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Journal of Scienti fic & Industri al Research

Vol. 6 1, May 2002, pp 395-402

SCI-TECH UPDATE

Vector graphics on the web

Multimedia technology is an increas ing ly im­portant part of the web. Therefore, multimedi a vendors are looking for better ways to present content s with a moti ve of maintaining the competi­ti ve edge. Scalable vector graphics (SVG) has assumed importance for the reason. At present , bitmap based image-formats are in use, viz, GIF (graphics ill terchange fo rmat), PNG (po rtable Iletwork graphics) and JPEG (des igned by the Joint Photographic Experts Group) and they could be large even after data compress ion and normally do not sca le well. Vector-graphics, on the other hand , do not have proble ms but the techno logy is proprie tary and incompatible. The World Wide Web Consortium (W3C) probably have solved the probl em with the release of an open SVG standard with broad industry support.

SVG was created by Mi crosoft , Netscape, and Opera Software, the browser deve lopers, and the web-design companies li ke Adobe Systems, Core l, Eas tman Kodak, Macromedi a, and Quark . SVG images are li ghtweight and loo k the same on hi gh reso luti on screens, as in workstati ons, or on a smart phone's tiny monochrome screen, limited onl y by the browser capabilities. SVG will le t the mobile dev ices and web-service industries prov ide a means for people to communicate and ex perience graphi cs more quickl y and more dynamicall y on any platform, and in any pl ace. The technology will a lso make the graphical-data exchange feas ible, eas ier, and eco­nomical over di ffe rent pl at forms, according to Vincent Hardy, an SVG-spec ificati on author and seni or staff engineer with the Sun M icrosystems. However, SVG may not be the best choice for a ll types of graphi cs and it a lso faces chall enge from other vector fo rmats. Products are on ly beginning to support the technology. Web-browser vendors and Webmas ters, both critica l to SVG 's success, have no spec i fi c pl ans to adopt the format, there fore, its future is still uncerta in .

Vector fi Ie formats, such as Intertype' s Foto­setter for fonts are there s ince 1950s. Vector fi Ie types are generall y assoc iated with graphi cs, but there are also vec tor formats that are not used in traditi onal graphics, like Lotus's ,WKS and Microsoft 's ,XLS spreadsheet formats. The first popular PC vector­graphics format was the computer graphics metafil e standard , which the ISO and ANSI adopted in 1987. Users have worked for years with vector-based sys tems on the Web, but the o lder technologies were se ldom thought of as graphics formats, e g, Adobe's Pos tscript and portabl e document fo rmats (PDF) are usuall y considered page descripti on languages. Macromedia 's F lash has s ince become a well-known vector-based animati on fo rmat and its popul arity demonstrated the potenti al de mand for vector technology.

As these tec hnologies are proprie tary requiring spec ia li zed authoring too ls, the W3C formed a working group in 1998 to develop an open vector­graphics standard . The W3C started the rechartered SVG W orking Group in June 2001 . The group marshaled the SVG 1.0 spec ification through its fi nal stages and is now workin g on ex tend ing the standard.

SVG is a blend of four vec tor technologies: Adobe's Prec is ion Graphics M arkup Language, a Postscript ex tens ion; W eb Schemati cs, deve loped by the Counc il for the Central Laboratory of the Re­search Council s (U K) to represent fl ow charts and other schematic sc ienti fic illustrati ons in Web document s; Microso ft 's Vector M arkup Language; and DrawML, an XML- and Java-based technology deve loped by Exco-so ft AB of Sweden. The group, however, chose to de fine a new language, as none of the submitted fo rmats was totall y acceptab le as is, and W3C d id not wish to lean towards any particu lar vendor.

The Technology - Bitmap (o r ras ter) formats arc exact pixel-by-pi xe l mappings of images, and

396 JSCIINDRES VOL6 1 MAY 2002 SCI-TECH UPDATE

each pixe l must be transferred from the Web se rver to the c li ent for rendering.

Vector techn o logy uses complex sets of image descripti ons to gu ide CPUs and graphics processors in rendering graphic e lements and the image descrip­tion s are written in programming formats such as XML or Postscript. It is qui cker to transm it a descrip­ti on o f an image than to send the entire image, vec tor graphics require less network bandwidth. As many vector images are lig ht we ight , they are particularly suitabl e fo r mobi le devices and ne tworks with littl e process ing power, sllla ll storage capaciti es and low bandwidth . SVG is basica ll y like other vector format s but it is standard ized and has broad industry support.

SVG expresses images first as sets of s impl e e lements, such as lines and curves, and then uses the m to he lp describe various aspec ts- such as size and pos iti on-of more comp lex geometri c shapes like c irc les and po lygons. As SVG is XML-based, users can add tex t to a graphic s imp ly by writing it into the XML code. Also, as XML perm its c ross­platfo rm operabi lity, Web deve lopers can c reate a s ing le set of descripti ons for an SVG image, whi ch a ll rec ipi ent s can then use as long as SVG is unde r­stood by the used browsers. [t e limin ates the need of different fil es for diffe rent pl atforms, as is the case with the bitmapped images. Smart ce llular phones and PDAs coul d access any SVG-comp li ant Web site, rathe r than rema in res tri cted to the s ites specifi­ca ll y des igned for mobil e tec hnol ogy.

With XML, re ndering eng ine o f a browser de­te rmines the most suitab le way to reso lve an image for the host device. Thus, SVG images can scale up or down and render to the resoluti on of the rece iving device. The approach a lso generates pa rti cu larl y accurate document print outs. Bitmapped graphi cs, on the othe r hand , di stort s w hen scaled to work with small di splay or a hi gh reso luti on printe r.

SVG is based on XML, that de ve lopers can use, both for images and tex t in the same document , thu s desc ribin g the document content and not just the appearance. Images can, the refore, conta in searc habl e tex tu a l informati on. The tex t may e ithe r desc ri be an image o r provide additi onal re levant informati on. Use rs ca n eas il y conduct tex t or Web searches of SVG graphi cs. For the same reason, SVG images work we ll w ith the sc reen readers used by people w ith vis ion probl ems.

The technology a lso has so me s ign ifica nt limita­tions , e g, unlike bitmap approaches, SVG can re nder only the two-dimens iona l images and it cannot easil y describe photographs, which are so graphica ll y compl ex that its SVG description produce exces­s ive ly large fil es. There fore, very compl ex images are like ly to stay in bitmap formats.

Using Familiar Technologies-To take advan­tage of newer Web-design technol ogies, the W3C required th at SVG be compat ibl e with several of stand ards of the consort ium, such as (see Scheme I):

• Cascading styl e sheets (CSS), used to create style sheets that de fin e how va ri ous Web· pages e lements appear,

• XSL (Ex tensible Sty le Language), a ll ows appli­cat ion of sing le style documen ts to mUltipl e pages, and

• the DOM (Document Object Mocle l) Core, an XML-based techn o logy that lets programmers c reate and modify We b pages as program objects.

XML parser

XML source with SVG code

Browser SVG viewer

CSS CSS parser cascad i ng,

spec i fi c ity, and inhe ri -tance e ng llle

SVG re ndering mac hine

SVG-animation viewers also need DOM CSS JavaScrip t SMIL/SVG

obj ect mode l

eng ine animation eng me

Scheme I-A typica l SVG viewer is based on several stand ardized tec hno logies . As SVG is based on XML, the basic viewer wou ld inc lude an XML parser. A CSS parser and CSS cascading, spec ifi c ity, and inhe rita nce eng ine wou ld read a document 's cascading style sheet, w hi ch defines how various Web-page e leme nts shou ld appear. An imated-SVG viewers work with the document object mode l and the DOM CSS , w hi ch le t pro­grammers create and mod i fy Web pages as pro­gram objects . The Synchronised Multimedia Integration Language (S MTL) uses XML tags to synchroni se a docume nt 's multimedia e le ments.

SCI-TECH UPDAT E J SC I IND RES VOL fi I APR IL 2002 397

Many developers already know XML, therefore, they can use famili ar tec hniques and too ls whe n learning and workin g with SVG. Developers can also use fami li ar technologies to make SVG images dynami c and interactive . The key to interac tivity is the JavaScrip t or any other scripting language set up to work with the DOM. As Dynamic HTML can be animated wi th JavaScript , so can SVG objects . Additi onall y, SVG can be written dynami ca ll y by a server app licati on, in the sa me way as HTML documents can. Developers can also animate SVG graphics with the W3C' s SMIL, that uses XML tags, rather than code, to synchroni se a document 's multimedia e lements. Though not wide ly used, SMIL is supported by Microsoft 's and Rea lNetwork's multimedi a pl ayers.

SVG Prnducts-SVG is not widely adopted yet, but several software tool s and other products already use the technology. The essential SVG URLs, given at the end , provide a li st of resources offering additi onal information about SVG specifi cations and implementati ons. For example, the Adobe Illustrator, Corel Draw, and Jasc WebDraw illustration-des ign too ls support SVG. In addition, the open source Apache Software Foundati on recently released Batik , a Java-based toolkit for SVG view ing and manipula­ti on. Quark will add SVG support to Quark Xpress 5 after the desktop-publi shing program's initi al release. Uni sys also plans to incorporate SVG into its Hermes editori al system. Adobe's SVG Viewer is now ava il ab le in a late beta editi on for OS versions beginning with Windows 98 and MacOS 8.6. This viewer works with most cu rrent Web browsers. Adobe is also incorporating SVG in to other parts of its product line, e g, the AlterCast imagi ng server can dynam ica ll y translate graphics in va ri ous formats , such as Java or Perl, into SVG for Web-serve r deli very.

In the near future SVG standard may be ex­panded, such as by develop ing guide l ines spec i fically fo r PDAs. SVG's success will depend on the Web­browser vendors. If Microsoft, Netscape, and Opera support SVG, it wi ll pl ay at least a minor role in Web des ign. However, browser vendors have not yet announced spec ific plans to adopt SVG. It is likely they wi ll do so eventuall y, though, because all of the vendors were on the W3C committee that worked on the standard.

The SVG wi ll face an uphill battl e even after incorporati on into browsers, e.g, Microsoft will probabl y support its own Vector Markup Language tec hnology. In addition , Macromedi a F las h will offer strong competition because it already has a large in stall ed base and is popular with des igners. Also, Flash offers an integrated format with its own scripting environmen t and other features that make it eas ier to work with than a combinati on of SVG, SMIL, JavaScript , and other W 3C standard s.

Once in browsers, the users who will matter are the Webmasters who dec ide what format to use for the graphics on their sites . They will wa it un til enough browsers support SVG and until such browsers are well deployed by the consumer base. Unti l then Macromedia Flash wi ll be used. Still , SVG is likely to be attractive as it an open standard that, unlike Flash, is not defined and controll ed by a single company. It is needed for real access ibility and better searching. It will , however, take a lot of developer support to prevent it turning into a dead end .

Essential SVG URLs

Worl Wide Web Consortium's (W3C's) current SVG specification: http://www.w3.org/TRlSVG/ex panded-toc.html

2 W3C's SVG tes t suite: http ://www . w3 .org/Graph ics/S V G/Test/

3 W3C's SVG implementati ons: http ://www.w3.org/G RAPHICS/SVG/SVG­[mp I emen ta t i on s

4 W3C's Amaya nati ve SVG browser and editor: http://www.w3.org/A maya!A maya. html

5 W3C's SVG mailing- li st archives: http ://li sts.w3.org/Archi ves/Public/www-svg/

6 Adobe Systems' SVG Viewer plug- in : http ://www.adobe.com/s vg/v iewer/ i nstall/beta. h tml

7 Apache Software Foundation 's Batik SV H browser and too lkit : http ://x ml.apache.org/bat iklsvgv iewer . html

8 Jasc Software's WebDraw nati ve SVG ed itor: http://www.jasc.com/products/webdra w

9 Mozilla .org's SVG support : http ://www.mozill a.org/projec ts/svg/

[Computer, 34 ( 12) (2001 ) 22-24].

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398 J SCIIND RES VOL61 MAY 2002 SCI-TECH UPDATE

Key access to cleaner water

Joh n Reed of the University of Northumbria, New cas tle, has shown th at oxygenation that is carri ed out s impl y by vigorou Iy shaking a bott le of water and expos ing it to the sun , is all that is needed to make su nli ght effec ti ve, holds the key to cleaner wate r.

More th an 1000 million people do not have ac­cess to clean drinking water and eac h year arou nd 3.4-m children di e from diseases contacted from con­taminated water. Reed has developed low cost methods or producing safe drinking water that cou ld save more li ves than man y more expensive and elaborate medical measures. Combination of sun li ght and simple oxygenati on is undergo ing trials in lndia as a means of purifying water to a poin t where it is safe to drink .

The acti on of UV I ight on water creates tempo­rary free radica ls that inacti vate faecal bacteri a in water. The results are permanent; once the pathogens have been inactivated they do not reac ti vate. One minute of shak ing is sufficient to repleni sh oxygen if the leve l fall s.

Reed has tested the method in India and South Afri ca. He has shown th at when loca ll y drawn, water is treated with oxygen and sunlight for 3-4 h, the water can pass Briti sh and American tests for drinking water quality.

Reed and coworkers at Cochin University in Kerala are ex ploring the best ways to use sunli ght and oxygenati on. As part of an India-based research project. they are also look ing at the limitations that weat her conditi ons impose on the tec hnique.

The pi lot studies aim to show which micro oga ni sms are inac ti vated by the process and which are not. Studies have been carri ed out in three areas with different c limates, flood prone UP, where cloud cover may be a limiting factor; arid Rajasthan ; and humid Kerala.

The first year's trial s aim to determine how best to use the technique, and its limitations. Then trials in the second year will measure the technique's effect on the incidence of water-borne di sease [Chem Brit ,

37 (No. IO)(200 1) p.14) .

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Thin film batteries developed

A new innovati ve concept of battery is deve l­oped by resea rchers at the Zone Indust ries which is innovati ve not onl y in its dimensi ons hut al so usage. Microbatteries are built with thin film tec hnologies. It can be integrated in small flat objec ts like smart cards or electronic shelf lab les. To create a mi crobattery one need.~ to shrink the dimensi ons of suc h an elec tri c cell to the order of a mi crometer. Such a task can be performed with thin film technol ogies.

These new so lid-state micropower sources have unit ce ll s of thi ckness of onl y 10 pm. They are composed of a pos itive titanium oxysulphide elec­trode, an amorphoLls lithiulll borate based e lectrolyte and a negat ive lithium e lectrode. All three are now in the form of thin films one film deposited on top of the other. The films arc depos ited using sputtering and thermal evaporati on tec hn olog ies. The res ulting mi crobattery has the ab ility to prov ide 100-200 pA/cm2 and an average vo ltage of 2.3 V. ew materials are also being deve loped fo r electrolyte and the pos iti ve electrode for enhancing the performance.

To protect the mi croactive battery from air and moisture while keepi ng the least thickness, it has to be encapsu lated by a ti ght barri er. A th in film of iron phosphate based glass depos ited on the battery by sputtering prov ides such a barri er.

A machine capable of producing 500 p batter­ies/week has been des igned. These micropower sources can be integrated on small fl at objects like tags, wireless electronic shelf edge labels or smart cards. For furth er detai Is, contact: e-mail : labo@ heUr. htlp://wwvv· .heUr [Cordis Focus, 29 (September 200 I) p. 13).

Epoxy paste replaces fibre glass tooling

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The Cessna Aircraft Company has discovered a seamless modelling paste (SMP) that can serve as a quick and accurate alternative to fibreglass and epoxy tooling in stretch form dies. The company uses a Ren RP 4569-1 RH paste to make 12 ft long stretch form dies for the Sovereign business jet 's tai l cone secti on. The two-component paste, which is ex truded over a steel substrate and machined after a 24-h cure, offers a significant speed advantage over dies created wi th

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SC I-TECH UPDATE J SC II ND RES \lOUl! API<IL 2002 399

traditional composite lay-up techniqucs. The new dies can be built in 120h VS nOh for old-slyle composite dies. The SMP also helps preserve d i mensiona I tolerances because it cloes not reCJu i re the use o f multiple too ling generati ons. Cessna expects each SMP di e to stretch 2000 to 3000 A l tail­cone sk ins at 250 tonnes of pressure. As it is aided by low shrin kage and it s 80 shore D surface hardness,

the SMP has produced dies ilccm ilte to ± 0.005 in

[Dc.\' N('l \·.\' , s(, (No 22) (200 I ) p. 151.

A photocntalyst that uses optical radiation developed

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Researchers at the National Institute of Ad­

vanced Industri es Sc ience and T echnology In co ll abora ti on w ill the Nati onal Institute for Material s

Sc ience, in Tsuku ba at Japan , havc dcveloped a photoca tal yst th:lt uses opti c:l1 redll c tion-whi ch

makes up 43 p CI' cent o f so lar cnergy - to split wilte r int o hydrogcn and oxygen. Th eoreti cally, it is poss ibl e to produce hydrogen by split t ing wat er wi th sunli ght, but thi s is dilli cult ;lIld inelli c ient in practice. Researchers ha vc now overcome onc of th c hurdles in hydrogen generat ion by deve loping a new ca talys t 1'0 1' the sp litting process. Earli er photoca ta­Iys ts have onl y responded to UV radiation , whi ch accou nt s f or j ust 4 per cent o f th e sun 's cnergy . Till now t he new photoca tal ys t has on I y ,lch ieved con ver­

sion ellic iences or 0 .66 per ccnt but thi s i'i gurc can be

improved.

In photoca talysis, the energy of the li ght ab­sorbed by the ca talyst is used to in iti ate chemical

reilctions. Sellliconductors are often used as photo­catalyst; the abso l-pti on o r li ght by the semiconductor exc ites an elec tron rrom the va lence band to the conducti on band, w here it ca ll participate in chemici11 reaction s. W hen the elec trons jump into the conduc­tion band , they leavc positive ' holes' behind in the

val ence band.

H owever, the large energy gn p between the conduc ti on and va lence b:lnd s in many selll i­

condll ctors mean s that onl y hi gh-energy ph otons -

such as UV photons - are 'lbsorbed. To crea te a suitable photocatalyst, they added nickel to th e semiconciuctor indiulll tantalate. Thi s reduced its

energy band gap from 2.6 to 2.3 V , which means that

v isibie photons have enough energy to exc i te elec­trons ac ross the band g'lp . The semi conductor was thcn immersed in w ater and illuminated w ith ,In arc lal1lp.

Prov ided that the conducti on band energy is hi gher than the " reducti on potenti al" 01' hydrogen the electrons cxc ita l ,lCross thc h;lnd gap wi ll drift to the Sll1'LI CC or the sC l1li condli ctor ;l11d combine w i th hydrogcn ions in th c w;lter to l1lakc hydrogcn gas . T o h:liancc it s reaction thc v;li encc-band energy IllUs t bc

lowcr than til c " Oxidati on Potcnti :li " or oxygen-thi s ;lilows the posi tivc holes to accept elec trons rrol1l oxygcn in tile water, crc;lting oxygen g;IS. Tilc ncw l1lateri al is also res ili ent cx istin g sClllicond uctors th ;lt use visible li ght c ither co rrode or becomc inert when

tiley come int o contact with wat er.

Thc c fri c iency fall s a long way short of 3 pe r cent neCCSS:l ry for a prac ti ca l techno logy ;md it is pl:lnned to raise it by increasing th c surface area of

the scmi-conductor ;l11d adju sting its 1;1 YOUI.

Tile piloto-catalyst sys tcm w ill be econollli cal compound w itil ex istin g so lar cc ll s systems rp/ivs World , ] 5 (No I ) (2002) p. 6].

New technology for acid and alkaline spi ll management

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A nsu l 's laboratory has introduced the lates t grou nclbreak ing product named TARGET-7 Vapor

Mi ti ga ti on and Neutrali zing Agent. It has been dcsigned to reducc th e il:lZardou s ri sk. o f chemica l sp ill s like chlorine di ox ide and amlllonia , thi s un ique

agent all ows 1'01' a onc step app li ca tion process to both contain haza rd ous vapors from ;1 spill and neutrali ze the sp ill ed product. 1t is bes t suited for dnngcrous flllllin g aci cl s or other il :1za rd oLI s chemi cal s w here spill time and application bec;lllle cri tical.

Dangerous ;lc id or alkaline sp ill s req uirc a two step process to all ev i ;l tc the haz:ml appl yi ng :l

neutl';l li zing agent to ;ldjust til e pH and app ly ing a stable foalll agen t to miti ga te th e hazardous va pors.

TARGET-7 agent performs its traditi onally ilard

process quickly , thereby signifi cantl y rcclu ci ng the hi gh ri sk of iluman ex posure.

Tile new agent was tes ted at three sit es in North A meri ca. T A RGET-7 agent success full y containeci

400 J seliND RES VOL 61 MAY 2002 SC I-TECII UPDATE

and neutra li zed chl or ine dioxide spills at two large paper mills and t itanium tetrachl oride at a large chemical plant. The tes ts have been cond uc ted on s ite due to toxicity of the c hemical s. During these tests a round the cont incn t, T A RGET- 7 outperformed other

mcthodologie<; of other types of products.

For more information on TARGET -7 contact: 800-862-6785 or 715-n5-74 15 [Cht'lil !lId Nt'\\,.\', 46 (No . 10)p.5IJ.

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Capsule makes a good image for gastrointestinal diagnoses

Israe li sc ient ist of G ive n Imaging Ltd of YO K have developed a capsule th at tra ve ls through the body and produces full- co lor images, enabling pa inl ess gastro intes tina l diagnoses. The unique M 2A capsule. contain s a mini ature video camera, fl as hing li ght . b:ll tery and compute r c hip . Mini ature e lectron­ics and comp lementary tec hno logy a ll ow the capsu le to transmi t high-quality video images, allowi ng doctors to view a range of d isorders o f the small in testine. Afte r fasti ng fo r 8h the pati ent swa ll ows the 2.5 cm long capsule w ith a g lassfull of wate r, and then wears a be lt bearing a w ireless recorde r. The recorde r receives signa ls as the capsule (whic h is not affec ted by the high ly ac idic environment of the gastrointestina l system) is prope lled th rough the small intestine by peri sta lsis-the natura l contracting moti ons of the di gesti ve system. The patient may conduct hi s normal da il y ac ti vities-eating, working, p lay ing and s leeping-until the capsul e is di scharged from the body a long with the stool. It is then re­tri eved and taken to a specia l compute r workstati on, where the images are processed using Gi ven Imag­ing's RAPID (Reporting and Processing of Images and Data) software . The end product is a short video cl ip of the small intes tine together with addit ion re levant info rmation from the di gesti ve tract.

The process enables gastroenterologists to find sources of unexpl a ined bleeding, abnormal growth s, as we ll as s igns of irritable bowel synd rome and other cond iti ons, which may then be treated as necessary. A lth ough it is not ex pec ted to repl ace endoscopies or colonoscop ies-which can be util ised fo r treatment (e .g ., taki ng b iops ies and pie rc ing off pre-cancerous po lyps) as we ll as for d iagnos is is be li eved that the

new techno logy will he lp the health system save considuabl e money, as less accurate and painful end oscopi es are mu ch more cos tl y than the $300 capsu le. Company officials explain that it is an adjunctive tool which thcy be licve \\ ill eventua l! y

playa s ignifi ca nt part in gas troentero logical medi­c ine .

In order to get approva l from the US Food and Drug Ad mini strat ion . the dev ice is being tested on 20 patients in London, New York and Israe l. It is not ye t planned to be used on pat ie nts who have had maj or abdom inal opera ti ons. a history o f abdomin al obstruct ion, those with pacemaker" or d iabetics , or on pregnant women.

The main potential advantage for pat ients is th at the dev ice wi ll prove to be comple te ly pa inless-they have j ust got to swall ow a ca psul e. One may be able to image the lower part of the small bowe l while the patient is wa lkin g arou nd . The stud y is desi gned to eva lu ate these aspec ts of the dev ice".

T he sys te m is intended to see ne w parts of the human body that we reall y have not exa mined before. T here are lots of patients bo th young and old, for whom th is method of d iagnos is coul d be ex tremely worth w hile. [Israel Today, (Sep/Oct 200 I) p. 4J.

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Stem cells: new hope for treating brain diseases

Trac ly McIntosh and hi s group of the Uni versity o f Penn sylvani a treatments for diff icul t conditi ons suc h as head injuri es, stroke, and progress ive neuro­logical di seases, like multiple scleros is and brain cancer.

E mbroyenal stem cell s have been successfull y used in many experiments, however due to ethical issues in vo lved in the ir use, researche rs a re now trying to use non-embroyena l ste m cell s, w hich res ide in e very ti ssue in the body and repl ace ol d Cell s when they die. But, without the knowledge that might by ga ined from study ing embryonic stem ce ll s, many of these efforts might be wasted , warn Jonathan Kni ght , Ali son M otluk and He len Phillips.

In a research by McIntosh, neura l stem cell s were shown to improve injured bra in 's functi oning in mice. Mc Intosh and hi s group induce equi va lent of concuss ion (injury to the bra in) in 48 mice. T hree

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SCI-TECH UPDATE J SCI IND RES VOL 61 APRIL 2002 401

days later, animal 's brain was inj ec ted vv ith either mouse neural stem cells or human kidney cells as a control.

After five weeks, mice when give n the ste m ce ll s showed a significant impro veme nt in cogn itive functi ons, as measured by the ir ab ility to naviga te a wa ter maze. Embryoni c st e m ce lls have also leu to advances in treating the animal eq ui vale nt o f motor neuron diseasc, which leaves humans unable to movc . Jefrrey Roth stei n of John s Hopkins Un ive rsit y, Baltimore has found that paral ysed rats what inj ected e mbroyenal stem ce ll s into the spinal fluid dramati ­cally rega ined partial leg movement .

Evan Snyder of Harva rd Medical Sclloo l in Bos­ton has reponed progress in using ste m ce lls to kill off cancerous brain ce lls . He is also working wi th non-cmbroyena l stem cells and successfull y ed ited strokes in mi ce . He induced strokes in adul t male rats and injected stem cell s from new born n li ce or a growth fac tor or both in the back of the ir brain, one day later.

These cells mi grated to the site of inj ury and rats showed some recovery. Those which got both, showed max imum recovery. Marc Peschansk i from the Crete il Laboratory of INSERM , the French National Health and Medical Research Institute, has obtained encouraging results with foetal stem cell s for patients suffering from Huntington's di sease-a brain di sease which affects movements and causes inte llectual de te ri orati on and psyc hos is.

The French team implanted e ight-day-o ld foe ta l stem ce ll s which had begun diffe rentiating into nervous ti ssue into the brain' s striatum region the region which he lps control movements, in five patients. Three of the patients showed improvement in movement and cognitive function .

Adult stem cell s are being used to treat condi ­tions like multiple schleros is, a disease in which insulating sheath of myalin surrounding nerve fibres dies , di srupting nerve transmiss ion, and paralys is.

Jeffrey Kocs i of Yole University , Connecticut used X-rays and inj ections of a tox ic chemical to damage di sc rete areas of mye lin in adult mormosets. He further injected stem cell s taken from the mon­key's brain a long with some growth factors into the affected region. Three weeks later, Kocsi reported "ex tensive remyel inat ion", according to the report. Fred Gage of the Salk Institute, Colifornia shows that

the fact that adult centra l nervous sys tem produces its own stem cells, which became neurons o nl y at some places, can be used to regenerate neurons when they arc damaged.

In case the stem ce ll s are taken out frol11 the sp inal coru and placeu in the part o f th e brain where neurons are born, they become capable o f differenti­ating into neurons. T lllls, some c he mica ls must be responsible for causing and it could be used to treat paral ys is.

Researchers have also repo rted success in con­verting borne marrow stem cells into the precursors of neurons [Chem Week, 46 (48) (200 1) p. 135 ; al<;o see PTI Sci Sen·, July 1-15 (200 I) p. 12].

Better imaging of brain disorders through improved magnetic resonance techniques

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Ten European magneti c resonance (MR) centres have collaborated on magnetic resonance imc:.ging in order to develop, us ing three d iffere nt MR tec h­niques, standard quality assurance and clinical protoco ls and to apply new techniques to both diseased and healthy human brains. The a im is the identificati on of pathophysiological factors important for diagnosis and treatment monitoring.

Magnetic resonance spectroscopic Imag lJlg (MRSI), water diffusion imaging, and perfusion ImaglJlg were the three techniques applied in the study.

With spectroscopic imaging a sing le slice meta­bolic imaging pulse sequence was developed in order to obtain quantitative metabolite concentrations. The centres participating in the study had to implement the pul se sequence in the ir respec tive MR scanners, which has led to the choice of a multi -echl o sequence with a single spatial phase, encoding step per cyc le. In vivo studies were performed on rats. In order to obtain a standard , measurement of the developed MRS! protocol were compared with measurements of TI and T 2 of water and metabo lites, and with ca lculations of metabolite concentrations. Measure­ments were performed at four different centres on six ' normal ' volunteers each. The research showed that MRSI results are appropri ate for purposes of com­pari son and interpretation.

402 J SCIIND RES VOL 61 MAY 2002 SC I-TEC H PDATE

For diffusion imaging, a multi-slice ec ho-p lanar spectroscopy sequence was used. Anisotropy effects are eliminated if the values of the anisotropy tensor at three perpendi cular di stances, viz. it s trace, are obtained whil e app lying two magneti c fie ld va lues at each one of the directors . Va li dat ion stud ies are still in progress in th is area.

The in vas ive perfusion imaging, the assessment of cerebral perfusion and blood vo lume was fac ili ­tated by the use of the contrast agent Gd-DTPA dU'ring fas t imaging.

The contrast agent, a paramagneti c ion (Gd) bound up in a large molecul e (DTPA) th at enhances the loca l magnetic fields, was bolus-injected and fo ll owed through its path with 6 anatoni ca l sli ces per second.

The aim of the study will not onl y lead better understandin g of the human brain , its physiology and metaboli sm, and to ease the economic burden brain di seases imposed on health care systems but, above a ll these factors it wi II ease the emot ional burden on suffe rers and their families [Cordis Focus, RTD­Results Supplement, No 30 (2001 ) p. 4].

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Anthrax used highly sensitive techniques that reveal differences between DNA and anthrax samples developed

The US Army Medical Research Institu te for Infections Diseases in Fort Detrick, Maryland , has analysed the samples of anthrax stocks held by research labs for identifying the source of the bioterrorist attacks that have killed five Ameri cans.

The search is now focussing on labs in the US from which th ose responsible for the attacks may ha ve obtained the bacteria. The test has been con­ducted in va ri ous lab samp les of the Ames strai n used in the attacks for catching the culprit s.

According to researchers the part icular var iant or Ames used in the attac ks was helel pr imaril y by the US Army Medical Research lnst itu te /"or In fec ti ons Diseases and distributed to a fair ly number of researchers. The researchers have deve loped hi ghl y sensiti ve techniques th at reveal tiny differences between the DNA of anthrax samples which are otherwise very hard to tear apan . Tesb are now under way to find how closely the geneti c fingerprint of the anthra x used in the attacks matches th ose of bacteri a held at different labs around the US.

Meanwhile, there has been proof that contami­nated mail has spread spores to unexpected destina­ti ons . Spores have been found in a letter that was handled at the victim 's local sorting office and sent to a nearby town. Its postmartum reveal s th at thi s letter passed through postal machines in Trenton , New Jersey, at nearl y the same time as anthrax- laced letters th at were sent to two senators.

It was not known that how many letters were contaminated as they passed through the sort ing machines. Although such letters may have spread Anthrax far and wide, the tin y doses they carry mi ght onl y be revea led if elderl y peop le or those with a weakened immune system are expo. ed and become sick [New Sci, 172(No.2320) (200 I) P 6].

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