Selection Cuts Research Articles

Taming a leading theoretical uncertainty in HH measurements via accurate simulations for bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \ extrm{b}\\overline{\ extrm{b}}\ extrm{H} $$\\end{document} production

We present a new simulation for Higgs boson production in association with bottom quarks (bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b}H $$\\end{document}) at next-to-leading order (NLO) accuracy matched to parton showers in hadronic collisions. Both contributions, the standard one proportional to the bottom-quark Yukawa coupling and the loop-induced one proportional to the top-quark Yukawa coupling from the gluon-fusion process, are taken into account in a scheme with massive bottom quarks. Therefore, we provide the full simulation of the bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b}H $$\\end{document} final state in the Standard Model, which constitutes also a crucial background to measurements for Higgs-boson pair (HH) production at the Large Hadron Collider when at least one of the Higgs bosons decays to bottom quarks. So far, the modeling of the bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b}H $$\\end{document} final state induced one of the dominant theoretical uncertainties to HH measurements, as the gluon-fusion component was described only at the leading order (LO) with uncertainties of O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{O} $$\\end{document}(100%). Including NLO corrections in its simulation allows us to reduce the scale dependence to O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{O} $$\\end{document}(50%) so that it becomes subdominant with respect to other systematic uncertainties. As a case study, we provide an in-depth analysis of the bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b}H $$\\end{document} background to HH measurements with realistic selection cuts in the 2b2γ channel. We also compare our novel simulation with the currently-employed ones, discussing possible issues and shortcomings of a scheme with massless bottom quarks. Finally, we propagate the effect of the new bb¯H\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ b\\overline{b}H $$\\end{document} simulation to HH searches in the 2b2γ and 2b2τ final states, and we find an improvement of up to 10% (20%) on the current (HL-LHC) limits on σSMHH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\sigma}_{\ extrm{SM}}^{HH} $$\\end{document}.

The Relationship between Stand Structure and Tree Growth Form—Investigating the Effects of Selection Cuttings in Mountainous Mixed Beech Forests

Among forest management methods, selection cutting puts into practice applications that follow the processes that naturally occur in the ecosystem. The purpose of this research was to investigate the effects of selection cutting on the stand structural characteristics and growth form of trees. The effect of selection cutting was evaluated in terms of the frequency and standing volume of trees and deadwood, diversity of tree species indices, stand structural complexity index (SCI), height-to-diameter ratio (HDR) or slenderness index, and live crown ratio of trees (LCR). These were measured and estimated through a systematic random plot sampling in two adjacent parcels with different management histories (parcel A, managed using the selection cutting method, and parcel B, managed using the protected method and without cutting trees) in mixed beech forests in Northern Iran. The results showed that the standing volume, Shannon index, deadwood volume, and SCI index in parcel A were lower than in parcel B. The selection cuttings had no effect on the HDR value of the upper-storey trees, while it decreased the HDR value of the middle-storey and light-demanding trees (maple and alder) and increased the HDR value of the lower-storey and beech trees. Also, the results showed that as a result of the implementation of selection cuttings, the total LCR of the lower-storey trees increased, but the total LCR of the upper-storey trees decreased compared to the protected forest. Furthermore, the results showed that tree growth form (HDR and LCR) are related to the SCI of the stands. These results showed that the implementation of the single-selection method had simplified the structure of the stands; also, with the changes made in the growth form of trees, the possibility of snow and wind damage was increased, especially in young trees. It is necessary to prioritize the ecological values of forest deadwood, thick trees, biological diversity, and the resistance of these stands against snow and wind damage in the next cutting operations.

Bioindication of the Dark Gray Soil State in the Pine Forests of the Krasnoyarsk Forest-Steppe under Anthropogenic Influence

The biological activity of dark gray soil was studied in a 100-year-old pine forb-green-moss forest of the Pogorelsky pine forest of the Krasnoyarsk forest-steppe. In 2017, selective cuttings were carried out in the pine forest, and in May 2022 there was a strong fire. To improve reforestation and increase the biological productivity of the soil, bio-fertilizer based on sawdust-soil substrate with the addition of urea and mycoproduct (SSSU + M) was applied to cut and burned areas. On the experimental plots (Paseka, Volok, Fon), an annual count of self-seeding of pine was carried out. Bioindication of the soil condition was assessed based on the total number and ratio of ecological-trophic groups of microorganisms, enzyme activity, microbial biomass content, intensity of basal respiration and specific respiration of microbial biomass. The application of biofertilizer to the cut areas alkalized the soil by 0.2–0.4 units, retained moisture, increased the content of nitrogen (by 5–14%) and microbial biomass (by 1.2–1.6 times), compared with the control options. The impact of biofertilizers on the germination and growth of self-seeding of pine was noted in the second year after application – in the experimental plots of self-seeding it was 4–6 times greater than in the control ones. The entry of burnt plant residues, coals and ash into the soil in the first week after the fire led to an increase in some microbiological indicators, the activity of urease and invertase, and the activation of carbotrophic microorganisms. However, by the end of the growing season, a decrease in microbiological activity was noted, which indicated a post-pyrogenic depression of microbocenoses. The introduction of biofertilizer on the burnt surface of the plots leveled the effect of pyrogenic effects and stimulated the formation of shoots of scots pine, the number of which was significantly higher than in the control plots. It was found that the universal bioindicators that adequately reflect the state of the soil after all anthropogenic impacts were microbial biomass, specific microbial respiration, enzymatic activity and the total number of microorganisms. A specific bioindication of the soil condition after the fire was an increase in the proportion of bacteria Serratia plymuthica, Bacillus mycoides and fungi of the genera Trichoderma, Penicillium and Mortierela.

Observation of Collider Muon Neutrinos with the SND@LHC Experiment.

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6 TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8 fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{μ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{μ} signal.

Functional Interaction of the Cruciate Ligaments, Posteromedial and Posterolateral Capsule, Oblique Popliteal Ligament, and Other Structures in Preventing Abnormal Knee Hyperextension

Background: The ligaments and soft tissue capsular structures of the knee joint that provide a resisting force to prevent abnormal knee hyperextension have not been determined. This knowledge is required for the diagnosis and treatment of knee hyperextension abnormalities. Purpose: To determine the resisting moment of knee ligament and capsular structures that resist knee hyperextension. Hypothesis: The combined posteromedial and posterolateral capsular structures function to provide a major restraint to prevent abnormal knee hyperextension. The anterior and posterior cruciate ligaments resist knee hyperextension but function as secondary restraints. Study Design: Descriptive laboratory study. Methods: A 6 degrees of freedom robotic system determined intact laxity limits in 24 cadaveric knees from 0° to 100° of knee flexion for anteroposterior limits at ±135 N, abduction-adduction limits at ±7 N·m, and external-internal limits at ±5 N·m. One loading method (n = 14 knees) used a static loading sequence with knee hyperextension to 27-N·m torque while maintaining all other degrees of freedom at zero load during sequential soft tissue cutting. The second method (n = 10 knees) used a cyclic loading sequence to decrease viscoelastic effects with soft tissue cutting at 0° of extension, followed by knee hyperextension to 27-N·m torque and cycled back to 0°. Selective soft tissue cuttings were performed of the following: oblique popliteal ligament, fabellofibular ligament, posterolateral capsule, posteromedial capsule with posterior oblique ligament, cruciate ligaments, lateral collateral ligament, popliteus, anterolateral ligament and iliotibial band, and superficial plus deep medial collateral ligaments. The sequential loss in the restraining moment with sectioning provides the function of that structure in resisting knee hyperextension. Results: The median resisting force to knee hyperextension, in descending order, was the posteromedial capsule and posterior oblique ligament (21.7%), posterorolateral ligament and fabellofibular ligament (17.1%), anterior and posterior cruciate ligaments (13% and 12.9%, respectively), superior and deep medial collateral ligament (9.6%), oblique popliteal ligament (7.7%), and lateral collateral ligament (5.4%). The combined posterior capsular structures provided 54.7% and the anterior and posterior cruciate ligaments 25.3% of the total resisting moment to prevent knee hyperextension. Conclusion: Diagnosis of abnormal knee hyperextension involves a combination of multiple ligament and soft tissue structures without 1 primary restraint. The posteromedial and posterolateral capsular structures provided the major resisting moment to prevent knee hyperextension. The cruciate ligaments produced a lesser resisting moment to knee hyperextension. Clinical Relevance: This is the first study to comprehensively measure all of the knee ligaments and capsular structures providing a resisting moment to abnormal knee hyperextension. These data are required for diagnostic and treatment strategies on the pathomechanics of abnormal knee hyperextension in patients after injury or developmental cases.

Long-term effects of clearcut and selective cut on seepage chemistry in a N-saturated spruce stand – Case study Höglwald

While comprehensive literature is available concerning the effects of clearcutting on N leaching via seepage water little information is available comparing different harvesting intensities. In order to close this gap of knowledge in 1999 an experiment comparing selective cut and clearcut at the Höglwald site was started. The Höglwald is a major Central European ecosystem study site and represents a typical spruce forest ecosystem in Southern Germany, subject to high nitrogen deposition. Bulk deposition, throughfall and seepage water concentrations at 0 and 40 cm depth were measured from 1999 until 2017 at three plots (control, clearcut, selective cut). Elemental fluxes were calculated using measured water fluxes (precipitation, throughfall) or calculated soil water fluxes using a hydrological model. Here we present the final results for the 17-year measurement period comparing different harvesting intensities from initial harvesting until the complete removal of all mature trees.Initial nitrate peaks after clearcutting the nitrogen saturated spruce ecosystems were very high (up to 34 mg nitrate-N l−1) but short-lived (2 years). Afterwards nitrate leaching strongly decreased to values close to zero due to reduced input and the demand of the upcoming vegetation. For the investigated 17-year period cumulative nitrogen losses at the clearcut plot were lower as compared to the uncut control. The selective cut was not able to prevent nitrate leaching in our N-saturated spruce stand. Here cumulative nitrogen losses in the first 17 years are similar compared to the uncut control due to a combination of ongoing high deposition and partially enhanced mineralisation after harvesting events.At our nitrogen saturated study site the selective cut showed no advantages concerning nitrate leaching via seepage water. From a silvicultural and forest ecological point of view, however, big cleared areas with their sudden change to a non-forest climate should be avoided due to several disadvantages like high initial mineralisation with its excessive nutrient release, the risk of grass invasion as well as higher stress and often lower quality of the planted trees.

Effects of thinning intensity and rotation length on albedo- and carbon stock-based radiative forcing in boreal Norway spruce stands

Abstract We investigated how thinning intensity and rotation length affect radiative forcing, and thus climate warming or cooling, through changes in albedo and carbon stocks in Norway spruce (Picea abies Kart. (L.)) stands. Forest ecosystem model simulations were conducted under the current climate on sub-mesic sites in central Finland (62oN). Even-aged management regime with a business-as-usual (baseline) thinning from below over an 80-year rotation length was used as the reference management regime with which others were compared. Other even-aged management regimes included baseline thinning with ±20 per cent changes in basal area thinning thresholds over rotation lengths of 80, 100 and 120 years. Additionally, we used as a comparison an uneven-aged management regime, with selective cuttings (from above) at ca. 15-year intervals, and no management regime, over the simulation periods of 80–120 years. Under even-aged management, a simultaneous decrease in thinning intensity and extension of rotation length from 80 to 120 years reduced total radiative forcing compared to the reference management regime. Thus, it had an overall net cooling effect. Under even-aged management with baseline thinning and/or higher thinning intensity with rotation lengths of 80–100 years, and under uneven-aged management, there was little net climatic effect. This was because the opposing effects of changes in albedo and ecosystem carbon stocks largely cancelled each other out. No management regime resulted in the highest net cooling effect but provided no harvest income for timber. Thus, proper incentives for forest owners would likely be required to promote such potential cooling effects in forest management.

Forward Modeling of Galaxy Populations for Cosmological Redshift Distribution Inference

We present a forward-modeling framework for estimating galaxy redshift distributions from photometric surveys. Our forward model is composed of: a detailed population model describing the intrinsic distribution of the physical characteristics of galaxies, encoding galaxy evolution physics; a stellar population synthesis model connecting the physical properties of galaxies to their photometry; a data model characterizing the observation and calibration processes for a given survey; and explicit treatment of selection cuts, both into the main analysis sample and for the subsequent sorting into tomographic redshift bins. This approach has the appeal that it does not rely on spectroscopic calibration data, provides explicit control over modeling assumptions and builds a direct bridge between photo-z inference and galaxy evolution physics. In addition to redshift distributions, forward modeling provides a framework for drawing robust inferences about the statistical properties of the galaxy population more generally. We demonstrate the utility of forward modeling by estimating the redshift distributions for the Galaxy And Mass Assembly (GAMA) survey and the Vimos VLT Deep Survey (VVDS), validating against their spectroscopic redshifts. Our baseline model is able to predict tomographic redshift distributions for GAMA and VVDS with respective biases of Δz ≲ 0.003 and Δz ≃ 0.01 on the mean redshift—comfortably accurate enough for Stage III cosmological surveys—without any hyperparameter tuning (i.e., prior to doing any fitting to those data). We anticipate that with additional hyperparameter fitting and modeling improvements, forward modeling will provide a path to accurate redshift distribution inference for Stage IV surveys.

Производительность и возобновление насаждений притундрового леса в Республике Коми

The paper highlights the evaluation results of the productivity and regeneration of stands in the Pechora forestry of the Komi Republic. At the research sites, the stands are mixed by composition and simple to complex by shape (with one or two stories). They are dominated by sphagnum spruce stands of Va - Vb quality classes. The total standing volume of stands varies from 44 to 161 m3/ha whereas the average volume increment varies from 0.49 to 1.46 m3/ha per year. The dependence of standing volume on the absolute and relative forest density is a closely correlated value being reliable at a high level of significance. Young spruce trees grow at 87 % and young birch trees - at 73 % of sample plots. 1/3 of the sample plots is characterized by the density of large spruce new growth exceeding 1.2 thousand units/ha. In this case, we can recommend natural reforestation by young growth conservation and care for it. At the other areas, the forest density varies from 0.25 to 0.8 thousand units/ha. Here, we also think that natural reforestation is an appropriate forest regeneration method but on condition of soil mineralization and with leaving seed trees. The relationship between the density of spruce or birch regrowth and the total stand stock can be expressed by the parabola equations. The maximum density of large spruce regrowth (1.75 thousand units/ha), calculated by these equations, corresponds to the stand stock of 84 m3/ha and relative stand density of 0.93. The maximum density of large birch regrowth (0.95 thousand units/ha) corresponds to the stand stock of 88 m3/ha and relative stand density of 0.98. Along with decreasing or increasing the stand stock value providing for the maximum regrowth density, the regrowth density values decrease. We explain the identified dependency as follows. In the given conditions, the maximum density of large regrowth that can further become a stand, can be achieved on condition of the optimal density and stock of stands that provide favorable conditions for regeneration and growth of young trees. Any decrease or increase in the density and stock of stands from the values being optimal for regeneration and growth of young trees weakens the protective role of maternal stand or, vice versa, increases its negative impact on the younger generation and, as a result, decreases the regrowth density under the canopy. The above mechanisms should be taken into account when conducting selective cuttings and cleaning cuttings under these conditions.

XGAPS: a sub-arcsec cross-match of galactic plane surveys

ABSTRACT We present a sub-arcsec cross-match of Gaia Data Release 3 (DR3) against the INT Galactic Plane Surveys (IGAPS) and the United Kingdom Infrared Deep Sky Survey (UKIDSS). The resulting cross-match of Galactic Plane Surveys (XGAPS) provides additional precise photometry (URGO, g, r, i, Hα, J, H, and K) to the Gaia photometry. In building the catalogue, proper motions given in Gaia DR3 are wound back to match the epochs of the IGAPS constituent surveys (INT Photometric HαSurvey of the Northern Galactic Plane, IPHAS, and the UV-Excess Survey of the Northern Galactic Plane, UVEX) and UKIDSS, ensuring high-proper motion objects are appropriately cross-matched. The catalogue contains 33 987 180 sources. The requirement of &amp;gt;3σ parallax detection for every included source means that distances out to 1–1.5 kpc are well covered. In producing XGAPS, we have also trained a Random Forest classifier to discern targets with problematic astrometric solutions. Selection cuts based on the classifier results can be used to clean colour-magnitude and colour–colour diagrams in a controlled and justified manner, as well as producing subsets of astrometrically reliable targets. We provide XGAPS as a 111 column table. Uses of the catalogue include the selection of Galactic targets for multi-object spectroscopic surveys as well as identification of specific Galactic populations.

Fiscal cuts in education and their effects: Politicising learned helplessness as a disciplinary technology in education leaders in Catalonia. An exploratory research study

The paper aims to explore how head teachers and other education service leaders and their teams have been experiencing shifts in their identities during the last decade of education cuts in Catalonia (Spain), and the possible effects during the current COVID-19 crisis on educational leaders. Our exploratory hypothesis covers the crisis years (2008–2015) and on into the non-recovery years (2015–2020) until the onset of the COVID-19 pandemic. During these years, through what Ball (2008) describes as a “ratchet effect,” education cuts and their everyday effects in schools produced learned helplessness (LH) in head teachers and leaders. Theoretically, we propose to examine this malaise from a political angle, seeing it as a disciplinary technology to transform education leaders’ identity and practices. To corroborate this, we conducted four interviews with head teachers of different public primary, secondary, and special education schools, and a psychopedagogical service leader in the same semi-rural area in Catalonia. The exploratory results show that the incremental and selective cuts soon became a new normal and created feelings of (political) learned helplessness that may be seen not as negative side effects but as a disciplinary technology that reshaped leaders’ subjectivity. At the same time, education leaders carried out some (ir)responsible practices of resistance that can be understood as care of the self and others. More research needs to be done with different agents to capture the complexity and ambiguity of cuts and LH as a political phenomenon.

Divergent growth responses of healthy and declining spruce trees to climatic stress: A case study from the Western Carpathians

Long-lived tree species optimize resource allocation processes, and there are likely trade-offs between the growth and response to environmental stressful conditions. The study aims to investigate the growth of healthy and declining Norway spruce trees using dendrochronological analysis. We have selected a natural high mountain spruce population and established 27 sampling plots in Poľana Mts. We measured 270 trees, from which we visually evaluated 133 individuals. Moreover, 51 trees were sampled for increment cores. Our study reveals thatspecific extreme combination of winter, spring and summer temperatures and precipitation sums within the particular year 1974 induced long-term growth divergence of neighboring spruce trees of comparable age and size and differentiated between healthy and declining (highly defoliated) trees. This period accounts for a decrease in size of relativized increments by 30.2% in declining trees compared to visually healthy individuals. Trees with a low ability to recover from climatic stress compensate the response to environmental conditions by lower growth rates. In high mountain temperate forests, the long-term growth decline of spruce trees last about 40 years. The single-tree selection silvicultural system should be preferred in high mountain conditions, where frequent small-scale, low-intensity disturbances drive stand dynamics. Trees showing low growth resilience to revealed combination of weather conditions should be preferentially removed from stands , especially within the transformation of even-aged spruce monocultures using selective cuttings.

Milky Way's Eccentric Constituents with Gaia, APOGEE, and GALAH

We report the results of an unsupervised decomposition of the local stellar halo in the chemodynamical space spanned by the abundance measurements from APOGEE DR17 and GALAH DR3. In our Gaussian mixture model, only four independent components dominate the halo in the solar neighborhood, three previously known, Aurora, Splash, and Gaia-Sausage/Enceladus (GS/E), and one new, Eos. Only one of these four is of accreted origin, namely, the GS/E, thus supporting the earlier claims that the GS/E is the main progenitor of the Galactic stellar halo. We show that Aurora is entirely consistent with the chemical properties of the so-called Heracles merger. In our analysis in which no predefined chemical selection cuts are applied, Aurora spans a wide range of [Al/Fe] with a metallicity correlation indicative of a fast chemical enrichment in a massive galaxy, the young Milky Way. The new halo component dubbed Eos is classified as in situ given its high mean [Al/Fe]. Eos shows strong evolution as a function of [Fe/H], where it changes from being the closest to GS/E at its lowest [Fe/H] to being indistinguishable from the Galactic low-α population at its highest [Fe/H]. We surmise that at least some of the outer thin disk of the Galaxy started its evolution in the gas polluted by the GS/E, and Eos is evidence of this process.

Electroweak corrections and shower effects to Higgs production in association with two jets at the LHC

We present an implementation of the full electroweak H + 2 jets production process at hadron colliders in the framework of the POWHEG BOX, a public tool for the matching of fixed-order perturbative calculations with parton shower generators. Our implementation allows for the simultaneous description of vector-boson fusion and Higgsstrahlung contributions. NLO-QCD and electroweak corrections are taken into account and matched to QCD and QED showers, respectively. The size of the fixed-order QCD and electroweak corrections is found to be moderate, but dependent on the considered selection cuts. QCD shower effects slightly modify the NLO-QCD predictions and are most pronounced for distributions of non-tagging jets. The impact of QED shower effects is small.

Increasing the intensity of regeneration treatments decreased beta diversity of temperate hardwood forest understory 20 years after disturbance

ContextIn temperate hardwood forests, increased intensity of soil and canopy disturbances tends to increase species richness due to the establishment of numerous early-successional plant species. However, while competitive pioneer species from early stages of succession can become recalcitrant and alter patterns of natural regeneration, very few studies have examined longer-term effects of these treatments on plant biodiversity.AimsIn this study, we investigated mid-term (ca. 20 years) effects of different regeneration treatments with varying soil and canopy disturbance intensities. We compared understory plant communities in temperate hardwood forests from all the South of Quebec (Canada).MethodsUsing circular experimental plots of 1962.5 m2 (radius = 25 m), we measured taxonomic and functional diversity indices and soil properties using four levels of disturbance intensity in six temperate hardwood forests of Quebec distributed along a longitudinal gradient. Reference forests, i.e. control forests with no silvicultural treatment known for ≥ 80 years, were compared to 20-year-old single-tree selection cuts, group-selection cuts and group-selection cuts with soil scarification.ResultsSpecies richness in both group-selection treatments was higher than that in reference forests. Plant equitability and beta diversity among sites in both group-selection treatments were lower than in single-tree selection cuts and control forests. More intense treatments contributed to the mid-term persistence of recalcitrant competitor species (e.g. Rubus idaeus L., Prunus pensylvanica L.f.) whereas soil scarification appears to have negative sustained effects on species known to be sensitive to regeneration treatments (e.g. Monotropa uniflora L., Dryopteris spinulosa Kuhn).ConclusionsIn temperate hardwood forests of Southern Quebec, silvicultural treatments of higher intensities resulted in detrimental effects on soil properties, especially in the surface horizon, 20 years after disturbance. This legacy, in turn, affected the composition and diversity of understory plant communities. The more intense silvicultural treatments contributed to the persistence of pioneer species better adapted to a wider range of environmental conditions and resulted in a decrease in understory plant community heterogeneity among sites. Conversely, single-tree selection cutting appeared to be the most appropriate silvicultural treatment for maintaining soil functions and heterogeneity of understory plant communities after 20 years; composition and structure being similar to long-undisturbed forests.

Economic Viability of Management Plants of Stryphnodendron adstringens (Mart.) Coville in North of Minas Gerais State

This study aimed to assess the economic viability of managing the Strypodendron adstringens Mart. Coville in the Cerrado sensu stricto in North of Minas Gerais. To achieve this goal we analyzed the economic feasibility of four management plans under selective cuts with 40, 50, 60 and 70% of basal area removed (G). The method consisted of building a cash flow for the species with a planning horizon for ten years. After obtaining the cash flow, with the help of economic engineering resources, we evaluated the financial indicators. These indicators consisted of Net Present Value (NPV), Internal Rate of Return (IRR), Discounted Payback period (PP) and Break-even Point (BEP). The results presented economically viable for all plans analyzed. But the plan 70% of basal area removed, stood out from the rest. Therefore it is concluded that the production of barks of barbatimão is economically viable since the intervention takes place in the percentage of 70% basal area within a sustainable management system.

Influence of Strip Clearcuts, Deer Exclusion and Herbicide on Initial Sapling Recruitment in Northern Hardwood Forests

Sapling recruitment in hardwood forests is often suppressed by overstory shade, interspecific competition, and browsing pressure from white-tailed deer (Odocoileus virginianus Zimmerman). In some northern hardwood stands, these three interacting factors may cause persistent recruitment failure of the dominant canopy species, sugar maple (Acer saccharum Marsh.), into the sapling size class. In this study, we compared initial (two-year) sugar maple and hophornbeam (Ostrya virginiana ((Mill.) K. Koch) seedling and sapling recruitment in strip clearcuts to strip selection cuts, with combinations of herbicide and deer exclosures, in a northern hardwood forest with limited sugar maple sapling recruitment. We found that sugar maple sapling recruitment was higher in exclosures, particularly in strip clearcuts. Moreover, mixed models predicted that exclosures in strip clearcuts with herbicide tended to benefit sugar maple sapling recruitment, especially when the pre-treatment density was less than ~1500 stems ha−1. Sapling density of hophornbeam was also promoted in exclosure plots but was negatively affected by herbicide. Graminoid and Rubus spp. cover was also limited by herbicide following harvest, potentially alleviating constraints on future sugar maple sapling recruitment. Our findings indicate that sugar maple sapling recruitment in strip clearcuts is similar to strip selection cuts unless browsing pressure and interspecific competition are also alleviated.

Recasting LHC searches for long-lived particles with MadAnalysis 5

We present an extension of the simplified fast detector simulator of MadAnalysis 5 – the SFS framework – with methods making it suitable for the treatment of long-lived particles of any kind. This allows users to make use of intuitive Python commands and straightforward C++ methods to introduce detector effects relevant for long-lived particles, and to implement selection cuts and plots related to their properties. In particular, the impact of the magnetic field inside a typical high-energy physics detector on the trajectories of any charged object can now be easily simulated. As an illustration of the capabilities of this new development, we implement three existing LHC analyses dedicated to long-lived objects, namely a CMS run 2 search for displaced leptons in the emu channel (CMS-EXO-16-022), the full run 2 CMS search for disappearing track signatures (CMS-EXO-19-010), and the partial run 2 ATLAS search for displaced vertices featuring a pair of oppositely charged leptons (ATLAS-SUSY-2017-04). We document the careful validation of all MadAnalysis 5 SFS implementations of these analyses, which are publicly available as entries in the MadAnalysis 5 Public Analysis Database and its associated dataverse.

Probing the in-medium $$P_T$$-broadening by $$\gamma $$+HF angular de-correlations

Angular correlations between vector boson and heavy flavors (HF) are potentially new effective tools to gain insight into the partonic interactions in the quark-gluon plasma (QGP). In this paper, we present the theoretical study of the azimuthal angular de-correlations of $$\gamma +$$ HF in nucleus-nucleus collisions as a new probe of the in-medium $$P_T$$ -broadening effect. The initial production of $$\gamma + $$ HF in p + p is generated by SHERPA which matches the next-to-leading hard processes with parton shower. The in-medium heavy quark evolution is implemented by a Monte Carlo Langevin simulation, which takes into account the collisional and radiative energy loss. We observe considerable suppression at $$\Delta \phi _{\gamma D}\sim \pi $$ and enhancement at $$\Delta \phi _{\gamma D}<2.8$$ in $$\gamma + $$ D azimuthal angular distribution in 0–10% Pb + Pb collisions at $$\sqrt{s_{NN}} = 5.02$$ TeV compared to the p + p baseline, which indicates evident in-medium $$P_T$$ -broadening of charm quarks. We also find that the overall modification patterns of $$\gamma + $$ D angular distribution are sensitive to the selection cut of D meson $$p_T$$ . Furthermore, by constructing the 2D ( $$x_{J}^{\gamma D}, \Delta \phi _{\gamma D}$$ ) correlation diagram, it’s possible to display the respective impact of the two aspects of jet quenching, energy loss and $$P_T$$ -broadening, on the final-state $$\gamma + $$ D observable simultaneously. Additionally, we find weaker angular de-correlations of $$\gamma + $$ B compared to $$\gamma + $$ D which may be helpful to understand the mass hierarchy in heavy-ion collisions. Finally, the nuclear modification of $$\Delta \phi _{\gamma D}$$ distributions in central 0–10% Au + Au collisions at RHIC energy is provided for completeness.

Taxation under direct democracy

Do citizens legislate different tax policies than parliaments? We provide quasi-experimental evidence for causal effects of direct democracy. Town meetings (popular assemblies) replace local councils in small German municipalities below a specific population threshold. RD and event study estimates consistently show that direct democracy comes with sizable but selective tax cuts. The burden of property taxes, which apply to all residents, decrease by some 10 to 15 percent under direct democracy. We do not find that business taxes change. Direct democracy allows citizens to design tax policies more individually than voting for a high-tax or low-tax party in elections.