Letters in 2012

Measurements of the anisotropy power spectrum of the cosmic near-infrared background radiation show the clustering amplitude to be larger than existing model predictions involving distant primordial galaxies or nearby faint galaxies: the fluctuations are proposed to originate from intrahalo stars of all galaxies with dark-matter haloes of 10⁹ to 10¹² solar masses at redshifts of about 1 to 4.

Using separation-of-function mutations of TPP1 that inhibit telomerase binding while maintaining telomere capping, a region on the surface of TPP1, the TEL patch, is identified and found to be required for both binding telomerase and enhancing its processivity.

Novel pathogenic infectious retroviruses, generated by recombination between replication-defective endogenous retroviruses in the absence of a functional antibody response, are identified; these recombinant retroviruses establish infection of mouse colonies and ultimately cause cancer.

Passive immunotherapy with a combination of neutralizing monoclonal antibodies is shown to be effective in suppressing HIV replication in a humanized mouse model.

A crystalline material is investigated that responds to a slowly increasing external stress by exhibiting impulsive ‘avalanche’ behaviour as well as smooth stress release that is approximately as slow as the external stress rate; unusual oscillatory behaviour in the avalanche time series is reported.

The results of sequencing the collared flycatcher genome, and re-sequencing population samples from this species and its sister species, the pied flycatcher, reveal the existence of areas of high sequence divergence compared to background levels, and suggest that complex repeat structures may drive species divergence and that sex chromosomes and autosomes are at different stages of speciation.

Single-molecule analysis of RecA filament assembly on its in vivo substrate, SSB-coated single-stranded DNA, reveals that a dimer of RecA is required for nucleation, and is followed by bidirectional growth of the filament through monomer addition; the recombination mediator RecOR accelerates nucleation and growth, and the addition of RecF further stimulates nucleation.

A new model of glacial isostatic adjustment used in conjunction with GRACE satellite data suggests that ice loss from Antarctica is contributing 0.19 millimetres per year to global mean sea level, which is substantially less than previous GRACE-based estimates.

Chronic exposure of bumblebees to two pesticides (a neonicotinoid and a pyrethroid) independently and in combination, at concentrations approximating field-level exposure, impairs natural foraging behaviour and increases worker mortality, with knock-on effects for brood development and colony success.

NMR spectroscopy is used to determine the three-dimensional structure of the full-length human chemokine receptor CXCR1 in phospholipid bilayers under physiological conditions.

The cytosolic concentration of citrate partially depends on its direct import across the plasma membrane by the Na⁺-dependent citrate transporter (NaCT); here the X-ray crystal structure of a bacterial homologue of NaCT is reported, which, along with transport-activity studies, suggests how specific conformational changes facilitate substrate translocation across the cellular membrane.

The E3 ubiquitin ligase cullin 3 is shown to bind BTB-zinc finger transcription factors to direct the ubiquitination of nuclear chromatin-associated factors to control transcription and cell-fate decisions in B- and T-cell populations.

Analysis of the respective crystal structures of the yeast single-component type-II NADH dehydrogenase Ndi1 in its substrate-free form and when bound to NADH, ubiquinone and NADH–ubiquinone shows that Ndi1 homodimerization through its carboxy-terminal domain is critical for its catalytic activity and membrane targeting.

Detailed characterization of the regulatory domain of a plasma-membrane Ca²⁺-ATPase — a calcium pump — in complex with calmodulin results in a two-step structural model that explains how calmodulin-mediated regulation of pump activation affords highly responsive control over the intracellular calcium concentration in eukaryotes.

Observations of hard X-rays from the remnant of supernova 1987A in the narrow band containing two direct-escape lines of ⁴⁴Ti at 67.9 and 78.4 keV imply that this radiation had sufficient energy to power the remnant at late times; the initial mass of ⁴⁴Ti is estimated to be near the upper bound of theoretical predictions.

Lunar magmatic rocks are shown to be enriched in the heavy isotopes of zinc and to have lower zinc concentrations than terrestrial or Martian igneous rocks; these variations represent the large-scale evaporation of zinc, most probably in the aftermath of the Moon-forming giant impact event.

Synchrotron radiation X-ray tomographic microscopy of a developmental series of Compagopiscis croucheri (Arthrodira) indicates that placoderms had true teeth, but that tooth and jaw development was not developmentally or structurally integrated in placoderms.

A genital herpes simplex vaccine strategy of immunization using attenuated virus with peripheral local chemokine application can establish a population of protective tissue-resident memory T cells.

Investigation of neural cells from post-mortem human brains and differentiated from patient-derived induced pluripotent stem cells shows that the LRRK2 mutation (G2019S) associated with familial and sporadic Parkinson's disease correlates with abnormalities at the nuclear envelope.

Coupling a superconducting cavity to an indium arsenide double quantum dot with a charge–cavity coupling rate of 30 megahertz shows that long-range spin qubit interactions may be feasible.