Diversion To learn better, take a nap It is by now well-established that sleep can be an important tool when it comes to enhancing memory and learning skills. Now, a new study has shed light on the role that dreams play in this important process. Led by scientists at Beth Israel Deaconess Medical Center (BIDMC) in the US, the new findings suggest that dreams may be the sleeping brain's way of telling us that it is hard at work on the process of memory consolidation, integrating our recent experiences to help us with performance-related tasks in the short run and, in the long run, translating this material into information that will have widespread application to our lives. "What's got us really excited, is that after nearly 100 years of debate about the function of dreams, this study tells us that dreams are the brain's way of processing, integrating and really understanding new information," explains senior author Dr Robert Stickgold, director of the Center for Sleep & Cognition at BIDMC and associate professor of psychiatry at Harvard Medical School. "Dreams are a clear indication that the sleeping brain is working on memories at multiple levels, including ways that will directly improve performance." At the outset, the authors hypothesised that dreaming about a learning experience during non-rapid eye movement (NREM) sleep would lead to improved performance on a hippocampus-dependent spatial memory task. (The hippocampus is a region of the brain responsible for storing spatial memory.) To test this hypothesis, the investigators had 99 subjects spend an hour training on a virtual maze task, a computer exercise in which they were asked to navigate and learn the layout of a complex 3D maze with the goal of reaching an endpoint as quickly as possible. Following this initial training, participants were assigned to either take a 90 min nap or engage in quiet activities but remain awake. At various times, subjects were also asked to describe what was going through their minds, or in the case of the nappers, what they had been dreaming about. Five hours after the initial exercise, the subjects were retested on the maze task. The results were striking. The non-nappers showed no signs of improvement on the second test -- even if they had reported thinking about the maze during their rest period. Similarly, the subjects who napped, but who did not report experiencing any maze-related dreams or thoughts during their sleep period, showed little, if any, improvement. But, the nappers who described dreaming about the task showed dramatic improvement, ten times more than that shown by those nappers who reported having no maze-related dreams. "These dreamers described various scenarios - seeing people at checkpoints in a maze, being lost in a bat cave, or even just hearing the background music from the computer game," explains first author Dr Erin Wamsley, a postdoctoral fellow at BIDMC and Harvard Medical School. These interpretations suggest that not only was sleep necessary to consolidate the information, but that the dreams were an outward reflection that the brain had been busy at work on this very task. The subjects who performed better were not more interested or motivated than the other subjects, but the authors noted one distinct difference. "The subjects who dreamed about the maze had done relatively poorly during training," explains Wamsley. "Our findings suggest that if something is difficult for you, it's more meaningful to you and the sleeping brain therefore focuses on that subject - it 'knows' you need to work on it to get better, and this seems to be where dreaming can be of most benefit." Furthermore, this memory processing was dependent on being in a sleeping state. Even when waking subjects rehearsed and reviewed the path of the maze in their minds, if they did not sleep, then they did not see any improvement, suggesting that there is something unique about the brain's physiology during sleep that permits this memory processing. "In fact," says Dr Stickgold, "this may be one of the main goals that led to the evolution of sleep. If you remain awake [following the test] you perform worse on the subsequent task. Your memory actually decays, no matter how much you might think about the maze. "We're not saying that when you learn something it is dreaming that causes you to remember it," he adds. "Rather, it appears that when you have a new experience it sets in motion a series of parallel events that allow the brain to consolidate and process memories." Ultimately, say the authors, the sleeping brain seems to be accomplishing two separate functions: while the hippocampus is processing information that is readily understandable (that is, navigating the maze), at the same time, the brain's higher cortical areas are applying this information to an issue that is more complex and less concrete (for example, how to navigate through a maze of job application forms). "Our [non-conscious] brain works on the things that it deems are most important," adds Dr Wamsley. "Every day, we are gathering and encountering tremendous amounts of information and new experiences," she adds. "It would seem that our dreams are asking the question: 'How do I use this information to inform my life?'" Could that coke lead to accelerated aging? Here's another reason to kick the soda habit. New research published online in the FASEB Journal shows that high levels of phosphates may add more 'pop' to sodas and processed foods than once thought. Researchers have found that the high levels of phosphates accelerate signs of aging and may also increase the prevalence and severity of age-related complications, such as chronic kidney disease and cardiovascular calcification; as well as induce severe muscle and skin atrophy. "Humans need a healthy diet and keeping the balance of phosphate in the diet may be important for a healthy life and longevity," said Dr M Shawkat Razzaque of the Department of Medicine, Infection & Immunity at the Harvard School of Dental Medicine in the US. "Avoid phosphate toxicity and enjoy a healthy life." To make this discovery, Dr Razzaque and colleagues examined the effects of high phosphate levels in three groups of mice. The first group of mice was missing a gene (klotho), which when absent, causes mice to have toxic levels of phosphate in their bodies. These mice lived 8 to 15 weeks. The second group of mice was missing the klotho gene and a second gene (NaPi2a), which when absent at the same time, substantially lowered the amount of phosphate in their bodies. These mice lived to 20 weeks. The third group of mice was like the second group (missing both the klotho and NaPi2a genes), except they were fed a high-phosphate diet. All of these mice died by 15 weeks, like those in the first group. This suggests that phosphate has toxic effects in mice, and may have a similar effect in other mammals, including humans. "Soda is the caffeine delivery vehicle of choice for millions of people worldwide, but comes with phosphorous as a passenger," said Dr Gerald Weissmann, editor-in-chief of the FASEB Journal. "This research suggests that our phosphorous balance influences the aging process, so don't tip it."

People become accustomed to a high-phosphate diet from an early age Climate Change Corner Electrical Blog

The dawn of building services in Hong Kong By Ir Prof Francis W H Yik, Ir Dr K T Chan, Dr C K Chau, Ir Dr W L Lee and Ir Dr Joseph H K Lai The research study on Hong Kong's building services profession, jointly undertaken by the Building Services Division of the Hong Kong Institution of Engineers and the Hong Kong Polytechnic University, included a review of the evolution of building services in Hong Kong. This short article is intended to share with readers of Hong Kong Engineer some interesting findings on the emergence of various building services in Hong Kong. Water supply and drainage Being necessities to human life, water supply and drainage were the first kinds of service provisions available in buildings in Hong Kong. Well before water supply became a municipal utility, primitive water supply systems made of bamboo were built to lead water from mountain streams into houses. In the early 1850s, the government constructed small tanks at the upper parts of main streams to store water for public use. Construction of the Pokfulam reservoir, the first reservoir in Hong Kong, started in the early 1860s and had undergone several phases of expansion by 1877. Thereafter, other reservoirs were built one after another (for example, Tai Tam and Wong Nai Chung reservoirs) and the water supply network was gradually expanded to cope with the rapid rise in water demand resulting from the growth in population and the expansion of urban areas in Hong Kong. In the early days, water was supplied for public use free of charge. There were restrictions on the hours of supply from public stand pipes but buildings with private plumbing systems were not subject to such restrictions, which led to wasteful use. From 1903 onwards, the government began to install water meters so that water users could be charged based on consumption (1). Poor provision of drainage facilities in buildings and the consequential health problems were key issues confronting the colonial government ever since Hong Kong came under British rule in 1842. Although the Buildings and Nuisances Ordinance of 1856 already made it unlawful to construct or reconstruct a house without a sufficient water closet and ashpit, enforcement of the law was not rigorous. Women and children normally used a pot whilst men had to resort to the use of public latrines. Night soil was handled manually, with contents of pots removed daily or once every several days. Typical houses had down pipes for disposal of kitchen wastewater, with the drains running from a kitchen to another below it until they reached a public sewer (2). In those days, making available living spaces for habitation was a more pressing concern than hygienic conditions to Chinese people in Hong Kong. However, the outbreak of the bubonic plague in 1894 rang the alarm that there was an imminent need to improve sanitary conditions in dwellings. Before World War II, dry closets were still used in Hong Kong and the traditional disposal method was to bury the waste. In the 1950s, 40% of all Hong Kong buildings were built in the pre-war years and most of them did not have a proper sewage system. In the late 50s, the use of water closets in individual flats was encouraged to enhance the sanitary conditions in the city. On 1 January 1965, a seawater flushing system was officially implemented in Hong Kong. Initially, use of seawater for flushing was charged according to the amount of water used. Since 1972, seawater flushing supplies have become free and there is no restriction on the amount of seawater that a household may use (1). Gas, phone and electricity In the later half of the 19th century, towngas, telephone and electricity became available in Hong Kong. The Hong Kong & China Gas Co Ltd, founded in 1862, was the first public utility company in Hong Kong. The company began to supply towngas in Hong Kong in 1864, to 500 street lamps and selected buildings through 24 km of mains (3). The telephone was first introduced to Hong Kong in 1877, extended to Kowloon in 1905 and then to the New Territories in 19314. The Hongkong Electric Co Ltd was established in 1889 and went into operation at 6:00pm on 1 December 1890, when it lit the first electric streetlight in Central, marking the dawn of the electric age in Hong Kong. The first power station was situated in Wan Chai and construction of the second in North Point commenced in 1915 (5). The CLP Group started out in 1901 as China Light & Power Co Ltd, supplying electricity to consumers in Kowloon and later in the New Territories as well (6). At the beginning of the 20th century, electricity was used primarily for lighting and powering factory machinery, but use of various domestic electric appliances including radios, electric fans and irons and refrigerators began to grow. Lifts in more prestigious buildings also started to emerge (6). The first lift in Hong Kong was installed at the Hong Kong Hotel in 1909 while the first escalator was installed much later, at the old Man Yee Building in 1957 (7). Radio Rediffusion began its wired radio broadcasting service in 1949 and launched its subscription-based television service on 29 May 19574. The Queen Mary Hospital was built before World War II and was, at the time, the most extensively equipped with building services systems, which included systems for electricity supply and limited emergency electricity supply, cold and hot water supply, diesel-fired boilers, drainage, towngas supply, medical gas supply, passenger and bed lifts, lighting and ceiling fans, radiators for winter space heating, refrigerators for cold storage, fire alarm break glass units and fire hydrants (8). Air-conditioning and fire services The third-generation headquarters of the Hongkong & Shanghai Banking Corporation (HSBC) (the predecessor of the current headquarters building), built in 1936 at 1 Queen's Road Central, was reportedly the first building in Hong Kong to be equipped with a central air-conditioning system (also one of the first with a steel frame structure) (9). Various government buildings built in the 1950s began to be equipped with central air-conditioning systems. American Engineering Corp and Jardine Engineering Corp were the first-generation contractors undertaking central air-conditioning system installation works in Hong Kong (8). Fully air-conditioned non-domestic buildings became increasingly common only in the 1960s. Air-conditioned premises started to become an attraction to customers, and later a necessity, for entertainment and catering businesses. The first generation of public housing blocks, which were built to accommodate victims of the 1953 Sek Kip Mei fire, were only provisioned with basic cold water supply and drainage (8). There were no electricity supply, kitchen or bathroom in individual flats; residents had to cook in the corridor outside their flats and use communal toilets and bathrooms in the buildings (10, 11). Public housing blocks built in the late 1950s became taller and were equipped with lifts and refuse chutes. Each flat had electricity supply, a dedicated kitchen and bathroom, and a balcony. For example, the So Uk Estate, which was first occupied in 1960, comprised several 16-storey blocks (12). Nonetheless, there were no fire hydrants or gas supply. Kerosene was the major fuel used by residents for cooking and water heating, which was later substituted by bottled LPG. Buildings built in the very early stage of Hong Kong's history hardly had any fire services provisions. The first fire brigade in Hong Kong was established in 1868, manned by a mix of policemen and volunteers, to provide the public with emergency fire-fighting services. The provision of fire services installations inside buildings was considered necessary as buildings became increasingly taller and more complex. Commencing on 7 February 1964, the Building Authority may refuse to grant approval or consent to work commencement if the submitted plans are not endorsed by the Director of Fire Services certifying his satisfaction with the minimum fire services provisions in a building (13). Although documented evidence has yet to be found, it is believed that fire services installations, such as fire alarms and hydrants, should have existed in buildings in Hong Kong long before their provision became a mandatory requirement (for example, Queen Mary Hospital as mentioned above). This is because, even in the absence of regulatory requirements, conditions in fire insurance policies would have compelled developers or owners to install fire services installations in their buildings as the Fire Insurance Association of Hong Kong was already in existence as early as 1895 (14). References 1. Water Services Department. http://www.info.gov.hk/water150/ 2. Pryor, E G: "A historical review of housing conditions in Hong Kong". http://sunzi1.lib.hku.hk/hkjo/view/44/4401232.pdf 3. Hong Kong and China Gas Co Ltd. http://www.towngas.com/ 4. PCCW Ltd, http://www.pccw.com/eng/AboutUs/CompanyProfile/Milestones.html 5. Cheng, S C: Past and present of Hong Kong - Issues of Interest (in Chinese; author's name and book title are translations of the authors of this article). Wan Li Book Co Ltd, 2005. 6. A Century of Light, CLP Centenary Souvenir Book, 2001. https://www.clpgroup.com/Abt/Res/Pub/Pages/default.aspx 7. E&M Safety News, May 2005. http://www.emsd.gov.hk/emsd/eng/pps/enm_safetynews_2005may.shtml 8. Kwok, P K: "The development of building services engineering in Hong Kong", in CIBSE Hong Kong Branch 25th Anniversary proceedings, The Chartered Institution of Building Services Engineers, Hong Kong Branch, November 2004. 9. Tse C H: Colonial Buildings of Hong Kong (in Chinese; author's name is translation of the authors of this article). Softrepublic Ltd, 2007. 10. Lung D P Y: "Urban development and buildings in Hong Kong", in Wang, G: Hong Kong History: New Perspectives, Vol 1, Ch 6, pp 211-279 (in Chinese). Joint Publishing (HK) Co Ltd, 1997. 11. Lim B and Nutt, T: "Planning and Location Aspects", in Yeung, Y M and Wong, T K Y (Ed): Fifty Years of Public Housing in Hong Kong - A Golden Jubilee Review and Appraisal. Chinese University Press, 2003. 12. Ng K C and Chu, C H: Memoirs of Architecture - Stories about the First Generation of Chinese Architects in Hong Kong (in Chinese; authors?names and book title are translations of the authors of this article). Economic Times Press, 2007. 13. McInnis, A: Butterworths Hong Kong Building Law Handbook, second edition, pg123. LexisNexis, 2002. 14. The Story of The Hong Kong Federation of Insurers. The Hong Kong Federation of Insurers, 1998. About the authors: Ir Prof Francis W H Yik, Ir Dr K T Chan, Dr C K Chau, Ir Dr W L Lee and Ir Dr Joseph H K Lai teach and undertake research at the Department of Building Services Engineering, the Hong Kong Polytechnic University.

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