697 research outputs found
Dopamine d1 receptor activity in the basolateral amygdala is important for mediating fear, reward and safety discrimination learning
Post traumatic stress disorder (PTSD) patients frequently show impairment in safety learning (Jovanovic, Kazama, Bachevalier, & Davis, 2012). Since the amygdala is known to be critical for emotional processing(Wassum & Izquierdo, 2015) and dopamine signaling in the amygdala is important for mediating both fear and reward learning, current experiments examined the role of dopamine signaling in the BLA in mediating both safety learning and reward seeking. We manipulated dopamine D1 receptor activity with a D1 receptor agonist (SKF 38393) or D1 receptor antagonist (SCH23390) either systemically or infused directly into the BLA 20 minutes prior to training rats in a fear-safety-reward cue discrimination learning task (Sangha, Chadick, & Janak, 2013). Systemic administration of either the D1 receptor agonist or antagonist impaired fear and safety discrimination learning. The systemic administration of the D1 receptor agonist, but not the antagonist, also impaired discriminative fear and discriminative reward seeking. BLA infusion of the agonist, but not the antagonist, replicated the impairment in fear and safety discrimination learning but not discriminative reward seeking. This study demonstrates that D1 receptor activity in the BLA is not needed for fear learning, safety learning or discriminative reward seeking, but an increase in dopamine D1 receptor activity within the BLA impairs fear suppression in the presence of the safety signal
The Polished MS-30 Stem With a Solid Centralizer: A Minimum 10-year Review of Radiological and Clinical Outcomes 拋光 MS-30 假體固體與實心置中器的結合:最少術後十年的造影和臨床結果
AbstractBackground/PurposeMS-30 is a triple tapered cemented femoral stem. Before 2005, it was used together with a solid centralizer. We wanted to investigate its effect on the migration behaviour and survivorship of polished stem with a minimum of 10 years.MethodsTwenty-seven hips in 26 patients were available for follow-up. The mean length of follow-up was 12.1 years. Clinical outcomes were documented with the Harris Hip Score. Radiographs were examined for evidence of aseptic loosening.ResultsThe average Harris Hip Score was 74.8. No stem was revised for aseptic loosening. Two stems (7.4%) developed radiolucent lines of more than 2 mm width with osteolysis. The mean subsidence was 0.77 mm. The survival rate at the 10th postoperative year, with aseptic loosening as the end point, was 100%.ConclusionThe polished MS-30 stem with a solid centralizer has a satisfactory long-term outcome. Its mean subsidence was less than that of other polished tapered stems reported in the literature
Mainland Chinese Tourists’ Expectations, Perceived Performance of and Satisfaction towards Shopping Malls in Hong Kong
Tourists from mainland China constitute one of the world's biggest and fastest-growing travel markets. The Hong Kong Tourism Board expects the frequency of the mainland Chinese tourists to grow steadily. One of the beneficiaries of this phenomenon is Hong Kong’s shopping malls. However, understanding of tourists from mainland China’s expectations from, perceived performance of and satisfaction with the shopping malls’ attributes in Hong Kong is inadequate. This study intends to fill this important gap. A survey questionnaire was employed for data collection. The main results reveal the mainland Chinese tourists’ levels of satisfaction, indifference and dissatisfaction as well as the relationship between shopping malls’ attributes and customer satisfaction
Six-Digit Stroke-based Chinese Input Method
Abstract-During the last three decades, more than one thousand Chinese input methods have been developed. However, people are still looking for better input methods in terms of easy to use, easy to remember, high input speed and small keypad implementation on handheld devices. The well-known strokebased Chinese input method using only five basic stroke types could achieve low learning curve and small numeric keypad implementation but its input speed is limited for complex Chinese characters with a lot of strokes. To tackle this problem, simplified stroke-based Chinese character and phrase coding methods using (3+3) rules are proposed in this paper. The proposed method only uses the first 3 stroke codes and the last 3 stroke codes to represent the first and last radical information of the character for achieving lower average code length and higher hit rate of first character on the candidate list. To further enhance the input speed, a very user-friendly (3+3) phrase coding rule is also proposed for inputting Chinese phrases in terms of 2-character, 3-character and long-character phrases. Three special key assignment designs are developed for practical implementation of the proposed Chinese character and phrase input method using conventional QWERTY keyboard, PC's numeric keypad and mobile phone 12-key keypad. Experimental results have shown that the proposed character coding can achieve lower average code length and higher Hit Rate of First Character as compared with conventional stroke-based method and some well-known Chinese input methods. The proposed coding rules are also very easy to use and remember
Multiple Block-Size Search Algorithm for Fast Block Motion Estimation
Abstract-Although variable block-size motion estimation provides significant video quality and coding efficiency improvement, it requires much higher computational complexity compared with fixed block size motion estimation. The reason is that the current motion estimation algorithms are mainly designed for fixed block size. Current variable block-size motion estimation implementation simply applies these existing motion estimation algorithms independently for different block sizes to find the best block size and the corresponding motion vector. Substantial computation is wasted because distortion data reuse among motion searches of different block sizes is not considered. In this paper, a motion estimation algorithm intrinsically designed for variable block-size video coding is presented. The proposed multiple block-size search (MBSS) algorithm unifies the motion searches for different block sizes into a single searching process instead of independently performing the search for each block size. In this unified search, the suboptimal motion vectors for different block sizes are used to determine the next search steps. Its prediction quality is comparable with that obtained by performing motion search for different block sizes independently while the computational load is substantially reduced. Experimental results show that the prediction quality of MBSS is similar to full search. Block matching, motion estimation, video coding, search pattern, directional search
What do we know about Housing Supply? The case of Hong Kong
The house price in Hong Kong is well-known to be "unaffordable." This paper relates the macroeconomy and the housing market of Hong Kong and argues that the housing supply plays a vital role in explaining the phenomenon. This paper also shows that there are some practical challenges in understanding the housing supply of Hong Kong, including the potentially complicated ownership structure of real estate development. While the discussion centers on the situation of Hong Kong, its lesson may also apply to the housing markets in other small open economies
What do we know about Housing Supply? The case of Hong Kong
The house price in Hong Kong is well-known to be "unaffordable." This paper relates the macroeconomy and the housing market of Hong Kong and argues that the housing supply plays a vital role in explaining the phenomenon. This paper also shows that there are some practical challenges in understanding the housing supply of Hong Kong, including the potentially complicated ownership structure of real estate development. While the discussion centers on the situation of Hong Kong, its lesson may also apply to the housing markets in other small open economies
Does an Oligopolistic Primary Market Matter? The Case of an Asian Housing Market
This paper takes advantage of the oligopolistic structure of the Hong Kong primary housing market and examines whether the time-variations of the market concentration are caused by or cause the variations of the local economic factors. The analysis also takes into consideration of the changes of the U.S. variables and commodity prices, which arguably may represent changes in the construction cost. We find clear evidence of time-varying responses of housing market variables to macroeconomic variables. Policy implications and directions for future research are also discussed
PLASER: Pronunciation Learning via Automatic Speech Recognition
PLASER is a multimedia tool with instant feedback designed to teach English pronunciation for high-school students of Hong Kong whose mother tongue is Cantonese Chinese. The objective is to teach correct pronunciation and not to assess a student's overall pronunciation quality. Major challenges related to speech recognition technology include: allowance for non-native accent, reliable and corrective feedbacks, and visualization of errors
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