The development of sparse edge coding in the mammalian visual cortex depends on early visual experience. In humans, there are multiple indicators that the statistics of early visual experiences has unique properties that may support these developments. However, there are no direct measures of the edge statistics of infant daily-life experience.
View Article and Find Full Text PDFFace perception and recognition are important processes for social interaction and communication among humans, so understanding how faces are mentally represented and processed has major implications. At the same time, faces are just some of the many stimuli that we encounter in our everyday lives. Therefore, more general theories of how we represent objects might also apply to faces.
View Article and Find Full Text PDFAcross the lifespan, humans are biased to look first at what is easy to see, with a handful of well-documented visual saliences shaping our attention (e.g., Itti & Koch, 2001).
View Article and Find Full Text PDFEpidemic strains of Pseudomonas aeruginosa are highly virulent opportunistic pathogens with increased transmissibility and enhanced antimicrobial resistance. Understanding the cellular mechanisms behind this heightened virulence and resistance is critical. Peptidoglycan (PG) is an integral component of P.
View Article and Find Full Text PDFRecent studies have found that infants show relational learning in the first year. Like older children, they can abstract relations such as same or different across a series of exemplars. For older children, language has a major impact on relational learning: labeling a shared relation facilitates learning, while labeling component objects can disrupt learning.
View Article and Find Full Text PDFPeptidoglycan is an important component of bacterial cell walls and a common cellular target for antimicrobials. Although aspects of peptidoglycan structure are fairly conserved across all bacteria, there is also considerable variation between Gram-positives/negatives and between species. In addition, there are numerous known variations, modifications, or adaptations to the peptidoglycan that can occur within a bacterial species in response to growth phase and/or environmental stimuli.
View Article and Find Full Text PDFInfection with Shiga toxin-producing Escherichia coli (STEC) results in hemorrhagic colitis and can lead to life-threatening sequelae including hemolytic uremic syndrome (HUS). Conventional treatment is intravenous fluid volume expansion. Antibiotic treatment is contraindicated, due in part to the elevated risk of HUS related to increased Shiga toxin (Stx) release associated with some antibiotics.
View Article and Find Full Text PDFPeptidoglycan (PG) is a critical component of the bacterial cell wall and is composed of a repeating β-1,4-linked disaccharide of -acetylglucosamine and -acetylmuramic acid appended with a highly conserved stem peptide. In Gram-negative bacteria, PG is assembled in the cytoplasm and exported into the periplasm where it undergoes considerable maturation, modification, or degradation depending on the growth phase or presence of environmental stressors. These modifications serve important functions in diverse processes, including PG turnover, cell elongation/division, and antibiotic resistance.
View Article and Find Full Text PDFMicrovascular muscle transfer is the gold standard for reanimation following chronic facial nerve paralysis, however, despite the regenerative capacity of peripheral motor axons, poor reinnervation often results in sub-optimal function. We hypothesized that injection of alginate hydrogels releasing growth factors directly into donor tissue would promote reinnervation, muscle regeneration, and function. A murine model of sciatic nerve ligation and neurorrhaphy was first used to assess the ability of gel delivery of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) to promote functional reinnervation.
View Article and Find Full Text PDFObjective: Scheduling interviews can be stressful and time-intensive for general surgery applicants and program coordinators. The objectives of this study were to determine whether computerized scheduling program (CSP) would decrease time to schedule interviews, reduce workload for residency coordinators, and improve applicant satisfaction.
Design: A prospective randomized controlled trial of 2 interview-scheduling methods was conducted.
This research tests whether analogical learning is present before language comprehension. Three-month-old infants were habituated to a series of analogous pairs, instantiating either the same relation (e.g.
View Article and Find Full Text PDFInfants fail to represent quantities of non-cohesive substances in paradigms where they succeed with solid objects. Some investigators have interpreted these results as evidence that infants do not yet have representations for substances. More recent research, however, shows that 5-month-old infants expect objects and substances to behave and interact in different ways.
View Article and Find Full Text PDFBiomaterial-based delivery of angiogenic growth factors restores perfusion more effectively than bolus delivery methods in rodent models of peripheral vascular disease, but the same success has not yet been demonstrated in clinically relevant studies of aged or large animals. These studies explore, in clinically relevant models, a therapeutic angiogenesis strategy for the treatment of peripheral vascular disease that overcomes the challenges encountered in previous clinical trials. Alginate hydrogels providing sustained release of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF) were injected into ischemic hind limbs in middle-aged and old mice, and also in young rabbits, as a test of the scalability of this local growth factor treatment.
View Article and Find Full Text PDFAntibiotic resistance constitutes one of the most serious threats to the global public health and urgently requires new and effective solutions. Bacteriophages are bacterial viruses increasingly recognized as being good alternatives to traditional antibiotic therapies. In this study, the efficacy of phages, targeting different cell receptors, against PAO1 biofilm and planktonic cell cultures was evaluated over the course of 48 h.
View Article and Find Full Text PDFPhosphoenolpyruvate carboxylase (PEPC) is a tightly controlled cytosolic enzyme situated at a crucial branch point of central plant metabolism. In developing castor oil seeds () a novel, allosterically desensitized 910-kD Class-2 PEPC hetero-octameric complex, arises from a tight interaction between 107-kD plant-type PEPC and 118-kD bacterial-type (BTPC) subunits. The native Ca-dependent protein kinase (CDPK) responsible for in vivo inhibitory phosphorylation of Class-2 PEPC's BTPC subunit's at Ser-451 was highly purified from COS and identified as RcCDPK1 (XP_002526815) by mass spectrometry.
View Article and Find Full Text PDFTo synthesize the cofactor thiamin diphosphate (ThDP), plants must first hydrolyze thiamin monophosphate (ThMP) to thiamin, but dedicated enzymes for this hydrolysis step were unknown and widely doubted to exist. The classical thiamin-requiring th2-1 mutation in Arabidopsis thaliana was shown to reduce ThDP levels by half and to increase ThMP levels 5-fold, implying that the THIAMIN REQUIRING2 (TH2) gene product could be a dedicated ThMP phosphatase. Genomic and transcriptomic data indicated that TH2 corresponds to At5g32470, encoding a HAD (haloacid dehalogenase) family phosphatase fused to a TenA (thiamin salvage) family protein.
View Article and Find Full Text PDFImported sucrose is cleaved by sucrose synthase (SUS) as a critical initial reaction in the biosynthesis of storage end-products by developing seeds. Although SUS is phosphorylated at a conserved seryl residue by an apparent CDPK (Ca-dependent protein kinase) in diverse plant tissues, the functions and mechanistic details of this process remain obscure. Thus, the native CDPK that phosphorylates RcSUS1 (Ricinus communis SUS1) at Ser in developing COS (castor oil seeds) was highly purified and identified as RcCDPK2 by MS/MS.
View Article and Find Full Text PDFRecently, we described the ubiquitylation of PYL4 and PYR1 by the RING E3 ubiquitin ligase RSL1 at the plasma membrane of This suggested that ubiquitylated abscisic acid (ABA) receptors might be targeted to the vacuolar degradation pathway because such ubiquitylation is usually an internalization signal for the endocytic route. Here, we show that FYVE1 (previously termed FREE1), a recently described component of the endosomal sorting complex required for transport (ESCRT) machinery, interacted with RSL1-receptor complexes and recruited PYL4 to endosomal compartments. Although the ESCRT pathway has been assumed to be reserved for integral membrane proteins, we show the involvement of this pathway in the degradation of ABA receptors, which can be associated with membranes but are not integral membrane proteins.
View Article and Find Full Text PDFExperience puts people in touch with nonsolid substances, such as water, blood, and milk, which are crucial to survival. People must be able to understand the behavior of these substances and to differentiate their properties from those of solid objects. We investigated whether infants represent nonsolid substances as a conceptual category distinct from solid objects on the basis of differences in cohesiveness.
View Article and Find Full Text PDFEndothelial progenitor cells are being broadly explored for the treatment of ischemic cardiovascular diseases, but their response to molecules commonly used to promote the growth of new blood vessels has not been fully characterized. In this study, angiogenic sprout formation in a 3-dimensional, in vitro model by one type of endothelial progenitor, outgrowth endothelial cells (OECs), was characterized in response to exposure to stromal cell-derived factor (SDF) and vascular endothelial growth factor (VEGF) and then compared to mature endothelial cells. Exposure to SDF alone did not increase angiogenic sprouting in comparison to control media, while a combination of VEGF and SDF demonstrated greater potency than VEGF alone for all cell types.
View Article and Find Full Text PDFBiomaterials may improve outcomes of endothelial progenitor-based therapies for the treatment of ischemic cardiovascular disease, due to their ability to direct cell behavior. We hypothesized that local, sustained delivery of exogenous vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF) from alginate hydrogels could increase recruitment of systemically infused endothelial progenitors to ischemic tissue, and subsequent neovascularization. VEGF and SDF were found to enhance in vitro adhesion and migration of outgrowth endothelial cells (OECs) and circulating angiogenic cells (CACs), two populations of endothelial progenitors, by twofold to sixfold, and nearly doubled recruitment to both ischemic and nonischemic muscle tissue in vivo.
View Article and Find Full Text PDFSucrose synthase (SUS) catalyzes the UDP-dependent cleavage of sucrose into UDP-glucose and fructose and has become an important target for improving seed crops via metabolic engineering. A UDP-specific SUS homotetramer composed of 93-kDa subunits was purified to homogeneity from the triacylglyceride-rich endosperm of developing castor oil seeds (COS) and identified as RcSUS1 by mass spectrometry. RcSUS1 transcripts peaked during early development, whereas levels of SUS activity and immunoreactive 93-kDa SUS polypeptides maximized during mid-development, becoming undetectable in fully mature COS.
View Article and Find Full Text PDFLipopolysaccharide is the predominant component of the Gram-negative cell wall occupying the outer leaflet of the outer membrane of Pseudomonas aeruginosa. Wild-type bacteria produce smooth LPS composed of lipid A, core oligosaccharide, and long O-antigen polysaccharide. In contrast, mutant bacteria defective in LPS biosynthesis produce rough LPS lacking the long O-antigen side chains.
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