920 research outputs found
Misincorporation Proteomics Technologies: A Review.
Proteinopathies are diseases caused by factors that affect proteoform conformation. As such, a prevalent hypothesis is that the misincorporation of noncanonical amino acids into a proteoform results in detrimental structures. However, this hypothesis is missing proteomic evidence, specifically the detection of a noncanonical amino acid in a peptide sequence. This review aims to outline the current state of technology that can be used to investigate mistranslations and misincorporations whilst framing the pursuit as Misincorporation Proteomics (MiP). The current availability of technologies explored herein is mass spectrometry, sample enrichment/preparation, data analysis techniques, and the hyphenation of approaches. While many of these technologies show potential, our review reveals a need for further development and refinement of approaches is still required
Correction: Steele et al. Misincorporation Proteomics Technologies: A Review. Proteomes 2021, 9, 2.
In the original publication, there was a mistake in Table 2 as published [...]
Coherent spinor dynamics in a spin-1 Bose condensate
Collisions in a thermal gas are perceived as random or incoherent as a
consequence of the large numbers of initial and final quantum states accessible
to the system. In a quantum gas, e.g. a Bose-Einstein condensate or a
degenerate Fermi gas, the phase space accessible to low energy collisions is so
restricted that collisions be-come coherent and reversible. Here, we report the
observation of coherent spin-changing collisions in a gas of spin-1 bosons.
Starting with condensates occupying two spin states, a condensate in the third
spin state is coherently and reversibly created by atomic collisions. The
observed dynamics are analogous to Josephson oscillations in weakly connected
superconductors and represent a type of matter-wave four-wave mixing. The
spin-dependent scattering length is determined from these oscillations to be
-1.45(18) Bohr. Finally, we demonstrate coherent control of the evolution of
the system by applying differential phase shifts to the spin states using
magnetic fields.Comment: 19 pages, 3 figure
Evidence for a flux transfer event generated by multiple X-line reconnection at the magnetopause
Magnetic flux transfer events (FTEs) are signatures of unsteady magnetic reconnection, often observed at planetary magnetopauses. Their generation mechanism, a key ingredient determining how they regulate the transfer of solar wind energy into magnetospheres, is still largely unknown. We report THEMIS spacecraft observations on 2007-06-14 of an FTE generated by multiple X-line reconnection at the dayside magnetopause. The evidence consists of (1) two oppositely-directed ion jets converging toward the FTE that was slowly moving southward, (2) the cross-section of the FTE core being elongated along the magnetopause normal, probably squeezed by the oppositely-directed jets, and (3) bidirectional field-aligned fluxes of energetic electrons in the magnetosheath, indicating reconnection on both sides of the FTE. The observations agree well with a global magnetohydrodynamic model of the FTE generation under large geomagnetic dipole tilt, which implies the efficiency of magnetic flux transport into the magnetotail being lower for larger dipole tilt
A Neural Spiking Approach Compared to Deep Feedforward Networks on Stepwise Pixel Erasement
In real world scenarios, objects are often partially occluded. This requires
a robustness for object recognition against these perturbations. Convolutional
networks have shown good performances in classification tasks. The learned
convolutional filters seem similar to receptive fields of simple cells found in
the primary visual cortex. Alternatively, spiking neural networks are more
biological plausible. We developed a two layer spiking network, trained on
natural scenes with a biologically plausible learning rule. It is compared to
two deep convolutional neural networks using a classification task of stepwise
pixel erasement on MNIST. In comparison to these networks the spiking approach
achieves good accuracy and robustness.Comment: Published in ICANN 2018: Artificial Neural Networks and Machine
Learning - ICANN 2018
https://link.springer.com/chapter/10.1007/978-3-030-01418-6_25 The final
authenticated publication is available online at
https://doi.org/10.1007/978-3-030-01418-6_2
Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago
Past sea-level records provide invaluable information about the response of ice sheets to climate forcing. Some such records suggest that the last deglaciation was punctuated by a dramatic period of sea-level rise, of about 20 metres, in less than 500 years. Controversy about the amplitude and timing of this meltwater pulse (MWP-1A) has, however, led to uncertainty about the source of the melt water and its temporal and causal relationships with the abrupt climate changes of the deglaciation. Here we show that MWP-1A started no earlier than 14,650 years ago and ended before 14,310 years ago, making it coeval with the Bolling warming. Our results, based on corals drilled offshore from Tahiti during Integrated Ocean Drilling Project Expedition 310, reveal that the increase in sea level at Tahiti was between 12 and 22 metres, with a most probable value between 14 and 18 metres, establishing a significant meltwater contribution from the Southern Hemisphere. This implies that the rate of eustatic sea-level rise exceeded 40 millimetres per year during MWP-1A
Neuronal characteristics of small-cell lung cancer
Wide ranging experimental evidence suggests that human small-cell lung cancer (SCLC) has a number of molecular and subcellular characteristics normally associated with neurones. This review outlines and discusses these characteristics in the light of recent developments in the field. Emphasis is placed upon neuronal cell adhesion molecules, neurone-restrictive silencer factor, neurotransmitters/peptides and voltage-gated ion, especially Na+ channels. The hypothesis is put forward that acquisition of such characteristics and the membrane ‘excitability' that would follow can accelerate metastatic progression. The clinical potential of the neuronal characteristics of SCLC, in particular ion channel expression/activity, is discussed in relation to possible novel diagnostic and therapeutic modalities
Environmental and diagenetic controls on the morphology and calcification of the Ediacaran metazoan Cloudina
Abstract Cloudina is a globally distributed Ediacaran metazoan, with a tubular, funnel-in-funnel form built of thin laminae (ca. 1–10 μm). To what degree local environmental controlled morphology, and whether early diagenesis controlled the degree of calcification of Cloudina, is debated. Here we test these hypotheses by considering assemblages from four, coeval localities from the Upper Omkyk Member, Nama Group, Namibia, from inner ramp to mid-ramp reef across the Zaris Subbasin. We show that sinuosity of the Cloudina tube is variable between sites, as is the relative thickness of the tube wall, suggesting these features were environmentally controlled. Walls are thickest in high-energy reef settings, and thinnest in the low-energy, inner ramp. While local diagenesis controls preservation, all diagenetic expressions are consistent with the presence of weakly calcified, organic-rich laminae, and lamina thicknesses are broadly constant. Finally, internal ‘cements’ within Cloudina are found in all sites, and pre-date skeletal breakage, transport, as well as syn-sedimentary botryoidal cement precipitation. Best preservation shows these to be formed by fine, pseudomorphed aragonitic acicular crystals. Sr concentrations and Mg/Ca show no statistically significant differences between internal Cloudina cements and botryoidal cements, but we infer all internal cements to have precipitated when Cloudina was still in-situ and added considerable mechanical strength, but may have formed post-mortem or in abandoned parts of the skeleton
A novel method for troubleshooting vascular injury during anatomic thoracoscopic pulmonary resection without conversion to thoracotomy
- …