Why Do Children Think Words Are Mutually Exclusive?

How do children learn what a word means when its uses are consistent with many possible meanings? One influential idea is that children rely on an inductive bias that ensures that novel words get assigned distinct meanings from known words-. Here, we explore the possibility that mutual-exclusivity phenomena do not reflect a bias but rather information encoded in the message. Learners might effectively be told when (and when not) to assume that word meanings are mutually exclusive.

Context sensitivity and the semantics of count nouns in the evaluation of partial objects by children and adults.

Previous research has documented that children count spatiotemporally-distinct partial objects as if they were whole objects. This behavior extends beyond counting to inclusion of partial objects in assessment and comparisons of quantities. Multiple accounts of this performance have been proposed: children and adults differ qualitatively in their conceptual representations, children lack the processing skills to immediately individuate entities in a given domain, or children cannot readily access relevant linguistic alternatives for the target count noun.

Fast mapping word meanings across trials: Young children forget all but their first guess.

Do children learn a new word by tracking co-occurrences between words and referents across multiple instances ("cross-situational learning" models), or is word-learning a "one-track" process, where learners maintain a single hypothesis about the possible referent, which may be verified or falsified in future occurrences ("propose-but-verify" models)? Using a novel word-learning task, we ask which learning procedure is utilized by preschool-aged children. We report on findings from three studies comparing the word-learning strategies across different populations of child learners: monolingual English learners, Spanish - English dual language learners, and learners at risk for language-delay. In all three studies, we ask what, if anything, is retained from prior exposures and whether the amount of information retained changes as children get older.

AS1411 aptamer and folic acid functionalized pH-responsive ATRP fabricated pPEGMA-PCL-pPEGMA polymeric nanoparticles for targeted drug delivery in cancer therapy.

Nonspecificity and cardiotoxicity are the primary limitations of current doxorubicin chemotherapy. To minimize side effects and to enhance bioavailability of doxorubicin to cancer cells, a dual-targeted pH-sensitive biocompatible polymeric nanosystem was designed and developed. An ATRP-based biodegradable triblock copolymer, poly(poly(ethylene glycol) methacrylate)-poly(caprolactone)-poly(poly(ethylene glycol) methacrylate) (pPEGMA-PCL-pPEGMA), conjugated with doxorubicin via an acid-labile hydrazone bond was synthesized and characterized.

Aptamer-conjugated polymeric nanoparticles for targeted cancer therapy.

Recent advances in cancer nanotechnology have led to the emergence of aptamer-enabled technologies to diagnose and treat cancer. Aptamers with their high binding sensitivity and specificity are highly attractive for a wide variety of applications in molecular targeting. Aptamer-escorted drug-loaded polymeric nanoparticles represent a promising technology, which facilitates controlled release and targeted approach to deliver drugs to the desired site with marginal or any collateral damage.

AS1411 aptamer tagged PLGA-lecithin-PEG nanoparticles for tumor cell targeting and drug delivery.

Liposomes and polymers are widely used drug carriers for controlled release since they offer many advantages like increased treatment effectiveness, reduced toxicity and are of biodegradable nature. In this work, anticancer drug-loaded PLGA-lecithin-PEG nanoparticles (NPs) were synthesized and were functionalized with AS1411 anti-nucleolin aptamers for site-specific targeting against tumor cells which over expresses nucleolin receptors. The particles were characterized by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).

Aptamer-labeled PLGA nanoparticles for targeting cancer cells.

Cancer is one of the leading causes of death in most parts of the world and is a very serious cause of concern particularly in developing countries. In this work, we prepared and evaluated the aptamer-labeled paclitaxel-loaded poly(lactic--glycolic acid) (PLGA) nanoparticles (Apt-PTX-PLGA NPs) which can ameliorate drug bioavailability and enable accurate drug targeting to cancer cells with controlled drug release for cancer therapy. Paclitaxel-loaded PLGA nanoparticles (PTX-PLGA NPs) were formulated by a single-emulsion/solvent evaporation method and were further surface-functionalized with a chemical cross-linker (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles.

FITC labeled silica nanoparticles as efficient cell tags: uptake and photostability study in endothelial cells.

The use of fluorescent nanomaterials has gained great importance in the field of medical imaging. Many traditional imaging technologies have been reported utilizing dyes in the past. These methods face drawbacks due to non-specific accumulation and photobleaching of dyes.