706 research outputs found
Differences in the nonverbal requests of Great Apes and human infants
This study investigated how great apes and human infants use imperative pointing to request objects. In a series of three experiments (infants, N = 44; apes, N = 12), subjects were given the opportunity to either point to a desired object from a distance or else to approach closer and request it proximally. The apes always approached close to the object, signaling their request through instrumental actions. In contrast, the infants quite often stayed at a distance, directing the experimenters' attention to the desired object through index-finger pointing, even when the object was in the open and they could obtain it by themselves. Findings distinguish 12-month-olds' imperative pointing from ontogenetic and phylogenetic earlier forms of ritualized reaching
Pathogens, toxins, and lipid rafts
Summary: The plasma membrane is not a uniform two-dimensional space but includes various types of specialized regions containing specific lipids and proteins. These include clathrin-coated pits and caveolae. The existence of other cholesterol- and glycosphingolipid-rich microdomains has also been proposed. The aim of this review is to illustrate that these latter domains, also called lipid rafts, may be the preferential interaction sites between a variety of toxins, bacteria, and viruses and the target cell. These pathogens and toxins have hijacked components that are preferentially found in rafts, such as glycosylphosphatidylinositol-anchored proteins, sphingomyelin, and cholesterol. These molecules not only allow binding of the pathogen or toxin to the proper target cell but also appear to potentiate the toxic action. We briefly review the structure and proposed functions of cholesterol- and glycosphingolipid-rich microdomains and then describe the toxins and pathogens that interact with them. When possible the advantage conferred by the interaction with microdomains will be discusse
90-РІЧЧЮ КІРОВОГРАДСЬКОГО МЕДИЧНОГО КОЛЕДЖУ ІМ. Є.Й. МУХІНА ПРИСВЯЧУЄТЬСЯ
The article presents main issues concerning palliative and hospice care to incurable patients that were discussed at the regional scientific-practical conference within the preparation for the anniversary of the educational institution.У статті наведено основні питання, що розглядались на регіональній науково-практичній конференції в рамках підготовки до ювілею навчального закладу стосовно паліативної та хоспісної допомоги інкурабельним хворим
Bacterial pore-forming toxins: The (w)hole story?
Abstract.: Pore-forming toxins (PFTs) are the most common class of bacterial protein toxins and constitute important bacterial virulence factors. The mode of action of PFT is starting to be better understood. In contrast, little is known about the cellular response to this threat. Recent studies reveal that cells do not just swell and lyse, but are able to sense and react to pore formation, mount a defense, even repair the damaged membrane and thus survive. These responses involve a variety of signal-transduction pathways and sophisticated cellular mechanisms such as the pathway regulating lipid metabolism. In this review we discuss the different classes of bacterial PFTs and their modes of action, and provide examples of how the different bacteria use PFTs. Finally, we address the more recent field dealing with the eukaryotic cell response to PFT-induced damag
Subspace Chronicles: How Linguistic Information Emerges, Shifts and Interacts during Language Model Training
Representational spaces learned via language modeling are fundamental to Natural Language Processing (NLP), however there has been limited understanding regarding how and when during training various types of linguistic information emerge and interact. Leveraging a novel information theoretic probing suite, which enables direct comparisons of not just task performance, but their representational subspaces, we analyze nine tasks covering syntax, semantics and reasoning, across 2M pre-training steps and five seeds. We identify critical learning phases across tasks and time, during which subspaces emerge, share information, and later disentangle to specialize. Across these phases, syntactic knowledge is acquired rapidly after 0.5% of full training. Continued performance improvements primarily stem from the acquisition of open-domain knowledge, while semantics and reasoning tasks benefit from later boosts to long-range contextualization and higher specialization. Measuring cross-task similarity further reveals that linguistically related tasks share information throughout training, and do so more during the critical phase of learning than before or after. Our findings have implications for model interpretability, multi-task learning, and learning from limited data.</p
Bedrijfsgebonden dierziekten op varkens-, rundvee- en pluimveebedrijven
In deze rapportage is een inventarisatie en prioritering van bedrijfsgebonden aandoeningen in de rundvee- varkens- en pluimveesector uitgewerkt. Deze kunnen de overheid en veehouderijsectoren een handvat geven voor een nadere invulling van haar Nationale Agenda Diergezondheid en behulpzaam zijn bij het formuleren van additioneel beleid. Bovendien geven ze aanwijzingen waar met nieuwe inspanningen winst kan worden geboekt bij bedrijfsgebonden diergezondheidsproblemen
Dual chaperone role of the c-terminal propeptide in folding and oligomerization of the pore-forming toxin aerolysin
Throughout evolution, one of the most ancient forms of aggression between cells or organisms has been the production of proteins or peptides affecting the permeability of the target cell membrane. This class of virulence factors includes the largest family of bacterial toxins, the pore-forming toxins (PFTs). PFTs are bistable structures that can exist in a soluble and a transmembrane state. It is unclear what drives biosynthetic folding towards the soluble state, a requirement that is essential to protect the PFT-producing cell. Here we have investigated the folding of aerolysin, produced by the human pathogen Aeromonas hydrophila, and more specifically the role of the C-terminal propeptide (CTP). By combining the predictive power of computational techniques with experimental validation using both structural and functional approaches, we show that the CTP prevents aggregation during biosynthetic folding. We identified specific residues that mediate binding of the CTP to the toxin. We show that the CTP is crucial for the control of the aerolysin activity, since it protects individual subunits from aggregation within the bacterium and later controls assembly of the quaternary pore-forming complex at the surface of the target host cell. The CTP is the first example of a C-terminal chain-linked chaperone with dual function
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