Elephant seal’s map sense tells them when to head ‘home’ — ScienceDaily


Annually, pregnant feminine elephant seals take an roughly 240-day trek over 10,000 kilometers throughout the Japanese North Pacific Ocean earlier than returning to their breeding seashores to present delivery inside 5 days of their arrival. Now, a examine showing February 28 within the journal biology Present Biology finds that this spectacular navigation means will depend on an inside map sense, which features very like a built-in GPS.

“We discovered that migrating elephant seals know the way far they’re from their breeding seaside 1000’s of kilometers away,” mentioned Roxanne Beltran of the College of California Santa Cruz. “Additionally they know roughly how lengthy it’ll take them to get again.”

Beltran and her colleagues, together with Dan Costa, knew that elephant seals are professional navigators. What they did not know was how the seals handle to make it again to the seaside simply in time for the breeding season.

Within the new examine, the researchers used satellite tv for pc monitoring information collected from greater than 100 grownup feminine seals. They found out when every of them rotated to go again to the seaside the place they began from.

The information revealed that seals determined to show round based mostly strongly on how distant they have been from the place they wanted to go. Their choices to show round weren’t associated to their physique situation, measured as quantity of physique fats.

“We have been shocked that foraging success or p.c physique fats was no more strongly associated to when seals start the return portion of the migration,” Beltran mentioned. “We anticipated that extremely profitable (i.e. fatter) seals would possibly finish their foraging journeys earlier, however that was not the case; as an alternative, it looks as if they’re nicely programmed to show round strategically based mostly on the place they’re and in flip how lengthy it’ll take them to get again.”

The researchers do not but know what sensory cues the elephant seals depend upon to maintain monitor of the place they’re and head in the correct path on the proper time, nevertheless it’s clear that they will regulate the timing of their travels based mostly on an inside notion of time and house.

The outcomes assist to raised perceive elephant seals, with necessary implications for his or her conservation, the researchers say. In future research, they hope to quantify precisely how exact the seals’ navigation means is and decide which cues are most necessary.

The work was funded by the Workplace of Naval Analysis, the E&P Sound and Marine Life Joint Business Challenge of the Worldwide Affiliation of Oil and Gasoline Producers, and the Nationwide Science Basis.

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Canada ‘Sixties Scoop’: Indigenous survivors map out their stories


Hundreds of indigenous youngsters in Canada had been forcibly faraway from their households between the Fifties and Nineteen Eighties, in what is named the “Sixties Scoop”.

They had been put into non-indigenous houses by welfare businesses, in an try to assimilate them into mainstream tradition.

Now survivors are mapping out their tales and discovering solace in connecting with others.

Video by Dan Lytwyn

Atomic changes can map subterranean structures


THE PAPER IN BRIEF

• Exact measurements of vertical gradients in gravity can be utilized to detect inhomogeneities in density underneath Earth’s floor.

• In a paper in Nature, Stray et al.1 report a sensible quantum sensor that makes use of atom interferometry to measure gravity gradients quickly, and with excessive sensitivity.

• The sensor is proven to be able to detecting a tunnel of two-metre-square cross-sectional space underneath a highway floor between two multi-storey buildings, situated in an city setting.

NICOLA POLI: A quantum sense for what lies beneath

Astronomical observations supply us in depth data of what lies above us by way of each electromagnetic and now gravitational2 alerts — even these from sources one billion kilometres away. However, in some ways, we lack the identical detailed data of what lies beneath our toes, even just a few metres under Earth’s floor. Though a number of geophysical monitoring methods exist, more often than not, digging remains to be the easiest way to study small options underneath the soil. Nonetheless, quantum sensors are gaining traction as a viable different to classical geophysical sensors.

Atomic gravimeters are quantum sensors that use a method known as atom interferometry to measure native gravitational acceleration on the premise of how the gravitational discipline impacts a freely falling cloud of atoms. In a typical configuration, gentle pulses are used to generate, separate and recombine matter waves (each particle might be described as a wave of matter), permitting them to intrude with one another. The interference sample detected in a gravimeter is then associated to the native gravitational discipline. Measurements based mostly on this precept might be amazingly exact, however they’re nonetheless topic to the results of noise. Atomic gradiometers overcome this drawback to a point by measuring gradients in such gravitational fields, as a substitute of absolute values.

Since their first demonstration as gravimeters and gradiometers greater than 20 years in the past3, atom interferometers have continued to enhance in efficiency. On the similar time, analysis has centered on make such devices compact and dependable sufficient for use outside for real-world purposes4,5. Stray and colleagues’ instrument is a notable advance on this line of analysis.

The workforce developed an hourglass configuration for his or her gradiometer, with which they carried out differential measurements on two clouds of ultracold rubidium atoms, separated vertically by one metre. This configuration offers sturdy and compact optics that stay correctly aligned over a interval of a number of months.

The instrument was able to non-destructively sensing a big cavity buried beneath Earth’s floor, by measuring the cavity’s tiny gravitational sign alone (Fig. 1a). The sensitivity proven by the system is round 20E (1E is 10–9 per sq. second) for a measurement taken over 10 minutes, which makes it round 30 occasions much less delicate than essentially the most delicate interferometer reported6. Nonetheless, the authors’ sensor is a step ahead by way of making atom gradiometers virtually helpful in real-world conditions.

Figure 1

Determine 1 | Gravity cartography in the actual world. a, Stray et al.1 developed a quantum sensor that measures vertical gradients of gravity, which can be utilized to determine variations in density. The system detected an underground tunnel situated beneath a highway floor between two multi-storey buildings (not proven), which might have an effect on the gradient sign and result in its attenuation. The anticipated location of the tunnel on the horizontal axis is marked in crimson. b, The sensor measured gradients in gravity (in models of E, the place 1E is 10–9 per sq. second) as a operate of the sensor’s place relative to the anticipated location of the tunnel. In addition to being at the very least as correct as current industrial instruments, the system can purchase knowledge extra quickly and is extra transportable than different quantum sensors of its sort. (Tailored from Fig. 3 of ref. 1.)

With pure long-term stability and really low sensitivity to environmental results akin to tilt and floor vibrations, along with an absence of mechanical components, atom gravimeters and gradiometers possess a transparent benefit over their classical counterparts. Stray and colleagues’ advance reveals that they may quickly be extra transportable and user-friendly, too.

ROMAN PAŠTEKA & PAVOL ZAHOREC: Sensible options for floor gravity mapping

Our fascination with gravity dates again to the traditional Greeks, and measuring gravitational acceleration was among the many first pursuits in fashionable science. Geophysicists within the eighteenth century used pendula to make such measurements7. However, since then, instruments for gravimetry have been the topic of intensive growth — from easy spring-based units, all the best way to present-day devices based mostly on quantum know-how. In bodily geodesy and utilized geophysics, gravimetry measurements at the moment are used to find out the dimensions and form of Earth, and to determine inhomogeneities within the density of Earth’s inside. Such measurements can reveal near-surface objects or support the examine of the lithosphere, the rocky outer fringe of Earth’s construction.

Gradients of gravitational acceleration are extra helpful than direct measurements on this respect: they’re delicate to shallow density distributions and may detect objects extra exactly (Fig. 1b). In terrestrial gravimetric surveys, vertical gradients in gravity might be approximated utilizing measurements from classical spring gravimeters, taken at completely different heights. However this process is time consuming, needing tens of minutes for every knowledge level, and its uncertainty relies on the accuracy of the gravimeter.

Stray et al. estimated that the uncertainty within the measurements taken with their instrument is healthier than that of economic gravimeters. Maybe extra importantly, they be aware that 10 knowledge factors might be collected in simply quarter-hour. From this standpoint, the workforce’s outcomes, along with these of different analysis teams8,9, might drastically change utilized gravimetry analysis — lending weight to the authors’ declare that the work constitutes a sort of ‘gravity cartography’.

Basically, gravity values (and particularly gradients) replicate the distribution of density inhomogeneities under Earth’s floor, however they’re additionally influenced by the results of terrain and close by buildings10. The important thing consider figuring out the magnitude of this impact is the close by topography, which is underestimated in some geophysical research, and must be taken under consideration. Gravitational attraction to close by buildings contributes a smaller, however measurable, addition to the gravity discipline (and its gradients), and should subsequently be estimated and faraway from the information utilizing numerical strategies, that are nicely developed.

Though the gravity-gradient methodology is extraordinarily helpful for detecting subsurface objects by way of density inhomogeneities, its limitations must be acknowledged. The likelihood of detecting a subsurface construction relies on the construction’s measurement and depth, in addition to on the diploma to which its density differs from that of the encircling soil or rock setting. From our expertise within the detection of subsurface cavities in archaeological prospection11, we will infer the likelihood of figuring out such cavities in widespread pure situations when utilizing an instrument with the uncertainty reported by Stray and colleagues.

We estimate that the utmost amplitude of the vertical gravity gradient arising from a tunnel of 1 metre cross-sectional diameter, mendacity one metre under Earth’s floor, is greater than six occasions this uncertainty threshold. For a tunnel with a diameter 4 occasions wider than this, we calculate that the identical most amplitude could be measured even when the tunnel had been as much as 4 metres under the floor. Such detection capability appears very promising for a lot of engineering and environmental purposes.

Competing Pursuits

The authors declare no competing pursuits.

Map: Which countries are accepting Ukrainian refugees? | Infographic News


Almost 120,000 individuals have fled Ukraine into Poland and different neighbouring international locations within the wake of Russia’s invasion, the UN has mentioned.

Almost 120,000 individuals have fled Ukraine into Poland and different neighbouring international locations within the wake of Russia’s invasion, the UN refugee company (UNHCR) has mentioned.

Automobiles have been backed up for a number of kilometres at some border crossings as authorities in Poland, Slovakia, Hungary, Romania and Moldova mobilised to obtain Ukrainians and supply shelter, meals and authorized assist. Filippo Grandi, the UN’s excessive commissioner for refugees, mentioned most of those that had left had headed to Poland and Moldova.

A lot of the arrivals had been ladies and kids. All males aged between 18 and 60 have been banned from leaving the nation to take up arms and battle.

Poland, which was already residence to an estimated 1.5 million Ukrainians earlier than Russia’s invasion and which has expressed steadfast help for Ukraine, has to this point seen the majority of these fleeing Ukraine cross into its territory.

INTERACTIVE- Where are Ukrainians fleeing day 3 - 120000[Al Jazeera]

International visa necessities for Ukrainians

On Friday, Eire introduced it was instantly lifting visa necessities for Ukrainians. The UN mentioned the variety of individuals looking for refuge outdoors of Ukraine to different international locations may rise to 5 million. A number of European international locations are making ready for an inflow of Ukrainian refugees and have provided humanitarian assist. The US mentioned it was offering emergency support however signalled that Europe must be their main vacation spot.

Ukrainians can journey to some 140 international locations and territories with out the necessity for a visa or with a visa on arrival. The map beneath reveals the visa necessities for Ukrainians as of February 26.

INTERACTIVE- Visa requirements for Ukrainians[Al Jazeera]

Closed airspace and cancelled flights

Ukraine closed its airspace to civilian flights on February 24, citing a excessive threat to security. Russia additionally closed its airspace for civilian flights on its western border with Ukraine and Belarus. A number of airways have cancelled flights to Kyiv. The European Union mentioned it could prohibit exports of plane components to Russia.

In current weeks, dozens of nations have urged their residents to depart Ukraine. Many airways have typically averted flying over jap Ukraine since 2014, after Malaysia Airways flight MH17, flying from Amsterdam to Kuala Lumpur, was shot down over separatist-held territory. All 298 individuals on board, 198 of whom had been Dutch residents, had been killed.

The map beneath reveals the flights over Europe on February 26.

INTERACTIVE- Closed airspace and cancelled flights over Ukraine[Al Jazeera]

Ukraine’s foremost inhabitants centres

Ukraine has an estimated inhabitants of 44 million – the seventh-largest in Europe. The nation includes 24 areas, generally known as oblasts. The nation’s inhabitants has declined because the Nineties with fertility charges among the many lowest on the earth. As of 2020, Ukraine’s fertility fee was simply 1.2. For context, to ensure that a inhabitants to stay secure, an general whole fertility fee of two.1 is required.

Ukraine is the second-largest nation in Europe, after Russia. At 603,550sq km (233,031sq miles), Ukraine is a bit smaller than the US state of Texas, about thrice smaller than India, half the scale of South Africa and about two and a half instances the scale of the UK.

The map beneath reveals the place the nation’s inhabitants are concentrated.

INTERACTIVE- Ukraine main population centres 2021[Al Jazeera]

Battle at a look

After months of tensions and intense diplomacy, Russian forces launched a “particular navy operation” in Ukraine on February 24. Explosions had been heard throughout the nation. Kyiv declared martial regulation, saying Ukraine will defend itself.

On Saturday, combating reached the streets of Ukraine’s capital as Russia presses forward with its invasion. Beneath is a abstract of the battle at a look.

INTERACTIVE- Conflict at a glance[Al Jazeera]