Neurotoxicity

Neurotoxicity refers to the direct or indirect effect of chemicals that disrupt the nervous system of humans or animals. Numerous chemicals can produce neurotoxic diseases in humans, and many more are used as experimental tools to disturb or damage the nervous system of animals. Some act directly on neural cells, others interfere with metabolic processes on which the nervous system is especially dependent. Some disrupt neural function, others induce maldevelopment or damage to the adult nervous system. Perturbations may appear and disappear rapidly, evolve slowly over days or weeks and regress over months or years, or cause permanent deficits. Neurotoxicity is usually self-limiting after exposure ceases and rarely progressive in the absence of continued exposure, although there may be a significant delay between exposure and manifestation of neurotoxic effects

A novel chromosome segregation mechanism during female meiosis.

In a wide range of eukaryotes, chromosome segregation occurs through anaphase A, in which chromosomes move toward stationary spindle poles, anaphase B, in which chromosomes move at the same velocity as outwardly moving spindle poles, or both. In contrast, Caenorhabditis elegans female meiotic spindles initially shorten in the pole-to-pole axis such that spindle poles contact the outer kinetochore before the start of anaphase chromosome separation. Once the spindle pole-to-kinetochore contact has been made, the homologues of a 4-μm-long bivalent begin to separate. The spindle shortens an additional 0.5 μm until the chromosomes are embedded in the spindle poles. Chromosomes then separate at the same velocity as the spindle poles in an anaphase B-like movement. We conclude that the majority of meiotic chromosome movement is caused by shortening of the spindle to bring poles in contact with the chromosomes, followed by separation of chromosome-bound poles by outward sliding

Matrix Completion With Variational Graph Autoencoders: Application in Hyperlocal Air Quality Inference

Inferring air quality from a limited number of observations is an essential task for monitoring and controlling air pollution. Existing inference methods typically use low spatial resolution data collected by fixed monitoring stations and infer the concentration of air pollutants using additional types of data, e.g., meteorological and traffic information. In this work, we focus on street-level air quality inference by utilizing data collected by mobile stations. We formulate air quality inference in this setting as a graph-based matrix completion problem and propose a novel variational model based on graph convolutional autoencoders. Our model captures effectively the spatio-temporal correlation of the measurements and does not depend on the availability of additional information apart from the street-network topology. Experiments on a real air quality dataset, collected with mobile stations, shows that the proposed model outperforms state-of-the-art approaches

Dynactin-dependent cortical dynein and spherical spindle shape correlate temporally with meiotic spindle rotation in Caenorhabditis elegans.

Oocyte meiotic spindles orient with one pole juxtaposed to the cortex to facilitate extrusion of chromosomes into polar bodies. In Caenorhabditis elegans, these acentriolar spindles initially orient parallel to the cortex and then rotate to the perpendicular orientation. To understand the mechanism of spindle rotation, we characterized events that correlated temporally with rotation, including shortening of the spindle in the pole-to pole axis, which resulted in a nearly spherical spindle at rotation. By analyzing large spindles of polyploid C. elegans and a related nematode species, we found that spindle rotation initiated at a defined spherical shape rather than at a defined spindle length. In addition, dynein accumulated on the cortex just before rotation, and microtubules grew from the spindle with plus ends outward during rotation. Dynactin depletion prevented accumulation of dynein on the cortex and prevented spindle rotation independently of effects on spindle shape. These results support a cortical pulling model in which spindle shape might facilitate rotation because a sphere can rotate without deforming the adjacent elastic cytoplasm. We also present evidence that activation of spindle rotation is promoted by dephosphorylation of the basic domain of p150 dynactin

Ictal high‐frequency oscillations at 80–200 Hz coupled with delta phase in epileptic spasms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88095/1/j.1528-1167.2011.03263.x.pd

La messa in sicurezza dell'area industriale di Priolo-Augusta rispetto ai rischi da terremoto e maremoto

I recenti forti terremoti che hanno interessato zone particolarmente industrializzate in Turchia ed in India (terremoto del 17.8.1999, Kocaeli, Turchia, Mw = 7.4; e terremoto di Guyarat, India, del 26.01.2001, Mw =7.7) hanno messo in evidenza che al danno prodotto dal terremoto si pu\uf2 aggiungere quello dovuto alle conseguenze di incidenti e/o rotture negli impianti, cosiddetti, \u201ca rischio di incidente rilevante\u201d. Il rischio totale nell\u2019area pu\uf2 quindi assumere valori estremamente elevati in termini economici, ambientali, e talvolta con perdita di vite umane. Ad esempio, nel caso del terremoto turco, il danneggiamento della raffineria Tupras di IZMIT ha provocato l\u2019incendio della stessa e la fuoriuscita di una quantit\ue0 rilevante di olio (Foto 1). Sulla base di quanto sopra e di quanto conosciuto, il presente studio si propone come elemento di base per l\u2019impostazione di interventi strutturali sugli impianti e sul territorio con l\u2019obiettivo di mettere il tutto in condizioni di sicurezza a fronte del terremoto (ed eventuale maremoto associato) atteso nell\u2019area. A questo scopo \ue8 stata realizzata un\u2019analisi per mettere in evidenza l\u2019entit\ue0 e la frequenza dei fenomeni naturali (terremoti e maremoti) che possono determinare significativi impatti sia sull\u2019ambiente fisico che su quello antropizzato (infrastrutture) nell\u2019area di Priolo-Augusta. Il progetto ha avuto come obiettivo iniziale la valutazione dei carichi dovuti a fenomeni naturali che, trasformati in termini ingegneristici, devono essere utilizzati per la verifica della idoneit\ue0 progettuale degli impianti industriali presenti nelle aree studiate. In particolare \ue8 stato valutato, dapprima, il terremoto di riferimento per la progettazione, in termini di picco massimo di accelerazione e spettro di risposta associato. In tale fase si \ue8 anche provveduto alla costruzione di scenari associati ad un eventuale maremoto. I siti prescelti sono esposti ad un elevato rischio sismico la cui definizione ha richiesto l\u2019adozione delle metodologie pi\uf9 avanzate disponibili. A tale scopo sono stati applicati diversi approcci innovativi sia di tipo sismologico che ingegneristico

The core planar cell polarity gene, Vangl2, directs adult corneal epithelial cell alignment and migration

This work was supported by a Biotechnology and Biological Sciences Research Council (BBSRC) DTG PhD studentship to A.F., an Anatomical Society PhD Studentship (‘The Roles of planar cell polarity genes in a classical anatomical system: the cornea’) to D.A.P./J.M.C. and BBSRC Project Grants BB/J015172/1 and BB/J015237/1 to J.D.W. and J.M.C., respectively.Peer reviewedPublisher PD

Una (aparente) excepción en la filosofía natural aristotélica: antiperístasis como acción en las cualidades contrarias y su interpretación en la tradición del comentario médico y filosófico medieval

This paper explores the scholastic debate about antiperistasis, a mechanism in Aristotle’s dynamics described in the first book of Meteorology as an intensification of a quality caused by the action of the contrary one. After having distinguished this process from a homonymous, but totally different, principle concerning the dynamics of fluids that Aristotle describes in his Physics, I focus on the medieval reception of the former. Scholastic commentators oriented their exegetical effort in elaborating a consistent explanation of an apparently paradoxical process like the intensification of a quality by the opposite one. From the fourteenth century onwards, most of the commentators resorted to the theory of the multiplication of species, according to which each entity acts through the emission of simulacra of the objects (species) that spread spherically in the medium. When these rays encounter an obstacle, such as a contrary quality, they are pushed back towards their source. The reflection of the species determined by the surrounding and opposite quality produces a concentration of the first one, which is therefore intensified. Another distinctive feature of the scholastic interpretation of Aristotle’s antiperistasis is the convergence between the discussions on inorganic and organic matter,physical and medical discourse. This convergence found its most significant expression in the adoptionof the model described in the first book of Aristotle’s Meteorology to the biological context of Hippocrates’s Aphorisms I, 15. Following Galen’s exegesis of this passage, medieval commentators established a link between physics and medicine substantially extraneous to Aristotle’s theory.Este artículo explora los debates escolásticos sobre la antiperístasis, un mecanismo en la dinámica de Aristóteles descrito en el primer libro de la Meteorología como una intensificación de una cualidad provocada por la acción de la cualidad contraria. Después de haber distinguido este proceso de un principio homónimo, relativo a la dinámica de los fluidos que Aristóteles describe en su Física, mi análisis se centra en la recepción medieval del primer proceso. Los comentaristas escolásticos orientaron su esfuerzo exegético hacia la elaboración de una explicación consistente de un proceso aparentemente paradójico como la intensificación de una cualidad por su cualidad contraria. A partir del siglo XIV, la mayoría de los comentaristas recurrió a la teoría de la multiplicación de especies, según la cual cada entidad actúa mediante la emisión de rayos virtuales (species) que se difunden de forma esférica en el medio. Cuando estos rayos encuentran un obstáculo, como una cualidad contraria, son empujados hacia su fuente. El reflejo de los rayos virtuales determinado por la cualidad circundante y contraria produce una concentración de la primera cualidad, que, como consecuencia, se intensifica. Otro rasgo distintivo de la interpretación escolástica de la antiperístasis de Aristóteles es la convergencia entre la reflexión sobre la materia orgánica e inorgánica, el discurso físico y médico. Esta convergencia encontró su expresión más significativa en la adopción del modelo descrito en el primer libro de la Meteorología de Aristóteles al contexto biológico de los Aforismos de Hipócrates I, 15. Siguiendo la exégesis de Galeno, los comentaristas medievales establecieron un vínculo entre la física y la medicina sustancialmente ajeno a la teoría de Aristóteles