A-Movement and the Binding Theory

In current GB theory, traces of movement, both A- and A′-movement, are assumed to be regulated by the binding theory as well as the ECP. However, in recent years it has been noted that the effects of the binding theory for traces of movement overlap with those of the ECP to a great extent and therefore, no harm is done even if traces are exempt from the binding theory. Specifically, my main concern in this paper is the validity of the binding theory for A-movement. In addition to data of the aforementioned kind, which merely suggests the redundancy of binding theory for movement, I present data which, crucially disconfirms the validity of the binding theory as a regulating principle for A-movement, namely, long-distance A-movement involved in ECM (raising)-constructions in some languages. Based on this data, I claim that traces of A-movement are not subject to binding theory, and thus the binding theory should be reserved only for the referential dependencies of lexical anaphors

QR, Interface Economy and Pied-Piping in English

The possibility of pied-piping in English differs depending on the types of clauses where pied-piping takes place and this has made it difficult to come up with a unitary analysis of pied-piping. The goal of this paper is to provide a unified analysis of pied-piping in English without excluding any of them from the general pied-piping mechanism. Based on cross-linguistic data, I claim that pied-piping is the result of feature percolation and that feature percolation is possible only from certain structural positions. An interesting prediction of this analysis combined with an assumption that covert movement can precede overt movement (Chomsky, 1998, etc.) is that an XP can be pied-piped by a wh-element which is not in its initial position on the surface. I claim that this is what underlies pied-piping by non-phrase-initial wh-elements in English. In addition, I propose that the covert movement of the wh-phrase involved in certain cases of pied-piping by non-phrase-initial wh-phrases in English is QR and that various properties manifested by this kind of pied-piping can be explained in terms of the unique properties of QR distinct from those of other A'-movements. Specifically, I show how adopting the view of QR as an operation motivated by Interface Economy, as proposed by Reinhart (1995) and Fox (1995, 2000), can shed light on why pied-piping by non-phrase-initial wh-elements yields less-than-perfect results except in appositive relative clauses and why clausal pied-piping is restricted in English unlike in other languages like Basque

A Critical Survey of GB/Minimalist Research on Case and A-Chains in Korean

Korean possesses a rich and interesting Case system whose investigation sheds light on theoretical treatments of Case and related phenomena. For this reason, constructions involving Case-theoretic problems have been actively and frequently researched in Korean syntax. In this paper, we critically survey research on Case done in the tradition of Chomskyan syntactic theory, i.e., GB theory and the Minimalist Program

Double Relativitization of Different Grammatical Functions in Korean

Contrary to the claim that only the subject of a clause can undergo double relativization (DR) in Korean (Han 1992), in this paper, I show that it is possible for all GFs to undergo DR but that not all GFs can undergo DR equally easily. I then address the questions (i) what kind of factors determine the DR possibilities of different GFs and (ii) what their nature is and how they can be explained. I claim that one of the important factors determining them is the GFs of the head nouns of the relative clauses from which DR takes place, to be more precise, the GF relations between the higher and the lower head nouns of double relative constructions (DRCs), and that the reason why this is so can be explained in terms of processing. DRCs, in principle, are ambiguous and based on the observation that the interpretation preferences of DRCs are generally determined in the lower relative clauses, I approach the task of explaining the DR possibilities of different GFs by explaining the interpretation preferences of the lower relative clauses. My claims are that they can be explained in terms of ambiguity resolution and that the two major factors figuring importantly in this are (i) the argument vs. adjunct status of the gap and (ii) the distance between gap and filler

The effect of mesenchymal stem cell transplantation on the recovery of bladder and hindlimb function after spinal cord contusion in rats

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells are widely used for transplantation into the injured spinal cord in vivo model and for safety, many human clinical trials are continuing to promote improvements of motor and sensory functions after spinal cord injury. Yet the exact mechanism for these improvements remains undefined. Neurogenic bladder following spinal cord injury is the main problem decreasing the quality of life for patients with spinal cord injury, but there are no clear data using stem cell transplantation for the improvement of neurogenic bladder for in vivo studies and the clinical setting.</p> <p>The purpose of this study was to delineate the effect of human mesenchymal stem cell (hMSCs) transplantation on the restoration of neurogenic bladder and impaired hindlimb function after spinal cord contusion of rats and the relationship between neurotrophic factors such as brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) and bladder and hindlimb functions.</p> <p>Results</p> <p>Modified moderate contusion injury were performed on the thoracic spinal cord of Sprague-Dawley rats using MASCIS impactor and hMSCs, human fibroblasts or phosphate-buffered saline were transplanted into injured spinal cord 9 days after injury for hMSC and two control groups respectively. Ladder test showed more rapid restoration of hindlimb function in hMSC group than in control group, but Basso, Beattie, and Bresnahan score and coupling score were not different significantly among hMSC and two control groups. Neurogenic bladder was not improved in either group. ED1 positive macrophages were significantly reduced in hMSC group than in two control groups, but ELISA and RT-PCR studies revealed BDNF and NT-3 levels in spinal cord and bladder were not different among hMSC and two control groups regardless the experimental duration.</p> <p>Conclusion</p> <p>hMSC transplantation was effective in reducing inflammatory reaction after spinal cord contusion of rats but not sufficient to recover locomotor and bladder dysfunction. BDNF and NT-3 levels in the spinal cord and bladder were not increased 28 and 56 days after hMSC transplantation.</p

Enteric Neural Crest Differentiation in Ganglioneuromas Implicates Hedgehog Signaling in Peripheral Neuroblastic Tumor Pathogenesis

Peripheral neuroblastic tumors (PNTs) share a common origin in the sympathetic nervous system, but manifest variable differentiation and growth potential. Malignant neuroblastoma (NB) and benign ganglioneuroma (GN) stand at opposite ends of the clinical spectrum. We hypothesize that a common PNT progenitor is driven to variable differentiation by specific developmental signaling pathways. To elucidate developmental pathways that direct PNTs along the differentiation spectrum, we compared the expression of genes related to neural crest development in GN and NB. In GNs, we found relatively low expression of sympathetic markers including adrenergic biosynthesis enzymes, indicating divergence from sympathetic fate. In contrast, GNs expressed relatively high levels of enteric neuropeptides and key constituents of the Hedgehog (HH) signaling pathway, including Dhh, Gli1 and Gli3. Predicted HH targets were also differentially expressed in GN, consistent with transcriptional response to HH signaling. These findings indicate that HH signaling is specifically active in GN. Together with the known role of HH activity in enteric neural development, these findings further suggested a role for HH activity in directing PNTs away from the sympathetic lineage toward a benign GN phenotype resembling enteric ganglia. We tested the potential for HH signaling to advance differentiation in PNTs by transducing NB cell lines with Gli1 and determining phenotypic and transcriptional response. Gli1 inhibited proliferation of NB cells, and induced a pattern of gene expression that resembled the differential pattern of gene expression of GN, compared to NB (p<0.00001). Moreover, the transcriptional response of SY5Y cells to Gli1 transduction closely resembled the transcriptional response to the differentiation agent retinoic acid (p<0.00001). Notably, Gli1 did not induce N-MYC expression in neuroblastoma cells, but strongly induced RET, a known mediator of RA effect. The decrease in NB cell proliferation induced by Gli1, and the similarity in the patterns of gene expression induced by Gli1 and by RA, corroborated by closely matched gene sets in GN tumors, all support a model in which HH signaling suppresses PNT growth by promoting differentiation along alternative neural crest pathways