Improved method for ex ovo-cultivation of developing chicken embryos for human stem cell xenografts

The characterization of human stem cells for the usability in regenerative medicine is particularly based on investigations regarding their differentiation potential in vivo. In this regard, the chicken embryo model represents an ideal model organism. However, the access to the chicken embryo is only achievable by windowing the eggshell resulting in limited visibility and accessibility in subsequent experiments. On the contrary, ex ovo-culture systems avoid such negative side effects. Here, we present an improved ex ovo-cultivation method enabling the embryos to survive 13 days in vitro. Optimized cultivation of chicken embryos resulted in a normal development regarding their size and weight. Our ex ovo-approach closely resembles the development of chicken embryos in ovo, as demonstrated by properly developed nervous system, bones, and cartilage at expected time points. Finally, we investigated the usability of our method for trans-species transplantation of adult stem cells by injecting human neural crest-derived stem cells into late Hamburger and Hamilton stages (HH26-HH28/E5-E6) of ex ovo-incubated embryos. We demonstrated the integration of human cells allowing experimentally easy investigation of the differentiation potential in the proper developmental context. Taken together, this ex ovo-method supports the prolonged cultivation of properly developing chicken embryos enabling integration studies of xenografted mammalian stem cells at late developmental stages.

Prolonged cultivation of hippocampal neural precursor cells shifts their differentiation potential and selects for aneuploid cells

Neural precursor cells (NPCs) are lineage-restricted neural stem cells with limited self-renewal, giving rise to a broad range of neural cell types such as neurons, astrocytes, and oligodendrocytes. Despite this developmental potential, the differentiation capacity of NPCs has been controversially discussed concerning the trespassing lineage boundaries, for instance resulting in hematopoietic competence. Assessing their in vitro plasticity, we isolated nestin+/Sox2+, NPCs from the adult murine hippocampus. In vitro-expanded adult NPCs were able to form neurospheres, self-renew, and differentiate into neuronal, astrocytic, and oligodendrocytic cells. Although NPCs cultivated in early passage efficiently gave rise to neuronal cells in a directed differentiation assay, extensively cultivated NPCs revealed reduced potential for ectodermal differentiation. We further observed successful differentiation of long-term cultured NPCs into osteogenic and adipogenic cell types, suggesting that NPCs underwent a fate switch during culture. NPCs cultivated for more than 12 passages were aneuploid (abnormal chromosome numbers such as 70 chromosomes). Furthermore, they showed growth factor-independent proliferation, a hallmark of tumorigenic transformation. In conclusion, our findings substantiate the lineage restriction of NPCs from adult mammalian hippocampus. Prolonged cultivation results, however, in enhanced differentiation potential, which may be attributed to transformation events leading to aneuploid cells.

Occurrence and characterization of injuries caused by Mycotretus apicalis Lacordaire, 1842 (Coleoptera: Erotylidae) on cultivation of Pleurotus sajor-caju

When carrying out experiments on the production of the edible mushroom Pleurotus sajor-caju in the Laboratory of Edible Mushrooms, Universidade Federal de Lavras, Lavras, Brazil, in the second half of 2007, the presence of beetles later identified as belonging to the species Mycotretus apicalis was verified. This is the first recorded instance of this insect in cultures of P. sajor-caju in Brazil. The larvae and adults of this insect feed on the fruiting bodies of commercial harvests, resulting in reduction in mushroom quality. To provide evaluation of the injuries caused by these insects, substrates colonized by P. sajor-caju were infested with 4, 8, 16, 32 and 64 insects per block of substrate being the qualitative and quantitative losses then noted. Despite the lack of an observed decrease in biological efficiency, the injuries caused by these insects affected the commercial quality of the mushrooms, which may result in economic losses. The results showed that infestations of 32 insects per 0.8 kg of substrate led to a depreciation in the prices of mushrooms meant to be sold.

Outdoor performance of forest seedlings pre-cultivated under artificial lights : effects of the light spectra used for pre-cultivation on the future establishment and development

Forest nurseries are essential for producing good quality seedlings, thus being a key element in the reforestation process. With increasing climate change awareness, nursery managers are looking for new tools that can help reduce the effects of their operations on the environment. The ZEPHYR project, funded by the European Commission under the Seventh Framework Programme (FP7), has the objective of finding new alternatives for nurseries by developing innovative zero-impact technologies for forest plant production. Due to their direct relationship to the energy consumption of the nurseries, one of the main elements addressed are the grow lights used for the pre-cultivation. New LED luminaires with a light spectrum tailored to the seedlings’ needs are being studied and compared against the traditional fluorescent lamps. Seedlings of Picea abies and Pinus sylvestris were grown under five different light spectra (one fluorescent and 4 LED) during 5 weeks with a photoperiod of 16 hours at 100 μmol∙m-2∙s-1 and 60% humidity. In order to evaluate if these seedlings were able cope with real field stress conditions, a forest field trial was also designed. The terrain chosen was a typical planting site in mid-Sweden after clear-cutting. Two vegetation periods after the outplanting, the seedlings that were pre-cultivated under the LED lamps have performed at least as well as those that were grown under fluorescent lights. These results show that there is a good  potential for lightning substitution in forestry nurseries.

Imagery cultivation vs. noise reduction : shamanic-like journeying as a psi-conducive alternative to the Ganzfeld protocol

Historically, psi effects have been linked to altered states of consciousness (ASCs; Bem and Honorton, 1994). In this context, arguably the most widely used technique is the Ganzfeld. However, in recent times, scholars (e.g., Alvarado, 1998; Braud, 2005; Scimeca, Boca, and Iannuzzo, 2001) have formulated cogent arguments that cast doubt on whether the Ganzfeld is, in fact, an ASC that is psi-conducive. Consequently, it may prove prudent to investigate other conditions that induce ostensible ASCs that are purportedly psi-conducive, and it would be wise to get feedback from test participants in these states. In this theoretical paper, we propose that psi effects may be enhanced (i.e., strengthened) using a shamanic-like treatment. On that basis, we argue that parapsychologists must go beyond the assumption that psi effects are optimised under conditions that are inherently passive procedures, and foster techniques that require cognitive action from test participants.

Perfecting nature : Friedrich Nietzsche's ideal and politics of cultivation

What I have called the Ideal of Cultivation is a fundamental ethical principle of civilisation, originated by aristocratic warriors in Greek antiquity who held that the true purpose of humanity is to perfect nature

It was then professed that individuals and even entire peoples could consciously develop and improve themselves in a way that was thought to obey the original lawful impulses of nature, a process which was likened to those of agriculture and animal husbandry.

Subsequently the cognate idea of a politics of cultivation arose which deemed that society should be organised specifically to produce more virtuous or perfect human types. Given their fundamental association with Hellenism both ideas have been revisited constantly in the intellectual history of the west, and most notably during the great secular periods, the Renaissance and Enlightenment when active attempts were made to retrieve the ideals of antiquity. Both ideas were particularly pervasive in the German enlightenment, the Aufklärung, and were assimilated by the succeeding Romantic generation.

In nineteenth century Germany, when interest in these ideas was quickly waning, the German philosopher Friedrich Nietzsche acquired an unswerving attachment to them and made the service of them his life's work.

The intention of this essay is to trace methodically the appearance of the Ideal of Cultivation in Nietzsche's philosophy and politics, and to outline his responses to a world which was abandoning the principles in which he deeply believed. This essay should be regarded as a case study in the long history of a fundamental ethical idea rather than one about the philosopher Nietzsche.

The mutual cultivation of subject and object in architecture

The relationship of the migrant figure and the house has been explored in previous research on the migrant house. In addition, the relationship between the migrant house and 1ts perception and representation within the local and national communities within the immigrant-receiving city has been analyzed. The approach and theoretical frameworks for this research involved an understanding of the relationship between the human subject and the object of architecture. Given that much poststructuralist theory has attended to the rethinking of human subjectivity and to rethinking the humanbody, traditional conceptualizations of the relationship between human subject and Object m architecture also need to be re-examined. This paper thus presents an exammatlon of one approach to this relationship, focusing on the exploratory and creative work of the late John Hejduk. Hejduk's Vladivostok presents an assembly of figure-objects that together are a literary metaphor for both society and the city. The paper Will argue that the human subject is imagined within an already ordered architectural sett1ng, and that the human subject cannot be thought prior to and outside the stage of architecture. Rather than searching for a causal or determining relat1onsh1p between subject and object this conceptual underpinning between the subject and object asks for an understanding of the dynamic and animated cultivation between them. In examining Hejduk's entry on the 'subjecUobject' in Vladivostok, the paper Will present an account of the mutual responsiveness that arises between human beings and architecture. It will argue that culture and subjectivity is internal rather than external or marginal to architecture.

Substrate Preparation Behaviors for the Cultivation of the Symbiotic Fungus in Leaf-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae)

Our findings revealed two distinct patterns of substrate preparation: the pattern of leaf-cutting ants foraging on dicotyledons is marked by highly fragmented substrate resulting in a more advanced initial decomposition. The pattern of leaf-cutting ants harvesting grasses is characterized by large pieces of substrate, resulting in little initial decomposition. Ants foraging on both types of plants are apparently intermediary between the two patterns, although more similar to the patterns of those foraging on dicotyledons. Also, the behavior of scraping the substrate was described for the first time, it is very important for the removal of the epicuticular wax layer of the leaves helping the growth of the symbiotic fungus.