252 research outputs found

    Evaluation of biological control strategies for polyphagotarsonemus latus (banks) and phyllocoptruta oleivora (ashmead) on valencia orange

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    The damage caused by P. latus and P. oleivora mites in the orange crop Valencia (Citrus sinensis L.) has an economical detrimental impact due to the external damage of the fruits. To evaluate the effect of biological control agents for these two pests, this work was carried out in a commercial crop in Caicedonia, Valle del Cauca, Colombia. The experimental design consisted of a randomized complete block, in which the following treatments were evaluated: (1) release of Phytoseiidae native species: Neoseiulus anonymus, Neoseiulus californicus, Iphiseiodes zuluagai and Amblyseius herbicolus (500 individuals / tree); (2) release of Chrysoperla carnea larvae (100 larvae/tree); (3) exclusion of beneficial agents (localized application of cypermethrin 2 cm3/l) and (4) farmer control (localized application of abamectin, 1.5 cm3/l). The releases and applications of the treatments were made on marked floral clusters and fruits in the middle third of each tree. Evaluations were made weekly until harvest time. For management of P. latus it was found that the treatments Phytoseiidae release, C. carnea release and abamectin application showed the least damage; exclusion of the beneficial agents demonstrated the importance of the natural control agents on this pest. For management of P. oleivora, C. carnea release and abamectin application showed the least damage. In release treatments of Phytoseiidae native species and the exclusion of beneficial agents, P. oleivora caused significant damage.El daño ocasionado por los ácaros Polyphagotarsonemus latus (Banks) y Phyllocoptruta oleivora (Ashmead) en el cultivo de naranja Valencia (Citrus sinensis L.) es reconocido tanto por el impacto económico como por el dao externo de los frutos. En este trabajo se evaluó el efecto de agentes biológicos para el control de estas plagas en un cultivo comercial de naranja Valencia en el municipio de Caicedonia, Valle del Cauca, Colombia. Se usó un diseo de bloques completos al azar para evaluar los tratamientos siguientes: (1) liberación de especies de Phytoseiidae nativos (Neoseiulus anonymus,Neoseiulus californicus, Iphiseiodes zuluagai y Amblyseius herbicolus en poblaciones de 500 individuos/árbol; (2) liberación de larvas de Chrysoperla carnea (100 larvas/árbol); (3) aplicación localizada de cipermetrina 2 cm3/l como tratamiento de exclusión de agentes benéficos; y (4) testigo consistente en el tratamiento utilizado por los agricultores (aplicación localizada de abamectina, 1.5 cm3/l). Las liberaciones de las especies benéficas y las aplicaciones de los tratamientos se realizaron sobre racimos florales y frutos marcados en el tercio medio de cada árbol. Las evaluaciones de daos se realizaron cada semana hasta la cosecha. Los tratamientos de liberación de Phytoseiidae, liberación de larvas de C. carnea y aplicación de abamectina presentaron el menor dao de P. latus; el tratamiento de exclusión de benéficos demostró la importancia de los agentes controladores naturales sobre la plaga. En el manejo de P. oleivora, los tratamientos de liberación de larvas de C. carnea y aplicación de abamectina presentaron los mejores resultados con el menor dao en frutos. La población de P. oleivora ocasionó daos significativos en el tratamiento de liberación de ácaros Phytoseiidae y exclusión de benéficos

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Búsqueda de enemigos naturales nativos de frankliniella occidentalis (pergande)(thysanoptera: thripidae), sobre dendranthema grandijlorum en el municipio de piendamo, cauca.

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    En la empresa "Flores del Cauca" en el municipio de Piendamó a 1S00 m.s.n.m. con temperatura promedia de 18° C y HR de SO ± 5%, se hizo una búsqueda de enemigos naturales nativos de F. occidentalis (Thysanóptera: Thripidae) sobre eras experimentales de Dendranthema grandiflorum libres de control químico. La búsqueda se extendió a los hospedantes alternos del tisanóptero en áreas aledañas al cultivo. Semanalmente se cosechaban plantas de crisantemo, se llevaban al laboratorio para la recolección de thrips y sus enemigos naturales nativos. En el laboratorio se realizaron bioensayos para probar la acción depredadora de algunos de los enemigos de F. occídentalis que fueron encontrados en crisantemo. Se encontraron los siguientes enemigos naturales nativos: El hemíptero Orius sp. (Anthocoridae). los ácaros Amblyseius herbjcolus. Euseius naindaimei y Thyplodromalus peregrinus (Phytoseiidae), larvas de Chrysopidae; los thrips leptothirs sp. y Haplotrips gowdeyi (Phlaeothripidae), un ácaro de la familia Ascidae; difereflles especies de arañas; larvas de la familia Coccinellidae y adultos de F. occidentalis infectados por hongos no identificados

    Direct observation of the dead-cone effect in quantum chromodynamics

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    The direct measurement of the QCD dead cone in charm quark fragmentation is reported, using iterative declustering of jets tagged with a fully reconstructed charmed hadron

    Direct observation of the dead-cone effect in quantum chromodynamics

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    At particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD) [1]. The vacuum is not transparent to the partons and induces gluon radiation and quark pair production in a process that can be described as a parton shower [2]. Studying the pattern of the parton shower is one of the key experimental tools in understanding the properties of QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass m and energy E, within a cone of angular size m/E around the emitter [3]. A direct observation of the dead-cone effect in QCD has not been possible until now, due to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible bound hadronic states. Here we show the first direct observation of the QCD dead-cone by using new iterative declustering techniques [4, 5] to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD, which is derived more generally from its origin as a gauge quantum field theory. Furthermore, the measurement of a dead-cone angle constitutes the first direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.The direct measurement of the QCD dead cone in charm quark fragmentation is reported, using iterative declustering of jets tagged with a fully reconstructed charmed hadron.In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). These partons subsequently emit further partons in a process that can be described as a parton shower which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQm_{\rm{Q}} and energy EE, within a cone of angular size mQm_{\rm{Q}}/EE around the emitter. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics

    Inclusive photon production at forward rapidities in pp and p–Pb collisions at sNN=5.02\sqrt{{{s}}_{\textrm{NN}}}={5.02} TeV

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    International audienceA study of multiplicity and pseudorapidity distributions of inclusive photons measured in pp and p–Pb collisions at a center-of-mass energy per nucleon–nucleon collision of sNN = 5.02\sqrt{s_{\textrm{NN}}}~=~5.02 TeV using the ALICE detector in the forward pseudorapidity region 2.3 < ηlab <<~\eta _\textrm{lab} ~< 3.9 is presented. Measurements in p–Pb collisions are reported for two beam configurations in which the directions of the proton and lead ion beam were reversed. The pseudorapidity distributions in p–Pb collisions are obtained for seven centrality classes which are defined based on different event activity estimators, i.e., the charged-particle multiplicity measured at midrapidity as well as the energy deposited in a calorimeter at beam rapidity. The inclusive photon multiplicity distributions for both pp and p–Pb collisions are described by double negative binomial distributions. The pseudorapidity distributions of inclusive photons are compared to those of charged particles at midrapidity in pp collisions and for different centrality classes in p–Pb collisions. The results are compared to predictions from various Monte Carlo event generators. None of the generators considered in this paper reproduces the inclusive photon multiplicity distributions in the reported multiplicity range. The pseudorapidity distributions are, however, better described by the same generators

    Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at s\sqrt{s} = 5.02 and 13 TeV

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    Two-particle transverse momentum correlations in pp and p-Pb collisions at LHC energies

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    Measurement of inclusive and leading subjet fragmentation in pp and Pb–Pb collisions at sNN \sqrt{s_{\textrm{NN}}} = 5.02 TeV

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    This article presents new measurements of the fragmentation properties of jets in both proton--proton (pp) and heavy-ion collisions with the ALICE experiment at the Large Hadron Collider (LHC). We report distributions of the fraction zrz_r of transverse momentum carried by subjets of radius rr within jets of radius RR. Charged-particle jets are reconstructed at midrapidity using the anti-kTk_{\rm{T}} algorithm with jet radius R=0.4R=0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kTk_{\rm{T}} algorithm with radii r=0.1r=0.1 and r=0.2r=0.2. In proton--proton collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zrz_r distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet fragmentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zrz_r distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark-gluon plasma (QGP). We find indications that there is a turnover in the ratio between the distributions in \mbox{Pb--Pb} and pp\mathrm{p\kern-0.05em p} collisions as zr1z_r \rightarrow 1, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP.This article presents new measurements of the fragmentation properties of jets in both proton–proton (pp) and heavy-ion collisions with the ALICE experiment at the Large Hadron Collider (LHC). We report distributions of the fraction zr_{r} of transverse momentum carried by subjets of radius r within jets of radius R. Charged-particle jets are reconstructed at midrapidity using the anti-kT_{T} algorithm with jet radius R = 0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kT_{T} algorithm with radii r = 0.1 and r = 0.2. In proton–proton collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zr_{r} distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet frag- mentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zr_{r} distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark–gluon plasma (QGP). We find no significant modification of zr_{r} distributions in Pb–Pb compared to pp collisions. However, the distributions are also consistent with a hardening trend for zr_{r}< 0.95, as predicted by several jet quenching models. As zr_{r} → 1 our results indicate that any such hardening effects cease, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP.[graphic not available: see fulltext]This article presents new measurements of the fragmentation properties of jets in both proton-proton (pp) and heavy-ion collisions with the ALICE experiment at the LHC. We report distributions of the fraction zrz_r of transverse momentum carried by subjets of radius rr within jets of radius RR. Charged-particle jets are reconstructed at midrapidity using the anti-kTk_{\rm{T}} algorithm with jet radius R=0.4R=0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kTk_{\rm{T}} algorithm with radii r=0.1r=0.1 and r=0.2r=0.2. In pp collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zrz_r distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet fragmentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zrz_r distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark-gluon plasma (QGP). We find no significant modification of zrz_r distributions in Pb-Pb compared to pp collisions. However, the distributions are also consistent with a hardening trend for zr<0.95z_r<0.95, as predicted by several jet quenching models. As zr1z_r \rightarrow 1 our results indicate that any such hardening effects cease, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP

    Kidney and Cardiovascular Effects of Canagliflozin According to Age and Sex: A Post Hoc Analysis of the CREDENCE Randomized Clinical Trial

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    Rationale &amp; Objective: It is unclear whether the effect of canagliflozin on adverse kidney and cardiovascular events in those with diabetic kid-ney disease varies by age and sex. We assessed the effects of canagliflozin among age group categories and between sexes in the Canagli-flozin and Renal Endpoints in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) study.Study Design: Secondary analysis of a random-ized controlled trial. Setting &amp; Participants: Participants in the CREDENCE trial. Intervention: Participants were randomly assigned to receive canagliflozin 100 mg/d or placebo.Outcomes: Primary composite outcome of kid-ney failure, doubling of serum creatinine con-centration, or death due to kidney or cardiovascular disease. Prespecified secondary and safety outcomes were also analyzed. Out-comes were evaluated by age at baseline (&lt;60, 60-69, and &gt;_70 years) and sex in the intention-to-treat population using Cox regression models.Results: The mean age of the cohort was 63.0 &amp; PLUSMN; 9.2 years, and 34% were female. Older age and female sex were independently associ-ated with a lower risk of the composite of adverse kidney outcomes. There was no evidence that the effect of canagliflozin on the primary outcome (acomposite of kidney failure, a doubling of serum creatinine concentration, or death from kidney or cardiovascular causes) differed between age groups (HRs, 0.67 [95% CI, 0.52-0.87], 0.63 [0.4 8-0.82], and 0.89 [0.61-1.29] for ages &lt;60, 60-69, and &gt;_70 years, respectively; P = 0.3 for interaction) or sexes (HRs, 0.71 [95% CI, 0.5 4-0.95] and 0.69 [0.56-0.8 4] in women and men, respectively; P = 0.8 for interaction). No differences in safety outcomes by age group or sex were observed.Limitations: This was a post hoc analysis with multiple comparisons.Conclusions: Canagliflozin consistently reduced the relative risk of kidney events in people with diabetic kidney disease in both sexes and across age subgroups. As a result of greater background risk, the absolute reduction in adverse kidney outcomes was greater in younger participants.Funding: This post hoc analysis of the CREDENCE trial was not funded. The CREDENCE study was sponsored by Janssen Research and Development and was conducted collaboratively by the sponsor, an academic-led steering committee, and an academic research organization, George Clinical.Trial Registration: The original CREDENCE trial was registered at ClinicalTrials.gov with study number NCT02065791
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