| 31. |
- Adameyko, I
(författare)
-
Neural circuitry gets rewired
- 2016
-
Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 354:6314, s. 833-834
-
Tidskriftsartikel (refereegranskat)abstract
- Former parasympathetic innervations of organs are now claimed sympathetic
|
|
| 32. |
- Adameyko, I
(författare)
-
Supracellular contractions propel migration
- 2018
-
Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 362:6412, s. 290-291
-
Tidskriftsartikel (refereegranskat)abstract
- Cytoskeletal cords connecting cells at the back of cell groups enable directional migration
|
|
| 33. |
- Adriani, O., et al.
(författare)
-
PAMELA Measurements of Cosmic-Ray Proton and Helium Spectra
- 2011
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 332:6025, s. 69-72
-
Tidskriftsartikel (refereegranskat)abstract
- Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.
|
|
| 34. |
- Aharonian, F., et al.
(författare)
-
Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi
- 2022
-
Ingår i: Science. - : American Association for Advancement of Science. - 0036-8075 .- 1095-9203. ; 376:6588, s. 77-80
-
Tidskriftsartikel (refereegranskat)abstract
- Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy [VHE: greater than or similar to 100 giga-electron volts] gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.
|
|
| 35. |
- Ahlberg, Per E
(författare)
-
The early evolution of the tetrapod humerus
- 2004
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 305:5691, s. 1715-1715
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 36. |
- Ahlström, Anders, et al.
(författare)
-
The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink
- 2015
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 348:6237, s. 895-899
-
Tidskriftsartikel (refereegranskat)abstract
- The growth rate of atmospheric carbon dioxide (CO2) concentrations since industrialization is characterized by large interannual variability, mostly resulting from variability in CO2 uptake by terrestrial ecosystems (typically termed carbon sink). However, the contributions of regional ecosystems to that variability are not well known. Using an ensemble of ecosystem and land-surface models and an empirical observation-based product of global gross primary production, we show that the mean sink, trend, and interannual variability in CO2 uptake by terrestrial ecosystems are dominated by distinct biogeographic regions. Whereas the mean sink is dominated by highly productive lands (mainly tropical forests), the trend and interannual variability of the sink are dominated by semi-arid ecosystems whose carbon balance is strongly associated with circulation-driven variations in both precipitation and temperature.
|
|
| 37. |
- Ahuja, SK, et al.
(författare)
-
A plea for justice for jailed medical workers
- 2006
-
Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 924-925
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 38. |
- Ajello, M., et al.
(författare)
-
A gamma-ray pulsar timing array constrains the nanohertz gravitational wave background
- 2022
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 376:6592, s. 521-523
-
Tidskriftsartikel (refereegranskat)abstract
- After large galaxies merge, their central supermassive black holes are expected to form binary systems. Their orbital motion should generate a gravitational wave background (GWB) at nanohertz frequencies. Searches for this background use pulsar timing arrays, which perform long-term monitoring of millisecond pulsars at radio wavelengths. We used 12.5 years of Fermi Large Area Telescope data to form a gamma-ray pulsar timing array. Results from 35 bright gamma-ray pulsars place a 95% credible limit on the GWB characteristic strain of 1.0 x 10(-14) at a frequency of 1 year(-1). The sensitivity is expected to scale with t(obs), the observing time span, as t(obs)(-13/6). This direct measurement provides an independent probe of the GWB while offering a check on radio noise models.
|
|
| 39. |
- Akbari, Parsa, et al.
(författare)
-
Sequencing of 640,000 exomes identifies GPR75 variants associated with protection from obesity
- 2021
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 373:6550
-
Tidskriftsartikel (refereegranskat)abstract
- Large-scale human exome sequencing can identify rare protein-coding variants with a large impact on complex traits such as body adiposity. We sequenced the exomes of 645,626 individuals from the United Kingdom, the United States, and Mexico and estimated associations of rare coding variants with body mass index (BMI). We identified 16 genes with an exome-wide significant association with BMI, including those encoding five brain-expressed G protein-coupled receptors (CALCR, MC4R, GIPR, GPR151, and GPR75). Protein-truncating variants in GPR75 were observed in ∼4/10,000 sequenced individuals and were associated with 1.8 kilograms per square meter lower BMI and 54% lower odds of obesity in the heterozygous state. Knock out of Gpr75 in mice resulted in resistance to weight gain and improved glycemic control in a high-fat diet model. Inhibition of GPR75 may provide a therapeutic strategy for obesity.
|
|
| 40. |
|
|
