Potential ecological impacts of climate intervention by reflecting sunlight to cool Earth

As the effects of anthropogenic climate change become more severe, several approaches for deliberate climate intervention to reduce or stabilize Earth’s surface temperature have been proposed. Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. While climate science research has focused on the predicted climate effects of SRM, almost no studies have investigated the impacts that SRM would have on ecological systems. The impacts and risks posed by SRM would vary by implementation scenario, anthropogenic climate effects, geographic region, and by ecosystem, community, population, and organism. Complex interactions among Earth’s climate system and living systems would further affect SRM impacts and risks. We focus here on stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth’s surface temperature. We outline current gaps in knowledge about both helpful and harmful predicted effects of SAI on ecological systems. Desired ecological outcomes might also inform development of future SAI implementation scenarios. In addition to filling these knowledge gaps, increased collaboration between ecologists and climate scientists would identify a common set of SAI research goals and improve the communication about potential SAI impacts and risks with the public. Without this collaboration, forecasts of SAI impacts will overlook potential effects on biodiversity and ecosystem services for humanity

Invariance and plasticity in the Drosophila melanogaster metabolomic network in response to temperature

BACKGROUND: Metabolomic responses to extreme thermal stress have recently been investigated in Drosophila melanogaster. However, a network level understanding of metabolomic responses to longer and less drastic temperature changes, which more closely reflect variation in natural ambient temperatures experienced during development and adulthood, is currently lacking. Here we use high-resolution, non-targeted metabolomics to dissect metabolomic changes in D. melanogaster elicited by moderately cool (18°C) or warm (27°C) developmental and adult temperature exposures. RESULTS: We find that temperature at which larvae are reared has a dramatic effect on metabolomic network structure measured in adults. Using network analysis, we are able to identify modules that are highly differentially expressed in response to changing developmental temperature, as well as modules whose correlation structure is strongly preserved across temperature. CONCLUSIONS: Our results suggest that the effect of temperature on the metabolome provides an easily studied and powerful model for understanding the forces that influence invariance and plasticity in biological networks. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12918-014-0139-6) contains supplementary material, which is available to authorized users

Supervillin modulation of focal adhesions involving TRIP6/ZRP-1

Cell–substrate contacts, called focal adhesions (FAs), are dynamic in rapidly moving cells. We show that supervillin (SV)—a peripheral membrane protein that binds myosin II and F-actin in such cells—negatively regulates stress fibers, FAs, and cell–substrate adhesion. The major FA regulatory sequence within SV (SV342-571) binds to the LIM domains of two proteins in the zyxin family, thyroid receptor–interacting protein 6 (TRIP6) and lipoma-preferred partner (LPP), but not to zyxin itself. SV and TRIP6 colocalize within large FAs, where TRIP6 may help recruit SV. RNAi-mediated decreases in either protein increase cell adhesion to fibronectin. TRIP6 partially rescues SV effects on stress fibers and FAs, apparently by mislocating SV away from FAs. Thus, SV interactions with TRIP6 at FAs promote loss of FA structure and function. SV and TRIP6 binding partners suggest several specific mechanisms through which the SV–TRIP6 interaction may regulate FA maturation and/or disassembly

Near-field iron and carbon chemistry of non-buoyant hydrothermal plume particles, Southern East Pacific Rise 15°S

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Marine Chemistry 201 (2018): 183-197, doi:10.1016/j.marchem.2018.01.011.Iron (Fe)-poor surface waters limit phytoplankton growth and their ability to remove carbon (C) from the atmosphere and surface ocean. Over the past few decades, research has focused on constraining the global Fe cycle and its impacts on the global C cycle. Hydrothermal vents have become a highly debated potential source of Fe to the surface ocean. Two main mechanisms for transport of Fe over long distances have been proposed: Fe-bearing nanoparticles and organic C complexation with Fe in the dissolved (dFe) and particulate (pFe) pools. However, the ubiquity and importance of these processes is unknown at present, and very few vents have been investigated for Fe-Corg interactions or the transport of such materials away from the vent. Here we describe the near-field contributions (first ~100 km from ridge) of pFe and Corg to the Southern East Pacific Rise (SEPR) plume, one of the largest known hydrothermal plume features in the global ocean. Plume particles (> 0.2 μm) were collected as part of the U.S. GEOTRACES Eastern Pacific Zonal Transect cruise (GP16) by in-situ filtration. Sediment cores were also collected to investigate the properties of settling particles. In this study, X-ray absorption near edge structure (XANES) spectroscopy was used in two complementary X-ray synchrotron approaches, scanning transmission X-ray microscopy (STXM) and X-ray microprobe, to investigate the Fe and C speciation of particles within the near-field non-buoyant SEPR plume. When used in concert, STXM and X-ray microprobe provide fine-scale and representative information on particle morphology, elemental co-location, and chemical speciation. Bulk chemistry depth profiles for particulate Corg (POC), particulate manganese (pMn), and pFe indicated that the source of these materials to the non-buoyant plume is hydrothermal in origin. The plume particles at stations within the first ~100 km down-stream of the ridge were composites of mineral (oxidized Fe) and biological materials (organic C, Corg). Iron chemistry in the plume and in the core-top suspended sediment fluff layer were both dominated by Fe(III) phases, such as Fe(III) oxyhydroxides and Fe(III) phyllosilicates. Particulate sulfur (pS) was a rare component of our plume and sediment samples. When pS was detected, it was in the form of an Fe sulfide mineral phase, composing ≤ 0.4% of the Fe on a per atom basis. The resuspended sediment fluff layer contained a mixture of inorganic (coccolith fragments) and Corg bearing (lipid-rich biofilm-like) materials. The particle morphology and co-location of C and Fe in the sediment was different from that in plume particles. This indicates that if the Fe-Corg composite particles settle rapidly to the sediments, then they experience strong alteration during settling and/or within the sediments. Overall, our observations indicate that the particles within the first ~ 100 km of the laterally advected plume are S-depleted, Fe(III)-Corg composites indicative of a chemically oxidizing plume with strong biological modification. These findings confirm that the Fe-Corg relationships observed for non-buoyant plume particles within ~ 100 m of the vent site are representative of particles within this region of the non-buoyant plume (~100 km). These findings also point to dynamic alteration of Fe-Corg bearing particles during transport and settling. The specific biogeochemical processes at play, and the implications for nutrient cycling in the ocean are currently unknown and represent an area of future investigation

Statistical Modeling of Extracellular Vesicle Cargo to Predict Clinical Trial Outcomes For Hypoplastic Left Heart Syndrome

Cardiac-derived c-kit+ progenitor cells (CPCs) are under investigation in the CHILD phase I clinical trial (NCT03406884) for the treatment of hypoplastic left heart syndrome (HLHS). The therapeutic efficacy of CPCs can be attributed to the release of extracellular vesicles (EVs). to understand sources of cell therapy variability we took a machine learning approach: combining bulk CPC-derived EV (CPC-EV) RNA sequencing and cardiac-relevan

Immediate Blood Draw for CD4+ Cell Count Is Associated with Linkage to Care in Durban, South Africa: Findings from Pathways to Engagement in HIV Care

Background Timely linkage to care by newly-diagnosed HIV+ individuals remains a significant challenge to achieving UNAIDS 90-90-90 goals. Current World Health Organization (WHO) guidelines recommend initiating anti-retroviral treatment (ART) regardless of CD4+ count, with priority given to those with CD4+ <350 cells/μl. We evaluated the impact of not having a day-of-diagnosis CD4+ count blood draw, as recommended by South African guidelines, on time to linkage, using data from a prospective cohort study. Methods Individuals (N = 2773) were interviewed prior to HIV counseling and testing at three public sector primary care clinics in the greater Durban area; 785 were newly-diagnosed and eligible for the cohort study; 459 (58.5%) joined and were followed for eight months with three structured assessments. Linkage to care, defined as returning to clinic for CD4+ count results, and day-of-diagnosis blood draw were self-reported. Results Overall, 72.5% did not have a day-of-diagnosis CD4+ count blood draw, and 19.2% of these never returned. Compared with a day-of-diagnosis blood draw, the adjusted hazard ratio of linkage (AHRlinkage) associated with not having day-of-diagnosis blood draw was 0.66 (95%CI: 0.51, 0.85). By 4 months, 54.8% of those without day-of-diagnosis blood draw vs. 75.2% with one were linked to care (chi-squared p = 0.004). Of those who deferred blood draw, 48.3% cited clinic-related and 51.7% cited personal reasons. AHRlinkage was 0.60 (95%CI: 0.44, 0.82) for clinic-related and 0.53 (95%CI: 0.38, 0.75) for personal reasons relative to having day-of-diagnosis blood draw. Conclusions Newly-diagnosed HIV+ individuals who did not undergo CD4+ count blood draw on the day they were diagnosed—regardless of the reason for deferring—had delayed linkage to care relative to those with same-day blood draw. To enhance prompt linkage to care even when test and treat protocols are implemented, all diagnostic testing required before ART initiation should be performed on the same day as HIV testing/diagnosis. This may require modifying clinic procedures to enable overnight blood storage if same-day draws cannot be performed, and providing additional counseling to encourage newly-diagnosed individuals to complete day-of-diagnosis testing. Tracking HIV+ individuals via clinic registries should commence immediately from diagnosis to reduce these early losses to care

Social Work and Countering Violent Extremism in Sweden and the UK

Social Work in Europe, is now being tasked with managing the “problems” of terrorism, i.e supporting those affected by terrorist attacks, managing returnees affiliated with Terrorist groups in the Middle East, or, as will be discussed here, identifying those at risk from radicalisation and extremism. Both Britain and Sweden have Counter-Terrorism policies, but recent developments in both countries, have made it a statutory requirement for social workers, to work within such policies. This paper seeks to explore the policies in both countries utilising a comparative approach, to consider the similarities in not only policy and practice, but also in the ethical consequences such policies pose for social workers across Europe. The exploration considers; the extent to which anti-radicalisation policies influence social work practices in Sweden and the UK and how they might undermine social work as a human rights profession. The results indicate that anti-radicalisation policies run the risk of reducing social work to become a ‘policing profession’ practicing social control. This has substantial consequences for social work and its global ethics, which should be considered and struggled against by social workers committed to principles of social justice and human rights

The Arecibo Legacy Fast ALFA Survey: II. Results of Precursor Observations

In preparation for the full Arecibo Legacy Fast ALFA extragalactic HI survey, precursor observations were carried out in Aug--Sep 2004 with the 7-beam Arecibo L-band feed array (ALFA) receiver system and the WAPP spectral processors. While these observations were geared mainly at testing and debugging survey strategy, hardware and software, approximately 36 hours of telescope time yielded science--quality data. From those observations, an initial list of 730 tentative detections of varying degree of reliability was extracted. Ninety--eight high signal-to-noise candidates were deemed to be bona fide HI line detections. To test our ability to discriminate cosmic signals from RFI and noise, 165 candidates ranging in reliability likelihood were re--observed with the single beam L--band wide system at Arecibo in Jan--Feb 2005. Of those, 41% were confirmed as real. We present the results of both the ALFA and single beam observations for the sample of 166 confirmed HI sources, as well as our assessment of their optical counterparts. Of the 166 sources, 62 coincide with previously known HI sources, while optical redshifts were available for an additional 18 galaxies; thus, 52% of the redshifts reported here were previously unknown. Of the 166 HI detections, 115 are identified with previously cataloged galaxies, of either known or unknown redshift, leaving 51 objects identified for the first time. Because of the higher sensitivity of the Arecibo system, fewer than 10% of the 166 HI sources would have been detected by a HIPASS--like survey of the same region. Three of the objects have HI masses less than 10^7 solar masses. The full ALFALFA survey which commenced in February 2005 should detect more than 100 times as many objects of similarly low HI mass over the next 5 years.Comment: 40 pages, including 4 tables and 8 figures; to appear in Astron. J.; see http://egg.astro.cornell.edu/alfalfa/pubs.ph