The Body Surface Area

Today I deployed my first Google application developed with the Google app engine (GAE). You have to be connected to the internet and establish an account with Google to use it. BSA Calculator is a body surface area (BSA) calculator with a simple layout in font that the visually challenged like me can read without squinting. The large font may also be helpful to the busy physician using an iPhone.

Physicians regularly use body surface area to calculate drug doses for their patients. Notably, the dosing of chemotherapeutic drugs like Cisplatin is determined according to BSA. I use it to control my diet. When my BSA climbs over 2.1 m², it is high time for me to act.

Estimating human body surface is not trivial. It is difficult to develop one formula that fits all, simply because we come in a wide range of shapes and sizes and the relationship between body height and body weight changes considerably while we grow up. Medcalc provides a handful of methods and references. The suggested formulas have been empirically derived from measurements of height and weight. J.D. Current, 1998, and Than Vu, 1999, critically review the methods in use. Boyd, 1935, published one method that is still widely employed. In recent years the method of Mosteller, 1987, has gained popularity. Both are available in BSAcalc.

References:

• Boyd E (1935) The growth of the surface area of the human body. University of Minnesota Press, Minneapolis.
• Mosteller RD (1987) Simplified Calculation of Body Surface Area. New England Journal of Medicine 317: 1098.

The BSA calculator accepts only metric dimensions (Système International). You may use the converter below to convert body height and weight from inches and pounds to centimeters and kilograms, respectively. Enter the body height in inches in the inches box and click on the centimeter box. In analogy, enter the body weight in lbs into the pound box and click on the metric weight box:

[in] :	[cm]:
[lbs]:	[kg] :

Converter © Donate to the effort through PayPalhere.

Proceed to the BSA calculator.

Addendum

• A authoritative study by Sacks and others (2009) in the New England Journal of Medicine (360:859-873) demonstrates that we can diminish our weight on reduced-calorie diets (02/26/09).

Who Owns Your Site?

Recently, a friend of mine was pondering some existential questions about websites. She had started an own business selling customized arts and crafts over the internet. She found an appealing name for her site. She tells us on the site, how her real business grew from an unreal idea. The site offers to customers options to create the product they like to purchase. Sales have been taking off. The business shows all signs of success.

My friend is not a web expert and outsourced site development and administration.  Now, questions arise about the ownership of the site. The details of site registration have fundamental implications for ownership, particularly when the site name is synonymous with the brand and the businesses vitally depends on brand recognition. The person who registers the domain name of the site with the registrar may actually own that name. This person may also own the administrative privileges to add and delete data and permit other parties access to site administration. The administrator can potentially read the e-mails on the site.

For those who are not savvy in the use of the terminal command line, I found an easy way to obtain information about your site. Go to Broadband Report's whois browser application, type in your domain name, that is the site name without "www.",  and hit return. Check carefully that the entries match your expectations.

How to Build a Silent PC: Episode II

In episode I, I narrated my first experience with building a personal desktop computer, describing important discoveries I made in the process. Earlier this year I build my second PC. Below I shall summarize the essential lessons I learned.

The purpose of this project was to provide my son with a powerful computer to use for his graphics and arts work as well as his games. My son is learning animation with Maya and chess with Chessmaster.This computer would be stationed in his room. The first machine I built boasts 7 fans. The noise these fans collectively produce is considerable. You would not want to have them in your bedroom. Therefore, I was looking for a very quiet design.

On my search for the noiseless machine, I happened on cases for home theater personal computers (HTPC). Computers for the control of high fidelity entertainment centers must be designed noiseless. Compared with standard cases, the fans in these cases commonly run very quietly. As a drawback, I did not find a case with a small form factor. Even the cases, that can house micro-sized (mATX) motherboards, are not much smaller than mid-size towers. At the high end of the price range I are the impressive cases by Zalman. I opted for Antec's Fusion V2, which is comparatively low in price.

Owing to my good experience with Micro-Star International and Advanced Micro Devices, I chose the K9MM-V motherboard and an Athlon 64 3500+ Socket AM2 central processing unit (SKU:CP2-AM2-3500 AV). I purchased both in a bundle for a bargain price from TigerDirect. The "V"s are important. They indicate that board and processor are designed to fully support virtualization. Microsoft's Hyper-V virtualization software is under development and can be tested with a compatibility check utility that AMD provides for download. I opted for Microsoft's Windows XP Professional x64 as operating system to let my son run his applications smoothly and perhaps will use Xen for virtualization.

In my first assembly, I had the CPU pre-installed. This time, I mounted it myself, before placing the board in the case. It was straight forward. A close check of the instructions in the MSI manual sufficed. You must ground yourself, before you start! The designated corner of the CPU and has to match up with that of socket on the board. When the chip is properly aligned, the pins slip smoothly into the holes of the socket. No force is needed. The chip is fastened by pushing down a lever. Then, I applied an even layer of thermal grease and mounted Ultraproduct's Ultra X-Wind CPU cooler on top. The fan has a diameter of 92 mm and provides air flow at 53.5 CFM. The motherboard was ready to be placed in the case. Next, I filled the the board's memory slots with a pair of 1-GB PC2-5300 DDR2 modules from PNY. Before you order the memory modules, validate the specifications with the recommendations on the manufacturer's site.

The case came with a 430-W power supply with all necessary connectors attached and provided two internal and one external drive bay. I loaded one internal bay with a Seagate SATA hard drive. The SATA cable came with the motherboard. The board features a second SATA input. I may install another SATA drive in the empty bay. The external drive bay was reserved for the DVD/CD drive. I installed Mad Dog's TF-DVDRW TSH652G IDE drive and connected it to the motherboard with the round cable included in the MSI kit.

Micro-ATX motherboards are about 2" shorter than the regular ATX boards, but still accommodate standard PCI and AGP cards. This was important to me, because I had PCI cards in stock and wanted to be able to use AGP graphics cards. I swapped out the ATI Radeon 9600 Pro card used in my first project for a 9800 series card and installed the old card in this computer. The reason was an important discovery. If you use a mATX motherboard, ensure that the graphics card you intend to use matches the shorter length of this board. The ATI Radeon 9600 card was sufficiently short.

The motherboard accommodated all connections from the case, except the firewire port. Therefore, one of the three PCI slots had to be reserved for a USB/firewire card that I purchased from CompUSA. Another slot was taken by a wireless network adapter card. I chose Cisco's Linksys WMP54G v41. The Linksys software does not function properly with Windows XP x64. A compatible driver for the card can found at Ralink support. The driver that matched my card can be downloaded at PCI/mPCI/CB(RT256x/RT266x). After insertion of the PCI card, restart the computer and the hardware wizard will announce that new hardware was detected and prompt you for a driver. At this juncture, the wizard has to be manually pointed to the RT61 file in the Ralink folder under program files (x64). If the wizard does not prompt you, the driver can be loaded manually for the network adapter in the device manager. Should Ralink terminate its support for XP, the driver I used is available for download at BMI under downloads.

As useful amenities, I added Gyration's gyrotools. The compact keyboard is light-weight and short. The buttons have a good feel. The optical air mouse doubles as remote control.

Addendum

• This post and the links therein have been considerably updated on Peter Reviews Products & Procedures (10/22/2008).

For Pros! Beginners try the teaching edition available at Autodesk (use link in the above text).
If you need more advice, check out this book. I own several books in this series and found them helpful.

Sergeant York's School House

During World War I, the U.S. Department of War invited Robert Yerkes and his colleagues to develop and implement a series of tests examining the intellectual abilities of its soldiers. The tests known as the Army Alpha and Beta Tests constituted the first empirical aptitude and ability studies carried out with sample sizes (over 1 million participants) sufficient for rigorous statistical analysis. They uncovered appalling deficiencies in the education of Americans. The worrisome results jolted the country. Federal and state governments began to confront the challenges of offering an education to the broad populace that would meet the needs of a rapidly developing industrial nation. The test results eventually inspired the G.I. Bill of 1944.

The fabled World War I hero Sergeant Alvin C. York did not need sophisticated statistical analysis to recognize the shortcomings of education in his world. He owned a farm in East Tennessee and knew the problem first hand. After military service, he spent much energy and a large part of his own assets to found a secondary school for the children of Fentress County. The Alvin C. York Institute was founded in 1927. Classes began in 1929. Though much progress has been made since, great need remains. The Tennessee Economic Council on Women reports that 59 % of the women living in Fentress County graduated from high school in 2000. That is about 15 % fewer than in the nation, according to a recent National Women's Law Center report. Only 6 % graduated from a four-year college.

The Institute was eventually incorporated into the public school system. In 1980, the original building was deemed too expensive to repair. The old facilities were closed and new ones were built on the premises. Now the old building is slated to be torn down. It is registered in the National Register of Historic Places. Members of the York family and friends of the Institute are attempting to raise funds for its preservation.

The Tennessean's Rachel Stults reports in her article entitled "Family, preservationists rally to save York's dream" published Apr. 22, 2008, that the building's years may soon be counted. Restoration would cost a daunting $ 5-10 million. Neither the state nor the county government are prepared to provide this large sum for a project that does not seem to help address persistent urgent needs. Can there be a rationale for investing 10 million dollars in a dilapidated building far from any economic hub of note?

The answer is yes. Tennessee's countryside is beautiful. Costs of living are low. It is a perfect location for industries that do not need to be near metropolitan areas, yet want a seat in the U.S. Internet-oriented services and e-commerce come to mind. Such high technology-oriented enterprises commonly hesitate to settle in rural areas, because the local work force does not have the expertise they seek. Like any high school in this state, today's Alvin C. York Institute already attempts to seed the knowledge for such jobs. A learning center for computer sciences in secondary education would greatly enhance the effort. The center could lend OLPC to those who cannot afford a computer. The little machines are also known as XO computers. They constitute cost effective, robust and powerful slim clients. I wrote about them in my post on this site on December 7, 2007, and am writing this post on one.

Instruction in the use of computers would help the children to develop the understanding and the skills needed to embrace the world wide web and elicit interest in internet careers. The preparedness for college would improve. The center's seat in the building that Alvin C. York conceived to bring opportunity to his people through education would represent a beacon of hope for those who live in rural America and feel left behind by the innovations of the 21^st century. It would demonstrate that York's dream can be fulfilled. The symbolism is priceless.

Build Your Own PC: Episode I

I grew up in an era in which kids learned basic car maintenance so that they knew how to fix problems on the road. I have worked with computers daily for decades, and I found it more and more vexing that I did not have the slightest idea of what was going on inside them. I could not even point out the vital parts of the creature, once the abdomen was uncovered. One day four years ago, I decided that the best way to find out was to construct one from parts. Below, I summarize this experience.

The process was actually fun. The computer cost about $1,500.- including the extras. These days, a turn-key PC sells for as low as $200.-. Of course, that version does not come close to the performance of the computer I built and a bare-bones PC with a comparable performance would cost at least $500.-. I can only speculate whether that system would be equipped with the same quality parts. The consideration is similar to buying a home in a new development. The base price for the home may be economic, but the quality of the piping, the fixtures, the flooring, you name it, will be poor. You may look at early and costly repairs. Of course, you are offered pricey upgrades. I opted for quality parts. To keep the running costs low, I chose a 350 W power supply. Assuming that the computer is consuming half that wattage on average, the monthly expense for electricity is about $11.- in our utility district. We have got three computers in our household that essentially run 24/7. The expenses add up accordingly.

It may seem dated to describe my first experience with computer assembly four years after the fact. Earlier this year, I build my second computer incorporating the lessons I learned from the first. Hence, I sum up the earlier experience in a first installment and will post important aspects of the most recent experience in a second installment.

I wanted a machine that could process great amounts of imaging data fast. I chose an MSI K8T MASTER2-FAR motherboard that accommodated two 64-bit AMD Opteron 242 central processing units (CPUs). I opted for this architecture at the time because it is compatible with Sun Microsystem's Solaris 10 operating system and I needed to run an application that was specifically compiled for Solaris. The latter is doubtlessly an advanced operating system geared toward servers supporting large networks and by far exceeds my small purpose. I found it more appropriate eventually to run the machine with Ubuntu's Linux-based operating system (currently version 8.04). The latter provides up-to-date Gnome and KDE desktops and the recent upgrades have proved flawless in execution and very stable.

Unfortunately, my CPUs are not yet the type that is enabled for virtualization. Thus, running virtual machines is not as efficient as with more recent AMD CPUs (look for "-V" in the name). Despite this shortcoming, I am running Microsoft's Windows XP on QEMU with satisfactory results.

I bought most parts from internet vendors. At the time, I did not feel confident enough to mount the CPUs myself and had that done for a small fee by Spartan Technologies from whom I purchased the motherboard, the processors and coolers. Everything else I put together. The assembly did not require a great level of experience and was straight forward. Following the instructions provided in MSI's motherboard manual was a safe route to success. An important rule to obey is ensuring that you are not statically charged by electrically grounding yourself before you touch any parts. That is, tape the exposed end of a copper cable to the skin of your arm with medical tape and wrap the other exposed end tightly around a water faucet in your kitchen or bathroom. Waterlines provide the best connection with the ground. At first, I was confused by the great variety of power supply connectors and the many different adapters. Closely studying the drawings and photographs in the MSI manual straightened out the misunderstandings. My choice of hard drives, the memory, the CD/DVD writer and the graphics card was guided by the list on the motherboard retailer's website of items that other customers bought with the motherboard. In the meantime, I have developed a few own preferences:

• I chose a Cooler Master Centurion CAC-T05 tower case and a Thermaltake Purepower 350W power supply.

• I prefer Kingston Technology memory. I purchased HyperX DDR400 PC3200R memory (KRX3200AK2/1G) for this machine. Before you order the memory modules, validate the specifications with the recommendations on the manufacturer's site.
  

• I prefer hard drives manufactured by Seagate Technology. They really served me well over the years. One is 15 years old and still works without fail. I decided to use two SATA drives mirrored in a RAID for user data. Both drives could be connected directly to the motherboard. An additional ATA drive stores the operating system.

• I chose Pioneer's DVD/CD writer DVR-108, perhaps because my first hifi headset was made by Pioneer.

• Unfortunately, the motherboard does not provide on-board firewire connectors. If firewire connectivity is desired, a PCI card needs to be installed, taking up one slot.

• I prefer the more expensive flexible rounded cables to connect the ATA hard drive and the DVD/CD writer to the motherboard over the conventional flat cables. The rounded cables come in lengths that match the distances in the case and are more flexible and thus easier to bend. A rounded ATA cable came with the motherboard. However, it was too long and stiff. I bought extra sets from directron.com. In general, SATA cable connectors are flimsy. While moving the computer to another room, they shook lose on the motherboard side, resulting in BIOS errors at boot time. I felt tempted to glue them in place with Silicon glue, but refrained.
  

• The MSI motherboard has four slots for PCI cards and one for an AGP graphics card. I chose a ATI Radeon 9600 Pro card. This card provides excellent support for a 19" LCD at 1024 x 768. I recommend to use a more upscale card for larger screens and higher resolutions. Moreover, I strongly recommend to ensure that the card of choice fits in the case before it is ordered. The Radeon 9600 card is comparably short. Upscale graphic cards can be quite long and the available space in the case must be shared with the thick cables connecting the hard drives and other peripherals to the motherboard. Room may run out even in a standard case for ATX-size motherboards.

• The heat sink on the Radeon 9600 graphics card processor and the fan are small. I decided to replace them with a copper heat sink and a larger fan I found at CompUSA (VGA Cooling Kit SKU 336044). The heat sink slightly egged on a capacitor on the card. I ground an indentation into the sink large enough for the components not to touch. Though rough, the solution improved cooling remarkably. Before mounting the heat sink on the processor, it is important to apply a thin layer of the thermal grease provided with the kit evenly on the chips surface. The kit came with a number of additional small heat sinks that can be glued on various integrated circuits on the board. I mounted them all, thinking that every little bit helps. The kit cost less than $20.- and visibly stabilized the cards performance. The screen does not flicker anymore when its hot. Finally, leaving the PCI slot next to the graphics card open considerably boosts heat dissipation.

• Running a wireless internet adapter PCI card on Linux is problematic. Before you order, ascertain that the manufacturer supports your operating system or, at least, that the drivers are available for the card of your choice. I have had satisfactory experience with D-Link's DWL-G520. Instructions for the installation and the configuration of the driver can be found here. By contrast, NETGEAR does not provide any support for Linux. An opensource project develops Linux drivers for ACX-111 chipset-based cards (e.g. NETGEAR's WG311). However, compiling and inserting kernel modules is needed, potentially interfering with your next kernel upgrade. You may be facing a new install instead of an upgrade.

• Finally, I can give some advice on fans. My computer houses seven fans, two in the case's front, one in the rear, one in the power supply, one on each CPU and one on the graphics card. As a result the machine vacuums up air-borne dust with remarkable efficiency. Once we had construction in the house several rooms away. An old wall was broken down. I forgot to turn off the computer on that day. The fine, invisible dust from the construction ruined the bearings of the spinners on the CPUs and the graphics card as well as the large fan in the case's rear. The fans did not stop spinning, but could not maintain the required speeds to cool the CPUs effectively. Temperatures reach more than 100° F (38° C) outside for several weeks over the summer where we live. It does not cool down much during the night and attempting to save on the electric bill exposed the CPUs to the risk of overheating. In this situation, the Cooler Master's Aerogate II fan and temperature control unit I had installed in one of the external bays in the case's front warned me of the impending disaster and saved the CPUs.

• I installed magnetic levitation fans and one of Y.S. Tech's tip magnetic driving (TMD) fans as replacements. I used teflon screws to mount the TMD fan. It is fabulous. A good demonstration of these fans can be found here.
  

Addendum

• This post and the links therein have been considerably updated on Peter Reviews Products & Procedures (10/22/2008).

You may wish to check out this
book, if you need more advice. I own a few in this series and found
them helpful.

Hurricanes & Brains

The networks of nerve cells in our brain are often described as self-organizing. That is, intrinsic features of the nerve cells and the fashion in which the cells relate determine the shape the network. However, the mechanisms underlying the capacity of the neural population to shape itself are poorly understood. Better insight may be gained from the examination of other natural phenomena with self-organizing properties that emerge from complex interactions between the phenomenon and its environment. In meteorology, hurricanes and tornadoes constitute examples of self-organization.

While I was a postdoctoral fellow at the National Institutes of Health 15 years ago, I was privileged to witness the presentation of a team of Russian researchers who developed a method to image changes in temperature within 0.1°  C on the surface of the brain through the skull. Local increases in temperature were associated with increases in cortical blood flow. Local cerebral blood flow, in turn, is related to nerve cell activity. The Russians sought to present a novel method to indirectly map cortical activity. Data obtained with this method was eventually reviewed years later in the journal Progress of Neurobiology.

In their presentation, the Russians showed temporal sequences of neural activation racing across cortex in a rat. The rat's whiskers on the face were stimulated. About one fifth of the rat's cortex processes sensory input from the whiskers. The animation showed bands of activation racing across the expanse of cortex nose-ward similar in appearance to tropical storms before the clouds coil around the center. This similarity sparked my interest in the development of tropical cyclones.

The hurricane season is about to begin. Reuters reported a week ago that an active Atlantic season is forecast. The National Hurricane Center (NHC) provides access to geographic information system (GIS) data that can be used as a starting point to examine the conditions conducive to self-organization. I am using Apple Macintosh computers for much of my work and compiled two software applications that may be useful in this process. One is a custom build of GRASS version 6.3 for Tiger. Version 7.0 for Leopard will be working before June 1. A demonstration of this application can be viewed at slideshare. The other application is a build of version 1.9 of degrib for Tiger. Version 1.91 for Leopard will be ready at the completion of GRASS 7.0. Instructions for the use of degrib can be found on the NHC web site. The applications run only on the Intel architecture. They are going to be available for download on my Sourceforge.net project site known as "Software for Small Budget Science". Join the effort!

Addenda

• Storms far out at sea may have interesting consequences. Watch this historic run or this year's Quicksilver Eddie Aikau Invitational held today (12/08/09):

• In this informative and richly illustrated report with the title "Studying Storms: NASA Looks For Hurricane's Secrets" aired today on NPR's Morning Edition, Jon Hamilton describes a meteorological reconnaissance mission examining Hurricane Karl. The cyclone formed in the Caribbean Sea and strengthened to a category 3 storm in less than a day after reaching the Gulf of Mexico where it made landfall near Veracruz on Sep. 17 (09/28/10).
  

About the World Wide Web and Access for Everybody

The steam engine and iron rails transformed our lives profoundly 200 years ago. The USA would be a very different place today without the railroad. I believe that the personal computer and the internet will transform our lives in even a more comprehensive fashion than the railroad. Unprecedented in our history, these tools enable us to exchange information globally and interact with each other almost instantly. In open source computing, people work together who live in Minsk, Mumbai, Shanghai and San Francisco, as if they sat across the street from each other. The resulting synergism is unprecedented in our history. On this post's day, SOURCEFORGE.NET hosts 164,138 projects and has 1,744,123 registered users.

It is essential for our future that everyone has access to the internet. Particularly, people in developing countries must not be left behind, if we wish to lessen the gap between the rich and the poor nations. That is why I encourage everybody to participate in the One Laptop per Child initiative.

Nicholas Negroponte, Professor at M.I.T., launched this initiative in 2002 with the idea to create a laptop computer affordable to people with little means. This computer was conceived to cost about $100.- and work anywhere, providing access to knowledge about our world to youngsters even in the remotest areas. The product ended up costing twice as much as initially hoped.

However, there is a way to ease the financial burden. When you participate in this initiative until Dec. 31, you purchase for a bit more than $400.- one computer for yourself and another for a kid somewhere out there who has hardly ever seen a sleek gadget like this before. I bought one for my ten year-old son. Imagine two sets of eyes beaming with curiosity and excitement, one set here and a second set somewhere else, when the kids unpack this wonder machine! Join in!

Addenda

• On Nov. 17, 2008, XO laptops can be purchased here (Oct. 18, 2008).
• Amazon is sold out for now (Jan. 12, 2009).
• Brian Stelter reported today in his The New York Times article entitled "Can CNN, the Go-to Site, Get You to Stay?" that cnn.com garners on average 1.7 billion page views per month. The web is the future (01/17/09)!
  
I could not emphasize the relevance of free global exchange of ideas better than Dr. Goodall in this 2002 presentation (07/07/10):

Broken Cups in Your OS X Cupboard

I work a lot with pictures professionally and have been using Apple computers for most of my career, except my Master's Thesis which I wrote on a DEC PDP 11. I was only a user. However, it always struck me with trepidation that I did not understand a thing of what was going on under the hood. I was eventually roped into computing, when the Apple operating system turned to UNIX around the year 2000. With the introduction of OS X, Apple had opened itself to Open Source computing which opened a new universe to me. Seven years later, I spent way more time with compiling packages than I ought to, and way more often than I liked, I ended up in a real fix. Regardless, the euphoria of empowerment outweighed the disappointment by far.

Today I report on one example of the kinds of adventure one may encounter on this road. Several months ago, I happened on the website of cups printing. Cups is the printing routine used in OS X. I found a pre-compiled binary of a more recent version than I had ready for installation. Since I wanted to be at the cutting edge, I downloaded the offering and installed it without reading the fine print. The result was that I could not print anymore. The fine print said that one had to re-install the operating system, if the update did not work. Oh!

I was not prepared to do that. So I compiled the most recent 1.4.x version for developers from source myself and installed it. After that, I could not even get passed the login window. I had a series of sweaty moments since then. I did not believe the functions that depend on cups! Much of OS X appears to depend on the cups library in one way or another. How can this be in the age decentralization? I managed to fix the problem by re-installing n older version in the single user mode.

Months later, I re-visited the cups website. The pre-compiled packages were gone, and it was recommended to try one the versions 1.3.x. After a number of tries, one of them worked and I offer the result on my SourceForge.net project (Software for Small Budget Science). The package is compiled with Tiger on Intel. It has worked well for me. Let my adventure be a warning.