Putative involvement of Thioredoxin h in early response to gravitropic stimulation of poplar stems

Gravity perception and gravitropic response are essential for plant development. In herbaceous species, it is widely accepted that one of the primary events in gravity perception involves the displacement of amyloplasts within specialized cells. However, the early signaling events leading to stem reorientation are not fully known, especially in woody species in which primary and secondary growth occur. Thirty-six percent of the identified proteins that were differentially expressed after gravistimulation were established as potential Thioredoxin targets. In addition, Thioredoxin h expression was induced following gravistimulation. In situ immunolocalization indicated that Thioredoxin h protein co-localized with the amyloplasts located in the endodermal cells. These investigations suggest the involvement of Thioredoxin h in the first events of signal transduction in inclined poplar stems, leading to reaction wood formation.     

Dodecyl Maltoside Protects Membrane Proteins In Vacuo

Molecular dynamics simulations have been used to characterize the effects of transfer from aqueous solution to a vacuum to inform our understanding of mass spectrometry of membrane-protein-detergent complexes. We compared two membrane protein architectures (an α-helical bundle versus a β-barrel) and two different detergent types (phosphocholines versus an alkyl sugar) with respect to protein stability and detergent packing. The β-barrel membrane protein remained stable as a protein-detergent complex in vacuum. Zwitterionic detergents formed conformationally destabilizing interactions with an α-helical membrane protein after detergent micelle inversion driven by dehydration in vacuum. In contrast, a nonionic alkyl sugar detergent resisted micelle inversion, maintaining the solution-phase conformation of the protein. This helps to explain the relative stability of membrane proteins in the presence of alkyl sugar detergents such as dodecyl maltoside.     

New perspectives of locomotor rehabilitation after stroke

The task-oriented approach incorporating treadmill walking for retraining gait early after stroke has contributed to promote locomotor recovery. To augment practice, training strategies such as mental practice and training in virtual environments are proposed. While the former offers more practice with less physical exertion, the latter allows safe practice in a variety of challenging environments. Work is under way to assess whether these new strategies can further enhance locomotor recovery.     

Darker female pigeons transmit more specific antibodies to their eggs than do paler ones

Melanin‐based coloration is widespread among vertebrates, yet the adaptive significance of such pigments remains elusive, particularly with regard to the link between melanin and immune‐mediated maternal effects. The aim of this study was to investigate whether melanin‐based coloration could signal the ability of mothers to mount a humoral response and to transfer maternal antibodies (Ab) to their young. We injected differently coloured (pale and dark) female feral pigeons (Columba livia) with Chlamydiae (a natural antigen) and Keyhole Limpet Haemocyanin (KLH, an artificial antigen), and found no significant difference in humoral response between differently coloured females. However, darker females transferred more Ab against Chlamydiae into their eggs than paler ones, despite similar circulating levels of Ab. In addition to this, melanin‐based coloration showed a high heritability value. This suggests that a genetically based coloured trait might be linked to the ability of females to transfer specific Ab against Chlamydiae (but not against KLH) to their offspring, independent of their ability to produce Ab. This suggests that transmission of maternal Ab is antigen dependent, and that melanin‐based coloration might signal female ability to transmit specific Ab against natural pathogens. © 2013 The Linnean Society of London     

A review of the subspecies status of the Icelandic Purple Sandpiper Calidris maritima littoralis

The Icelandic Purple Sandpiper Calidris maritima littoralis (C.L. Brehm, 1831) represents one member of a poorly understood subspecies complex. Currently, differences in size define two other subspecies: Calidris maritima belcheri Engelmoer & Roselaar, 1998, which breeds in north‐eastern Canada along the Hudson Bay and James Bay, and Calidris maritima maritima (Brunnich, 1764), which breeds along the Arctic coasts elsewhere in northern Canada, Greenland, Svalbard, Scotland, and Fennoscandia, to northern central Siberia. There are large size differences amongst populations of C. m. maritima, however. As an Arctic/Alpine breeding bird, C. m. littoralis could provide an interesting perspective on the evolutionary changes following a northwards expansion of a species after glacial retreat. Considering the extent of the ice sheet in the northern hemisphere during the last glaciation, and the short period of time since it ended, the correct attribution of subspecies status for C. m. maritima may reflect either rapid diversification from a single population or ancestral splits of distinct evolutionary lineages that survived in isolation at southern latitudes. We applied morphometric subspecies criteria, diagnosability by Amadon's rule, and genetic analysis of five nuclear introns, and the mitochondrial DNA markers cytochrome oxidase c subunit I (COI) and NADH dehydrogenase subunit 2 (ND2), to geographically separate breeding populations in order to examine the subspecies status of the Icelandic population. The results do not provide support for the subspecies status of the Icelandic population because the nominate and Icelandic subspecies fail to uphold Amadon's rule, and genetic analyses indicate that the study populations derive from a single shared refugium. © 2015 The Linnean Society of London     

Persistent and novel threats to the biodiversity of Kazakhstan’s steppes and semi-deserts

Temperate grasslands have suffered disproportionally from conversion to cropland, degradation and fragmentation. A large proportion of the world’s remaining near-natural grassland is situated in Kazakhstan. We aimed to assess current and emerging threats to steppe and semi-desert biodiversity in Kazakhstan and evaluate conservation research priorities. We conducted a horizon-scanning exercise among conservationists from academia and practice. We first compiled a list of 45 potential threats. These were then ranked by the survey participants according to their perceived severity, the need for research on them, and their novelty. The highest-ranked threats were related to changes in land use (leading to habitat loss and deterioration), direct persecution of wildlife, and rapid infrastructure development due to economic and population growth. Research needs were identified largely in the same areas, and the mean scores of threat severity and research need were highly correlated. Novel threats comprised habitat loss by photovoltaic and wind power stations, climate change and changes in agriculture such as the introduction of biofuels. However, novelty was not correlated with threat severity or research priority, suggesting that the most severe threats are the established ones. Important goals towards more effective steppe and semi-desert conservation in Kazakhstan include more cross-sector collaboration (e.g. by involving stakeholders in conservation and agriculture), greater allocation of funds to under-staffed areas (e.g. protected area management), better representativeness and complementarity in the protected area system and enhanced data collection for wildlife monitoring and threat assessments (including the use of citizen-science databases).     

Plasmonic Enhancement by a Continuous Gold Underlayer: Application to SERS Sensing

Plasmonics - In this paper, we report on an improved enhancement of the surface-enhanced Raman scattering (SERS) effect. Such improvement is obtained by using a continuous gold film (underlayer),...     

Selective estrogen receptor degraders with novel structural motifs induce regression in a tamoxifen-resistant breast cancer xenograft

Potent estrogen receptor ligands typically contain a phenolic hydrogen-bond donor. The indazole of the selective estrogen receptor degrader (SERD) ARN-810 is believed to mimic this. Disclosed herein is the discovery of ARN-810 analogs which lack this hydrogen-bond donor. These SERDs induced tumor regression in a tamoxifen-resistant breast cancer xenograft, demonstrating that the indazole NH is not necessary for robust ER-modulation and anti-tumor activity.