Results 121 to 130 of about 1,969,454 (306)

Late Pleistocene fossil find in Svalbard: the oldest remains of a polar bear (Ursus maritimus Phipps, 1744) ever discovered

open access: yes, 2009
During recent fieldwork in Svalbard, a well preserved subfossil left mandible of a polar bear (Ursus maritimus Phipps, 1774) was discovered. A 14C age determination shows that it is older than 45 Ky (kilo-years), and an age determination with infrared ...
Wiig, Øystein, Ingólfsson, Ólafur
core   +1 more source

Deep Polar Codes

open access: yesIEEE Transactions on Communications
In this paper, we introduce a novel class of pre-transformed polar codes, termed as deep polar codes. We first present a deep polar encoder that harnesses a series of multi-layered polar transformations with varying sizes. Our approach to encoding enables a low-complexity implementation while significantly enhancing the weight distribution of the code.
Geon Choi, Namyoon Lee
openaire   +2 more sources

Structural and biochemical insights into the thermostable esterase Ta0887 from Thermoplasma acidophilum

open access: yesFEBS Open Bio, EarlyView.
In this study, a novel esterase from the thermoacidophilic archaeon Thermoplasma acidophilum was biochemically and structurally characterized. Our results demonstrate that Ta0887 is a highly thermostable esterase that preferentially hydrolyzes p‐nitrophenyl hexanoate and possesses an α‐helical cap domain that likely contributes to its substrate ...
Alejandro Delgado‐Rey   +4 more
wiley   +1 more source

Review of The expeditions of the first International Polar Year 1882–83, by William Barr

open access: yes, 2009
It is probably safe to assume that no readers of Polar Research are unaware that we have just come through a fourth International Polar Year (IPY). All science is, or should be, based on the previous achievements of others, and thus the experiences and ...
Barr, Susan
core   +1 more source

Modelling polar bear maternity den habitat in east Svalbard

open access: yes, 2020
We evaluated a novel tool that predicts possible maternity den habitat of the polar bear (Ursus maritimus) based on a physical snow transport model, a digital terrain model and weather data.
Aars, Jon   +2 more
core   +1 more source

Genetic dissection of human ABCE1 in yeast reveals separable requirements for ribosome recycling and suppression of aberrant reinitiation

open access: yesFEBS Open Bio, EarlyView.
Human ABCE1 cannot functionally replace its yeast ortholog. Yeast–human chimera analysis identified NBD1 as a major interspecies barrier. Genetic screening yielded hABCE1 revertants that rescue yeast viability but fail to suppress aberrant translation reinitiation in the 3′ UTR.
Eriko Nakata   +3 more
wiley   +1 more source

Review of Legacies and change in polar sciences: historical, legal and political reflections on the International Polar Year, edited by JM Shadian & M Tennberg

open access: yes, 2010
The International Polar Year (IPY) of 2007–09 was an international scientific enterprise that encompassed all polar regions, and built on the legacies bequeathed by earlier endeavours stretching back to the late 19th century.
Dodds, Klaus
core   +1 more source

Fast Node Polar Decoding Method Based on Hybrid Parity Check and CRC

open access: yesIEEE Access
In the case of short code, polar code demonstrates superior performance compared with Low Density Parity Check (LDPC) code. Particularly in low coding rate scenario, the complexity of Polar code encoding and decoding is significantly lower than that of ...
Zongmiao He   +5 more
doaj   +1 more source

Polar codes for distributed hierarchical source coding

open access: yesAdvances in Mathematics of Communications, 2015
We show that polar codes can be used to achieve the rate-distortion functions in the problem of hierarchical source coding also known as the successive refinement problem. We also analyze the distributed version of this problem, constructing a polar coding scheme that achieves the rate distortion functions for successive refinement with side ...
Min Ye 0005, Alexander Barg
openaire   +3 more sources

Chronobiology of Cancer: How Aging Fuels Oncogenesis at the Molecular Level

open access: yesAging and Cancer, EarlyView.
This graphical abstract illustrates the key biological pathways linking aging with cancer development and progression. In the upper left, cumulative exposure to ultraviolet radiation, toxins, and reactive oxygen species (ROS) causes DNA damage and genomic instability, whereas age‐related decline in repair mechanisms, such as ATM/ATR, BER, and NER ...
Anu Singh, Aroonima Misra, Sufian Zaheer
wiley   +1 more source

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