This is mainly due to the fact that the GPS antenna is occasionally covered by sea water and cannot normally receive high-quality satellite GPS signals.
One type of α-SPD is gray platelet syndrome (GPS), caused by mutations in the neurobeachin-like 2 (NBEAL2) gene that results in a bleeding diathesis, thrombocytopenia, splenomegaly, and progressive myelofibrosis.
We observed absence of NBEAL2 in platelets from GPS patients with 3 different genotypes, and reduced/truncated platelet NBEAL2 has been reported for others.
However, in case the received GPS power is decreased, the performance of the conventional RLL algorithm degrades, or it cannot estimate the roll angle anymore, therefore, for operating the RLL algorithm in a weak signal environment, this paper designs a method to increase the signal-to-noise ratio (SNR) by overlapping multiple GPS signals' correlator outputs and a method to compensate the decreased response of a rotation discriminator at low-signal strength.
This study shows for the first time proteins interacting with Nbeal2 and points to the dysregulation of the canonical signaling pathway of Dock7 as a possible cause of the aberrant formation of platelets in GPS cases and <i>Nbeal2-</i>deficient mice.
Based on this new model, the developed simulator can present how the GPS signals (L1 and L2 carrier frequencies, C/A, P(Y) and L2C modulations) are transmitted (scattered and absorbed) through vegetation medium and received by GPS receivers.
The functions of the NBEAL2 protein have not been explored outside platelet biology, but there are reports of increased frequency of infection and abnormal neutrophil morphology in patients with GPS.
Loss-of-function mutations in the human <i>NBEAL2</i> gene or Nbeal2 deficiency in mice cause gray platelet syndrome, a bleeding disorder characterized by macrothrombocytopenia, splenomegaly, and paucity of α-granules in megakaryocytes and platelets.
The autosomal recessive form of GPS is linked to loss of function mutations in NBEAL2, which is predicted to regulate granule trafficking in megakaryocytes, the platelet progenitors.
Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps) exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10-7).
Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps) exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10-7).
We studied platelet function and bone marrow (BM) features in five GPS patients with NBEAL2 autosomal recessive mutations from four unrelated families.
We present here a novel Nbeal2(-/-) murine model of GPS and demonstrate that the lack of α-granules is due to their loss from platelets/mature megakaryocytes (MKs), and not by initial impaired formation.
We present here a novel Nbeal2(-/-) murine model of GPS and demonstrate that the lack of α-granules is due to their loss from platelets/mature megakaryocytes (MKs), and not by initial impaired formation.
As in GPS, Nbeal2(-/-) mice exhibit splenomegaly, macrothrombocytopenia, and a deficiency of platelet α-granules and their cargo, including von Willebrand factor (VWF), thrombospondin-1, and platelet factor 4.
Here we show that Nbeal2-knockout mice display the characteristics of human GPS, with defective α-granule biogenesis in MKs and their absence from platelets.