises and joint ventures in China

This study compared state-owned enterprises (SOEs) and joint ventures (JVs) in light of organizational culture practices. Data were obtained via a survey participated by 781 respondents from five enterprises. Factoring identified four cultural dimensions: Participation, Teamwork, Supervision, and Meetings. All four dimensions, except Participation, were rated significantly higher by respondents from SOEs as compared to the ratings in JVs. Based on the findings, this study concluded that culture practices valued in one type of enterprise might be liability in another. The implication for management is to gear culture practices to the characteristics of the organization to make it successful.

The influence of national culture on the level and outcome of IS decision making in the IS maintenance/redevelopment decision

Would the outcome of a Global multinational organization’s decision be the same if the same decision were to be made in different countries throughout the world? Within the same organization, we propose that national cultural differences can influence decision making in different countries and cultural clusters. While much work has been done on organizational cultural influences, this study examines the influence that national culture has on organizational decision making in respect to the evolution/redevelopment decision that organizations face when a system is believed to be entering the obsolescence phase. Building on findings from the Globe research program, we show by empirical testing of a theoretical model that national cultural dimensions are significantly associated with a) the outcome of the decision to enhance or re-develop a system, and b) the organizational level at which such decisions are made. This research is significant as a means to improve management decision making, particularly with regard to the enhancement versus re-development decision. The research suggests that a relatively uniform sub-culture exists across the global IS project level but that national cultural dimensions play a more important role in determining the organizational management level at which decisions are made.

The Principles of Creation of Teaching Materials and Organization of Ukrainian Language Learning Process using Distance Support in Senior Classes

The article deals with the topicality and problems of using information and communication technologies in secondary education, conditions and methods for Ukrainian language learning with the distance support in senior classes. The article shows the principal similarity of distance learning to training one. The common and specific principles of creation of teaching materials for a distance learning course are described. It reveals the conditions of effective organization of Ukrainian language learning with distance support on the material of distance course “Business Ukrainian and Culture of Communication”.

Person-organization fit and incentives:a causal test

We investigate the effects of organizational culture and personal values on performance under individual and team contest incentives. We develop a model of regard for others and in-group favoritism that predicts interaction effects between organizational values and personal values in contest games. These predictions are tested in a computerized lab experiment with exogenous control of both organizational values and incentives. In line with our theoretical model we find that prosocial (proself) orientated subjects exert more (less) effort in team contests in the primed prosocial organizational values condition, relative to the neutrally primed baseline condition. Further, when the prosocial organizational values are combined with individual contest incentives, prosocial subjects no longer outperform their proself counterparts. These findings provide a first, affirmative, causal test of person-organization fit theory. They also suggest the importance of a 'triple-fit' between personal preferences, organizational values and incentive mechanisms for prosocially orientated individuals.

Megfelelő kultúra = kiváló teljesítmény? (Appropriate culture = excellent performance?)

A szervezeti kultúra meghatározza azokat az alapvető értékeket, feltételezéseket, értelmezéseket és megközelítéseket, amelyek a szervezetet jellemzik. A definíciók sokszínűsége is bizonyítja, hogy a szervezeti kultúrában kifejeződik mindaz, amitől a szervezet egyedi. A vállalat teljesítményét számos tényező befolyásolja, ezek lehetnek külső, a vállalkozás által nagyrészt befolyásolhatatlan tényezők, de lehetnek belső, a vállalkozás által jelentősen befolyásolható tényezők. A kihívásokra adott egyedi, szervezetenként eltérő válaszok a vállalatok eltérő stratégiáiban, szervezeti felépítéseiben és szervezeti kultúráiban – mint a vállalat által befolyásolható tényezőkben – fejeződnek ki. A szerzők dolgozatukban egy empirikus kutatás eredményeinek egy részét mutatják be, amely az említett tényezők és a vállalati teljesítmény összefüggéseit tárja fel. Jelen tanulmány a vállalati teljesítmény és a szervezeti kultúra közti kapcsolatokat vizsgálja. A cikk elemzi, hogy melyek lehetnek azok a kulturális jellemzők, amelyek elősegíthetik a vállalati teljesítmény növelését. _________ The organizational culture determines the fundamental values, assumptions, interpretations and approaches which characterize the organization. The variability of definitions evidences that everything is expressed in organizational culture that makes organization specific. Corporate performance is influenced by numerous factors, these can be external ones not to be influenced by the company, and internal ones, being influenced by the company. The individual answers to challenges are expressed in different strategies, organizational structures and culture of companies as factors to be influenced by the companies. Authors present one part of the results of an empirical research, exploring connections between the mentioned factors and organizational cultures. The article analyses which cultural characteristics can enhance corporate performance.

Vágyott kultúra és reális értékítélet - Tudásmenedzsment-rendszer kiépítésének előfeltétele egy felsőoktatási intézményben (Desired culture and real value judgement – Precondition of development a knowledge management system in a higher education institution)

A tudásmenedzsment-rendszerek kiépítése és működtetése egyre népszerűbb vállalati cél. A legnagyobb igyekezet ellenére is kudarccal végződhet egy ilyen változás megvalósítása, ha a szükséges feltételek nélkül próbálkozunk ezzel a beavatkozással a szervezet életében. Az egyik legfontosabb előfeltétel a bizalomra, közös tanulásra, fejlődésre épülő, nyitott szervezeti kultúra, mely a tanulószervezeti jellemzőkkel írható le. A szerzők kutatásukban arra voltak kíváncsiak, milyen elképzeléseik, vágyaik vannak a felsőoktatásban oktató kollégáknak az ideálisnak nevezett szervezeti kultúráról. Ezeket az elképzeléseket egy külső tanácsadó cég által végzett kérdőíves felmérésen alapuló vizsgálat segítségével tudták meg, melynek kiértékelésére a circumplex-módszer szolgált. Az eredményeket összevetették a tanulószervezeti jellemzőkkel, vizsgálva azt a hipotézist, miszerint az oktató kollégák tudat alatt is olyan ideális szervezetet képzelnek el, mely a tanulószervezeti kultúra jellemzőivel azonos. _________ To create and to operate a knowledge management system is becoming a more and more popular target of the companies. Realizing the changes above can result in a failure – in spite of the biggest will – if organizations lack certain prerequisites which are necessary in companies’ lives. One of the most important prerequisites is organizational culture which can be characterized by confidence, common learning, development and open atmosphere. This is called a learning organizational culture. In their research the authors would have liked to know what kind of dreams the colleagues have about their own organizational culture. They achieve these results from an investigation with questionnaires which were realized by an advisory team. To evaluating the results of this investigation circumplex method was used. These results were compared with the characteristics of learning organization to confirm our hypothesis. According to this idea colleagues have the same images about their successful organization as the characteristics of learning organizations.