Tense-aspect processing in second language learners

This dissertation provides a language processing perspective on the study of second language acquisition (SLA) of tense and aspect. Of special interest are the universal vis-à-vis language- specific dimensions of temporal and aspectual semantics involved. According to the Aspect Hypothesis (AH, e.g. Andersen & Shirai, 1994), the initial acquisition and subsequent emergence of (perfective) past tense and progressive aspect morphology follow a semantic-driven, universal sequence. The AH appeals to a cognitive-based prototype account (Shirai & Andersen, 1995), and has gained ample empirical support from offline data in the past two decades. Mounting evidence of transfer, however, has begun to emerge in recent psycholinguistic research, suggesting that grammatical aspectual categories such as the English progressive have non-trivial influence on principles of information organization in language comprehension among L2 learners and bilingual speakers (Stutterheim & Carroll, 2006). This dissertation undertakes a psycholinguistic investigation of L2 learners’ processing of English past and progressive morphology. Participants included native English speakers as well as English L2 learners from Korean, German, and Mandarin Chinese backgrounds, whose L1s differ systematically with respect to past and progressive morphology. This cross-linguistic design enabled a systematic testing of both the prototype and transfer hypotheses in one single study. Three word-by-word self-paced reading experiments examined L2 learners’ automaticity in morphological processing, the universality of tense-aspect prototypes, and aspectual coercion. Experiment I generated evidence that L2 learners were generally capable of detecting tense- aspect morphosyntactic errors online. Reading time results from Experiment II revealed that L2 learners did not show uniform processing advantages afforded by tense-aspect prototypes. Instead, there exist L1 effects in prototypes, at least from evidence in processing L2 tense-aspect distinctions. Experiment III investigated the processing consequences of aspectual coercion in L2 learners, and results indicated strong L1 influence. The most robust finding across the three experiments is that the L2 learners showed clear L1-based variations in their performance, reflecting a strong tendency for transfer. Notably, these results were obtained after controlling for L2 proficiency and inflected verb form frequencies. A more prominent role of L1 influence is implicated in L2 learners’ representation of tense-aspect prototypes than previously assumed

Continuous Monitoring of Distributed Data Streams over a Time-based Sliding Window

The past decade has witnessed many interesting algorithms for maintaining statistics over a data stream. This paper initiates a theoretical study of algorithms for monitoring distributed data streams over a time-based sliding window (which contains a variable number of items and possibly out-of-order items). The concern is how to minimize the communication between individual streams and the root, while allowing the root, at any time, to be able to report the global statistics of all streams within a given error bound. This paper presents communication-efficient algorithms for three classical statistics, namely, basic counting, frequent items and quantiles. The worst-case communication cost over a window is $O(\frac{k} {\epsilon} \log \frac{\epsilon N}{k})$ bits for basic counting and $O(\frac{k}{\epsilon} \log \frac{N}{k})$ words for the remainings, where $k$ is the number of distributed data streams, $N$ is the total number of items in the streams that arrive or expire in the window, and $\epsilon < 1$ is the desired error bound. Matching and nearly matching lower bounds are also obtained.Comment: 12 pages, to appear in the 27th International Symposium on Theoretical Aspects of Computer Science (STACS), 201

A Case of Initially Undiagnosed Chikungunya Arthritis Developing into Chronic Phase in a Nonendemic Area

This case report described a 40-year-old lady presented with fever, headache, arthralgia, myalgia, and impaired liver function after returning from the Philippines. Chikungunya virus (CHIKV) and dengue serology were negative. Eight weeks after initial presentation, she experienced inflammatory polyarthritis mimic rheumatoid arthritis. This time CHIKV-IgM was detected, together with a >4-fold rise of CHIKV-polyvalent-antibody titre. The first CHIKV-IgM negative sample was reexamined and was CHIKV-PCR positive. CHIKV infection was confirmed and diagnosis of CHIKV-related arthritis was made. A quarter of CHIKV infected individuals develop post-CHIKV rheumatisms that affect quality of life and may need treatment with Disease Modifying Antirheumatic Drugs. This case highlights the importance of considering CHIKV infection in patients present with symmetrical polyarthritis particularly after travel to endemic regions. Testing of both CHIKV acute and convalescent-phase serum for CHIKV antibodies and PCR is recommended in suspicious case

A case of Hemiplegia Vegetativa Alterna, Paroxysmal Sympathetic Hyperactivity and Ogilvie's Syndrome: the role of central sympathetic pathways in their pathophysiology

Meeting Theme: Degenerative Lumbar SpineOral-Poster Presentation 1Hemiplegia vegetativa alterna (HVA) is the clinical syndrome of contralateral hemiparesis, hemisensory loss, hemihyperhydrosis and ipsilateral Horner’s syndrome1,2. The term vegetativa alterna denotes that a single brainstem lesion manifests with ipsilateral and contralateral, i.e. crossed, signs of autonomic (“vegetative”) sympathetic nervous system dysfunction. Fewer than five cases have been reported and most were a result of stroke involving the occlusion of posterior cerebral artery (PCA) perforators that supply the anterolateral mesencephalon. We describe a 46 year old male who suffered from aneurysmal subarachnoid hemorrhage and exhibited HVA as …published_or_final_versio

Microsatellite instability and mismatch repair gene mutations are common in young colorectal cancer patients in Hong Kong

Conference Theme: Challenges to Specialists in the 21st centurypublished_or_final_versio

The effect of severity of disc degeneration on mesenchymal stem cells' ability to regenerate the intervertebral disc: a rabbit model

Conference Theme: Spinal Motion Segment: From Basic Science to Clinical ApplicationThis Open Access journal suppl. entitled: Abstracts of European Cells and Materials VI /SRN I - Spinal Motion Segment: From Basic Science to Clinical Applicationpostprin

Accretion-induced Collapse of Dark Matter-admixed Rotating White Dwarfs: Dynamics and Gravitational-wave Signals

We present two-dimensional hydrodynamic simulations of the accretion-induced collapse (AIC) of rotating white dwarfs admixed with an extended component of dark matter (DM) comprising of sub-GeV degenerate fermionic DM particles. We find that the DM component would follow the collapse of the normal matter (NM) component to become a bound DM core. Thus, we demonstrate how a DM-admixed neutron star could form through DM-admixed AIC (DMAIC) for the first time, with the dynamics of DM taken into account. The gravitational-wave (GW) signature from the DMAIC shows distinctive features. In the diffusive DM limit, the DM admixture indirectly suppresses the post-bounce spectral peak of the NM GWs. In the compact DM limit, the collapse dynamics of the DM in a Milky Way event generate GWs that are strong enough to be detectable by Advanced LIGO as continuous low-frequency ($< 1000$ Hz) signals after the NM core bounce. Our study not only is the first-ever computation of GW from a collapsing DM object but also provides the key features to identify DM in AIC events through future GW detections.Comment: 14 pages, 13 figure