Exploring influencing factors of short-lived buildings in China's urban renewal : evidence from Chongqing

With the fast development of urban sprawl and renewal in China, many buildings are ���non-nature��� short-lived, i.e. demolished after only a few years. For this concern, this research explores the influencing factors of short-lived buildings and provides the scientific foundation for sustainable urban management and planning. Cases for this research are 1734 buildings demolished in Jiangbei district, the middle region of Chongqing City. Internal and external factors for the short-lived buildings are identified by applying logistic analysis. The results indicate that nine factors have significant influence on short-lived buildings. This research also find that buildings with low density, utilization and compensation while high land development potential are more likely to become short-lived buildings.

Investigation on mechanical behaviour of AM60 magnesium alloys

Purpose: In this work, tension, impact, bend and fatigue tests were conducted in an AM60 magnesium alloy. The effects of environmental temperature and loading rates on impact and tension behavior of the alloy were also investigated. Design/methodology/approach: The tests were conducted using an Instron universal testing machine. The loading speed was changed from 1 mm/min to 300 mm/min to gain a better understanding of the effect of strain rate. To understand the failure behavior of this alloy at different environmental temperatures, Charpy impact test was conducted in a range of temperatures (-40~35��C). Plane strain fracture toughness (KIC) was evaluated using compact tension (CT) specimen. To gain a better understanding of the failure mechanisms, all fracture surfaces were observed using scanning electron microscopy (SEM). In addition, fatigue behavior of this alloy was estimated using tension test under tension-tension condition at 30 Hz. The stress amplitude was selected in the range of 20~50 MPa to obtain the S-N curve. Findings: The tensile test indicated that the mechanical properties were not sensitive to the strain rates applied (3.3x10-4~0.1) and the plastic deformation was dominated by twining mediated slip. The impact energy is not sensitive to the environmental temperature. The plane strain fracture toughness and fatigue limit were evaluated and the average values were 7.6 MPa.m1/2 and 25 MPa, respectively. Practical implications: Tested materials AM60 Mg alloy can be applied among others in automotive industry aerospace, communication and computer industry. Originality/value: Many investigations have been conducted to develop new Mg alloys with improved stiffness and ductility. On the other hand, relatively less attention has been paid to the failure mechanisms of Mg alloys, such as brittle fracture and fatigue, subjected to different environmental or loading conditions. In this work, tension, impact, bend and fatigue tests were conducted in an AM60 magnesium alloy.

Enhancing Research Productivity of TEFL Academic in China : A Mixed Method Study

As research has become an important indicator of TEFL academics��� overall performance in Chinese higher education institutions, it is critical that TEFL academics are able to meet the expectation of conducting research. This mixed-method study (an initial survey followed by a qualitative collective case study)investigated research productivity of Chinese TEFL academics and associated influences, with the ultimate objective of constructing a framework to help build their research capacity in the future. The findings from this study revealed that the 182 Chinese TEFL academics��� research productivity during 2004-2008 was relatively low. Four influences were identified that impacted on thier research productivity: TEFL disciplinary influences, institutional and departmental research environments, individual characteristics desirable for research, and TEFL academics��� perceptions about research. Drawing upon the above findings, a Framework towards Enhancing Chinese TEFL Academics��� Research Productivity (FECTARP) was constructed. The FECTAR presented a framework for Chinese institutions and TEFL departments to enhance their TEFL academics' research capacity.

The effect of ��-alanine on buffering capacity and exercise performance during and following high-intensity exercise in healthy males

Intense exercise induced acidosis occurs after accumulation of hydrogen ions as by-products of anaerobic metabolism. Oral ingestion of ��-alanine, a limiting precursor of the intracellular physiochemical buffer carnosine in skeletal muscle, may counteract detrimental effects of acidosis and benefit performance. This study aimed to investigate the effect of ��-alanine as an ergogenic aid during high intensity exercise performance. Five healthy males ingested either ��-alanine or placebo (Pl) (CaCO3) in a crossover design with 6 wk washout between. Participants performed two different intense exercise protocols over consecutive days. On the first day a repeated sprint ability (RSA) test was performed. On the second day a cycling capacity test measuring the time to exhaustion (TTE) was performed at 110% of maximum workload achieved in a pre supplementation max test (CCT110%). Non-invasive quantification of carnosine, prior to, and following each supplementation, with in vivo magnetic resonance spectrometry was performed in the soleus and gastrocnemius muscle. Time to fatigue (CCT110%), peak and mean power (RSA), blood pH, and plasma lactate were measured. Muscle carnosine concentration was not different prior to ��-alanine supplementation and increased 18% in the soleus and 26% in the gastrocnemius, respectively after supplementation. There was no difference in the measured performance variables during the RSA test (peak and average power output). TTE during the CCT110% was significantly enhanced following the ingestion of BAl (155s �� 19.03) compared to Pl (134s �� 26.16). No changes were observed in blood pH during either exercise protocol and during the recovery from exercise. Plasma lactate after BAI was significantly higher than Pl only from the 15th minute following exercise during the CCT110%. Greater muscle carnosine content following 6wk supplementation of ��-alanine enhanced the potential for intracellular buffering capacity. This translated into enhanced performance during the CCT110% high intensity cycling exercise protocol but not during the RSA test. The lack of change in plasma lactate or blood pH indicates that 6wks ��-alanine supplementation has no effect on anaerobic metabolism during multiple-bout high-intensity exercise. Changes measured in plasma lactate during recovery support the hypothesis that ��-alanine supplementation may affect anaerobic metabolism particularly during single bout high intensity.

Chinese TEFL teachers��� perceptions about research and influences on their research endeavours

English has always occupied a key position in China���s education. The quality of English education depends largely on the quality of the English teaching force. Improving the overall quality of Teaching English as a Foreign Language (TEFL) teachers entails advancing both their teaching and research competence. This study, with its focus on Chinese TEFL teachers working in a higher education institution, was set up in a context where Chinese higher education colleges are being transformed into universities and research is becoming a crucial aspect of all teachers��� work. This small-scale case study investigated a group of Chinese TEFL teachers��� perceptions about research and their individual and workplace characteristics that influenced their research endeavours. The findings revealed that Chinese TEFL teachers recognised the significance of research for teaching, professional growth and career advancement. However, lack of individual characteristics such as research and disciplinary knowledge, confidence in research and intrinsic motivation impeded their research efforts. Their institution and departments seemed to encourage research; yet, more specific financial and academic support to start and sustain their research endeavours is required. This study���s findings provide implications for both individual teachers and their institutions to engage TEFL teachers more actively in research.

A BIM-based collaborative design platform for variegated specialty design

With the increase in complexity of engineering projects and design quality in the construction industry, the traditional two-dimensional "Information Island" approach to design is becoming less able to meet current design needs due to its lack of coordination and information sharing. Collaborative design using a Build Information Modeling (BIM) technology platform promises to provide an effective means of designing and communicating through networking and real-time data sharing. This paper first analyzes the shortcomings of the two-dimensional design process and the potential application of collaborative design. By combining the attributes of BIM, a preliminary BIM-based building design collaborative platform is developed to improve the design approach and support a more collaborative design process. A real-life case is presented to demonstrate the feasibility and validity of the platform and its use in practice. From this, it is shown that BIM has the potential to realize effective information sharing and reduce errors, thereby improving design quality. The BIM-based building design collaborative platform presented is expected to provide the support needed for the extensive application of BIM in collaborative design and promote a new attitude to project management.

Improving safety communication of ethnic minorities in the construction industry of Hong Kong

The construction workforce in Hong Kong is experiencing a severe ageing problem and labour shortage. One initiative to enhance the supply of manpower is to assist ethnic minorities joining the industry. It is foreseeable that the percentage of ethnic minorities in the construction workforce will keep increasing. Statistics show that ethnic minorities were nearly 30% more likely to have work-related injuries than local workers in some developed countries. However, official statistics on the safety of ethnic minorities are not available in Hong Kong. A search in newspaper archive revealed that ethnic minorities in the construction industry of Hong Kong are subjected to higher fatality rate than local workers, just as is the case in many developed countries. This reflects that the safety of ethnic minorities has not received the attention it rightly deserves. Safety communication has been one of the key factors leading to accidents. Safety communication barriers of ethnic minorities impede them from receiving safety training and acquiring safety information effectively. Research towards improving the safety communication of ethnic minorities in the construction industry of Hong Kong becomes more urgent. This paper will provides an initial report on a research project which focuses on improving the safety communication of ethnic minorities in the construction industry of Hong Kong. Quantitative and qualitative research methods including Social Network Analysis (SNA) applied in conducting the research are first discussed. Preliminary statistics of construction accidents related to ethnic minorities in Hong Kong are then presented.

Conformational Spread as a Mechanism for Cooperativity in the Bacterial Flagellar Switch

The bacterial flagellar switch that controls the direction of flagellar rotation during Chemotaxis has a highly cooperative response. This has previously been understood in terms of the classic two-state, concerted model of allosteric regulation. Here, we used high-resolution optical microscopy to observe switching of single motors and uncover the stochastic multistate nature of the switch. Our observations are in detailed quantitative agreement with a recent general model of allosteric cooperativity that exhibits conformational spread-the stochastic growth and shrinkage of domains of adjacent subunits sharing a particular conformational state. We expect that conformational spread will be important in explaining cooperativity in other large signaling complexes.

Conformational Spread in the Flagellar Motor Switch: A Model Study

The reliable response to weak biological signals requires that they be amplified with fidelity. In E. coli, the flagellar motors that control swimming can switch direction in response to very small changes in the concentration of the signaling protein CheY-P, but how this works is not well understood. A recently proposed allosteric model based on cooperative conformational spread in a ring of identical protomers seems promising as it is able to qualitatively reproduce switching, locked state behavior and Hill coefficient values measured for the rotary motor. In this paper we undertook a comprehensive simulation study to analyze the behavior of this model in detail and made predictions on three experimentally observable quantities: switch time distribution, locked state interval distribution, Hill coefficient of the switch response. We parameterized the model using experimental measurements, finding excellent agreement with published data on motor behavior. Analysis of the simulated switching dynamics revealed a mechanism for chemotactic ultrasensitivity, in which cooperativity is indispensable for realizing both coherent switching and effective amplification. These results showed how cells can combine elements of analog and digital control to produce switches that are simultaneously sensitive and reliable. �� 2012 Ma et al.

The mechanical and inflammatory low back pain (MIL) index: development and validation

Abstract Background The purpose of this study was the development of a valid and reliable ���Mechanical and Inflammatory Low Back Pain Index��� (MIL) for assessment of non-specific low back pain (NSLBP). This 7-item tool assists practitioners in determining whether symptoms are predominantly mechanical or inflammatory. Methods Participants (n���=���170, 96 females, age���=���38��������14 years-old) with NSLP were referred to two Spanish physiotherapy clinics and completed the MIL and the following measures: the Roland Morris Questionnaire (RMQ), SF-12 and ���Backache Index��� (BAI) physical assessment test. For test-retest reliability, 37 consecutive patients were assessed at baseline and three days later during a non-treatment period. Face and content validity, practical characteristics, factor analysis, internal consistency, discriminant validity and convergent validity were assessed from the full sample. Results A total of 27 potential items that had been identified for inclusion were subsequently reduced to 11 by an expert panel. Four items were then removed due to cross-loading under confirmatory factor analysis where a two-factor model yielded a good fit to the data (��2���=���14.80, df���=���13, p���=���0.37, CFI���=���0.98, and RMSEA���=���0.029). The internal consistency was moderate (�����=���0.68 for MLBP; 0.72 for ILBP), test-retest reliability high (ICC���=���0.91; 95%CI���=���0.88-0.93) and discriminant validity good for either MLBP (AUC���=���0.74) and ILBP (AUC���=���0.92). Convergent validity was demonstrated through similar but weak correlations between the ILBP and both the RMQ and BAI (r���=���0.34, p���<���0.001) and the MLBP and BAI (r���=���0.38, p���<���0.001). Conclusions The MIL is a valid and reliable clinical tool for patients with NSLBP that discriminates between mechanical and inflammatory LBP. Keywords: Low back pain; Psychometrics properties; Pain measurement; Screening tool; Inflammatory; Mechanical

Visible light enhanced oxidant free dehydrogenation of aromatic alcohols using Au-Pd alloy nanoparticle catalysts

We find that visible light irradiation of gold���palladium alloy nanoparticles supported on photocatalytically inert ZrO2 significantly enhances their catalytic activity for oxidant-free dehydrogenation of aromatic alcohols to the corresponding aldehydes at ambient temperatures. Dehydrogenation is also the dominant process in the selective oxidation of the alcohols to the corresponding aldehydes with molecular oxygen. The alloy nanoparticles strongly absorb light and exhibit superior catalytic and photocatalytic activity when compared to either pure palladium or gold nanoparticles. Analysis with a free electron gas model for the bulk alloy structure reveals that the alloying increases the surface charge heterogeneity on the alloy particle surface, which enhances the interaction between the alcohol molecules and the metal NPs. The increased surface charge heterogeneity of the alloy particles is confirmed with density function theory applied to small alloy clusters. Optimal catalytic activity was observed with a Au : Pd molar ratio of 1 : 186, which is in good agreement with the theoretical analysis. The rate-determining step of the dehydrogenation is hydrogen abstraction. The conduction electrons of the nanoparticles are photo-excited by the incident light giving them the necessary energy to be injected into the adsorbed alcohol molecules, promoting the hydrogen abstraction. The strong chemical adsorption of alcohol molecules facilitates this electron transfer. The results show that the alloy nanoparticles efficiently couple thermal and photonic energy sources to drive the dehydrogenation. These findings provide useful insight into the design of catalysts that utilize light for various organic syntheses at ambient temperatures.

Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects on proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration.