Do seismic waves and fluid flow sense the same permeability?

We study the discrepancy between the effective flow permeability and the effective seismic permeability, that is, the effective permeability controlling seismic attenuation due to wave-induced fluid flow, in 2D rock samples having mesoscopic heterogeneities and in the presence of strong permeability fluctuations. In order to do so, we employ a numerical oscillatory compressibility test to determine attenuation and velocity dispersion due to wave-induced fluid flow in these kinds of media and compare the responses with those obtained by replacing the heterogeneous permeability field by constant values, including the average permeability as well as the effective flow permeability of the sample. The latter is estimated in a separate upscaling procedure by solving the steady-state flow equation in the rock sample under study. Numerical experiments let us verify that attenuation levels are less significant and the attenuation peak gets broader in the presence of such strong permeability fluctuations. Moreover, we observe that for very low frequencies the effective seismic permeability is similar to the effective flow permeability, while for very high frequencies it approaches the arithmetic average of the permeability field.

State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology.

Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing.

Alzheimer disease: curly fibers and tangles in organs other than brain.

The filamentous brain lesions that define Alzheimer disease (AD) consist of senile plaques and neurofibrillary tangles. Undulated pathological filaments--curly fibers or neuropil threads--also occur in the neuropil. Beta-amyloid precursor proteins are synthesized by many cells outside the central nervous system and recently, deposition of beta-amyloid-protein was reported to occur in non-neuronal tissues. In addition, increasing data claim the importance of chronic inflammation in the pathogenesis of AD. These observations suggest that AD may be a widespread systemic disorder. Here we report that pathological argyrophilic filaments with histochemical properties of amyloid showing striking morphological similarity to curly fibers and/or tangles accumulate not only in ependymal layer and in epithelial cells of choroid plexus, but also in several other organs (e.g. liver, pancreas, ovary, testis, thyroid) in AD. The ependyma, choroid plexus, and various organs of 39 autopsy cases were analyzed. In search of curly fiber and tangle-like changes in organs other than brain, 395 blocks from 21 different tissues of 24 AD cases, 5 cases with discrete or moderate AD-type changes, and 10 control cases were investigated. We found in non-neuronal cells "curly fibers" or "tangles" immunoreactive with antibodies to P component, Tau-protein, ubiquitin, fibronectin, and Apolipoprotein-E, but lacking immunoreactivity with antibodies to neurofilament proteins. Ultrastructurally they consist of densely packed straight and paired helical filaments and closely resemble neurofibrillary tangles and neuropil threads. These observations indicate that the formation of "curly fibers" and "tangles" is not unique to the central nervous system. The results suggest that AD might be a systemic disorder or that similar fibrillary changes to tangles and curly fibers may also be associated with other amyloidosis than beta-amyloidosis. Further investigations are necessary to understand the pathogenetic interest of these fibrillary changes outside the CNS.

Verí sense antídot per al Sòcrates històric i la tragèdia barroca al Verí del teatre de Rodolf Sirera. (Una dosi extrema de sadisme per aturar els excessos de la ficció teatral).

Socrates' serene attitude before his death -although this is questioned-, as described by Xenophon in his Apologia Socratis becomes for the playwright Rodolf Sirera a useful reference in an effort to reflect boldly on the limits of theatrical fiction in another clear example of the Classical Tradition, including that derived from Baroque Tragedy. However, in this case, it is judged severely to make us more conscious of the risk of turning life into a mere theatrical performance and human beings into actors and actresses in a play they did not write.

The transcription factor c-Maf controls touch receptor development and function.

The sense of touch relies on detection of mechanical stimuli by specialized mechanosensory neurons. The scarcity of molecular data has made it difficult to analyze development of mechanoreceptors and to define the basis of their diversity and function. We show that the transcription factor c-Maf/c-MAF is crucial for mechanosensory function in mice and humans. The development and function of several rapidly adapting mechanoreceptor types are disrupted in c-Maf mutant mice. In particular, Pacinian corpuscles, a type of mechanoreceptor specialized to detect high-frequency vibrations, are severely atrophied. In line with this, sensitivity to high-frequency vibration is reduced in humans carrying a dominant mutation in the c-MAF gene. Thus, our work identifies a key transcription factor specifying development and function of mechanoreceptors and their end organs.

Specific fibroblastic niches in secondary lymphoid organs orchestrate distinct Notch-regulated immune responses.

Fibroblast-like cells of secondary lymphoid organs (SLO) are important for tissue architecture. In addition, they regulate lymphocyte compartmentalization through the secretion of chemokines, and participate in the orchestration of appropriate cell-cell interactions required for adaptive immunity. Here, we provide data demonstrating the functional importance of SLO fibroblasts during Notch-mediated lineage specification and immune response. Genetic ablation of the Notch ligand Delta-like (DL)1 identified splenic fibroblasts rather than hematopoietic or endothelial cells as niche cells, allowing Notch 2-driven differentiation of marginal zone B cells and of Esam(+) dendritic cells. Moreover, conditional inactivation of DL4 in lymph node fibroblasts resulted in impaired follicular helper T cell differentiation and, consequently, in reduced numbers of germinal center B cells and absence of high-affinity antibodies. Our data demonstrate previously unknown roles for DL ligand-expressing fibroblasts in SLO niches as drivers of multiple Notch-mediated immune differentiation processes.

La biografia catalana contemporània (notes sense ànim d'exhaustivitat)

Notes and comments about the importance of the historical biography in contemporary Catalonia, emphasizing the overcoming of the expectation and of the criticism of the historiography influenced by Marxism.

La biografia catalana contemporània (notes sense ànim d'exhaustivitat)

Notes and comments about the importance of the historical biography in contemporary Catalonia, emphasizing the overcoming of the expectation and of the criticism of the historiography influenced by Marxism.

Design de biblioteca virtual centrado no usuário: a abordagem do Sense-Making para estudos de necessidades e procedimentos de busca e uso da informação

Analisa a abordagem do Sense-Making na busca e uso da informação.

"A renewed sense of purpose": Mothers' and fathers' experience of having a child following a recent stillbirth.

Background Most research has focused on mothers¿ experiences of perinatal loss itself or on the subsequent pregnancy, whereas little attention has been paid to both parents¿ experiences of having a child following late perinatal loss and the experience of parenting this child. The current study therefore explored mothers¿ and fathers' experiences of becoming a parent to a child born after a recent stillbirth, covering the period of the second pregnancy and up to two years after the birth of the next baby.MethodIn depth interviews were conducted with 7 couples (14 participants). Couples were eligible if they previously had a stillbirth (after 24 weeks of gestation) and subsequently had another child (their first live baby) who was now under the age of 2 years. Couples who had more than one child after experiencing a stillbirth and those who were not fluent in English were excluded. Qualitative analysis of the interview data was conducted using Interpretive Phenomenological Analysis.ResultsFive superordinate themes emerged from the data: Living with uncertainty; Coping with uncertainty; Relationship with the next child; The continuing grief process; Identity as a parent. Overall, fathers' experiences were similar to those of mothers', including high levels of anxiety and guilt during the subsequent pregnancy and after the child was born. Coping strategies to address these were identified. Differences between mothers and fathers regarding the grief process during the subsequent pregnancy and after their second child was born were identified. Despite difficulties with bonding during pregnancy and at the time when the baby was born, parents' perceptions of their relationship with their subsequent child were positive.ConclusionsFindings highlight the importance of tailoring support systems not only according to mothers' but also to fathers' needs. Parents¿, and particularly fathers', reported lack of opportunities for grieving as well as the high level of anxiety of both parents about their baby's wellbeing during pregnancy and after birth implies a need for structured support. Difficulties experienced in bonding with the subsequent child during pregnancy and once the child is born need to be normalised.

Interior sense mobles. A l'entorn d'una possible hermenèutica en Adorno

Theodor W. Adorno construeix la modernitat com la fase final d'un procés d'emancipació que ha conduït justament al contrari del que es pretenia. L'alliberament del mite ha portat a una situació històrica en la qual l'encobriment ideològic del món és total. Això té conseqüències per a un pensament que vol ser crític, ja que haurà de trobar un lloc des d'on es pugui interpretar la història per tal de salvar la veritat d'un possible món diferent. En el moment de màxima ocultació ideològica i de màxim absurd -és conegut que Adorno es refereix al món contemporani com al temps després d'Auschwitz- Adorno intentarà entendre què ha passat amb aquest subjecte que s'ha preocupat excessivament per la seva identitat. Mitjançant l'aplicació del model psicoanalític d'interpretació a textos de Beckett i Kafka reconstruirà la història de l'emancipació fallida del subjecte modern. Amb aquestes interpretacions Adorno se situa no només molt a prop de la pràctica psicoanalítica, sinó també de la tradició hermenèutica clàssica.

«S'ha de practicar, el problema és la solució» sense ús no hi ha prou aprenentatge: les pràctiques lingüístiques dels joves sabadellencs

El present article pretén conèixer les tries i els usos lingüístics dels joves de Sabadell. L'estudi se centra en els individus presents a l'escola secundària amb edats compreses entre 14 i 19 anys. En concret es basa a conèixer la importància de l'escola en l'adquisició de la segona llengua d'aquests joves, així com els factors que influencien en la tria i l'ús d'una llengua determinada en els diferents contextos. Donada la diversitat sociocultural actual de Catalunya els individus seleccionats representen les diverses tipologies principals existents segons el seu origen etnicolingüístic (català, castellà i bilingüe), combinat amb la composició del seu entorn bàsic de socialització (xarxes socials), i amb altres aspectes geogràfics, demogràfics i econòmics.

Do seismic waves sense fracture connectivity?

A defining characteristic of fractured rocks is their very high level of seismic attenuation, which so far has been assumed to be mainly due to wave-induced fluid flow (WIFF) between the fractures and the pore space of the embedding matrix. Using oscillatory compressibility simulations based on the quasi-static poroelastic equations, we show that another important, and as of yet undocumented, manifestation of WIFF is at play in the presence of fracture connectivity. This additional energy loss is predominantly due to fluid flow within the connected fractures and is sensitive to their lengths, permeabilities, and intersection angles. Correspondingly, it contains key information on the governing hydraulic properties of fractured rock masses and hence should be accounted for whenever realistic seismic models of such media are needed.