Gadfly petrels Pterodroma spp. are among the most threatened bird taxa. Conservation interventions have been successfully developed and applied for some gadfly petrel species, but a substantial gap ...remains in conservation science for this group in the tropical Pacific Ocean. The Vanuatu Petrel Pterodroma cervicalis occulta is an ideal exemplar to develop a pipeline for conservation science in tropical Pacific gadfly petrels as it is subject to many of the challenges facing other gadfly petrel taxa in the region. We review over 40 pelagic Vanuatu Petrel records and five research expeditions to the only known colony on the island of Vanua Lava, Vanuatu. These records provide a baseline from which to recommend conservation research actions for the taxon. The population status, taxonomy, distribution, and threat profile of the taxon are all poorly known, and these areas are high priorities for future research.
The most severe form of malaria in humans is caused by the protozoan parasite Plasmodium falciparum. The invasive form of malaria parasites is termed a merozoite and it employs an array of parasite ...proteins that bind to the host cell to mediate invasion. In Plasmodium falciparum, the erythrocyte binding-like (EBL) and reticulocyte binding-like (Rh) protein families are responsible for binding to specific erythrocyte receptors for invasion and mediating signalling events that initiate active entry of the malaria parasite. Here we have addressed the role of the cytoplasmic tails of these proteins in activating merozoite invasion after receptor engagement. We show that the cytoplasmic domains of these type 1 membrane proteins are phosphorylated in vitro. Depletion of PfCK2, a kinase implicated to phosphorylate these cytoplasmic tails, blocks P. falciparum invasion of red blood cells. We identify the crucial residues within the PfRh4 cytoplasmic domain that are required for successful parasite invasion. Live cell imaging of merozoites from these transgenic mutants show they attach but do not penetrate erythrocytes implying the PfRh4 cytoplasmic tail conveys signals important for the successful completion of the invasion process.
Galaxy protoclusters, which will eventually grow into the massive clusters we see in the local Universe, are usually traced by locating overdensities of galaxies
. Large spectroscopic surveys of ...distant galaxies now exist, but their sensitivity depends mainly on a galaxy's star-formation activity and dust content rather than its mass. Tracers of massive protoclusters that do not rely on their galaxy constituents are therefore needed. Here we report observations of Lyman-α absorption in the spectra of a dense grid of background galaxies
, which we use to locate a substantial number of candidate protoclusters at redshifts 2.2 to 2.8 through their intergalactic gas. We find that the structures producing the most absorption, most of which were previously unknown, contain surprisingly few galaxies compared with the dark-matter content of their analogues in cosmological simulations
. Nearly all of the structures are expected to be protoclusters, and we infer that half of their expected galaxy members are missing from our survey because they are unusually dim at rest-frame ultraviolet wavelengths. We attribute this to an unexpectedly strong and early influence of the protocluster environment
on the evolution of these galaxies that reduced their star formation or increased their dust content.
When herbivorous insects interact, they can increase or decrease each other's fitness. As it stands, we know little of what causes this variation. Classic competition theory predicts that competition ...will increase with niche overlap and population density. And classic hypotheses of herbivorous insect diversification predict that diet specialists will be superior competitors to generalists. Here, we test these predictions using phylogenetic meta‐analysis. We estimate the effects of diet breadth, population density and proxies of niche overlap: phylogenetic relatedness, physical proximity and feeding‐guild membership. As predicted, we find that competition between herbivorous insects increases with population density as well as phylogenetic and physical proximity. Contrary to predictions, competition tends to be stronger between than within feeding guilds and affects specialists as much as generalists. This is the first statistical evidence that niche overlap increases competition between herbivorous insects. However, niche overlap is not everything; complex feeding guild effects indicate important indirect interactions.
Grassland ecosystems, which are known to be sensitive to climate change, have shown minimal responses of soil carbon (C) and nitrogen (N) pools to increased moisture availability, despite ...moisture-induced changes in plants and soil microbes (e.g., expected drivers of soil C and N). However, it is not clear if this apparent limited response is due to an unresponsive belowground system or because alterations in multiple soil organic matter (SOM) component pools and fluxes offset each other. To investigate potential responses of C and N in SOM to decadal increases in precipitation, we sampled soils from a 30-year precipitation augmentation experiment in an annually burned mesic grassland. We measured C and N in three SOM fractions which vary in their plant and microbial controls 1) free particulate OM (fPOM), 2) occluded POM plus heavy, coarse OM (oPOM + hcOM), and 3) mineral-associated OM (MAOM), as well as amino sugars, pyrogenic C and N, and root quality metrics. We found no changes in bulk C or N under increased precipitation, but SOM fractions were modified. Altered plant inputs and soil N availability appeared to drive the responses of fPOM N and oPOM + hcOM C:N, which were increased and decreased, respectively, by increased precipitation. In contrast, the observed increase in MAOM C and N under increased precipitation could not be connected to a specific driver, suggesting additional plant, microbial, or mineral measurements may be required. Regardless, our results indicate that investigating SOM fractions may more directly connect soil C and N pools and their drivers, compared to measuring only bulk SOM. Further, our finding of greater stable OM (MAOM) under increased precipitation suggests soil C storage could provide a negative feedback to climate change with increased moisture availability, but the lack of bulk SOM response suggests that this feedback is not strong in mesic grasslands.
•Responses of SOM C and N and its drivers to 30 yrs of ∼30% increased precipitation•No response of total SOM C and N but SOM fractions had differing responses•Responses of POM pools were likely related to changes in plant inputs and N cycling•Responses of MAOM were hard to connect to measured plant and microbial drivers•Increased MAOM but not SOM C suggests weak negative feedback to climate change
This study was designed to investigate the effect of exercise intensity on cardiorespiratory fitness and coronary heart disease risk factors. Maximum oxygen consumption (Vo(2 max)), lipid, ...lipoprotein, and fibrinogen concentrations were measured in 64 previously sedentary men before random allocation to a nonexercise control group, a moderate-intensity exercise group (three 400-kcal sessions per week at 60% of Vo(2 max)), or a high-intensity exercise group (three 400-kcal sessions per week at 80% of Vo(2 max)). Subjects were instructed to maintain their normal dietary habits, and training heart rates were represcribed after monthly fitness tests. Forty-two men finished the study. After 24 wk, Vo(2 max) increased by 0.38 +/- 0.14 l/min in the moderate-intensity group and by 0.55 +/- 0.27 l/min in the high-intensity group. Repeated-measures analysis of variance identified a significant interaction between monthly Vo(2 max) score and exercise group (F = 3.37, P < 0.05), indicating that Vo(2 max) responded differently to moderate- and high-intensity exercise. Trend analysis showed that total cholesterol, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, and fibrinogen concentrations changed favorably across control, moderate-intensity, and high-intensity groups. However, significant changes in total cholesterol (-0.55 +/- 0.81 mmol/l), low-density lipoprotein cholesterol (-0.52 +/- 0.80 mmol/l), and non-high-density lipoprotein cholesterol (-0.54 +/- 0.86 mmol/l) were only observed in the high-intensity group (all P < 0.05 vs. controls). These data suggest that high-intensity training is more effective in improving cardiorespiratory fitness than moderate-intensity training of equal energy cost. These data also suggest that changes in coronary heart disease risk factors are influenced by exercise intensity.
The timing, context and nature of the first people to enter Sahul is still poorly understood owing to a fragmented archaeological record. However, quantifying the plausible demographic context of ...this founding population is essential to determine how and why the initial peopling of Sahul occurred. We developed a stochastic, age-structured model using demographic rates from hunter-gatherer societies, and relative carrying capacity hindcasted with LOVECLIM's net primary productivity for northern Sahul. We projected these populations to determine the resilience and minimum sizes required to avoid extinction. A census founding population of between 1,300 and 1,550 individuals was necessary to maintain a quasi-extinction threshold of ≲0.1. This minimum founding population could have arrived at a single point in time, or through multiple voyages of ≥130 people over ~700-900 years. This result shows that substantial population amalgamation in Sunda and Wallacea in Marine Isotope Stages 3-4 provided the conditions for the successful, large-scale and probably planned peopling of Sahul.
External pressure chambers can affect local blood flow, central blood flow, and the distribution of venous volume. Small chambers generating positive pressures are used for wound healing, while large ...chambers applying negative pressures are being investigated to reduce vision problems in astronauts. The purpose of this study is to determine the differences in systemic versus local effects generated by different‐sized chambers at different external pressures, specifically looking at the venous blood shifts, cardiac response, and local microvascular blood flow changes. Our hypotheses are: (1) larger pressure chambers will lead to more systemic effects such as venous and central blood redistributions, while smaller chambers will impact local microvascular flow more, and (2) the magnitude of effects seen in each chamber will depend on the magnitude of applied pressure. We measured the effect of 2 different pressure chamber sizes (unilateral leg and unilateral ankle) and 4 external pressure magnitudes (−40, −20, 20 and 40 mmHg) on skin and muscle microvascular flows (measured with photoplethysmography, PPG), lower leg circumference (measured with strain‐gauge plethysmography, SGP), and heart rate, blood pressure, and stroke volume (measured with Nexfen finger sphygmonometer). Five subjects were tested (3 female and 2 male, with average age, weight and height of 23 years, 65 kg, and 167 cm). A 2 way repeated measures ANOVA documented a significant effect of pressure magnitude on skin and muscle microvascular flow compared to ambient pressure, but no effect of chamber size and no interaction. The maximum increase in microvascular blood flow was 110 ± 70 % (p > 0.05) in muscle and 30.5 ± 40.24 % (p> 0.05) in skin, with both occurring at 20 mmHg in the leg chamber. The largest decrease in microvascular flow was 67.4 ± 7.5 % (p = 0.051) in the muscle and 76.7 ± 7.5 % (p = 0.014) in the skin, with both occurring at −40 mmHg in the ankle chamber. The power of pairwise comparisons between blood flows at different applied pressures was 0.30, suggesting that the number of subjects limits the detection of significant changes. Calf circumference and cardiovascular parameters were not affected by area or magnitude of pressure application. Smaller chambers had no effect on lower limb venous blood or central blood shifts.
Support or Funding Information
Supported by NASA grant NNX13AJ12G.
This is from the Experimental Biology 2018 Meeting. There is no full text article associated with this published in The FASEB Journal.
Octoploid strawberry (
) is a valuable specialty crop, but profitable production and availability are threatened by many pathogens. Efforts to identify and introgress useful disease resistance genes ...(R-genes) in breeding programs are complicated by strawberry's complex octoploid genome. Recently-developed resources in strawberry, including a complete octoploid reference genome and high-resolution octoploid genotyping, enable new analyses in strawberry disease resistance genetics. This study characterizes the complete R-gene collection in the genomes of commercial octoploid strawberry and two diploid ancestral relatives, and introduces several new technological and data resources for strawberry disease resistance research. These include octoploid R-gene transcription profiling,
N/
S analysis, expression quantitative trait loci (eQTL) analysis and RenSeq analysis in cultivars. Octoploid fruit eQTL were identified for 76 putative R-genes. R-genes from the ancestral diploids
and
were compared, revealing differential inheritance and retention of various octoploid R-gene subtypes. The mode and magnitude of natural selection of individual
R-genes was also determined via
N/
S analysis. R-gene sequencing using enriched libraries (RenSeq) has been used recently for R-gene discovery in many crops, however this technique somewhat relies upon
knowledge of desired sequences. An octoploid strawberry capture-probe panel, derived from the results of this study, is validated in a RenSeq experiment and is presented for community use. These results give unprecedented insight into crop disease resistance genetics, and represent an advance toward exploiting variation for strawberry cultivar improvement.
Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 ...July-2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA-we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020-2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data.
PDF
