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An accurate estimate of site-specific underground thermal properties from thermal response tests (TRTs) is vital to the efficient and sustainable use of ground source heat pump (GSHP) systems. During a conventional TRT, the ground is perturbed by a heat injection and the response is measured in time. Despite the simplicity of the concept, conventional TRT fails to take into account the ground thermal response to heat extraction, which may affect the reliability of the thermal properties derived. To address the problem, an improved TRT based on both heat injection and extraction was proposed in this study. The improvements were demonstrated with an in-situ test carried out in Taiyuan, China. The measurement results showed that the ground thermal conductivity in Taiyuan was 1.56 W/(m K) and the borehole thermal resistance was 0.22 (m K)/W. The results also showed that, in the case of Taiyuan, ground thermal conductivities derived solely from heat injection test and heat extraction test were, respectively, 7.6% higher and 8.3% lower than that from the improved TRT. Thus, compared with the conventional TRT, the improved TRT consisting of both heat injection and extraction tests can provide test data more accurately reflect the annual performance of GSHP systems.

Angelman syndrome (AS) is a neurodevelopmental disorder with unique behavioral phenotypes, seizures, and distinctive electroencephalographic (EEG) patterns. Recent studies identified motor, social communication, and learning and memory deficits in a CRISPR engineered rat model with a complete maternal deletion of theUbe3agene. It is unknown whether this model recapitulates other aspects of the clinical disorder. We report here the effect ofUbe3amaternal deletion in the rat on epileptiform activity, seizure threshold, and quantitative EEG. Using video-synchronized EEG (vEEG) monitoring, we assessed spectral power and epileptiform activity early postnatally through adulthood. While EEG power was similar to wild-type (WT) at 1.5 weeks postnatally, at all other ages analyzed, our findings were similar to the AS phenotype in mice and humans with significantly increased δ power. Analysis of epileptiform activity in juvenile and adult rats showed increased time spent in epileptiform activity in AS compared with WT rats. We evaluated seizure threshold using pentylenetetrazol (PTZ), audiogenic stimulus, and hyperthermia to provoke febrile seizures (FSs). Behavioral seizure scoring following PTZ induction revealed no difference in seizure threshold in AS rats, however behavioral recovery from the PTZ-induced seizure was longer in the adult group with significantly increased hippocampal epileptiform activity during this phase. When exposed to hyperthermia, AS rat pups showed a significantly lower temperature threshold to first seizure than WT. Our findings highlight an age-dependence for the EEG and epileptiform phenotypes in a preclinical model of AS, and support the use of quantitative EEG and increased δ power as a potential biomarker of AS.

Status epilepticus (SE) is a prevalent disorder associated with significant morbidity, including the development of epilepsy and mortality. Cardiac arrhythmias (i.e. inappropriate sinus tachycardia and bradycardia, asystole, and atrioventricular blocks) are observed in patients following SE. We characterized ictal (during a seizure) and interictal (between seizure) cardiac arrhythmogenesis following SE using continuous electrocardiography and video electroencephalography (vEEG) recordings throughout a 14-day monitoring period in an intrahippocampal chemoconvulsant mouse model that develops epilepsy. We quantified heart rhythm abnormalities and examined whether the frequency of cardiac events correlated with epileptiform activity, circadian (light/dark) cycle, the presence of seizures, and survival during this period of early epileptogenesis (the development of epilepsy) following SE. Shortly following SE, mice developed an increased interictal heart rate and heart rhythm abnormalities (i.e. sinus pause and sinus arrhythmias) when compared to control mice. Heart rhythm abnormalities were more frequent during the light cycle and were not correlated with increased epileptiform activity or seizure frequency. Finally, SE animals had early mortality, and a death event captured during vEEG recording demonstrated severe bradycardia prior to death. These cardiac changes occurred within 14 days after SE and may represent an early risk factor for sudden death following SE.

Though area in office buildings has expanded significantly in Hong Kong in the decade to 2013, increase in cooling energy use has been rather moderate. The factors and policy instruments that contributed to the impressive enhancement in energy usage efficiency are not available in published literature. Data of sixty-six office developments were examined to evaluate the role of policy instruments in bringing about the visible improvement. Numerical analyses reveal that use of chiller units with higher efficiency and fresh water cooling tower (FWCT) systems have contributed significantly to reduce cooling energy use of office space in Hong Kong. It is important to note that policies promulgated have played a key role in encouraging designers of office space to opt for energy efficient systems. The BEAM Plus certification for all public buildings has contributed the most (efficacy = 0.09) to the success in moderation of electricity consumption for cooling of office space. The FWCT scheme and the Building Energy Codes have had efficacies amounting to 0.076 and 0.026, respectively. Interestingly, the new OTTV requirement, used for regulation and monitoring of thermal performance of building envelopes, has had a negative rate of efficacy (0.018), implying that the government needs to review its appropriateness.

The heat source types in China were not limited to the coal, other types of energy were introduced into the heating energy consumption in recent years, and therefore the specific regional impact of the heating emissions could not be obtained accurately according to the current achievement. Based on this, this study aimed to quantify the impact of the heating emissions on the air quality in an efficient and accurate way. A new method was proposed for investigating the quantitative impact of the heating emissions on the air quality index in this paper and its assumptions and accuracy were verified as well. The data employed in this method is extracted from Ministry of Environmental Protection Data Centre, Qingyue open source and Shanghai Central Meteorological Observatory. The key prerequisites of the proposed method were discussed in this study. By calculating, the averaged absolute difference of the meteorological parameters, namely Clo, WD, WS and P, is 3.58%, 2.40%, 3.21% and 3.94%, respectively. The difference ratio of the industrial emissions relative to the total emissions is as low as 4.3%. The optimal principal component number is six for the proposed method, which can satisfy the accuracy requirement with minimum workload. Compared with the results in previous similar studies, the proposed method showed excellent performance in analyzing the regional impact of the heating emissions on ambient air quality in China. Moreover, a total of 64 North cities in China were analyzed based on the proposed method to promote the knowledge on the influence of heating emissions on the environmental quality and the related parameters were provided in this study.

The fresh water supply is finite, but the fresh water demand is infinite. A sustainable supply of fresh water is emerging as one of the most critical resource issues in the world. Hong Kong is one of the highest per capita fresh water users in the world. This has led to many government initiatives to promote water-saving habits in Hong Kong. However, after almost a decade of efforts, there has been no obvious reduction in consumption. Little has been done to identify the reason for this. Through the use of questionnaire surveys, site measurements, and controlled experiments, the aim of this study is to investigate the level of adoption of different water-saving habits, the most influential water-saving habits, and the barriers to the adoption of water-saving habits in residential buildings in Hong Kong. It was found that if the policies are targeted to break the identified barriers, then there is a potential for reducing the total domestic fresh water consumption in Hong Kong by 14.7%. It was also found that the knowledge of water scarcity and good water use habits are not the barriers to the adoption of water-saving habits in Hong Kong households. Rather, the government should draw public&rsquo, s attention to the environmental impact of water usage and the high fresh water consumption level of Hong Kong people to break the knowledge barrier and should re-examine the water tariff to break the motivation barrier. The results of this study provide useful information for decision makers in the context of water conservation in Hong Kong as well as elsewhere in the world.

Residential buildings represent a predominant source of energy consumption in most subtropical cities. To enhance the energy performance of this sector, the use of reversible room air-conditioners (RRACs) for combined space heating and domestic hot water (DHW) production is proposed. The idea arises from the fact that in subtropical regions RRACs sized for cooling always have excessive heating capacities to allow a parallel production of DHW. In order to assess the techno-economic feasibility of the proposed initiative, a representative housing estate in Hong Kong consisting of 12,800 residential units was selected for an extensive simulation study. Results confirmed the technical viability of the proposed system. It was found that a wide adoption of the technology has the potential to reduce 7.7% of Hong Kong residential energy consumption and 744,192 t of CO2e emissions. The tolerable capital cost (TCC) approach was adopted for yearly economic viability analysis. The average TCC for individual residential units was found ranging from HK$2,241 to HK$26,286 depending on the household size, electricity price, and economic settings. This study provides preliminary evidence to confirm the viability of the proposed technology and opens a new way for residential energy savings in Hong Kong and elsewhere in the subtropical.

Increase in cooling energy usage of the residential sector in Hong Kong has been moderate in the most recent ten years (2004–2013). Factors and drivers responsible for this are of interest to policy makers in search of performance improvement but such information is not available in extant literature. This paper reviews the policy instruments introduced in Hong Kong during this period of time and examines the different engineering factors contributing to improvements in cooling energy efficiency. Whether the policy instruments have been instrumental in bringing about changes in engineering design and thus improvement in cooling energy efficiency is evaluated on the basis of the equipment and building envelope characteristics of 64 residential developments in Hong Kong. Different statistical analyses reveal that the use of more energy efficient room air-conditioning units (COP), smaller window-to-wall ratios (WWR) and walls with higher U-values are the engineering factors (WallU) that have contributed to moderation of growth of energy consumption; these were driven by policies introduced by the Hong Kong Government. Regarding the sensitivity of the three engineering factors, it was found that COP was the highest amounting to 0.455, followed in descending order by WallU and WWR. Their sensitivities were 0.289 and 0.006, respectively.

Replacement of air-cooled chillers with water-cooled chillers for air-conditioning plants in existing buildings can yield a significant amount of energy savings, especially in a sub-tropical climate. However, due to variations in weather conditions and building operation patterns, the amount of actual energy saving is often uncertain in these retrofits. These uncertainties impose a risk of saving shortfalls when Energy Service Companies (ESCOs) guarantee building owners for a certain amount of energy savings in Energy Performance Contracting (EPC) projects. This study presents a probabilistic approach to estimating a range of possible energy savings with the associated confidence levels for chiller replacement in existing buildings, taking into account the annual variations in the influential parameters affecting energy savings. The influential factors include building cooling loads, system control and operation systems, as well as chiller plant characteristics. The proposed approach involves: the use of correlation analysis for identifying influential parameters; EnergyPlus for simulating energy use of chiller plant; and a Monte Carlo approach for simulating the probability of post-retrofit energy savings. A commercial building where the air-cooled chillers were replaced with water-cooled chillers is used to illustrate the proposed approach. Results show that the variations in annual energy savings for chiller replacement projects can be estimated with a defined degree of certainty. In the case study project, the possible annual energy savings during the post-retrofit period range from 1,149,000 kWh (37.6% of baseline consumption) to 1,504,000 kWh (49.2% of ditto) at 90% statistical significance. The risk mitigation measures for this type of energy retrofit are discussed as well.

The use of storage-enhanced heat recovery room air-conditioner (SEHRAC) to supply hot water and provide space cooling for energy saving has been confirmed effective, but the heat recovery process can lead to significant refrigerant pressure fluctuations. Whether an expansion device can function properly despite the fluctuations is decisive to the successful use of SEHRAC. Capillary tube (CT) and thermostatic expansion valve (TEV) are the two most used expansion devices in SEHRAC, but a suitable type has never been identified in extant literature. In this study, laboratory experiments were conducted to enable a side-by-side comparison of the two expansion devices. A prototype SEHRAC, which could be switched between the CT and TEV systems, was designed and setup in a test facility for two identical sets of experiments. For each set of experiments, a series of tests under different outdoor temperatures were conducted. It was found that an overall better performance was achieved by the TEV system. The space cooling and water heating capacities were on average 16.3–19.4% and 18.5–23.4% larger than the CT system. The overall coefficient of performance was also found 12.5–20.9% higher. The results confirmed that TEV is preferred for use in SEHRAC.

Compared with conventional energy retrofit projects, Energy Performance Contracting (EPC) projects present a different risk picture to the contracting parties as its primary focus is to deliver promised energy savings to building owners (hosts). This study aims to identify the key risks inherent in EPC projects, and investigate the hosts’ concerns on the use of EPC, as well as propose practical measures to enhance the wider adoption of EPC. Two separate questionnaire surveys were conducted with respondents comprising ESCOs (n = 34) and hosts (n = 168) in Hong Kong. Results indicate that the key risks to ESCOs are possible payment default of hosts after installation, uncertainty of baseline measurement, and increase in installation costs in EPC projects. For hosts, their primary concerns in considering the use of EPC include possible long payback periods, project complexities and repayment ability. In addition, the respondents agree with three practical measures to enhance the adoption of EPC in future, including the promotion of successful projects, modification of government procurement practices, and government's backup of loans. The findings of this study provide useful pointers to key stakeholders of EPC projects for harnessing their risk perceptions and mitigating their concerns on this procurement approach.

China building energy codes (CBEC) have been introduced for over two decades but little has been publicized in literature. LEED on the contrary is the most publicized building environmental assessment scheme. To enable better understanding of the compliance standards of CBEC, this paper presents the energy performance assessment results (represented by energy and energy cost savings) of three office buildings in China (one in Beijing and two in Shanghai) using the current versions of CBEC and LEED. The energy and energy cost savings of the three buildings were predicted based on hour-by-hour simulations using the weather data and energy tariffs of Beijing and Shanghai where the three studied buildings are located, and their actual building and system characteristics. The study revealed that LEED in general sets more stringent requirements than CBEC in indoor design conditions, building envelope characteristics and air-conditioning system features. Amongst various building end uses, energy use for air-conditioning was found dominating the assessment results, and the use of energy efficient measures not forming part of the baseline criteria, could lead to 2 to 5% reduction in the overall building energy use. The two schemes were benchmarked against BEAM Plus and their weaknesses were also unveiled.

Angelman syndrome (AS) is a genetic neurodevelopmental disorder, most commonly caused by deletion or mutation of the maternal allele of the UBE3A gene, with behavioral phenotypes and seizures as key features. Currently no treatment is available, and therapeutics are often ineffective in controlling AS-associated seizures. Previous publications using the Ube3a maternal deletion model have shown behavioral and seizure susceptibility phenotypes, however findings have been variable and merit characterization of electroencephalographic (EEG) activity. In this study, we extend previous studies comparing the effect of genetic background on the AS phenotype by investigating the behavioral profile, EEG activity, and seizure threshold. AS C57BL/6J mice displayed robust behavioral impairments, spontaneous EEG polyspikes, and increased cortical and hippocampal power primarily driven by delta and theta frequencies. AS 129 mice performed poorly on wire hang and contextual fear conditioning and exhibited a lower seizure threshold and altered spectral power. AS F1 hybrid mice (C57BL/6J × 129) showed milder behavioral impairments, infrequent EEG polyspikes, and fewer spectral power alterations. These findings indicate the effect of common genetic backgrounds on the Ube3a maternal deletion behavioral, EEG, and seizure threshold phenotypes. Our results will inform future studies on the optimal strain for evaluating therapeutics with different AS-like phenotypes.

Factors affecting a residential unit's price are always of interest to homebuyers and building developers, especially in a city like Hong Kong which is known for expensive housing. Literature review indicates that the governing factors can be categorized into architectural and environmental attributes. Among different methods commonly used for pricing, the hedonic price approach is viewed as the most suitable. However, the successful use of this method requires that homebuyers know and choose the attributes. Whilst choosing architectural attributes are not a problem for homebuyers, the same does not apply to environmental attributes. Previous studies by the authors have proposed some simple indicators for quantifying the environmental attributes. Based upon the developed performance indicators and the transaction records of two representative housing estates (Royal Ascot = RA and City One Shatin = COS), details of the properties, including transaction prices, architectural particulars and environmental characteristics were numerically transformed for the hedonic price analysis. The analysis results revealed that the willingness to pay (percentage of house price in parenthesis) for architectural and environmental attributes was HK$302.3/ft2 (5.8%) and HK$886.8/ft2 (28.2%), respectively, for RA and HK$1672.7/ft2 (31.9%) and HK$111.5/ft2 (3.5%) for COS. It was found that elasticity of substitution (ES) of environmental attributes contributed 3.4–13.3% of the property price, compared to 0.6–5.5% for architectural attributes., Highlights • Key architectural and environmental attributes affecting property price were identified. • Willingness to pay (WTP) and elasticity of substitution (ES) of the key attributes were determined using the hedonic price approach. • Homebuyers were found to be valuing the environmental attributes much higher than the architectural attributes. • The WTP and ES values as well as the findings revealed in this study are valuable information to building developers and homebuyers.

a b s t r a c t Storage-enhanced heat recovery room air-conditioner (SEHRAC) is considered one of the most effective measures to curb energy use in residential dwellings. However, little has been done on optimal design of the storage tank. For application in dense living environment like Hong Kong, another concern is whether or not the amount of recoverable heat can meet the household water heating demand. In this study, a typical residential estate in Hong Kong was chosen for supply and demand analysis. The analysis was based on hour-by-hour simulations using actual building characteristics and previously identified utilization patterns. It was found that with the use of SEHRAC, the daily cumulative recoverable heat far exceeds the daily household water heating demand. For optimal design of the storage tank, an air-conditioner model (REFMOD) was developed to enable ascertaining the operating parameters at the refrigerant side of SEHRAC. Other design requirements of the storage tank including the minimum required heat storage capacity and heat transfer effectiveness were determined. The potential energy and energy cost savings, as well as CO2 emission reduction for wider application of SEHRAC were estimated as 9.3% of the overall contribution of the residential sector in Hong Kong.

LEED and BEAM Plus have been formally launched for more than 10 years. They are the two most recognized building environmental assessment schemes in China. Previous works have been done on benchmarking the energy assessment of the two schemes. However, benchmarking was either based on their earlier versions of which substantial changes have been made, or focused on their assessment issues and metrics without making reference to actual building characteristics. This paper compares the energy performance assessment results of three new office buildings in China (one in Beijing and two in Shanghai) using current versions of LEED and BEAM Plus. The three office buildings were chosen for their similarities in design. The study revealed that despite the variations in different aspects between LEED and BEAM Plus, assessment results of the three studied buildings were comparable. Amongst various building end uses, energy use for air-conditioning was found dominating the assessment results. Comparison results also show that although different tariff systems are adopted in Beijing and Shanghai, the difference will not affect the assessment results as long as same tariff system is used for predicting the energy cost of the baseline and design cases.

Buildings are key target of policies that aim at promoting environmentally sustainable development. Amongst policy instruments that address environmental burdens incurred by buildings, labelling and certification schemes are arguably the most cost-effective. Since the first building environmental assessment scheme was launched in the 1990's, similar schemes have emerged in about 30 countries. These are mainly domestic schemes tailored to suit local contexts. Whilst most of these schemes take a voluntary, market driven approach, some have become a part of mandatory building approval requirements, though different certification schemes may co-exist in some regimes. Benchmarking the strengths and characteristics of different schemes has been advocated. In this connection, this paper provides a comprehensive review and comparison of the issues and metrics of five representative assessment schemes, namely, BREEAM, LEED, CASBEE, BEAM Plus and the Chinese scheme ESGB. Comparison of these five schemes shows that BREEAM and LEED are the most comprehensive. A two-phase certification method is adopted in LEED, CASBEE and BEAM Plus, which is considered preferable. Statistical analysis also reveals that there is a moderate degree of agreement amongst the five schemes on weights and ranks of weights allocated to five key assessment aspects. Through comparison, the weighting coefficients adopted by ESGB were found the most representative. Strengths and characteristics of the five schemes have been identified for reference of policy makers in developing their domestic schemes.

Desiccant cooling system for active humidity control and to conserve energy has been in commercial applications for over two decades. However, its use in humid wet markets has never been examined. A gas-fired desiccant cooling system has been installed in a wet market in Hong Kong. In this study, the annual energy saving in conjunction with the use of desiccant cooling system was investigated by in-situ measurements, site surveys and simulations. The verified computer model was used for further simulations. It was found that for the use of a minimum ventilation rate of 10.3 L/s/person, the use of desiccant cooling system as compared to conventional system saved 4% of the energy and could achieve the desired space conditions. A parametric study under various ventilation rates indicated that use of desiccant cooling system in wet markets in hot and humid Hong Kong would lead to energy and energy cost savings, as well as CO2 emission reduction amounting from 1% to 13%. The savings were more evident when wet markets were designed for a ventilation rate of 20 L/s/person. Furthermore, the actual occupancy profile, and lighting and small power densities determined in this study would be useful for future studies on wet market., Highlights • The study is motivated by an actual desiccant cooling system installed in a wet market in Hong Kong. • The study focuses on side-by-side comparison of the desiccant and conventional systems. • Desiccant cooling system can better achieve the desired space air conditions. • Desiccant cooling system can lead to energy, energy cost and CO2 emission savings. • The results are useful for wider application of alternative energy source for cooling of wet markets.

Visual Abstract, Numerous studies have shown epilepsy-associated cognitive deficits, but less is known about the effects of one single generalized seizure. Recent studies demonstrate that a single, self-limited seizure can result in memory deficits and induces hyperactive phosphoinositide 3-kinase/Akt (protein kinase B)/mechanistic target of rapamycin (PI3K/Akt/mTOR) signaling. However, the effect of a single seizure on subcellular structures such as dendritic spines and the role of aberrant PI3K/Akt/mTOR signaling in these seizure-induced changes are unclear. Using the pentylenetetrazole (PTZ) model, we induced a single generalized seizure in rats and: (1) further characterized short- and long-term hippocampal and amygdala-dependent memory deficits, (2) evaluated whether there are changes in dendritic spines, and (3) determined whether inhibiting hyperactive PI3K/Akt/mTOR signaling rescued these alterations. Using the PI3K inhibitor wortmannin (Wort), we partially rescued short- and long-term memory deficits and altered spine morphology. These studies provide evidence that pathological PI3K/Akt/mTOR signaling plays a role in seizure-induced memory deficits as well as aberrant spine morphology.

Excessive lead has been found in drinking water in Hong Kong in tests carried out in 2015. Investigations have identified that the problem in public rental housing estates was caused by the problematic solders used in the plumbing, and recommendations on enhancing the quality control system and strengthening the relevant water quality standards have been proposed. The cause for the same problem happening in other premises where soldering has not been adopted for water pipe connections is left unidentified. Considering the unidentified cause and the recommendations made, this study aims to identify the gaps in practice followed in Hong Kong for safeguarding the water quality of new installations. A holistic review of governing ordinances and regulations, products and materials used and the testing and commissioning requirements adopted in Hong Kong and elsewhere in the world were conducted. Based on international practices and parametric analysis, it was found that there are gaps in practices followed in Hong Kong, which are directly and indirectly leading to the lead-in-water crisis. Recommendations for improvement in the quality control system, and the water quality standards including the allowable lead content and leaching limit for products and materials and the testing and commissioning requirements on plumbing installations have been made. The review and the identified gaps would become useful reference for countries in strengthening their relevant water quality standards.

BREEAM, LEED, CASBEE, BEAM Plus and Chinese ESGB have been formally launched at different stages in the last twenty years. How well the certified and rated buildings compare with each other is always an interest of building designers and policy-makers. This paper presents a side-by-side comparison of energy use assessments of the five schemes. The comparisons are on the assessment method and criteria, default parameters, trade-offs allowed, performance scales, approved simulation tools, performance indicators and assessment results. Comparison results showed that all the five schemes are based on relative performance. It was also found that despite the variations in default parameters among the five schemes, market positions of certified buildings are comparable. LEED was found to be the most stringent and relatively less flexible in its assessment criteria. Nonetheless, the energy cost budget approach, adopted only by LEED, is able to fulfil emission reduction and cost saving objectives on the condition that a “fuel neutral” approach should be adopted.

The combined space cooling and hot water preheating system that utilizes the rejected condenser heat is considered one of the most cost effective energy conservation measures. However, simultaneous consumption characteristics are absent in public domain. Questionnaire surveys have been conducted to obtain the relevant information from 126 households residing in high-rise public rental residential buildings in Hong Kong, achieving a confidence level of 95%. The candidate households were selected by a convenience sampling approach, and the questionnaire was constructed using either forced-choice format or in numeric response format. The data obtained were verified by correlation analysis. Data collected includes the occupancy pattern, the installed air-conditioner and water heater characteristics, and the utilization pattern of air-conditioning and hot water. Based upon the collected data and site measurements, hourly, daily and monthly heat recovery and hot water heating demand profiles were established, as well as the correlation between tap water and outdoor air temperatures. The combined profiles enable the evaluation of the feasible use of the combined system, and for future sizing of hot water storage tanks. The potential energy and fuel cost saving associated with the use of the proposed combined system for typical public rental housing in Hong Kong was estimated to be 50%.

Summary Purpose: Kv4.2 subunits contribute to the pore-forming region of channels that express a transient, A-type K+ current (A-current) in hippocampal CA1 pyramidal cell dendrites. Here, the A-current plays an important role in signal processing and synaptic integration. Kv4.2 knockout mice show a near elimination of the A-current in area CA1 dendrites, producing increased excitability in this region. In these studies, we evaluated young adult Kv4.2 knockout mice for spontaneous seizures and the response to convulsant stimulation in the whole animal in vivo and in hippocampal slices in vitro. Methods: Electroencephalogram electrode-implanted Kv4.2 knockout and wild-type mice were observed for spontaneous behavioral and electrographic seizures. The latency to seizure and status epilepticus onset in Kv4.2 knockout and wild-type mice was assessed following intraperitoneal injection of kainate. Extracellular field potential recordings were performed in hippocampal slices from Kv4.2 knockout and wild-type mice following the bath application of bicuculline. Results: No spontaneous behavioral or electrographic seizures were observed in Kv4.2 knockout mice. Following kainate, Kv4.2 knockout mice demonstrated a decreased seizure and status epilepticus latency as well as increased mortality compared to wild-type littermates. The background strain modified the seizure susceptibility phenotype in Kv4.2 knockout mice. In response to bicuculline, slices from Kv4.2 knockout mice exhibited an increase in epileptiform bursting in area CA1 as compared to wild-type littermates. Discussion: These studies show that loss of Kv4.2 channels is associated with enhanced susceptibility to convulsant stimulation, supporting the concept that Kv4.2 deficiency may contribute to aberrant network excitability and regulate seizure threshold.

Mandatory energy codes to curb energy use of residential buildings have been formally launched in China for more than two decades but little has been publicized in literature. Similar codes are not available for residential buildings in Hong Kong, but most residential buildings in Hong Kong, especially public housing estates, are HK-BEAM certified to demonstrate their compliance with regulatory and basic design requirements. Given HK-BEAM is internationally recognized and there are doubts about the effectiveness of the China codes, how the energy efficiency of the HK-BEAM certified buildings compare with buildings in compliance with the China codes is of interest to most building designers and policy makers. This paper describes how the energy efficiency of a case study building in compliance with the China codes compare with the one in compliance with HK-BEAM. The energy simulation by HTB2 and BECRES reveal that the case study building in compliance with the China codes is 51.1% better in energy use. In the study, the relative impact of each compliance criterion on energy use and cooling load has been quantified by sensitivity analysis. The sensitivity values indicate that energy use is most sensitive to air-conditioning operation hours, indoor design temperature, coefficient of performance (COP) of the room air-conditioners (RAC) units, and the envelop characteristics. The results of this study indicate that a HK-BEAM certified building cannot satisfy the China codes requirements. This provides good reference to the policy makers, the building owners, and to the China and Hong Kong Governments when considering reciprocal recognition of building energy codes.

Water-cooled air-conditioning systems (WACS) are widely used in the commercial sector for energy efficiency, but not in the domestic sector. It has been found that there are no mathematical models and energy simulation programs to enable detailed investigation and evaluation into the energy performance of water-cooled air-conditioners. To improve the applicability of water-cooled air-conditioners in the domestic sector, the development of a prediction model for energy performance analysis is needed. This paper addresses the development of an empirical model for predicting the operational performance and energy consumption for the use of water-cooled air-conditioners. The model consists of four sub-models which has taken into account the energy consumption of the condenser water system. A prototype WACS was set up and tested in an environmental chamber to validate the resultant model. The overall COP of the WACS was found to be greater than 3 at 90% rated capacity. The predictions from the model compared well with the experimental results, with RMS error within 11%.

The latest (4/04 and 5/04) versions of the Hong Kong Building Environmental Assessment Method (HK-BEAM), one covering new buildings and the other existing buildings, have been formally launched in 2005. The paper describes the building energy performance assessment method in these latest HK-BEAM versions. With the use of the energy budget approach, the assessment framework is applicable to a wide range of buildings that may comprise different mixes of premises types. The new scheme provides bonus credits for provisions that allow utilization of renewable energy sources. For existing buildings, it makes allowances for plant performance degradation and constraints to implementation of improvement measures in existing buildings. So far, the new assessment method has been applied to six building developments, including commercial complexes and residential developments. The assessment results are presented and discussed in the paper.

Optimizing system configuration is always an interest of building designers. By statistical analysis of the design data of 50 commercial buildings in Hong Kong and the performance data of 186 chiller models, it is ascertained that the chiller capacity and the fraction of full-load capacity have little influence on the system’s energy performance. Following on this, this paper presents an evaluation of the energy performance of a multiple-chiller system consisting of 2–10 equally sized chillers. Such an analysis was based on performance data from three major manufacturers. It is found that the energy efficiency of multiple-chiller system improves with a higher number of chillers, and the maximum saving is estimated to be 9.5%. Based on the results of the study, a simplified model relating energy use with number of chillers has been established. The model can help designers more quickly determine how the energy efficiency can be weighted against other factors, such as the additional plant room space and the financial implications.

Many, but not all, rebate-type demand side management (DSM) programmes worldwide have met with success. The rebate rate offered is a critical factor to success but a rational rebate scale determination method that would help strike a proper balance between the incentive offered and the effectiveness of the programme is lacking. For the DSM programmes recently launched in Hong Kong, the rebate rates are disproportionate to the cost and performance of the promoted energy-saving measures, resulting in diverse participation rates among the programmes. This paper presents a conceptual framework for formulating the rebate scales for incentive-based DSM programmes for commercial buildings, which would attract participation of building owners and boost electricity saving. The establishment of the scale starts from developing a performance curve that relates the cost effectiveness and the long-term benefits of different energy-saving DSM measures. The rebate scale is set based on the premise that a proportionally higher rebate rate should be offered for the adoption of each additional measure, which would yield a diminished marginal rate of return. Analysis showed that replacing the current rebate scale by the proposed scale would lead to benefits, both to the building owners and the utility companies.

Regulatory control forms the bedrock of the environmental policies of many countries. Whilst this interventionist approach can ensure a certain minimum standard would be achieved, far greater results can be achieved if it is augmented by a voluntary assessment-scheme. The benefits of having both approaches are explored in the paper with reference to the building energy codes and a voluntary building environmental-performance assessment scheme HK-BEAM, both of which are being implemented in Hong Kong. Quantification of the possible range of energy saving was based on the design characteristics of 22 commercial buildings in Hong Kong. The need for and the benefits of using the energy assessments within HK-BEAM as an alternative compliance route to the building energy codes are confirmed and the compliance criteria are established. The potential energy-saving through the use of the regulatory and the voluntary-based approaches were estimated to be from about 8% to more than 30%.

Oversized equipment is one of the key factors for poor energy performance of commercial buildings in Hong Kong. Similar situations exist also in many buildings in different parts of the world. The use of realistic design criteria has been identified as an effective method to reduce the equipment oversizing problem. A set of realistic design criteria for lighting power density, occupation density, and appliances' load-intensity for various types of premises have been established based on data obtained in walk-through surveys of energy end-uses in 31 Hong Kong office buildings. Potential electricity savings through the use of realistic design criteria were estimated to be 6–22% of the electricity consumption of Hong Kong, which corresponds to an annual cost of HK$12.2–44.7 billion.

Extracelluar signal-regulated kinase (ERK) pathway activation has been demonstrated following convulsant stimulation; however, little is known about the molecular targets of ERK in seizure models. Recently, it has been shown that ERK phosphorylates Kv4.2 channels leading to down-regulation of channel function, and substantially alters dendritic excitability. In the kainate model of status epilepticus (SE), we investigated whether ERK phosphorylates Kv4.2 and whether the changes in Kv4.2 were evident at a synaptosomal level during SE. Western blotting was performed on rat hippocampal whole cell, membrane, synaptosomal, and surface biotinylated extracts following systemic kainate using an antibody generated against the Kv4.2 ERK sites and for Kv4.2, ERK, and phospho-ERK. ERK activation was associated with an increase in Kv4.2 phosphorylation during behavioral SE. During SE, ERK activation and Kv4.2 phosphorylation were evident at the whole cell and synaptosomal levels. In addition, while whole-cell preparations revealed no alterations in total Kv4.2 levels, a decrease in synaptosomal and surface expression of Kv4.2 was evident after prolonged SE. These results demonstrate ERK pathway coupling to Kv4.2 phosphorylation. The finding of decreased Kv4.2 levels in hippocampal synaptosomes and surface membranes suggest additional mechanisms for decreasing the dendritic A-current, which could lead to altered intrinsic membrane excitability during SE.