The eyes have it

Weekend Herald - - SCIENCE& TECH -

enew­able en­ergy sources are a hot topic right now and have been listed as one of the most ef­fi­cient tools we have in the fight against cli­mate change.

Here in New Zealand, hy­dropower, geo­ther­mal and wind en­ergy are the pri­mary sources of our re­new­able power, how­ever another that could soon be added to the list is hu­man tears.

This is thanks to new re­search pub­lished this week in the jour­nal Ap­plied Physics Letters which dis­cov­ered that a pro­tein present in our tears, saliva and milk can also be used to gen­er­ate elec­tric­ity.

The pro­tein, called lysozyme, was dis­cov­ered by Alexan­der Flem­ing in 1922. He found it showed an­tibac­te­rial ac­tiv­ity when tested on nasal mu­cus bac­te­ria do­nated from a pa­tient suf­fer­ing with a head cold.

Six years later, Flem­ing went on to dis­cover the an­tibi­otic peni­cillin, which has saved mil­lions of lives, but lysozyme con­tin­ued to have his­tor­i­cal sig­nif­i­cance as the first en­zyme struc­ture to have been solved and fully mapped in three di­men­sions us­ing a tech­nique called x- ray dif­frac­tion.

The study this week found that when crys­tallised, lysozyme pro­teins dis­play piezo­elec­tric­ity — the process of con­vert­ing me­chan­i­cal en­ergy into elec­tri­cal en­ergy, mean­ing that when you squeeze a piezo­elec­tric ma­te­rial it can cre­ate an elec­tri­cal field, and in re­verse if you ap­ply an elec­tric field the ma­te­rial can change shape.

You have prob­a­bly used piezo­elec­tric­ity a few times al­ready to­day. For the watch wear­ers amongst us, it’s what keeps a quartz watch on time; the mi­cro­phone in your com­puter will use piezo­elec­tric­ity to turn the sound en­ergy from your voice into elec­tri­cal sig­nals that your com­puter can process, and if you have a gas stove at home, the click­ing sound from the ig­ni­tion but­ton is It might be lin­ger­ing bash­fully on the icy outer edges of our so­lar sys­tem, hid­ing in the dark, but sub­tly pulling strings be­hind the scenes. It’s a pos­si­ble “Planet Nine” — a world per­haps 10 times the mass of Earth and 20 times fur­ther from the sun than Nep­tune.

The signs so far are in­di­rect, but add up to a com­pelling case nonethe­less.

One of its most ded­i­cated track­ers, in fact, says it’s now harder to imag­ine our so­lar sys­tem with­out a miss­ing Planet Nine than with one.

“There are now five dif­fer­ent lines of ob­ser­va­tional ev­i­dence point­ing to the ex­is­tence of Planet Nine,” said Kon­stantin Baty­gin, a plan­e­tary astro­physi­cist at Cal­tech in Pasadena, Cal­i­for­nia, whose team may be clos­ing in on the heav­enly body. com­ing from a piezo­elec­tric ma­te­rial be­ing squeezed and cre­at­ing an elec­tri­cal spark.

Quartz is the most com­monly used piezo­elec­tric ma­te­rial, but many other ma­te­ri­als with an asym­met­ric atomic struc­ture can also ex­hibit piezo­elec­tric prop­er­ties in­clud­ing topaz, su­crose and lead ti­tanate.

In ad­di­tion to nat­u­ral ma­te­ri­als,

“If you were to re­move this ex­pla­na­tion and imag­ine Planet Nine does not ex­ist, then you gen­er­ate more prob­lems than you solve.

“All of a sud­den, you have five dif­fer­ent puz­zles, and you must come up with five dif­fer­ent the­o­ries to ex­plain them.”

Baty­gin and his co- au­thor on a new study, Cal­tech as­tronomer Mike Brown, de­scribed the first three clues last year, and two more bi­o­log­i­cal ma­te­ri­als in­clud­ing wood, bone and ten­dons are also piezo­elec­tric. The chal­lenge is that th­ese bi­o­log­i­cal ma­te­ri­als are made up of fi­brous pro­tein struc­tures which make them dif­fi­cult to process and crys­tallise and un­suit­able for com­mer­cial use.

With their glob­u­lar struc­ture, the lysozyme pro­teins are much eas­ier to have since emerged. One sug­gested Planet Nine could have tilted the plan­ets of our so­lar sys­tem dur­ing the last 4.5 bil­lion years, ex­plain­ing a long­stand­ing mys­tery.

The other in­volved ob­jects from the Kuiper Belt that or­bit in the op­po­site di­rec­tion to ev­ery­thing else in the so­lar sys­tem. “No other model can ex­plain the weird­ness of th­ese high- in­cli­na­tion or­bits,” Baty­gin said.

“It turns out that Planet Nine pro­vides a nat­u­ral av­enue for their gen­er­a­tion.”

The re­main­ing step, of course, is to find Planet Nine it­self. If dis­cov­ered, it would be a home­com­ing of sorts, or at least a fam­ily re­u­nion.

Over the past 20 years, sur­veys of plan­ets around other stars in our galaxy have found the most com­mon types to be “su­per Earths” and their some­what larger cousins — big­ger than Earth but smaller than Nep­tune. Yet th­ese com­mon, gar­den­va­ri­ety plan­ets are con­spic­u­ously ab­sent from our so­lar sys­tem. Weigh­ing in at roughly 10 times Earth’s mass, the pro­posed Planet Nine would make a good fit. crys­tallise as a thin film just by evap­o­rat­ing on to a glass slide.

The re­searchers used an ac­tu­a­tor to ap­ply pres­sure to squash the film and mea­sured the volt­age us­ing elec­trodes. Their re­sults found the lysozyme pro­tein crys­tals pro­duced the same or­der of mag­ni­tude of piezo­elec­tric­ity as the stan­dard go- to ma­te­rial quartz. While it may sound enough to make women ex­pe­ri­enc­ing the nau­sea of early preg­nancy scoff, re­searchers have sug­gested morn­ing sick­ness can take a toll on ex­pec­tant dads.

New re­search out of Aus­tralia’s Edith Cowan Univer­sity ex­am­ined the ex­pe­ri­ence of 300 ex­pec­tant cou­ples and found more sup­port was needed for the part­ners of women ex­pe­ri­enc­ing nau­sea and vom­it­ing dur­ing preg­nancy. The study aimed to gauge ex­pec­tant fa­thers’ aware­ness of what their part­ners were go­ing through, and the af­fect it had on the dads them­selves.

The study found 82 per cent of fa­thers were aware that their part­ner ex­pe­ri­enced morn­ing sick­ness. Of th­ese, 20 per cent re­ported no nau­sea or vom­it­ing, mild 30 per cent, mod­er­ate 37 per cent and se­vere 13 per cent. The part­ners of all 11 women for­mally di­ag­nosed with hy­per­eme­sis gravi­darum, re­ported the nau­sea and vom­it­ing was se­vere.

Re­searchers asked ex­pec­tant fa­thers about their part­ners’ con­di­tion and their own men­tal health and found a sig­nif­i­cant known as Nanogirl, is an Auck­land Univer­sity nan­otech­nol­o­gist who is pas­sion­ate about get­ting Ki­wis hooked on sci­ence. Tweet her your sci­ence ques­tions

Al­though quartz is an abun­dant ma­te­rial, the ad­van­tage of the lysozyme crys­tals could be their in­creased bio­com­pat­i­bil­ity as they are from a bi­o­log­i­cal source.

This could make them safe to use in­side the body and has the po­ten­tial to open up new ap­pli­ca­tions in en­ergy har­vest­ing for med­i­cal de­vices such as pace­mak­ers and bi­o­log­i­cal pumps.

Al­ter­na­tively, with its known an­tibac­te­rial ac­tiv­ity, the lysozyme crys­tal could be evap­o­rated on to sur­faces and used as a bio­com­pat­i­ble an­timi­cro­bial coat­ing for med­i­cal in­stru­ments and de­vices.

Al­though still in the pre­lim­i­nary stages of re­search, there is no need to panic about hu­man tear in­crease in dads’ anx­i­ety levels.

Al­though there was some sup­port avail­able for preg­nant women dur­ing preg­nancy, the fa­thers were of­ten left to fend for them­selves, lead re­searcher Julie Sar­tori said.

“The study showed that in fam­i­lies where the mother ex­pe­ri­enced mod­er­ate or se­vere morn­ing sick­ness, fa­thers re­ported much higher levels of anx­i­ety.” That anx­i­ety was linked to five main fac­tors — dis­rup­tion to work, feel­ings of frus­tra­tion and help­less­ness, con­cern over de­pres­sion in their part­ner, worry for the de­vel­op­ing baby, and a “sense of be­ing ma­nip­u­lated”. also har­vest­ing be­com­ing the next elec­tric­ity gen­er­at­ing in­dus­try. In ad­di­tion to tears and saliva, lysozyme is also found in the egg whites of birds, and pow­dered hen egg whites are al­ready a com­mer­cial source of the pro­tein. Hav­ing said that, a fu­ture where you have to squeeze your tears to charge your smart­phone could pos­si­bly lead to a resur­gence of ro­man­tic com­edy movies. A new study has drawn a link between night shift and obe­sity. Re­searchers from the Chi­nese Univer­sity of Hong Kong an­a­lysed data from 28 pre­vi­ous stud­ies to find that night shift work was con­nected to a 29 per cent in­crease in a worker’s chance of be­com­ing over­weight or obese.

The weight was mostly cen­tred around the worker’s stom­achs, say the sci­en­tists, and mostly af­fected those who worked nights per­ma­nently, rather than those who worked ro­tat­ing shifts. “Glob­ally, nearly 0.7 bil­lion work­ers are en­gaged in a shift work pat­tern,” said the study’s se­nior au­thor, Dr Lap Ah Tse.

“Our study re­vealed that much of the obe­sity and over­weight among shift work­ers is at­trib­ut­able to such a job na­ture.

“Obe­sity has been ev­i­dent to be pos­i­tively as­so­ci­ated with sev­eral ad­verse health out­comes, such as breast can­cer, car­dio­vas­cu­lar dis­eases.” The re­searchers sug­gest ad­just­ing work sched­ules to avoid ex­tended ex­po­sure to long- term night work could lighten the load, lit­er­ally.

sci­ence writer Jamie Mor­ton: @ jamien­zher­ald

Can night shift make you fat?

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