Aim: While fire is recognized as an integral part of the Earth system, the ability of humans to shape fire regimes both spatially and temporally remains poorly understood. Our goals were to identify ...the extent of fire regimes exhibiting two annual fire seasons and to investigate the environmental correlates of such regimes at the global scale. Location: All areas of the globe exhibiting relevant fire activity, at 0.5° spatial resolution. Time period: 2002-2012. Major taxa studied: (not applicable). Methods: The modality of fire seasonality at the global scale was classified using a 10-year record of satellite-derived fire activity and model fitting of circular statistical distributions. The main environmental correlates controlling global fire regimes were then analysed over bimodal and unimodal areas using the Kolmogorov–Smirnov test. Results: About 25% of the global land surface with relevant fire activity has two significantly distinct fire seasons per year, with at least one of these seasons occurring under sub-optimal fire weather conditions. In these bimodal areas, population density and the fraction of fires occurring in actively managed land, especially in croplands and pastures, are significantly higher than in neighbouring unimodal areas. Results reveal that through these land-use and management practices humans have a strong influence on global patterns of fire seasonality. Main conclusions: We identified a bimodal seasonality pattern, previously unreported at the global scale, and show that it reveals an anthropogenic fingerprint on fire regimes. Insights into where and when fire is actively employed as a land management tool enhance our understanding of the role of fire in the Earth system, and highlight the need to better understand how fire practices may change in the future.
A large set of distinct ionic liquid (IL)-impregnated metal–organic framework (MOF) composites were produced by a direct-contact method to study their performance as sorbents for gas separation ...applications. The IL anion/cation impact on the sorption capacity and ideal CO2/CH4 selectivity were fully detailed. A reproducible methodology and rigorous characterization were defined to evaluate the IL impact on the IL@ZIF-8 performance. Results show that the IL impregnation was successful, the ZIF-8 structure is conserved after IL incorporation, and the microporous composites are thermally stable at the working temperatures. CO2 and CH4 adsorption–desorption equilibria in the composites were measured at the temperature of 303 K and up to 16 bar of pressure. The respective data were then compared with that obtained for pristine ZIF-8. At high pressure, all composites show reversible, although inferior, gas uptake (total pore volume loss due to IL pore occupation/blockage). At low pressure, because of synergistic effects arising from IL–MOF interactions, one composite displays superior CO2 uptake compared to ZIF-8. Four IL@ZIF-8 composites show distinct low-pressure trends from ZIF-8, due to their IL structure/size, with an increase in the selectivity that can be above 40% at 0.5 bar. An IL-free basis analysis was also assessed considering a normalization of the gas uptake per gram of ZIF-8 in the composites. This shows that ILs do have an impact on the adsorption capacity of the composites. A new approach, based on the materials’ pore volume as a key factor, is discussed toward the sorption data of the IL@ZIF-8 composites. Through mapping of the composites data, it is possible to understand the effect of the IL for high- and low-pressure applications. The results obtained herein indicate that IL@MOF composites are potential alternative materials for low-pressure gas separation.
A well-functioning monetary transmission mechanism is critical for monetary policy. As the Dominican Republic recently adopted an inflation targeting regime, it is even more relevant to guarantee ...that changes in the monetary policy rates are quickly and fully reflected in retail rates, to eventually influence aggregate demand and inflation. This paper estimates the interest rate pass-through of the monetary policy rate to retail rates and explores asymmetries in the adjustment. We find evidence of complete pass-through to retail rates, confirming the effectiveness of the monetary policy transmission mechanism. However, our results also suggest a faster pass-through to lending rates than to deposit rates and asymmetric adjustments of short-term rates, as deposit rates respond faster to policy rate cuts and lending rates respond faster to policy rate hikes. Measures to enhance competition in the financial system could help to achieve a symmetric adjustment of retail rates.
A family of Mn(
ii
)Ln(
iii
) dinuclear and tetranuclear complexes (Ln = Gd and Dy) has been prepared from the compartmental ligands
N
,
N
′-dimethyl-
N
,
N
...′-bis(2-hydroxy-3-formyl-5-bromobenzyl)ethylenediamine (H
2
L
1
) and
N
,
N
′,
N
′′-trimethyl-
N
,
N
′′-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H
2
L
2
). The Mn(
ii
)Gd(
iii
) complexes exhibit antiferromagnetic interactions between Mn(
ii
) and Gd(
iii
) ions in most cases, which are supported by Density Functional Theory (DFT) calculations. Experimental magneto-structural correlations carried out for the reported complexes and other related complexes found in bibliography show that the highest ferromagnetic coupling constants are observed in di-μ-phenoxido bridged complexes, which is due to the planarity of the Mn-(μ-O)
2
-Gd bridging fragment and to the high Mn-O-Gd angles. The effect of these angles has been studied by DFT calculations performed on a di-μ-phenoxido doubly bridged model. The magneto-thermal properties of the Mn(
ii
)Gd(
iii
) based complexes have also been measured, concluding that the magnitude of the Magneto-Caloric Effect (MCE) is due to the strength rather than to the nature of the magnetic coupling. Moreover, when two Mn(
ii
)Gd(
iii
) dinuclear units are connected by two carbonato-bridging ligands the MCE is enhanced, obtaining a maximum magnetic entropy change of 36.4 Jkg
−1
K
−1
at Δ
B
= 7 T and
T
= 2.2 K. On the other hand, one of the dinuclear Mn(
ii
)Dy(
iii
) complexes displays Single-Molecule Magnet (SMM) behaviour with an energy barrier of 14.8 K under an applied external field of 1000 Oe.
Magneto-structural correlations reveal the basis to design Mn(
ii
) and lanthanide-based complexes with magneto-caloric effect or slow relaxation of the magnetization.
In this paper is presented a higher-order model for static and free vibration analyses of magneto-electro-elastic plates, which allows the study of thin and thick plates. The finite element model is ...a single layer triangular plate/shell element with 24 degrees of freedom for the generalized mechanical displacements. Two degrees of freedom are introduced per each element layer, one corresponding to the electrical potential and the other for magnetic potential. Solutions are obtained for different laminations of the magneto-electro-elastic plate, as well as for the purely elastic plate as a special case. Results are compared with alternative models for static and free vibrations situations.
Acyl(σ-norbornenyl)rhodium(III) dimer Rh(μ-Cl)(C9H6NCO)(C7H9)L2 (1) (C7H9 = σ-norbornenyl; L = 4-picoline, isoquinoline) reacts with diphenylphosphine oxide (SPO) to undergo a one-pot reaction ...involving (i) cleavage of the chloride bridges and coordination of the phosphine, (ii) C–C bond coupling between acyl and norbornenyl in a 18e species, and (iii) ligand-assisted outer-sphere O(P)-to-O(C) hydrogen transfer, to afford mononuclear 16e species RhCl{(C9H6NC(O)C7H9)(Ph2PO)H}(L) (2) containing a quinolinyl-(norbornenylhydroxyalkyl) fragment hydrogen-bonded to a κ1-P-phosphinite ligand. Pentacoordinated 2, which adopt a distorted trigonal bipyramidal structure, are kinetic reaction products that transform into the thermodynamic favored isomers 3. Structures 3 contain an unusual weak η1-C anagostic interaction involving the rhodium atom and one carbon atom of the olefinic C–H bond of the norbornenyl substituent in the chelating quinolinyl-hydroxyalkyl moiety. Their structure can be described as pseudoctahedral, through a 5 + 1 coordination, with the anagostic interaction in a trans disposition with respect to the phosphorus atom of the phosphinite ligand. Complexes were characterized in solution by NMR spectroscopy and electrospray ionization mass spectrometry. Complex RhCl{(C9H6NC(O)C7H9)(Ph2PO)H}(4-picoline) (3a) was also identified by X-ray diffraction. Density functional theory calculations confirm the proposed structures by a plausible set of mechanisms that accounts for the 1 (monomer) → 2 → 3 transformation. Lowest-energy pathways involve reductive elimination of quinolinylnorbornenylketone, still coordinated in the rhodium(I) species thus formed, followed by O-to-O hydrogen transfer from κ1-P-SPO to the sp3 hybridized carbonyl group (formal alkoxide) avoiding the otherwise expected classical release of ketone. Theoretical 13C NMR studies also confirm the experimental spectral data for the considered structures.
This work reports the syntheses, crystal structures, magnetic properties and DFT calculations of six novel polynuclear NiII compounds Ni2(μ-HL1)2(μ-N3)N3·(CH3OH)2·2H2O (1), ...Ni2(μ-HL1)2(μ-N3)Na2Ni2(μ-L1)2(μ-N3)2(CH3OH)(N3)·4CH3OH (2), Ni4(μ-L1)2(μ-N3)4(CH3OH)2·2CH3OH (3), Na2Ni4(μ-L1)2(μ-OAc)2(μ-N3)4(CH3OH)4·2CH3OH (4), Ni4(μ-L1)2(μ-Cl)2(Cl)2 (5), and Ni3(μ-L1)2(acac)2(H2O)2 (6), with uncommon structures and rare mixed-bridges between NiII ions, which were prepared from the versatile polytopic Mannich base ligand N,N′-dimethyl-N,N′-bis(2-hydroxy-3-methoxy-5-methylbenzyl)ethylenediamine (H2L1). The anionic coligand (azide, chloride, acetate and acetylacetonate) and reaction conditions play crucial roles in determining the final structure of these compounds and consequently their magnetic properties. Compound 1 contains a Ni2 cationic unit with rare di-μ-phenoxido/μ1,1-azide triple mixed bridges whereas complex 2 is made from the same Ni2 cationic unit as 1, cocrystallized with Na2Ni2 neutral units, in which double μ1,1,1-azide bridges connect the NiII and NaI anions. Complexes 3 and 4 are Ni4 complexes with defective dicubane and linear structures, respectively. Complex 3 has two distinct types of mixed bridges, μ-phenoxido/μ1,1,1-azido and μ1,1-azido/μ1,1,1-azido and a double di-μ1,1,1-azido bridge, the latter connecting the face-sharing NiII ions. In 4, rare μ-phenoxido/μ1,1-azide/syn–syn acetate triple mixed bridges connect central and terminal NiII atoms whereas a double μ1,1-azide planar bridging fragment links the central NiII ions. Complex 5 has a defective-dicubane structure with double μ-phenoxido/μ3-chloro mixed bridges and di-μ3-chloro bridges, whereas complex 6 has a bent structure with very uncommon single μ-phenoxido bridges. The analysis of the magnetic properties reveals that in complexes 1–4 all magnetic pathways transmit ferromagnetic interactions leading to S = 2 ground states for 1 and 2 and S = 4 ground states for 3 and 4. In complex 5, the double μ-phenoxido/μ3-chloro mixed bridges and di-μ3-chloro bridges mediate antiferro- and ferromagnetic interactions, respectively, giving rise to a S = 0 ground state. Complex 6 shows antiferromagnetic interactions between the NiII ions through single μ-phenoxido bridging groups, leading to an S = 1 ground state. DFT calculations on the X-ray structures and model compounds were performed to support the magneto-structural data of the above compounds.
Six novel Ni(II) complexes, ranging from mononuclear to tetranuclear, have been prepared from the polytopic symmetrical Mannich base ligand ...N,N'-dimethyl-N,N'-bis(2-hidroxy-3-formyl-5-bromo-benzyl)ethylenediamine (H2L) and different anionic coligands: Ni(H2L)(NO3)(H2O)NO3·H2O (), Ni2(μ-L)(acac)2(H2O)·CH3CN (), Ni2(μ-L)(μ-OAc)(NCS) (), Ni3(μ-L)2(μ-OH2)2(H2O)(CH3CN)(NO3)2·4CH3CN (), Ni4(μ-L)2(μ-OAc)2(μ-OCH3)2·6H2O·2CH3OH () and Ni4(μ-L)2(μ-OAc)2(μ-N3)2·2H2O·CH3OH (). These complexes have been characterized by single crystal X-ray diffraction, magnetic measurements and DFT theoretical calculations. The structural analysis of these complexes reveals that the anionic coligand and reaction conditions play a fundamental role in determining their final structures and magnetic properties. Compound contains a monomeric cationic unit with the nickel ion coordinated in the external O4 site of the compartmental ligand H2L, which acts in a neutral zwitterionic form. Complexes and are dinuclear Ni2 neutral entities, in which the Ni(II) ions are connected through two μ-phenoxido bridging groups. The Ni(O)2Ni bridging fragment in is almost planar, whereas in is bent due to the additional presence of a syn-syn acetate bridge connecting the Ni(II) atoms. Complex has a bent trinuclear structure with double μ-phenoxido/μ-water bridges between the central and terminal nickel atoms. Complexes and are Ni4 complexes with defective dicubane structures, in which triple μ-phenoxido/μ1,1,1-X/syn-syn acetate and double μ-phenoxido/μ1,1,1-X mixed bridges connect central and terminal Ni(II) atoms, whereas double μ1,1,1-X bridging ligands link the central Ni(II) ions (X = methoxido and azido groups for and , respectively). Magnetic susceptibility measurements reveal that complex shows a moderate antiferromagnetic interaction between the Ni(II) ions through the double di-μ-phenoxido bridge, leading to a S = 0 ground state. Compared to , complex shows a much weaker magnetic exchange interaction due the counter-complementarity effect provoked by the additional presence of the syn-syn acetate bridging group, as well as the non-planarity of the bridging fragment. In complex , the double μ-phenoxido/μ-water mixed bridges lead to very weak antiferromagnetic interactions between the central and external Ni(II) ions. Overall ferromagnetic interactions are found for , and , although in not all the magnetic pathways transmit ferromagnetic interactions. A detailed analysis of the magnetic exchange interactions transmitted through the different pathways as well as DFT calculations on the X-ray structures of compounds were performed to support the magneto-structural data of these compounds.
Survivors from sepsis are in an immunosuppressed state that is associated with higher long-term mortality and risk of opportunistic infections. Whether these factors contribute to neoplastic ...proliferation, however, remains unclear. Tumor-associated macrophages (TAM) can support malignant cell proliferation, survival, and angiogenesis. We addressed the relationship between the post-sepsis state, tumor progression and TAM accumulation, and phenotypic and genetic profile, using a mouse model of sepsis resolution and then B16 melanoma in mice. In addition, we measured the serum concentrations of TNFα, TGFβ, CCL2, and CXCL12 and determined the effect of in vivo CXCR4/CXCL12 inhibition in this context. Mice that survived sepsis showed increased tumor progression both in the short and long term, and survival times were shorter. TAM accumulation, TAM local proliferation, and serum concentrations of TGFβ, CXCL12, and TNFα were increased. Naïve mice inoculated with B16 together with macrophages from post-sepsis mice also had faster tumor progression and shorter survival. Post-sepsis TAMs had less expression of MHC-II and leukocyte activation-related genes. Inhibition of CXCR4/CXCL12 prevented the post-sepsis-induced tumor progression, TAM accumulation, and TAM in situ proliferation. Collectively, our data show that the post-sepsis state was associated with TAM accumulation through CXCR4/CXCL12, which contributed to B16 melanoma progression.
Externalising behaviours are becoming a remarkably prevalent problem during adolescence, often precipitating both externalising and internalising disorders in later adulthood. Psychological ...treatments aim to increase the social functioning of adolescents in order for them to live a more balanced life and prevent these negative trajectories. However, little is known of the intervening variables and mediators involved in these treatments' change mechanisms. We conducted a systematic review, exploring the available evidence on mediators of psychological treatments for externalising behaviours and symptoms amongst adolescents (10 to 19 years old).
A systematic search was performed on Medline and PsycINFO databases, which identified studies from inception to February 23, 2020. Eligible studies included randomised controlled trials that enrolled adolescents with externalising symptoms and behaviours as, at least, one of the primary outcomes. A group of 20 reviewers from the COST-Action TREATme (CA16102) were divided into 10 pairs. Each pair independently screened studies for inclusion, extracted information from the included studies, and assessed the methodological quality of the included studies and the requirements for mediators, following Kazdin's criteria. Risk of bias of RCTs was assessed by the Mixed Methods Appraisal Tool. Extracted data from the included studies were reported using a narrative synthesis.
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA), after removing duplicates, 3,660 articles were screened. Disagreements were resolved by consensus. In a second stage, 965 full-text articles were assessed for eligibility. A total of 14 studies fulfilled all inclusion criteria. The majority were related to systemic psychological treatment approaches. Two types of mediators were identified as potentially being involved in the mechanisms of change for better social improvements of adolescents: to increase healthier parent-adolescent relationships and parental discipline. However, there were significant and non-significant results amongst the same mediators, which led to discussing the results tentatively.
Family variables were found to be the largest group of investigated mediators, followed by relational, behavioural, and emotional variables. No cognitive or treatment-specific mediators were identified. Both adequate behavioural control of adolescents' peer behaviour and a better positive balance in their relationships with their parents seemed to buffer the effects of externalising behaviours in adolescents. Several methodological limitations concerning mediation testing design, outcome measures, and mediator selection have been identified.
Ethical approval was not required. PROSPERO registration number: CRD42021231835.
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