World Of Tourism

It has been long been known that bacteria swim by rotating their tail-like structure called the flagellum. (See the swimming bacteria in the figure.) The rotating motion of the flagellum is powered by a molecular engine located at the base of the flagellum. Just as engaging the clutch of a car connects its gear to its engine and delivers power to its wheels, engaging the molecular clutch of a bacterium connects its gear to its engine and delivers power to its flagellum.

Now, a paper appearing in the June 20 issue of Science describes, for the first time, how the flagellum's rotations are stopped so that bacteria stop moving. Here's how the stopping mechanism works: while a bacterium is swimming, it releases a protein (shown in red in the stationary bacterium in the figure) that flows between its gear and engine. The presence of this protein detaches the bacterium's gear from its engine and thereby stops the delivery of power to its flagellum. This process is analogous to disengaging the clutch of a car, which detaches its gear from its engine and thereby stops the delivery of power to its wheels.

Once the delivery of power to bacterium's flagellum stops, the flagellum stops rotating, and the bacterium's swimming ends.

An improved understanding of how flagella work may give nanotechnologists ideas about how to regulate tiny engines of their own creation. The flagellum is one of nature's smallest and most powerful motors. The flagellum of some bacteria can, for example, rotate more than 200 times per second, driven by 1,400 piconewton-nanometers of torque. That's quite a bit of (miniature) horsepower for a machine whose width stretches only a few dozen nanometers.

The research team was led by Kris Blair of the University of Indiana and included Daniel Kearns of the University of Indiana and Linda Turner and Howard Berg of Harvard University. Their study was funded by the National Science Foundation and the National Institutes of Health.

The sun is shining, the weather is sweet and I'm smiling. To be honest, it's more like a stupid grin. For some unknown reason, today feels good. I think this was the first morning in a string of mornings that I found myself smiling as I unlocked my car door. Then, to my delight, I heard on the radio that it's International Smile Day. What a coincidence! It feels like I'm strolling through a rerun of the Brady Bunch, smiling people and good, wholesome times. Maybe even something out of the Love Boat. Everyday should be International Smile Day.

Thinking of this day, I realized that people don't smile enough, laugh enough, play enough. The other night while brushing my teeth, my partner made a funny gesture, let's just say it was clean but not appropriate blog material and I almost fell over backwards laughing. I was clutching my stomach in sheer hilariousness (if there is such a word) and I couldn't honestly remember the last time I had laughed so hard. It felt amazing. Isn't it incredible what a gut wrenching laugh can do? What I don't understand is why we don't do it more often?

I was driving in my car this morning feeling like I could conquer the world and a car pulled up next to me at the robot. As I sat humming a tune and smiling form ear to ear, I looked over at a little boy sitting in the backseat, he looked a little miserable and sleepy. I remember those mornings on the way to school, the last thing I felt like doing was smiling. So as he turned to look at me with his blank stare and his chubby cheeks, I started dancing ad pulling faces at him, I was acting like a mad person. I started laughing and I could see a small smile of shock and maybe even a hint of amusement cross his face.

As I drove away, I found myself still having a good laugh for a few minutes. I like to think that he laughed too, even if it was at a crazy lady. Laughter truly is the best medicine and I will be smiling and laughing the whole of today and who knows maybe even tomorrow and the day after that and the day after that..........Let's hope happiness and cheer spreads like a wild fire, one small step that won't change the world but it's a start and that's all we really need. Keep smiling!

The following represents a clarification of EPA's policy concerning the regulation of imported and domestically produced kit cars and kit car packages. Kit vehicles are understood by EPA to typically involve new bodies, used drivetrains and new or used chassis. Used components may or may not be refurbished. This policy applies to kits or assembled kit cars only. This policy does not apply to regular production vehicles offered for importation into or produced in the United States.

1. Fully-assembled kit cars are "motor vehicles" under the Clean Air Act. Complete kit car packages are also "motor vehicles" under the Clean Air Act. These are packages which contain all of the major components needed for assembly (i.e., body, chassis, engine and transmission). As "motor vehicles" they are subject to all applicable emission regulations. If an assembled kit car or complete kit car package is offered for importation and the kit is not covered by an EPA certificate of conformity issued to an original equipment manufacturer, an EPA Form No. 3520-1 must be filed at the port of entry and the vehicle must be imported by an Independent Commercial Importer (ICI) eligible to import such vehicles or kits. The ICI then must ensure that the vehicle or kit complies with all applicable emission requirements.
2. An assembled kit car or complete kit car package which meets the following guidelines will be considered to be a rebuilt vehicle of a previously certified configuration and will be considered to be covered by that configuration's original EPA certificate of conformity.
   1. The components of the drivetrain (engine, transmission, differential) must be exclusively or substantially used and/or rebuilt. Regardless of the combination of new and used components, the engine must be used or used and rebuilt. The engine block and cylinder head(s) must be used, other components of the engine may be new. "Used" means the component has been in a vehicle that has been titled to an ultimate purchaser. A rebuilt component is defined as a used component which has been refurbished with new or other used parts.
   2. All emission-related components and settings must conform in all material respects to those of one previously certified configuration. Therefore, all part numbers for the emission-related components of a fully assembled kit vehicle or complete kit car package must match or be traceable to the numbers specified in the application for certification of a previously certified configuration.
   3. Consistent with EPA Advisory Circular (AC) 64, which deals with modifications performed before sale to the ultimate purchaser, the vehicle weight of the kit configuration can be no more than 500 pounds greater than the weight of the originally certified configuration.
   4. All catalytic converters, oxygen sensors, and charcoal canisters must be new, original equipment parts.
   5. Kit vehicles must: (1) have the same transmission configuration (i.e., manual, automatic, semi-automatic, number of forward gears, and shift calibration) as the originally certified configuration; and (2) consistent with AC 17F, have an N/V ratio (speed of vehicle in miles per hour/speed of engine in revolutions per minute) which matches the N/V ratio of the originally certified configuration within three (3) percent in every gear.*
      • *The Agency would consider minor variations to these limitations upon an appropriate demonstration that the altered configuration will meet Federal emission requirements.
   6. Each vehicle and its accompanying documentation must be clearly labeled as to the make, model year, engine family, subfamily, and tune-up specifications represented by the originally certified vehicle.
   7. If the originally certified configuration required unleaded fuel, then the vehicles must have fuel filler neck restrictors and unleaded fuel labels which meet the requirements of 40 CFR 80.24.
3. The production, sale and importation of automotive bodies alone (i.e., no chassis, engine or transmission) are not regulated by EPA since such units are not considered "motor vehicles" under the Clean Air Act. EPA form 3520-1 is not required for imported automotive bodies. A motor vehicle from which the engine has been removed is still a motor vehicle and is not considered a body.
4. The production, sale and importation of vehicle parts (engines, transmissions, chassis, vehicle bodies, etc.) are not regulated by EPA because parts are not considered motor vehicles under the Clean Air Act. However if the parts constitute a disassembled vehicle or an approximate disassembled vehicle, the combination is considered a motor vehicle under the Clean Air Act. Any attempt to use this policy to circumvent the Clean Air Act or the Imports regulations will be considered a violation of the Clean Air Act and will be strictly enforced. An example of such circumvention is:
   • A kit car maker who also provides the engine and transmission before or after production/importation of the body/chassis.
5. "Motor vehicles" must comply with the Clean Air Act and may not be disassembled nor purchased in a disassembled form for the purposes of evading the Clean Air Act or the Imports regulations. In these situations the kit car body/chassis combination must be certified by the manufacturer, must be in a configuration which was previously certified by EPA subject to the guidelines discussed at "2" above or, in the case of an importation, an EPA form 3520-1 must be filed at the port of entry and the vehicle imported by an eligible ICI who must ensure that the kit car body/chassis complies with all applicable emission requirements. At the present time, there are no ICIs eligible to import kit cars.
6. Except with regard to kit vehicles meeting the guidelines at "2" above; an individual or firm that assembles kits for hire or resale, that produces assembled kit cars for resale or that produces complete kit car packages for resale will be considered to be a manufacturer of new motor vehicles under the Clean Air Act. Such manufacturers and their vehicles are subject to all applicable regulations under the Act including civil penalties of up to $25,000 per vehicle for each new motor vehicle distributed in commerce, sold, offered for sale, or introduced, or delivered for introduction, into commerce, unless such vehicle is covered by a certificate of conformity issued by EPA.