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1.
Phys Rev Lett ; 131(5): 051801, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595210

RESUMO

MINERvA has measured the ν_{µ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{µ} energies and at produced π^{+} energies and angles, E_{π}>1 GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10 GeV.

2.
Phys Rev Lett ; 131(1): 011801, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37478458

RESUMO

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{µ}A→µ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{µ} beam with ⟨E_{ν}⟩≈6 GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

3.
Phys Rev Lett ; 130(16): 161801, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37154647

RESUMO

This Letter presents the first simultaneous measurement of the quasielasticlike neutrino-nucleus cross sections on C, water, Fe, Pb, and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5 GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielasticlike interactions, which are major contributors to long-baseline neutrino oscillation data samples.

5.
Nature ; 614(7946): 48-53, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725994

RESUMO

Scattering of high energy particles from nucleons probes their structure, as was done in the experiments that established the non-zero size of the proton using electron beams1. The use of charged leptons as scattering probes enables measuring the distribution of electric charges, which is encoded in the vector form factors of the nucleon2. Scattering weakly interacting neutrinos gives the opportunity to measure both vector and axial vector form factors of the nucleon, providing an additional, complementary probe of their structure. The nucleon transition axial form factor, FA, can be measured from neutrino scattering from free nucleons, νµn → µ-p and [Formula: see text], as a function of the negative four-momentum transfer squared (Q2). Up to now, FA(Q2) has been extracted from the bound nucleons in neutrino-deuterium scattering3-9, which requires uncertain nuclear corrections10. Here we report the first high-statistics measurement, to our knowledge, of the [Formula: see text] cross-section from the hydrogen atom, using the plastic scintillator target of the MINERvA11 experiment, extracting FA from free proton targets and measuring the nucleon axial charge radius, rA, to be 0.73 ± 0.17 fm. The antineutrino-hydrogen scattering presented here can access the axial form factor without the need for nuclear theory corrections, and enables direct comparisons with the increasingly precise lattice quantum chromodynamics computations12-15. Finally, the tools developed for this analysis and the result presented are substantial advancements in our capabilities to understand the nucleon structure in the weak sector, and also help the current and future neutrino oscillation experiments16-20 to better constrain neutrino interaction models.

6.
Artigo em Inglês | MEDLINE | ID: mdl-36427802

RESUMO

AIM: Our aim was to analyse the performance of [11C]choline PET/CT in prostate cancer (PCa) surveillance, especially in patients with prostate specific antigen (PSA) < 1 ng/mL. MATERIAL AND METHODS: Three hundred and twenty-nine [11C]choline PET/CT examinations from 191 patients (68.2 ±â€¯7.2 years) submitted for PCa surveillance or biochemical recurrence were retrospectively evaluated. PSA at study was 13.0 ±â€¯84.2 ng/mL. Main initial treatment was radical prostatectomy (RP) in 81 patients, and other treatments (radiotherapy, chemotherapy, hormonotherapy) in 110. PET/CT was acquired 20' after injection of 555-740 MBq of [11C]choline. Minimum follow-up was 12 months. RESULTS: Two hundred and nineteen (66.6%) out of the 329 PET/CT examinations were positive. The percentage of positive examinations was significantly higher in patients with other initial treatment than RP compared to patients with RP (85.6% vs. 43.6%, respectively). One hundred and thirty PET/CT (59.4%) showed local recurrence, 48 (21.9%) distant recurrence, and 41 (18.7%) local plus distant recurrence. Initial therapeutic approach was changed in 139 cases (63.5%). In the subgroup of 81 [11C]choline PET/CT scans performed with PSA < 1 ng/mL, 23 (28.4%) showed a positive result. Initial therapeutic approach was changed in 9 (11.1%). Three (4.8%) out of 63 patients died as per PCa. CONCLUSION: [11C]choline PET/CT demonstrated its effectiveness in PCa surveillance and restaging, even in patients with serum PSA < 1 ng/mL. The diagnostic performance was different depending on the initial treatment, been higher in patients with non-surgical treatment.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Humanos , Masculino , Colina , Antígeno Prostático Específico , Estudos Retrospectivos , Radioisótopos de Carbono , Pessoa de Meia-Idade , Idoso
7.
Phys Rev Lett ; 129(2): 021803, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35867435

RESUMO

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{µ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20 GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

8.
Mycotoxin Res ; 38(3): 175-183, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35501595

RESUMO

The production of beauvericin (BEA) by Fusarium oxysporum AB2 in liquid medium (SmF) was compared to that on solid medium (SSF) on inert support (polyurethane foam or PUF), using a previously optimised medium. The analysis included two different concentrations of the medium (1 × and 3 ×). Under SSF, the production of BEA (22.8 mg·L-1) was higher relative to SmF (0.8 mg·L-1). The production increased proportionally in the concentrated medium (3 ×) (65.3 mg·L-1); using the concentrated medium in SmF, the production of BEA was completely inhibited, although more biomass was produced. The peak of BEA production was reached on day 7 and remained stable until day 11; sustained production after several days has not been achieved in similar reports. The presence of BEA was corroborated by high-performance liquid chromatography (HPLC) and mass spectrometry. The BEA production profile is shown performing mixed cultures of Fusarium oxysporum AB2 and Epicoccum nigrum TORT using the same system, increasing the production of BEA up to 84.6 mg·L-1. We propose SSF using polyurethane foam (PUF) as a solid support as a new culture system for obtaining secondary metabolites such as BEA.


Assuntos
Depsipeptídeos , Fusarium , Técnicas de Cocultura , Fermentação , Fusarium/metabolismo
9.
BMC Ophthalmol ; 22(1): 152, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35366846

RESUMO

BACKGROUND: Treatment of open angle glaucoma (OAG) and/or ocular hypertension (OHT) focuses on achievement of target intraocular pressure (IOP), with the objective of slowing disease progression. However, ocular surface health is an important consideration in the optimization of treatment. We report 6 patient cases in which enhanced IOP control was achieved following appropriate management of ocular surface inflammation and a therapeutic switch to the preservative-free (PF) tafluprost (0.0015%)/timolol (0.5%) fixed-dose combination (FC). CASE PRESENTATION: Six patient cases, aged 48-74 years, presented with OAG or OHT. Each patient had signs and symptoms of ocular surface disease (OSD). Cases 1-3 were each receiving maximal medical therapy for OAG; regimens comprising prostaglandin analogue (PGA), ß-blocker, carbonic anhydrase inhibitor (CAI) and α-2 agonist agents (including treatments containing preservative agent). Cases 1 and 2 reported IOP values ≥23 mmHg in each eye, and wide IOP fluctuations were identified when reviewing patient data concerning case 3 (11-20 mmHg). Maximal therapy was ceased and PF tafluprost/timolol FC was initiated, after which the signs and symptoms of OSD were improved and IOP was reduced (≤18 mmHg for cases 1-3) and stabilized. Cases 4 and 5 were diagnosed with OAG and case 6 had OHT. Each had symptoms and signs of OSD and were treated with a preserved PGA monotherapy (latanoprost 0.005% or bimatoprost 0.03%). At presentation, IOP was 24 mmHg in both eyes (case 4), ≥18 mmHg (case 5) and ≥ 22 mmHg (case 6). Following a switch to the PF tafluprost/timolol FC, OSD symptoms were improved and IOP was 14 mmHg (both eyes; case 4), ≤14 mmHg (case 5) and 16 mmHg (both eyes; case 6). CONCLUSIONS: In addition to IOP-lowering efficacy, approaches to the management of OAG and OHT should consider the impact of treatment tolerability and the susceptibility of these patients to OSD. The presence of ocular surface inflammation appears to be detrimental to adherence and therefore to the effectiveness of topical medications. Addressing OSD through the use of PF FC formations, such as the PF tafluprost/timolol FC, reduces exposure to potentially toxic agents and facilitates improvements in IOP control.


Assuntos
Glaucoma de Ângulo Aberto , Hipertensão Ocular , Idoso , Anti-Hipertensivos , Glaucoma de Ângulo Aberto/tratamento farmacológico , Humanos , Pessoa de Meia-Idade , Prostaglandinas F , Timolol/uso terapêutico
10.
J Dairy Sci ; 105(4): 3367-3376, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35181136

RESUMO

Clinical endometritis (CE) and subclinical endometritis (SCE) are diseases that affect dairy cows during the puerperium, causing negative effects on the animals' milk production and fertility. The objective of this study was to assess the main bacteria related to cases of CE and SCE from uterine samples of dairy cows in Brazilian herds. Selective and differential media were used for isolation of aerobic and anaerobic bacteria and further MALDI-TOF mass spectrometry (MS) identification. A total of 279 lactating dairy cows with 28 to 33 d in milk from 6 commercial farms were evaluated. Initially, cows were classified in 3 groups: cytologic healthy cows (n = 161), cows with CE (n = 83), and cows with SCE (n = 35). Healthy animals presented 97 species, followed by the CE group with 53 identified species, and SCE cows presented only 21 bacterial species. We found a significantly higher isolation rate of Trueperella pyogenes in CE (26.5%) cows compared with healthy and SCE cows. Some anaerobic species were exclusively isolated from the CE group, even though they presented lower frequency. Interestingly, 18.1% of samples from CE cows and 40% of SCE cows were negative to bacterial isolation. Despite the use of culture-dependent methods instead of molecular methods, the present study enabled the identification of a complex community of 127 different species from 48 genera, composed of aerobic and anaerobic bacterial species among the 3 different animal groups. The method of sample collection, culture, and identification by MALDI-TOF MS were essential for the success of the analyses.


Assuntos
Doenças dos Bovinos , Endometrite , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Endometrite/microbiologia , Endometrite/veterinária , Feminino , Lactação , Leite/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária
11.
Clin Exp Dermatol ; 46(8): 1427-1433, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33899948

RESUMO

BACKGROUND: Onychoscopy is a technique that uses a dermatoscope for the evaluation of specific features of different skin conditions that are not visible to the naked eye. There are few studies establishing parameters for the diagnosis of onychomycosis based on onychoscopy. Determining the sensitivity and specificity of a potentially new diagnostic test for onychomycosis requires an evaluation study of this new diagnostic test, as there are limited studies reporting onychoscopy results. AIM: To determine the sensitivity, specificity, positive predictive value and negative predictive value of onychoscopy findings in a Colombian population with onychomycosis. METHODS: We assessed outpatients with a diagnosis of toenail onychomycosis confirmed by potassium hydroxide preparation or fungal culture. Onychoscopy was performed using a dermatoscope, and digital images collected using a smartphone. RESULTS: The onychoscopy findings were: longitudinal striae, distal spiked pattern, distal irregular termination, linear edge and ruins aspect, while some patients were confirmed as having traumatic onycholysis. A statistically significant association was found between the clinical symptoms of onychomycosis and both the clinical feature of dyschromia and the onychoscopy feature of longitudinal striae. CONCLUSION: We suggest that this technique is an alternative method that should be used in patients with onychopathies because it has the potential to differentiate onychomycosis from traumatic onycholysis and another nail involvement.


Assuntos
Dermoscopia , Onicomicose/diagnóstico por imagem , Colômbia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Unhas/diagnóstico por imagem , Unhas/lesões , Onicomicose/microbiologia , Onicomicose/patologia , Valor Preditivo dos Testes
12.
Radiologia (Engl Ed) ; 63(3): 209-217, 2021.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33678459

RESUMO

BACKGROUND AND AIMS: Bibliometrics makes it possible to measure the relative importance of a scientific journal in its field. The current study analyzed the scientific publications in Radiología and the bibliometric parameters of the journal in the period comprising 2010 through 2019. MATERIALS AND METHODS: We reviewed the bibliometrics for Radiología through information obtained from three sources: Scopus, the online version of the journal, and the publisher (Elsevier). We retrospectively analyzed aspects related to the editorial process (final decision and speed), the articles published (type, subspecialty of radiology, and imaging technique), the trends in citation and various indices (CiteScore, SNIP, and SJR), visibility, downloads, author characteristics (geographical origin and institutional collaboration), and the most cited articles. RESULTS: The number of articles published in Radiología gradually decreased during the decade, and the time to publication increased. Original research articles account for the largest share of the articles published. The most common subject areas were radiology of the digestive tract and neuroradiology. Nevertheless, the bibliometric indicators and the number of downloads of articles increased every year. Regarding the authorship of the articles published, although authors from Spain predominate, the participation of authors from other countries became increasingly common. Collaboration among different institutions also became increasingly common in the period analyzed. CONCLUSIONS: This review shows the progression of the journal's scientific work and some aspects that must be addressed to favor the growth of Radiología.

13.
Radiologia (Engl Ed) ; 63(2): 193-205, 2021.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33551121

RESUMO

Acute abdomen is a common reason for consultation in the emergency department. A broad spectrum of entities, including diverse diseases of the gastrointestinal tract, can cause acute abdomen. Although computed tomography is the technique most widely used to evaluate acute abdomen in the emergency department, abdominal ultrasound is often performed first and allows bowel disease to be suspected. This article describes the ultrasound features of diverse bowel diseases that can cause acute abdomen, such as acute diverticulitis, bowel obstruction, gastrointestinal perforation, bowel ischemia, intraabdominal fat necrosis, and miscellaneous processes such as endometriosis, foreign bodies, or vasculitis. Radiologists must be familiar with the different features of abnormal bowel that can be detected incidentally in patients without clinical suspicion of bowel disease. This article focuses on ultrasonographic signs of bowel disease; other articles in this series cover the ultrasonographic signs of acute appendicitis, inflammatory bowel disease, and infectious diseases.

14.
Rev Neurol ; 71(12): 455-459, 2020 Dec 16.
Artigo em Espanhol | MEDLINE | ID: mdl-33319348

RESUMO

INTRODUCTION: Radiation therapy is a very useful treatment for central nervous systemS neoplasms. The time range of its complications is very wide; they appear even many years after its completion. These late complications behave clinically and radiologically similar to a relapse; a functional diagnostic study with radioactive isotopes can help to make a therapeutic decision. CASE REPORT: A male suddenly presented deficient neurological symptoms in the same site where he received radiation therapy 25 years earlier for a pilocytic astrocytoma. The MRI findings suggested a lacunar stroke but a finding in the perfusion sequence forced us to be more precise in the diagnosis. A PET-CT 11C-methionine was performed which showed an increased uptake compatible with neoplasia. The spontaneous regressive evolution of the symptoms inclined us to take a conservative attitude. Lacunar ictus was confirmed on MRI three months later. CONCLUSIONS: The reappearance of neurological symptoms years after radiotherapy of a brain neoplasm poses a diagnostic dilemma. Current diagnostic techniques are very accurate but present false positives. The various nuclear medicine techniques, in particular PET-CT 11C-methionine, are a diagnostic aid. With the presentation of this case we intend to draw attention to one of the late complications of radiation therapy and the various differential diagnoses. Diagnostic and therapeutic advances have increased the life expectancy of cancer patients, so these late complications are expected to be more frequent.


TITLE: Ictus lacunar como complicación muy tardía de la radioterapia: valor de las técnicas de medicina nuclear.Introducción. La radioterapia es un tratamiento de gran utilidad en las neoplasias del sistema nervioso central. El rango temporal de sus complicaciones es muy amplio, ya que aparecen incluso muchos años más tarde de haberla finalizado. Estas complicaciones tardías se comportan clínica y radiológicamente de forma similar a una recidiva; un estudio funcional diagnóstico con isótopos radiactivos puede ayudar a tomar una decisión terapéutica. Caso clínico. Varón que presentó de forma brusca sintomatología neurológica deficitaria en la misma localización donde 25 años antes había recibido radioterapia por un astrocitoma pilocítico. La resonancia magnética sugería un ictus lacunar, pero un hallazgo en la secuencia de perfusión obligaba a ser más preciso en el diagnóstico. Una tomografía por emisión de positrones-tomografía computarizada (PET-TC) con C11-metionina mostró un aumento de captación compatible con neoplasia. La evolución espontánea regresiva de los síntomas inclinó a tomar una actitud conservadora. Una resonancia magnética realizada tres meses más tarde confirmó el ictus lacunar. Conclusiones. La reaparición de síntomas neurológicos años más tarde de la radioterapia de una neoplasia cerebral supone un dilema diagnóstico. Las técnicas diagnósticas actuales son muy precisas, pero presentan falsos positivos. Las distintas técnicas de medicina nuclear, en concreto la PET-TC con C11-metionina, suponen una ayuda diagnóstica. Con este caso se pretende llamar la atención sobre una de las complicaciones tardías de la radioterapia y los distintos diagnósticos diferenciales. Los avances diagnósticos y terapéuticos han aumentado la esperanza de vida de los pacientes oncológicos, con lo que estas complicaciones tardías se prevén más frecuentes.


Assuntos
Astrocitoma/radioterapia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Medicina Nuclear , Radioterapia/efeitos adversos , Acidente Vascular Cerebral Lacunar/diagnóstico , Acidente Vascular Cerebral Lacunar/etiologia , Adulto , Astrocitoma/cirurgia , Infarto Encefálico/diagnóstico , Infarto Encefálico/tratamento farmacológico , Infarto Encefálico/etiologia , Neoplasias Encefálicas/cirurgia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Masculino , Metionina/administração & dosagem , Metionina/metabolismo , Recidiva Local de Neoplasia , Medicina Nuclear/instrumentação , Medicina Nuclear/métodos , Tomografia por Emissão de Pósitrons/métodos , Acidente Vascular Cerebral Lacunar/tratamento farmacológico , Fatores de Tempo , Tomografia Computadorizada por Raios X
15.
Radiologia (Engl Ed) ; 62(6): 517-527, 2020.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33127091

RESUMO

Ultrasound is being increasingly used to study the digestive tract because it has certain advantages over other techniques such as endoscopy, CT enterography, and MR enterography. Ultrasound can be used to evaluate the bowel wall and the elements that surround it without the need for contrast agents; its ability to evaluate the elasticity and peristalsis of these structures is increasing interest in its use. This article describes the techniques and modalities of bowel ultrasound, as well as the normal features of the bowel wall and contiguous structures. It uses a practical approach to review the main pathological findings and their interpretation, and the different patterns of presentation, which will help orient the diagnosis.


Assuntos
Intestinos , Ultrassonografia , Meios de Contraste , Humanos , Intestinos/diagnóstico por imagem , Intestinos/patologia , Tomografia Computadorizada por Raios X
16.
Neurocase ; 26(6): 364-367, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33125299

RESUMO

Frontotemporal dementia (FTD) is a heterogeneous syndrome characterized by the progressive damage of frontal and temporal brain regions. These networks largely overlap with those involved in pain and temperature processing. Although the impaired perception of pain and temperature has been previously described to be relatively common in patients with FTD, these symptoms are often not consistently assessed by Neurologists. We present the case of a patient with a probable behavioral variant FTD who died due to scalding with hot water in the shower. Impairments in the perception of pain and temperature might have played a fundamental role in this accident.


Assuntos
Queimaduras/etiologia , Demência Frontotemporal/complicações , Percepção da Dor , Transtornos da Percepção/etiologia , Sensação Térmica , Idoso , Evolução Fatal , Humanos , Masculino , Percepção da Dor/fisiologia , Transtornos da Percepção/complicações , Sensação Térmica/fisiologia
17.
PLoS One ; 15(6): e0234636, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555720

RESUMO

The bacteriophage population is vast, dynamic, old, and genetically diverse. The genomics of phages that infect bacterial hosts in the phylum Actinobacteria show them to not only be diverse but also pervasively mosaic, and replete with genes of unknown function. To further explore this broad group of bacteriophages, we describe here the isolation and genomic characterization of 116 phages that infect Microbacterium spp. Most of the phages are lytic, and can be grouped into twelve clusters according to their overall relatedness; seven of the phages are singletons with no close relatives. Genome sizes vary from 17.3 kbp to 97.7 kbp, and their G+C% content ranges from 51.4% to 71.4%, compared to ~67% for their Microbacterium hosts. The phages were isolated on five different Microbacterium species, but typically do not efficiently infect strains beyond the one on which they were isolated. These Microbacterium phages contain many novel features, including very large viral genes (13.5 kbp) and unusual fusions of structural proteins, including a fusion of VIP2 toxin and a MuF-like protein into a single gene. These phages and their genetic components such as integration systems, recombineering tools, and phage-mediated delivery systems, will be useful resources for advancing Microbacterium genetics.


Assuntos
Actinobacteria/virologia , Bacteriófagos/genética , Variação Genética , Genoma Viral , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Composição de Bases , DNA Viral/genética , Genes Virais , Genômica , Filogenia , Proteínas Virais de Fusão/genética
18.
Animal ; 14(7): 1351-1361, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32026801

RESUMO

Reproductive traits have a major influence on the economic effectiveness of horse breeding. However, there is little information available. We evaluated the use of reproductive traits as selection criteria in official breeding programs to increase the reproductive efficiency of breeding studs, analysing 696 690 records from the pedigree data of eight Spanish horse populations, with different breeding purposes. The reproductive parameters studied in both sexes were age at first foaling (AFF), age at last foaling, average reproductive life and generational interval. In the females, the average interval between foaling (AIF) and interval between first and second foaling were also studied. There were clear differences between sexes and breeds, which may be due to management practices, breeding purposes and the status of the populations, rather than to differences in actual physiological conditions. Riding mares were the most precocious (AFF, 1937.64 to 2255.69 days) and had a more intensive reproductive use (AIF, 625.83 to 760.07 days), whereas sires used for meat production were the most precocious males (AFF, 1789.93 to 1999.75 days), although they had a shorter reproductive life (1564.34 to 1797.32 days). Heritabilities (0.02 to 0.42 in females and 0.04 to 0.28 in males) evidenced the genetic component of the reproductive traits, with Sport Horses having the higher average values. These results support the selection by AFF to improve reproductive aspects because of its medium-high heritability and its positive correlations with other important reproductive traits. The inclusion of the AIF is also recommended in sport populations, because this determines the length of the breaks between foaling and conditions the reproductive performance of the dams, as well as their selective intensity, genetic gain and genetic improvement. It is therefore an important economic parameter in breeding studs.


Assuntos
Cruzamento , Cavalos , Reprodução , Animais , Feminino , Cavalos/genética , Masculino , Carne , Linhagem , Fenótipo , Reprodução/genética
20.
J Mol Model ; 25(9): 289, 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31471730

RESUMO

In quantum chemical calculations, there are two facts of particular relevance: the position-dependent mass Schrödinger equation (PDMSE) and the exponential-type potentials used in the theoretical study of vibrational properties for diatomic molecules. Accordingly, in this work, the treatment of exactly solvable PDMSE for exponential-type potentials is presented. The proposal is based on the exactly solvable constant mass Schrödinger equation (CMSE) for a class of multiparameter exponential-type potentials, adapted to the position-dependent-mass (PDM) kinetic energy operator in the O von Roos formulation. As a useful application, we consider a PDM distribution of the form [Formula: see text], where the different parameters can be adjusted depending on the potential under study. The principal advantage of the method is that solution of different specific PDM exponential potential models are obtained as particular cases from the proposal by means of a simple choice of the involved exponential parameters. This means that is not necessary resort to specialized methods for solving second-order differential equations as usually done for each specific potential. Also, the usefulness of our results is shown with the calculation of s-waves scattering cross-section for the Hulthén potential although this kind of study can be extended to other specific potential models such as PDM deformed potentials.

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