SciByte

simian immunodeficiency virus, or SIV, which causes AIDS in monkeys

it is hoped an HIV-form of the vaccine candidate can soon be tested in humans

approach involves the use of cytomegalovirus, or CMV, a common virus already carried by a large percentage of the population

the researchers discovered that pairing CMV with SIV had a unique effect

a modified version of CMV engineered to express SIV proteins generates and indefinitely maintains so-called "effector memory" T-cells that are capable of searching out and destroying SIV-infected cells

About 50 percent of monkeys given highly pathogenic SIV after being vaccinated with this vaccine became infected with SIV but over time eliminated all trace of SIV from the body

vaccine mobilized a T-cell response that was able to overtake the SIV invaders in 50 percent of the cases treated

testing suggests SIV was banished from the host

lab is now investigating the possible reasons why only a subset of the animals treated had a positive response in hopes that the effectiveness of the vaccine candidate can be further boosted

more than 60,000 kilometers per hour

August 25, when solar particles disappeared for good

combined with a surge in higher-energy particles from other stars, suggested that Voyager had exited the heliosphere

Several well-publicized studies made that claim

colleagues resisted that conclusion

lacked evidence of what they thought would be the key signature of interstellar space: a shift in the direction of the magnetic field

Solar plasma produces a distinctive magnetic field because it all comes from the same source

scientists expected that the field would shift in interstellar space, where particles flit around in all directions

Not everyone agrees, including a few holdouts on the Voyager team

have written a paper demonstrating how plasma could become dense enough within the heliosphere to produce

measurement

many other astrophysicists say the evidence is overwhelming that Voyager 1 has crossed the heliopause, but they acknowledge that they have to determine why the magnetic field direction didn’t shift

NASA estimates that Voyager 1 has enough plutonium fuel to keep all its instruments powered for another seven years

August 25, 2012 — the same date, coincidentally, that the world lost its most famous human space explorer, Neil Armstrong

For several months, the relative position of Voyager 1

remains some lingering evidence of the nearby heliosphere beyond the heliopause.

April

there are variations in some of Voyager's measurements that may be due to the nearby presence of the heliosphere

11.6 billion miles from the sun, or about 125 astronomical units.

it takes more than 17 hours for a radio signal to travel from the spacecraft

The signal strength is so incredibly weak that it takes both a 230-foot and a 110-foot-diameter antenna to receive our highest resolution data

moving outward from the sun at about 3.5 AU per year

it is not farther out than the Oort Cloud

it will take 300 more years reach the Oort cloud and the spacecraft is closer to our Sun than any other star

the plasma environment Voyager 1 now travels through has definitely changed from what comes from our Sun to the plasma that is present in the space between stars.

debate

There’s also been a

between the latest various science papers and their authors

Scientists thought that when the spacecraft had crossed over into interstellar space, the magnetic field direction would change

that didn’t happen

scientists determined they needed to look at the properties of the plasma instead

The Sun’s heliosphere is filled with ionized plasma from the Sun

Outside that bubble, the plasma comes from the explosions of other stars millions of years ago

The main tell-tail difference is the interstellar plasma is denser.

the real instrument that was designed to make the measurements on the plasma quit working in the 1980’s

Instead they used the plasma wave instrument, located on the 10-meter long antennas on Voyager 1 and

from the Sun

a massive Coronal Mass Ejection

The antennas have radio receivers at the ends – “like the rabbit ears on old television sets

The CME erupted from the Sun in March 2012, and eventually arrived at Voyager 1′s location 13 months later, in April 2013

Because of the CME, the plasma around the spacecraft began to vibrate like a violin string

The pitch of the oscillations helped scientists determine the density of the plasma

the particular oscillations meant the spacecraft was bathed in plasma more than 40 times denser than what they had encountered in the outer layer of the heliosphere

The plasma wave science team reviewed its data and found an earlier, fainter set of oscillations in October and November 2012 from other CMEs

extrapolation of measured plasma densities from both events, the team determined Voyager 1 first entered interstellar space in August 2012

certainly in a new region at the edge of the solar system where things are changing rapidly

not yet able to say that Voyager 1 has entered interstellar space

the data are changing in ways that the team didn’t expect

after further review, the Voyager team generally accepts the August 2012 date as the date of interstellar arrival

The charged particle and plasma changes were what would have been expected during a crossing of the heliopause

expect the fields and particles science instruments on Voyager will continue to send back data through at least 2020

, it was first questioned in August of 2012, with more speculation in December 2012, then in March of 2013

Then about a month ago

Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft

emitted signals are currently very dim, at about 23 watts — the power of a refrigerator light bulb

Voyager mission controllers still talk to or receive data from Voyager 1 and Voyager 2 every day

planetary alignment that only happens every 176 years enabled the two spacecraft to join together to reach all the outer planets in a 12 year time period

By the time the signals get to Earth, they are a fraction of a billion-billionth of a watt

Data from Voyager 1′s instruments are transmitted to Earth typically at 160 bits per second

signal from Voyager 1 takes about 17 hours to travel to Earth.

After the data are transmitted to JPL and processed by the science teams, Voyager data are made publicly available

Scientists do not know when Voyager 1 will reach the undisturbed part of interstellar space where there is no influence from our Sun

They also are not certain when Voyager 2 is expected to cross into interstellar space, but they believe it is not very far behind.

While Voyager 1 will keep going, we will not always be able to communicate with it, as we do now

In 2025 all instruments will be turned off, and the science team will be able to operate the spacecraft for about 10 years after that to just get engineering data

In the year 40,272 AD, Voyager 1 will come within 1.7 light years of an obscure star in the constellation Ursa Minor

science team carefully choose a few stopping points for study along the way to help characterize the local terrain

Curiosity has arrived at Waypoint 1

has now driven nearly 20% of the way towards the base of the giant layered mountain

Altogether, the team selected five ‘Waypoints’ to investigate for a few days each

stay just a couple of sols at Waypoint 1 and then we hit the road again

Waypoint 1’ is an area of intriguing outcrops that was chosen based on high resolution orbital imagery taken by NASA’s Mars Reconnaissance Orbiter (MRO)

Curiosity will only stay a short time at each of the stops, the measurements collected at each ‘Waypoint’ will provide essential clues to the overall geologic and environmental history

scientists goal is to compare the floor of Gale Crater to the sedimentary layers of 3 mile high (5 kilometer high) Mount Sharp

Waypoint 1 is just over 1 mile along the approximately 5.3-mile (8.6-kilometer) route from ‘Glenelg’ to the entry point at the base of Mount Sharp

Curiosity spent over six months investigating the ‘Yellowknife Bay’ area inside Glenelg before departing on July 4, 2013

On Sept. 5, Curiosity set a new one-day distance driving record for the longest drive yet by advancing 464 feet (141.5 meters) on her 13th month

As Curiosity neared Waypoint 1 she stopped at a rise called ‘Panorama Point’ on Sept. 7

will not conduct any drilling here or at the other waypoints

unless there is some truly remarkable discovery

If all goes well Curiosity could reach the entry point to Mount Sharp sometime during Spring 2014, at her current driving pace

Issus coleoptratus

juveniles

have an intricate gearing system that locks their back legs together, allowing both appendages to rotate at the exact same instant, causing the tiny creatures jump forward.

, is believed to be the first functional gearing system ever discovered in nature

The finding,

used electron microscopes and high-speed video capture to discover the existence of the gearing and figure out its exact function.

To jump, both of the insect’s hind legs must push forward at the exact same time

The reason for the gearing, they say, is coordination

The researchers’ high-speed videos showed that the creatures

cocked their back legs in a jumping position, then pushed forward, with each moving within 30 microseconds

jump at speeds as high as 8.7 miles per hour

30 millionths of a second

the skeleton is used to solve a complex problem that the brain and nervous system can’t

The gears are located at the top of the insects’ hind legs

and include 10 to 12 tapered teeth, each about 80 micrometers wide (or 80 millionths of a meter).

In all the Issus hoppers studied, the same number of teeth were present on each hind leg, and the gears locked together neatly

adults of the same insect species don’t have any gearing—as the juveniles grow up and their skin molts away

the adult legs are synchronized by an alternate mechanism (a series of protrusions extend from both hind legs, and push the other leg into action).

hypothesize that this could be explained by the fragility of the gearing

if one tooth breaks, it limits the effectiveness of the design

isn’t such a big problem for the juveniles, who repeatedly molt and grow new gears before adulthood

for the mature Issus, replacing the teeth would be impossible

There have been gear-like structures previously found on other animals

but they’re purely ornamental