Tropical forests store large amounts of carbon and high biodiversity, but are being degraded at alarming rates. The emerging global Forest and Landscape Restoration (FLR) agenda seeks to limit global ...climate change by removing carbon dioxide from the atmosphere through the growth of trees. In doing so, it may also protect biodiversity as a free cobenefit, which is vital given the massive shortfall in funding for biodiversity conservation. We investigated whether natural forest regeneration on abandoned pastureland offers such cobenefits, focusing for the first time on the recovery of taxonomic diversity (TD), phylogenetic diversity (PD) and functional diversity (FD) of trees, including the recovery of threatened and endemic species richness, within isolated secondary forest (SF) fragments. We focused on the globally threatened Brazilian Atlantic Forest, where commitments have been made to restore 1 million hectares under FLR. Three decades after land abandonment, regenerating forests had recovered ~20% (72 Mg/ha) of the above‐ground carbon stocks of a primary forest (PF), with cattle pasture containing just 3% of stocks relative to PFs. Over this period, SF recovered ~76% of TD, 84% of PD and 96% of FD found within PFs. In addition, SFs had on average recovered 65% of threatened and ~30% of endemic species richness of primary Atlantic forest. Finally, we find positive relationships between carbon stock and tree diversity recovery. Our results emphasize that SF fragments offer cobenefits under FLR and other carbon‐based payments for ecosystem service schemes (e.g. carbon enhancements under REDD+). They also indicate that even isolated patches of SF could help to mitigate climate change and the biodiversity extinction crisis by recovering species of high conservation concern and improving landscape connectivity.
We investigated whether natural forest regeneration on abandoned pastureland offers such cobenefits, focusing for the first time on the recovery of taxonomic, phylogenetic diversity and functional diversity of trees, including the recovery of threatened and endemic species, within isolated secondary forest (SF) fragments. Our results emphasize that SF fragments offer cobenefits under FLR and other carbon‐based payments for ecosystem service schemes (e.g. carbon enhancements under REDD+). They also indicate that even isolated patches of SF could help to mitigate climate change and the biodiversity extinction crisis by recovering species of high conservation concern and improving landscape connectivity improving landscape connectivity.
► We produced multi-walled carbon nanotubes powder by pyrolysis of camphor mixed with ferrocene, and then used non-oxidative and oxidative acidic treatments for iron removal. ► We analyzed the ...elimination and/or oxidation of iron nanoparticles by X-ray photoelectron spectroscopy, monitoring Fe2p, O1s and C1s peaks. ► We carried out complementary investigation by thermogravimetric analysis, atomic absorption spectroscopy, Raman Spectroscopy and transmission electron microscopy (TEM) to evaluate the effectiveness of each treatment. ► A purity degree higher than 98% was achieved only with non-oxidative treatments using sonification process.
A detailed analysis by X-ray photoelectron spectroscopy was carried out on multi-walled carbon nanotube (MWCNT) surfaces after non-oxidative and oxidative purification treatments in liquid-phase. The MWCNT were produced by pyrolysis of camphor and ferrocene, that provides a high yield but with high iron contamination (∼15%wt). The elimination and/or oxidation of iron nanoparticles were monitored by Fe2p and O1s core level. Oxygen-based functional groups attachment was also investigated by C1s fitting. The effectiveness of each treatment in iron removal was evaluated by thermogravimetric analysis (TGA) and atomic absorption spectroscopy (AAS). The integrity of the MWCNT structure was verified by Raman spectroscopy (RS) and transmission electron microscopy (TEM). A purity degree higher than 98% was achieved only with non-oxidative treatments using sonification process.
We use microfocus Brillouin light scattering spectroscopy to study the interaction of spin current with magnetic fluctuations in a Permalloy microdisk located on top of a Pt strip carrying an ...electric current. We show that the fluctuations can be efficiently suppressed or enhanced by different directions of the electric current. Additionally, we find that the effect of spin current on magnetic fluctuations is strongly influenced by nonlinear magnon-magnon interactions. The observed phenomena can be used for controllable reduction of thermal noise in spintronic nanodevices.
Terahertz near fields of gold metamaterials resonant at a frequency of 0.88 THz allow us to enter an extreme limit of nonperturbative ultrafast terahertz electronics: Fields reaching a ponderomotive ...energy in the keV range are exploited to drive nondestructive, quasistatic interband tunneling and impact ionization in undoped bulk GaAs, injecting electron-hole plasmas with densities in excess of 10^{19} cm^{-3}. This process causes bright luminescence at energies up to 0.5 eV above the band gap and induces a complete switch-off of the metamaterial resonance accompanied by self-amplitude-modulation of transmitted few-cycle terahertz transients. Our results pave the way towards highly nonlinear terahertz optics and optoelectronic nanocircuitry with subpicosecond switching times.
Cavity magnon polaritons are mixed quasiparticles that arise from the strong coupling between cavity photons and quantized magnons. Combining high-speed photons with long-coherence-time magnons, such ...polaritons promise to be a potential candidate for quantum information processing. For harnessing coherent information contained in spatially distributed polariton states, it is highly desirable to manipulate cavity magnon polaritons in a two-dimensional system. Here, we demonstrate that tunable cavity magnon polariton transport can be achieved by strongly coupling magnons to microwave photons in a cross-cavity. An analog to the dynamic Hall effect has been demonstrated in a planar cavity spintronic device, where the propagation of cavity-magnon-polaritons is deflected transversally due to hybrid magnon-photon dynamics. Implementing this device as a Michelson-type interferometer using the coherent nature of the dynamic Hall and longitudinal signals, we have developed a proof-of-principle logic device to control the amplitude of cavity-magnon-polaritons by encoding the input microwave phase.
We have developed a refined geologic map and stratigraphy for lower Mount Sharp using coordinated analyses of new spectral, thermophysical, and morphologic orbital data products. The Mount Sharp ...group consists of seven relatively planar units delineated by differences in texture, mineralogy, and thermophysical properties. These units are (1–3) three spatially adjacent units in the Murray formation which contain a variety of secondary phases and are distinguishable by thermal inertia and albedo differences, (4) a phyllosilicate‐bearing unit, (5) a hematite‐capped ridge unit, (6) a unit associated with material having a strongly sloped spectral signature at visible near‐infrared wavelengths, and (7) a layered sulfate unit. The Siccar Point group consists of the Stimson formation and two additional units that unconformably overlie the Mount Sharp group. All Siccar Point group units are distinguished by higher thermal inertia values and record a period of substantial deposition and exhumation that followed the deposition and exhumation of the Mount Sharp group. Several spatially extensive silica deposits associated with veins and fractures show that late‐stage silica enrichment within lower Mount Sharp was pervasive. At least two laterally extensive hematitic deposits are present at different stratigraphic intervals, and both are geometrically conformable with lower Mount Sharp strata. The occurrence of hematite at multiple stratigraphic horizons suggests redox interfaces were widespread in space and/or in time, and future measurements by the Mars Science Laboratory Curiosity rover will provide further insights into the depositional settings of these and other mineral phases.
Key Points
We have developed a stratigraphy for lower Mount Sharp using analyses of new spectral, thermophysical, and morphologic orbital data products
Siccar Point group records a period of deposition and exhumation that followed the deposition and exhumation of the Mount Sharp group
Late state silica enrichment and redox interfaces within lower Mount Sharp were pervasive and widespread in space and/or in time
Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the ...atmosphere) have the potential to do greater damage than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects. Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave, but owing to lack of observations this is uncertain. Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (±100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.185×10(12) joules). We show that a widely referenced technique of estimating airburst damage does not reproduce the observations, and that the mathematical relations based on the effects of nuclear weapons--almost always used with this technique--overestimate blast damage. This suggests that earlier damage estimates near the threshold impactor size are too high. We performed a global survey of airbursts of a kiloton or more (including Chelyabinsk), and find that the number of impactors with diameters of tens of metres may be an order of magnitude higher than estimates based on other techniques. This suggests a non-equilibrium (if the population were in a long-term collisional steady state the size-frequency distribution would either follow a single power law or there must be a size-dependent bias in other surveys) in the near-Earth asteroid population for objects 10 to 50 metres in diameter, and shifts more of the residual impact risk to these sizes.
Background. Pneumocystis jirovecii pneumonia (PCP) remains the leading cause of opportunistic infection among human immunodeficiency virus (HIV)– infected persons. Previous studies of PCP that ...identified case-fatality risk factors involved small numbers of patients, were performed over few years, and often focused on patients who were admitted to the intensive care unit. Objective. The objective of this study was to identify case-fatality risk factors present at or soon after hospitalization among adult HIV-infected patients admitted to University College London Hospitals (London, United Kingdom) from June 1985 through June 2006. Patients and Methods. We performed a review of case notes for 494 consecutive patients with 547 episodes of laboratory-confirmed PCP. Results. Overall mortality was 13.5%. Mortality was 10.1% for the period from 1985 through 1989, 16.9% for the period from 1990 through June 1996, and 9.7% for the period from July 1996 through 2006 (P=.142). Multivariate analysis identified factors associated with risk of death, including increasing patient age (adjusted odds ratio AOR, 1.54; 95% confidence interval CI, 1.11– 2.23; P=.011), subsequent episode of PCP (AOR, 2.27; 95% CI, 1.14– 4.52; P=.019), low hemoglobin level at hospital admission (AOR, 0.70; 95% CI, 0.60– 0.83; P< .001), low partial pressure of oxygen breathing room air at hospital admission (AOR, 0.70; 95% CI, 0.60– 0.81; P< .001), presence of medical comorbidity (AOR, 3.93; 95% CI, 1.77– 8.72; P=.001), and pulmonary Kaposi sarcoma (AOR, 6.95; 95% CI, 2.26– 21.37; P=.001). Patients with a first episode of PCP were sicker (mean partial pressure of oxygen at admission ° standard deviation, 9.3° 2.0 kPa) than those with a second or third episode of PCP (mean partial pressure of oxygen at admission ° standard deviation, 9.9° 1.9 kPa; P=.008), but mortality among patients with a first episode of PCP (12.5%) was lower than mortality among patients with subsequent episodes of PCP (22.5%) (P=.019). No patient was receiving highly active antiretroviral therapy before presentation with PCP, and none began highly active antiretroviral therapy during treatment of PCP. Conclusions. Mortality risk factors for PCP were identifiable at or soon after hospitalization. The trend towards improved outcome after June 1996 occurred in the absence of highly active antiretroviral therapy.
This article reviews the development of the new U.S. lung allocation system that took effect in spring 2005. In 1998, the Health Resources and Services Administration of the U.S. Department of Health ...and Human Services published the Organ Procurement and Transplantation Network (OPTN) Final Rule. Under the rule, which became effective in 2000, the OPTN had to demonstrate that existing allocation policies met certain conditions or change the policies to meet a range of criteria, including broader geographic sharing of organs, reducing the use of waiting time as an allocation criterion and creating equitable organ allocation systems using objective medical criteria and medical urgency to allocate donor organs for transplant. This mandate resulted in reviews of all organ allocation policies, and led to the creation of the Lung Allocation Subcommittee of the OPTN Thoracic Organ Transplantation Committee. This paper reviews the deliberations of the Subcommittee in identifying priorities for a new lung allocation system, the analyses undertaken by the OPTN and the Scientific Registry for Transplant Recipients and the evolution of a new lung allocation system that ranks candidates for lungs based on a Lung Allocation Score, incorporating waiting list and posttransplant survival probabilities.
Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial ...communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus 'more microbes, fewer viruses'.
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