Juan C. Marin

Juan C. Marin
  • University of Bío-Bío

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Publications (928)
Article
Genomic adaptation and introgression can occur during the speciation process, enabling species to diverge in their frequencies of adaptive alleles or acquire new alleles that may promote adaptation to environmental changes. There is limited information on introgression in organisms from extreme environments and their responses to climate change. To...
Article
The increased availability of quality genomic data has greatly improved the scope and resolution of our understanding of the recent evolutionary history of wild species adapted to extreme environments and their susceptibility to anthropogenic impacts. The guanaco (Lama guanicoe), the largest wild ungulate in South America, is a good example. The gu...
Article
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Maqui (Aristotelia chilensis) is a small tree endemic to Patagonia. It is currently being actively domesticated for its edible berries, which have high polyphenol content and anti-oxidant capability. However, little is known about its population structure and evolutionary history, information which is useful for the design of effective conservation...
Preprint
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Maqui ( Aristotelia chilensis [Molina] Stuntz) is a small endemic Patagonian tree that is currently being domesticated actively because of its edible berries, which have extremely high polyphenol content and anti-oxidant capability. Maqui can be easily propagated and is an efficient colonizer of deforested habitats to the point of often becoming an...
Article
Although guanacos (Lama guanicoe) are widely distributed throughout much of their historic range, they are often restricted to small, isolated populations that are at risk of inbreeding and loss of genetic diversity. Here we document and interpret baseline patterns of genetic variation in a guanaco population inhabiting in the Bolivian Chaco that i...
Article
Although guanacos (Lama guanicoe) are widely distributed throughout much of their historic range, they are often restricted to small, isolated populations that are at risk of inbreeding and loss of genetic diversity. Here we document and interpret baseline patterns of genetic variation in a guanaco population inhabiting in the Bolivian Chaco that i...
Article
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Simple Summary Determining the impacts of human activities on natural populations is important for biodiversity conservation. In this paper, we study the past and more recent effects of urbanization and livestock activity on the genetic diversity and population structure of endemic guanaco populations of the arid Monte and Patagonian Steppe of cent...
Article
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The study of South American camelids and their domestication is a highly debated topic in zooarchaeology. Identifying the domestic species (alpaca and llama) in archaeological sites based solely on morphological data is challenging due to their similarity with respect to their wild ancestors. Using genetic methods also presents challenges due to th...
Preprint
Full-text available
The study of South American camelids and their domestication is a highly debated topic in zooarchaeology. Identifying the domestic species (alpaca and llama) in archaeological sites based solely on morphological data is challenging due to their similarity with respect to their wild ancestors. Using genetic methods also present challenges due to the...
Article
Selective breeding of the guanaco and vicuña indisputably led to the domestic llama and alpaca. However, the place, time and process of domestication remain poorly documented, exacerbated by increased evidence of historic and recent introgression among both domestic populations, especially those involving alpaca. Here, we report the first comprehen...
Article
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Background: Despite their regional economic importance and being increasingly reared globally, the origins and evolution of the llama and alpaca remain poorly understood. Here we report reference genomes for the llama, and for the guanaco and vicuña (their putative wild progenitors), compare these with the published alpaca genome, and resequence s...
Article
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We describe a non-invasive technique to isolate genomic DNA from connective tissue present in the antlers of deer of the genus Hippocamelus. This method is simpler and more effective than conventional more-destructive procedures which damage the collection material. This method is applicable to all cervids that annually regenerate their antlers.
Article
A molecular genetic protocol for distinguishing pure and hybrid South American camelids was developed to provide strong, quantifiable, and unbiased species identification. We detail the application of the approach in the context of a criminal case in the Andes Mountains of central Chile where the defendants were alleged to have illegally hunted thr...
Article
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The vicuña (Vicugna vicugna) is the most representative wild ungulate of the high Andes of South America with two recognized morphological subspecies, V. v. mensalis in the north and V. v. vicugna in the south of its distribution. Current vicuña population size (460,000–520,000 animals) is the result of population recovery programs established in r...
Article
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The domestication of wild vicuña and guanaco by early pre-Inca cultures is an iconic example of wildlife management and domestication in the Americas. Although domestic llamas and alpacas were clearly selected for key, yet distinct, phenotypic traits, the relative patterns and direction of selection and domestication have not been confirmed using g...
Article
Vicuñas and guanacos are two species of wild South American camelids that are key ruminants in the ecosystems where they occur. Although closely related, these species feature differing ecologies and life history characters, which are expected to influence both their genetic diversity and population differentiation at different spatial scales. Here...
Article
Wildlife forensic science in the investigation of poaching of vicuña - Volume 50 Issue 1 - Benito A. González, Juan Carlos Marín, Victor Toledo, Edgard Espinoza
Article
Data from Z decays in DELPHI have been searched for [(B- d(o))over bar] → D<sup>star</sup>+ l(-) (ν) over bar (l) with the D<sup>star</sup>+ decaying to D(0)pi(+) and D-0 → K(-)pi(+), K(-)pi(+)pi(+)pi(- ) or K- pi(+)(pi(0)). These events are used to measure the CKM matrix element \V-cb\ and the form factor slope, rho(A1)(2): F- D<sup>star</sup...
Article
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The hadronic part of the Electron Structure Function (ESF) has been measured for the first time, using e+e- data collected by the DELPHI experiment at LEP, at centre-of-mass energies sqrt(s) = 91.2-209.5 GeV. The data analysis is simpler than that of the measurement of the photon structure function. The ESF data are compared to predictions of pheno...
Article
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Background Endometrial function is essential for embryo implantation. The aim of this study was to analyze gene expression profiles from individual endometrial samples obtained from women with repeated implantation failure after IVF in oocyte donation programs. Methods Seventeen volunteers were recruited: women who had previously participated as r...
Article
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Thirty-nine microsatellite loci that are highly conserved in red deer, sika deer, reindeer, Soay sheep, and other artiodactyls were tested in two vulnerable and endangered Neotropical deer (pudu: Pudu puda and huemul: Hippocamelus bisulcus) with the aim of producing a standardized set of markers that can be used successfully in noninvasive samples...
Article
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Fifteen guanacos were introduced to Staats Island in the Falklands/Malvinas archipelago from Patagonia in the 1930s. Twenty five years later, the population was culled from 300 to 10-20 individuals, but quickly rebounded to a population of almost 400 animals that today retain the genetic signature of the founding event and later bottleneck. The goa...
Article
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AimOur aim was to determine the combined impacts of Pleistocene climatic oscillations and glacial periods with recognized biogeographical barriers on the evolutionary history of huemul deer (Hippocamelus bisulcus). LocationSouthern Chile and Argentina's Andean forest, and Patagonian fjords. Methods We examined the phylogeography of huemul using 772...
Article
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Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distributio...
Article
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A small, new species of gerbil rodents of the genus Eligmodontia from the southwestern dunes of the Atacama Desert in northern Chile is described; the genus had not been reported for this western lowland region. Our description is based on cytogenetic and molecular data, as well as cranial and external morphology. In order to support this hypothesi...
Article
Full-text available
A small, new species of gerbil rodents of the genus Eligmodontia from the southwestern dunes of the Atacama Desert in northern Chile is described; the genus had not been reported for this western lowland region. Our description is based on cytogenetic and molecular data, as well as cranial and external morphology. In order to support this hypothesi...
Article
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A comprehensive study of the phylogeography and population genetics of the largest wild artiodactyl in the arid and cold-temperate South American environments, the guanaco (Lama guanicoe) was conducted. Patterns of molecular genetic structure were described using 514 bp of mtDNA sequence and 14 biparentally inherited microsatellite markers from 314...
Article
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We developed eight polymorphic microsatellite loci for the huemul (Hippocamelus bisulcus) and tested for cross-species amplification in six other ungulate species. Microsatellite loci were typed in 58 individuals from the Lago Cochrane National Reserve, Chile. Two to five alleles were observed per locus (mean 3.4) and observed heterozygosity ranged...
Article
Comparative phylogeography describes the patterns of evolutionary divergence and whether or not they are congruent, in co-distributed populations of different taxa. If the populations of these taxa have been co-distributed for a prolonged time, and if the times between processes of perturbation or vicariance have been more or less stable, it is exp...
Article
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Island–continent isolation scenarios have played major roles in the understanding and development of evolutionary theories. During the last glacial maximum (LGM) in southern Chile, ice sheet advances and retreats formed the Patagonian archipelago along the southern Pacific Ocean. Chiloé Island is the largest island from the archipelago isolated fro...
Article
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The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementary methods are used to reconstruct the energy of weakly decaying b-hadrons, \(E_{\mathrm{B}}^{\mathrm{weak}}\). The average value of \(x^{\mathrm{weak}}_{\mathrm{B}} = E_{\mathrm{B}}^{\mathrm{weak}}/E_{\mathrm{b...
Article
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Single top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were accumulated at centre-of-mass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1pb−1. No evidence for a signal was found. Limits on t...
Article
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The endometrium is a dynamic tissue whose changes are driven by the ovarian steroidal hormones. Its main function is to provide an adequate substrate for embryo implantation. Using microarray technology, several reports have provided the gene expression patterns of human endometrial tissue during the window of implantation. However it is required t...
Conference Paper
Full-text available
Entre las tres especies de ciervos chilenos, el Pudú (Pudu puda, Molina, 1782) es uno de los ciervos mas pequeños del mundo con 40 cm de altura (Hershkovitz, 1982). Este habita los bosques templados lluviosos del sur de Chile y Argentina, lugar del cual es endémico (Wemmer, 1998). Su distribución geográfica abarca desde los 36º a los 49º S en Chile...
Article
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An analysis of the direct soft photon production rate as a function of the parent jet characteristics is presented, based on hadronic events collected by the DELPHI experiment at LEP1. The dependences of the photon rates on the jet kinematic characteristics (momentum, mass, etc.) and on the jet charged, neutral and total hadron multiplicities are r...
Article
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The data taken by Delphi at centre-of-mass energies between 189and 209GeV are used to place limits on the CP-conserving trilinear gauge boson couplings DgZ1\Delta g^{Z}_{1}, λ γ and Δκ γ associated to W + W − and single W production at Lep2. Using data from the jj ℓ ν, jjjj, jjX and ℓ X final states, where j, ℓ and X represent a jet, a lepton and...
Article
Full-text available
The data taken by DELPHI at centre-of-mass energies between 189 and 209 GeV are used to place limits on the CP-conserving trilinear gauge boson couplings Delta_g1z, lambda_gamma and Delta_kappag associated to W+W- and single W production at LEP2. Using data from the jjlv, jjjj, jjX and lX final states, where j, l and X represent a jet, a lepton and...
Article
Full-text available
  Guanaco (Lama guanicoe) is a protected and widely distributed ungulate in South America. A poacher, after killing guanacos in Valle Chacabuco, Chilean Patagonia, transported and stored the meat. Samples were retrieved by local police but the suspect argued that the meat was from a horse. Mitochondrial cytochrome b gene (774 pb), 15 loci microsate...
Article
Full-text available
A study of the inclusive charged hadron production in two-photon collisions is described. The data were collected with the DELPHI detector at LEP II. Results on the inclusive single-particle pTpT distribution and the differential charged hadrons dσ/dpTdσ/dpT cross-section are presented and compared to the predictions of perturbative NLO QCD calcula...
Article
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In a study of the reaction e − e +→W − W + with the DELPHI detector, the probabilities of the two W particles occurring in the joint polarisation states transverse–transverse (TT), longitudinal–transverse plus transverse–longitudinal (LT) and longitudinal–longitudinal (LL) have been determined using the final states WW®lnq[`(q)]WW{\rightarrow}l\nu...
Article
We present the results of a palaeogenetic analysis of two Late Pleistocene camelids originating in southern Chile. Our analysis of two mitochondrial DNA fragments (control region and cytochrome b gene) reveals that these specimens do not belong to an extinct taxon, but rather to extant vicuña (Vicugna vicugna), whose modern distribution is restrict...
Article
Measurements are presented of R_b, the ratio of the b bbar cross-section to the q qbar cross-section in e+e- collisions, and the forward-backward asymmetry A^b_FB at twelve energy points in the range sqrt(s) = 130-207 GeV. These results are found to be consistent with the Standard Model expectations. The measurements are used to set limits on new p...
Article
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Single photons detected by the DELPHI experiment at LEP2 in the years 1997-2000 are reanalysed to investigate the existence of a single extra dimension in a modified ADD scenario with slightly warped large extra dimensions. The data collected at centre-of-mass energies between 180 and 209 GeV for an integrated luminosity of ~650 pb^{-1} agree with...
Article
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Measurements are presented of R b, the ratio of the b[`(b)]{\mathrm{b}}\bar{\mathrm{b}} cross-section to the q[`(q)]{\mathrm{q}}\bar{\mathrm{q}} cross-section in e+e− collisions, and the forward-backward asymmetry A FBb at twelve energy points in the range Ös=130\sqrt{s}=130 –207GeV. These results are found to be consistent with the Standard M...
Article
A study of the inclusive charged hadron production in two-photon collisions is described. The data were collected with the DELPHI detector at LEP II. Results on the inclusive single-particle p_T distribution and the differential charged hadrons dsigma/dp_T cross-section are presented and compared to the predictions of perturbative NLO QCD calculati...
Article
Full-text available
The production of two high-p T jets in the interactions of quasi-real photons in e + e − collisions at Ö{see}\sqrt{s_{ee}} from 189GeV to 209GeV is studied with data corresponding to an integrated e + e − luminosity of 550pb−1. The jets reconstructed by the k ⊥ -cluster algorithm are defined within the pseudo-rapidity range −1<η<1 and with jet...
Article
Full-text available
The production of two high-p_T jets in the interactions of quasi-real photons in e+e- collisions at sqrt{s_ee} from 189 GeV to 209 GeV is studied with data corresponding to an integrated e+e- luminosity of 550 pb^{-1}. The jets reconstructed by the k_T cluster algorithm are defined within the pseudo-rapidity range -1 < eta < 1 and with jet transver...
Article
Full-text available
Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) in dimuon events at LEP1 were studied in two photon kinematic ranges: 0.2 < E_gamma <= 1 GeV and transverse momentum with respect to the parent muon p_T < 40 MeV/c, and 1 < E_gamma <= 10 GeV and p_T < 80 MeV/c . A good agreement of the observed photon rate with predicti...
Article
Full-text available
Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) in dimuon events at LEP1 were studied in two photon kinematic ranges: 0.2<E γ ≤1GeV and transverse momentum with respect to the parent muon p T <40MeV/c, and 1<E γ ≤10GeV and p T <80MeV/c. A good agreement of the observed photon rate with predictions from QED for th...
Article
Full-text available
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions....
Article
Full-text available
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions....
Article
Full-text available
The effect of the heavy b-quark mass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (ℓ=uds) in events with n=2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quarks, R...
Article
A measurement of the W boson mass and width has been performed by the DELPHI collaboration using the data collected during the full LEP2 programme (1996–2000). The data sample has an integrated luminosity of 660 pb-1 and was collected over a range of centre-of-mass energies from 161 to 209 GeV. Results are obtained by applying the method of direct...
Article
Full-text available
A measurement of the W boson mass and width has been performed by the DELPHI collaboration using the data collected during the full LEP2 programme (1996–2000). The data sample has an integrated luminosity of 660pb-1 and was collected over a range of centre-of-mass energies from 161 to 209GeV. Results are obtained by applying the method of direct r...
Article
Full-text available
Polydactylism, a genetic defect characterized by partial or complete duplication of the digit, has been described in a wide range of vertebrates. Among ungulates, polydactyly appears to be relatively common in domestic camelids, with reports in dromedary camels (Camelus dromedarius), llama (Lama glama) and alpaca (Vicugna pacos). However, in wild S...
Article
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A determination of the single W spin density matrix (SDM) elements in the reaction e+e-→W+W-→lνqq̄(l=e/μ) is reported at centre-of-mass energies between 189 and 209 GeV. The data sample used corresponds to an integrated luminosity of 520 pb-1 taken by DELPHI between 1998 and 2000. The single W SDM elements, ρττ’W± (τ,τ’=± 1 or 0), are determined as...
Article
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Guanacos (Lama guanicoe) are the most important native herbivorous species in the South American steppes and the dominant ungulate in a fauna rich in rodents but poor in large mammal species. Between 2 and 4 subspecies are usually recognized within Lama guanicoe, based on subtle morphological differences and geographic distribution. To evaluate whe...
Article
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This paper presents the final interpretation of the results from DELPHI on the searches for Higgs bosons in the minimal supersymmetric extension of the Standard Model (MSSM). A few representative scenarios are considered, that include CP conservation and explicit CP violation in the Higgs sector. The experimental results encompass the searches for...
Article
A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean L...
Article
Full-text available
The effect of the heavy b-quark mass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (ℓ=uds) in events with n=2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quarks, R...
Article
Full-text available
Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) in dimuon events at LEP1 were studied in two photon kinematic ranges: 0.2 < Eγ ≤ 1 GeV and transverse momentum with respect to the parent muon pT < 40 MeV/c, and 1 < Eγ ≤ 10 GeV and pT < 80 MeV/c. A good agreement of the observed photon rate with predictions from QED fo...
Article
This paper presents the final interpretation of the results from DELPHI on the searches for Higgs bosons in the Minimal Supersymmetric extension of the Standard Model (MSSM). A few representative scenarios are considered, that include CP conservation and explicit CP violation in the Higgs sector. The experimental results encompass the searches for...
Article
Full-text available
The effect of the heavy b-quark mass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (l = uds) in events with n = 2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quark...
Article
Full-text available
The production of two high-p T jets in the interactions of quasi-real photons in e + e − collisions at from 189 GeV to 209 GeV is studied with data corresponding to an integrated e + e − luminosity of 550 pb−1. The jets reconstructed by the k ⊥ -cluster algorithm are defined within the pseudo-rapidity range −1<η<1 and with jet transverse momentum,...
Article
The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in "parasitic mode" between individual e(+)e(-) interactions and the total live time of this data taking is equivalent to 1.6 x 10(6) s. The DELPHI apparatus is located about 100 m underground and...
Article
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Measurements of Zγ* production are presented using data collected by the DELPHI detector at centre-of-mass energies ranging from 183 to 209GeV, corresponding to an integrated luminosity of about 667pb-1. The measurements cover a wide range of the possible final state four-fermion configurations: hadronic and leptonic (e+e-qq̄, μ+μ-qq̄, qq̄νν̄), ful...
Article
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Neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis of the reactions e+e-→Zγ, using data from the final states γff̄, with f=q or ν, from e+e -→ZZ, using data from the four-fermion final states qq̄qq̄, q...
Chapter
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This chapter re-analyzes 12S rRNA (759 bp) and cytochrome b gene (1140 bp) sequence data from relevant species and breeds to investigate the origins and domestication of guinea pigs, or cuyes, (Cavia porcellus). It describes and compares Peruvian and north-Chilean sites with both domesticated (living Andean creole and European breeds) and wild spec...
Article
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In the reaction e+e-→WW→(q1q̄2)(q3q̄4) the usual hadronization models treat the colour singlets q1q̄2 and q3q̄4 coming from two W bosons independently. However, since the final state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft gluon exchange. This effe...
Article
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Publicación ISI Email : jcmarin@ubiobio.cl; mwbruford@Cardiff.ac.uk; jwheeler@conopa.org The vicuna (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity ha...
Article
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Four camelid species exist in South America: two wild, the guanaco (Lama guanicoe) and the vicuña (Vicugna vicugna), and two domestic, the alpaca (Lama pacos) and the llama (Lama glama). However, the origin of the domestic species has been a matter of debate. In the present study, variations in chromosome G banding patterns and in two mitochondrial...
Article
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Publicación ISI Email : jmarin@med.uchile.cl Four camelid species exist in South America: two wild, the guanaco (Lama guanicoe) and the vicuna (Victigna vicugna), and two domestic, the alpaca (Lama pacos) and the llama (Lama glama). However, the origin of the domestic species has been a matter of debate. In the present study, variations in chromoso...
Article
Full-text available
A search for the pair production of fourth generation b’-quarks was performed using data taken by the DELPHI detector at LEP-II. The analysed data were collected at centre-of-mass energies ranging from 196 to 209 GeV, corresponding to an integrated luminosity of 420 pb-1. No evidence for a signal was found. Upper limits on BR(b’→bZ) and BR(b’→cW) w...
Article
Full-text available
To investigate the origins and domestication of guinea pigs, or cuyes (Cavia porcellus), we re-analyzed 12S rRNA (759 bp) and cytochrome b gene (11 40 bp) sequence data from relevant species and breeds. Seventeen pre-Columbian mummified cuyes from southern Peru and northern Chile sites are described and compared with both domesticated (living Andea...
Article
Full-text available
To investigate the origins and domestication of guinea pigs, or cuyes (Cavia porcellus), we re-analyzed 12S rRNA (759 bp) and cytochrome b gene (1140 bp) sequence data from relevant species and breeds. Seventeen pre-Columbian mummified cuyes from southern Peru and northern Chile sites are described and compared with both domesticated (living Andean...
Article
In the reaction e+e- -> WW -> (q_1 qbar_2)(q_3 qbar_4) the usual hadronization models treat the colour singlets q_1 qbar_2 and q_3 qbar_4 coming from two W bosons independently. However, since the final state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft...
Article
The quark model does not exclude states composed of more than three quarks, like pentaquark systems. Controversial evidence for such states has been published in the last years, in particular: for a strange pentaquark Theta(1540)+; for a double-strange state, the Xi(1862)--, subsequently called Phi(1860)--; and for a charmed state, the Theta_c(3100...
Article
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The study of quark jets in e+e- reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark and gluon jet samples of different purities are selected in three-jet events from hadronic decays of the Z coll...
Article
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The comb...
Article
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The exclusive and semi-exclusive branching ratios of the tau lepton hadronic decay modes (h- v_t, h- pi0 v_t, h- pi0 pi0 v_t, h- \geq 2pi0 v_t, h- \geq 3pi0 v_t, 2h- h+ v_t, 2h- h+ pi0 v_t, 2h- h+ \geq 2pi0 v_t, 3h- 2h+ v_t and 3h- 2h+ \geq 1pi0 v_t) were measured with data from the DELPHI detector at LEP.
Article
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Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qq̄ disintegrations of the Z0 were studied in the kinematic range 0.2<Eγ<1GeV and transverse momentum with respect to the closest jet direction pT<80MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions i...
Article
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Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Ca...
Article
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Measurements of the Xi- and anti-Xi+ masses, mass differences, lifetimes and lifetime differences are presented. The anti-Xi+ sample used is much larger than those used previously for such measurements. In addition, the Xi production rates in Z -> b anti-b and Z -> q anti-q events are compared and the position xi* of the maximum of the xi distribut...
Article
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The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The comb...
Article
Full-text available
Double-tagged interactions of photons with virtualities Q^2 between 10GeV^2 and 200GeV^2 are studied with the data collected by DELPHI at LEP2 from 1998 to 2000, corresponding to an integrated luminosity of 550pb^-1. The gamma*gamma* -> mu+mu- data agree with QED predictions. The cross-section of the reaction gamma*gamma* -> hadrons is measured and...
Article
An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light= \ell \equiv u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predic...
Article
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To test whether there are differences between living lineages of domestic guinea pigs Cavia porcellus, we studied 118 specimens from six breeds collected along six Andean countries as well as 15 from the wild cavy species (Cavia tschudii). The mean weight and body length of 15 adult wild cavies (295 +/- 31 g, 242 +/- 8.3 mm) were significantly smal...
Article
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An experimental study of the normalized three-jet rate of b quark events with respect to light quark events (light= l = u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions tre...
Article
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This book presents in ecah chapter the reserch results of the different lines included in the MACS project. Each chapter is author by the responsable resercher assiciated with MACs project
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The exclusive and semi-exclusive branching ratios of the tau lepton hadronic decay modes (h^-nu_tau, h^-pi0nu_tau, h^-pi0pi0nu_tau, h^- >= 2pi0nu_tau, h^- >= 3pi0nu_tau, 2h^-h^+nu_tau, 2h^-h^+pi0nu_tau, 2h^-h^+ >= 2pi0nu_tau, 3h^-2h^+nu_tau and 3h^-2h^+ >= 1pi0nu_tau) were measured with data from the DELPHI detector at LEP.
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A search for excited lepton production in e+e- collisions was performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies ranging from 189 GeV to 209 GeV, corresponding to an integrated luminosity of approximately 600 pb-1. No evidence for excited lepton production was found. In searches for pair-produced excited lep...
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The pseudoscalar meson \eta_b has been searched for in two-photon interactions at LEP II. The data sample corresponds to a total integrated luminosity of 617 pb^-1 at centre-of-mass energies ranging from 161 to 209 GeV. Upper limits at a confidence level of 95% on the product {\Gamma_\gamma\gamma}(\eta_b) x BR(\eta_b)are 190, 470 and 660 eV/c^2 for...
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This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e−→ff¯ process for centre-of-mass energies above the Z resonance, from s√∼130 -207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study...

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