La política como encuentro y respons-habilidad. Aprender a conversar con los otros enigmáticos

Partint de la qüestió que planteja què podria ser la política del nou materialisme feminista, aquest article aborda les possibilitats derivades de (re-)conceptualitzar allò polític en termes d’encontres i involucrament (no principalment com a matèria d’elecció i decisió, sinó com «l’única manera d’imaginar-nos que podem sobreviure» (Bernice Johnson Reagon). En aquesta època de normes antropocèntriques hegemòniques d’allò polític (David Scott), veig importants contribucions de nous materialismes (feministes) en el desafiament de reconsiderar les nostres maneres de trobar-nos amb els Altres (humans i més que humans). «Altres» que, sense atenir-se necessàriament a les regles del joc, són tanmateix forces agentives. El reconeixement de la nostra dependència fonamental com a éssers vivents embullats en mons humans i més-que-humans proporciona motius ètics per a treballar en maneres de trobar «Altres» que accepten i fins i tot reben bé el fet que les nostres certituds no romandran estables en el procés. Proposo una lectura del replantejament antifundacionalista que fa Judith Butler de les nocions humanistes d’intencionalitat i agència política a través de la crítica, per part de Karen Barad, de la seva atribució del dinamisme i la historicitat de la matèria únicament a l’agència de la llengua o la cultura. Suggereixo que el replantejament de la subjectivitat política que fa Butler pugui ser reactivat i polit tenint en compte la crítica de Barad mitjançant una revisió de la reivindicació de Butler que la matèria és «un “això que” que provoca i causa». Sostinc que això confon tota distinció clara entre passivitat i activitat, i així es dóna lloc a una transformació de la nostra comprensió de la subjectivitat i l’agència en termes d’estar-amb i respondre a la manera d’abordar l’enigmàtic tema de l’altre (Basile).Starting from the question of what the politics of new feminist materialisms could be, this article addresses the possibilities of (re-)conceptualizing the political in terms of encounters and involvedness, but not foremost as a matter of choice and decision but as “the only way you can figure you can stay alive” (Reagon, 1983). In our times of hegemonic anthropocentric rule of the political (Scott, 1999), I see important contributions of new (feminist) materialisms to the challenge of reconsidering our modes of encountering “others” (human and more-than-human), who, without necessarily playing by the rules, are nevertheless agentive forces. Acknowledging our fundamental dependency as living beings enmeshed in human and more-than-human worlds provides ethical grounds for working on modes of encountering “others” that accept and even embrace the fact that our own certainties will not remain stable in the process. I propose a reading of Judith Butler’s anti-foundationalist rethinking of humanist notions of intentionality and political agency (2011) through Karen Barad’s critique of her attribution of matter’s dynamism and historicity solely to the agency of language or culture (2007). I suggest that Butler’s rethinking of political subjectivity can be re-invigorated and sharpened, in light of Barad’s critique (2007), by revisiting Butler’s claim that matter is “a ‘that which’ which prompts and occasions”. I argue that this confounds any clear distinction of passivity and activity, thereby enabling a transformation of our understanding of subjectivity and agency in terms of being-with and responding to the enigmatic address of the other (Basile, 2005).Partiendo de la pregunta de cuál podría ser la política de los nuevos materialismos feministas, este artículo contempla las posibilidades de (re)plantearla en términos de encuentros e implicación, de manera que ya no se basa en elegir y decidir, sino que es «el único modo en que crees que puedes seguir con vida» (Reagon, 1983). En nuestra época de dominio hegemónico antropocéntrico de lo político (Scott, 1999), veo aportaciones importantes de los nuevos materialismos (feministas) al desafío de replantearnos nuestros modos de relacionarnos con los «otros» (humanos y más que humanos), los cuales, sin necesariamente seguir las reglas, constituyen no obstante fuerzas agentivas. Reconocer nuestra dependencia fundamental como seres vivos enredados en mundos humanos y más que humanos ofrece la base ética para trabajar en modos de relacionarse con «otros» que aceptan e incluso adoptan el hecho de que nuestras certezas no permanecerán estables en tal proceso. Propongo interpretar el replanteamiento antifundacionalista que elabora Judith Butler (2011) de las nociones de intencionalidad y agencia política a través de la crítica de Karen Barad (2007), según la cual Butler solamente atribuye dinamismo e historicidad de la materia a la agencia del lenguaje o la cultura. Sugiero reanimar y perfilar el replanteamiento de la subjetividad política de Butler a través de la crítica de Barad (2007), cuando revisa la afirmación de Butler de que la materia es «aquello que  provoca y ocasiona». Argumento que esta afirmación  impide distinguir claramente entre pasividad y actividad, por lo que permite modificar nuestra comprensión de la subjetividad y agencia en términos de «estar con» y responder al tratamiento enigmático del otro (Basile, 2005)

Fibroblast-Derived Induced Pluripotent Stem Cells Show No Common Retroviral Vector Insertions

Several laboratories have reported the reprogramming of mouse and human fibroblasts into pluripotent cells, using retroviruses carrying the Oct4, Sox2, Klf4, and c-Myc transcription factor genes. In these experiments the frequency of reprogramming was lower than 0.1% of the infected cells, raising the possibility that additional events are required to induce reprogramming, such as activation of genes triggered by retroviral insertions. We have therefore determined by ligation-mediated polymerase chain reaction (LM-PCR) the retroviral insertion sites in six induced pluripotent stem (iPS) cell clones derived from mouse fibroblasts. Seventy-nine insertion sites were assigned to a single mouse genome location. Thirty-five of these mapped to gene transcription units, whereas 29 insertions landed within 10 kilobases of transcription start sites. No common insertion site was detected among the iPS clones studied. Moreover, bioinformatics analyses revealed no enrichment of a specific gene function, network, or pathway among genes targeted by retroviral insertions. We conclude that Oct4, Sox2, Klf4, and c-Myc are sufficient to promote fibroblast-to-iPS cell reprogramming and propose that the observed low reprogramming frequencies may have alternative explanations

Ecological State of the Kola River, Northwestern Russia : The Kola Water Quality -project

The Kola River is situated in Northwestern Russia, Kola Peninsula, which is an area with about 70 year long history of copper and nickel mining and smelting. However, environmental effects on the Kola River, caused by industry and other human activities, are not studied thoroughly. Area of the Kola River basin is 3850 km2. The river flows 83 km from south to north and enters the Kola Bay of the Barents Sea in front of the Kola City. The Kola River is vital for the reproduction of salmon and it is also an important source of drinking water for about half a million people in the city of Murmansk and in the surrounding settlements. In the Kola Water Quality -project in years 2001–2004 one the main objectives was to define the ecological status of the Kola River. The Näätämöjoki River in northern Finland and Norway was surveyed as a reference area. This publication includes ecological studies carried out by North Ostrobothnia Regional Environment Centre (NOREC, Finland) and The Murmansk Areal Department for Hydrometeorology and Environmental Monitoring (MUGMS, Russia). Chapters concerning macroinvertebrate studies were written by Kristian Meissner (NOREC/SYKE). Studies on macrozoobenthos after federal Russian hydrobiological monitoring methods are grouped in separate chapters and were reported by Sergey Kotov (MUGMS). Chapters concerning fish communities were written by Heikki Erkinaro (NOREC, Finnish Game and Fisheries Research Institute). Diatom community analyses were reported by Hanna Halmeenpää and Pirjo Niemelä (NOREC). Chapters concerning hydromorphological state of the river (River Habitat Survey) were written by Janne Alahuhta (NOREC) and chapters on macrophyte survey by Juha Riihimäki (Finnish Environment Institute). Studies on metal concentrations in aquatic bryophytes were reported by Hanna Halmeenpää (NOREC) and Kari-Matti Vuori (Finnish Environment Institute). Chapters concerning bacterioplankton and phytoplankton were written by Natalya Masuk (MUGMS), chapters on zooplankton by Natalya Dvornikova (MUGMS). Chapters concerning physical and chemical water quality of the rivers Kola and Näätämöjoki were written by Marina Zueva (MUGMS) and Hanna Halmeenpää (NOREC). Hanna Halmeenpää and Pirjo Niemelä (NOREC) took the responsibility of editing the report and writing of common chapters. On grounds of the ecological studies, the Kola River can be divided into three separate areas. At the upper river sections (K2-K3) the ecological status ranged from good to moderate. Signs on nutrient and metal (copper, nickel) loading could be detected both in water quality and in aquatic organisms. The ecological status of the mid-section (K4-K8) of the Kola River basin ranged from good to high. No major human impact could be seen. The estuary section (K9-K12) of the Kola River represented the moderate ecological status. This was probably caused by small, heavily polluted tributaries (Varlamov, Medvegiy and Zemlanoy) draining organic load and nutrient rich waters into main flow and also by other anthropogenic loading along the lower river section. The ecological status of the reference river Näätämöjoki was high on grounds of all the biological parameters used in this study

Promotion of Reprogramming to Ground State Pluripotency by Signal Inhibition

Induced pluripotent stem (iPS) cells are generated from somatic cells by genetic manipulation. Reprogramming entails multiple transgene integrations and occurs apparently stochastically in rare cells over many days. Tissue stem cells may be subject to less-stringent epigenetic restrictions than other cells and might therefore be more amenable to deprogramming. We report that brain-derived neural stem (NS) cells acquire undifferentiated morphology rapidly and at high frequency after a single round of transduction with reprogramming factors. However, critical attributes of true pluripotency—including stable expression of endogenous Oct4 and Nanog, epigenetic erasure of X chromosome silencing in female cells, and ability to colonise chimaeras—were not attained. We therefore applied molecularly defined conditions for the derivation and propagation of authentic pluripotent stem cells from embryos. We combined dual inhibition (2i) of mitogen-activated protein kinase signalling and glycogen synthase kinase-3 (GSK3) with the self-renewal cytokine leukaemia inhibitory factor (LIF). The 2i/LIF condition induced stable up-regulation of Oct4 and Nanog, reactivation of the X chromosome, transgene silencing, and competence for somatic and germline chimaerism. Using 2i /LIF, NS cell reprogramming required only 1–2 integrations of each transgene. Furthermore, transduction with Sox2 and c-Myc is dispensable, and Oct4 and Klf4 are sufficient to convert NS cells into chimaera-forming iPS cells. These findings demonstrate that somatic cell state influences requirements for reprogramming and delineate two phases in the process. The ability to capture pre-pluripotent cells that can advance to ground state pluripotency simply and with high efficiency opens a door to molecular dissection of this remarkable phenomenon

Low metabolic activity of biofilm formed by Enterococcus faecalis isolated from healthy humans and wild mallards (Anas platyrhynchos)

It is widely known that Enterococcus faecalis virulence is related to its biofilm formation. Although Enterococci are common commensal organisms of the gastrointestinal tract, the difference between commensal and pathogen strains remain unclear. In this study, we compare the biochemical profile of the biofilms formed by two groups of medical and two groups of commensal strains. The medical strains were isolated as pathogens from infections of urinary tract and other infections (wounds, pus and bedsores), and the commensal strains were taken from faeces of healthy volunteers and faeces of wild mallards (Anas platyrhynchos) living in an urban environment. The properties of biofilms formed by medical and commensal strains differed significantly. Commensal strains showed lower metabolic activity and glucose uptake and higher biofilm biomass than the medical ones. Consistent with glucose uptake experiments, we found that the glucose dehydrogenase gene was more expressed in medical strains. These results indicate that higher metabolic activity and lower protein concentration of E. faecalis cells within biofilms are formed during infections.This work was supported by the Medical University of Gdansk research grant (GUMed W-65) and was financed partly by University of Gdansk research grant (BW 1440-5-0099-7). We are grateful to Katarzyna Zolkos for her help in catching mallards and Magdalena Remisiewicz for correcting the English. Catarina Seabra helped in preparing assays

Dynamic single cell imaging of direct reprogramming reveals an early specifying event

available in PMC 2010 November 1.The study of induced pluripotency often relies on experimental approaches that average measurements across a large population of cells, the majority of which do not become pluripotent. Here we used high-resolution, time-lapse imaging to trace the reprogramming process over 2 weeks from single mouse embryonic fibroblasts (MEFs) to pluripotency factor–positive colonies. This enabled us to calculate a normalized cell-of-origin reprogramming efficiency that takes into account only the initial MEFs that respond to form reprogrammed colonies rather than the larger number of final colonies. Furthermore, this retrospective analysis revealed that successfully reprogramming cells undergo a rapid shift in their proliferative rate that coincides with a reduction in cellular area. This event occurs as early as the first cell division and with similar kinetics in all cells that form induced pluripotent stem (iPS) cell colonies. These data contribute to the theoretical modeling of reprogramming and suggest that certain parts of the reprogramming process follow defined rather than stochastic steps.Burroughs Wellcome Fund (Career Award at the Scientific Interface)Pew Charitable TrustsMassachusetts Life Sciences Center (New Investigator grant)Broad Institute (Investigator of the Merkin Foundation for Stem Cell Research)Howard Hughes Medical Institute (Early Career Scientist)Alfred P. Sloan FoundationNational Institutes of Health (U.S.) (Pioneer Award

Small RNA-mediated regulation of iPS cell generation

The generation of induced pluripotent stem cells is limited by the low reprogramming efficiency of somatic cells. Here, three clusters of miRNAs are shown to enhance reprogramming efficiency by targeting the TGF-β and p53 pathways, which inhibit the process

Nuclear Reprogramming Strategy Modulates Differentiation Potential of Induced Pluripotent Stem Cells

Bioengineered by ectopic expression of stemness factors, induced pluripotent stem (iPS) cells demonstrate embryonic stem cell-like properties and offer a unique platform for derivation of autologous pluripotent cells from somatic tissue sources. In the process of nuclear reprogramming, somatic tissues are converted to a pluripotent ground state, thus unlocking an unlimited potential to expand progenitor pools. Molecular dissection of nuclear reprogramming suggests that a residual memory derived from the original parental source, along with the remnants of the reprogramming process itself, leads to a biased potential of the bioengineered progeny to differentiate into target tissues such as cardiac cytotypes. In this way, iPS cells that fulfill pluripotency criteria may display heterogeneous profiles for lineage specification. Small molecule-based strategies have been identified that modulate the epigenetic state of reprogrammed cells and are optimized to erase the residual memory and homogenize the differentiation potential of iPS cells derived from distinct backgrounds. Here, we describe the salient components of the reprogramming process and their effect on the downstream differentiation capacity of the iPS populations in the context of cardiovascular regenerative applications

Pre-B cell to macrophage transdifferentiation without significant promoter DNA methylation changes

Transcription factor-induced lineage reprogramming or transdifferentiation experiments are essential for understanding the plasticity of differentiated cells. These experiments helped to define the specific role of transcription factors in conferring cell identity and played a key role in the development of the regenerative medicine field. We here investigated the acquisition of DNA methylation changes during C/EBPα-induced pre-B cell to macrophage transdifferentiation. Unexpectedly, cell lineage conversion occurred without significant changes in DNA methylation not only in key B cell- and macrophage-specific genes but also throughout the entire set of genes differentially methylated between the two parental cell types. In contrast, active and repressive histone modification marks changed according to the expression levels of these genes. We also demonstrated that C/EBPα and RNA Pol II are associated with the methylated promoters of macrophage-specific genes in reprogrammed macrophages without inducing methylation changes. Our findings not only provide insights about the extent and hierarchy of epigenetic events in pre-B cell to macrophage transdifferentiation but also show an important difference to reprogramming towards pluripotency where promoter DNA demethylation plays a pivotal role