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1.
Eur Phys J C Part Fields ; 81(4): 322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720713

RESUMO

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

2.
Phys Rev Lett ; 123(13): 131801, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31697542

RESUMO

We report the first measurement of the double-differential and total muon neutrino charged current inclusive cross sections on argon at a mean neutrino energy of 0.8 GeV. Data were collected using the MicroBooNE liquid argon time projection chamber located in the Fermilab Booster neutrino beam and correspond to 1.6×10^{20} protons on target of exposure. The measured differential cross sections are presented as a function of muon momentum, using multiple Coulomb scattering as a momentum measurement technique, and the muon angle with respect to the beam direction. We compare the measured cross sections to multiple neutrino event generators and find better agreement with those containing more complete treatment of quasielastic scattering processes at low Q^{2}. The total flux integrated cross section is measured to be 0.693±0.010(stat)±0.165(syst)×10^{-38} cm^{2}.

3.
Eur Phys J C Part Fields ; 78(1): 82, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31258394

RESUMO

The development and operation of liquid-argon time-projection chambers for neutrino physics has created a need for new approaches to pattern recognition in order to fully exploit the imaging capabilities offered by this technology. Whereas the human brain can excel at identifying features in the recorded events, it is a significant challenge to develop an automated, algorithmic solution. The Pandora Software Development Kit provides functionality to aid the design and implementation of pattern-recognition algorithms. It promotes the use of a multi-algorithm approach to pattern recognition, in which individual algorithms each address a specific task in a particular topology. Many tens of algorithms then carefully build up a picture of the event and, together, provide a robust automated pattern-recognition solution. This paper describes details of the chain of over one hundred Pandora algorithms and tools used to reconstruct cosmic-ray muon and neutrino events in the MicroBooNE detector. Metrics that assess the current pattern-recognition performance are presented for simulated MicroBooNE events, using a selection of final-state event topologies.

4.
Phys Rev Lett ; 117(19): 192501, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27858422

RESUMO

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

5.
Phys Rev Lett ; 116(18): 181801, 2016 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-27203315

RESUMO

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{µ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{µ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{µ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained µ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3} eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3} eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{µ} disappearance parameters measured by T2K.

6.
Phys Rev Lett ; 113(24): 241803, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25541766

RESUMO

The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ∼1 GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged ν(e) charged current cross section on carbon is measured to be ⟨σ⟩(ϕ)=1.11±0.10(stat)±0.18(syst)×10⁻³8 cm²/nucleon. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23×10⁻³8 cm²/nucleon and the GENIE prediction is 1.08×10⁻³8 cm²/nucleon. The total ν(e) charged current cross-section result is also in agreement with data from the Gargamelle experiment.

7.
Phys Rev Lett ; 112(18): 181801, 2014 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-24856687

RESUMO

New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter θ23. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57×10(20) protons on target, T2K has fit the energy-dependent νµ oscillation probability to determine oscillation parameters. The 68% confidence limit on sin(2)(θ23) is 0.514(-0.056)(+0.055) (0.511±0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Δm32(2)=(2.51±0.10)×10(-3) eV(2)/c(4) (inverted hierarchy: Δm13(2)=(2.48±0.10)×10(-3) eV(2)/c(4)). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.

8.
Phys Rev Lett ; 112(6): 061802, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24580687

RESUMO

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm(32)(2) and a CP violating phase δ(CP). In this neutrino oscillation scenario, assuming |Δm(32)(2)|=2.4×10(-3) eV(2), sin(2)θ(23)=0.5, and Δm322>0 (Δm(32)(2)<0), a best-fit value of sin(2)2θ(13)=0.140(-0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at δ(CP)=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of θ(13) from reactor experiments, some values of δ(CP) are disfavored at the 90% C.L.

9.
Phys Rev Lett ; 111(21): 211803, 2013 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-24313479

RESUMO

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(θ23)=0.514±0.082 and mass splitting |Δm(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.

10.
Phys Rev Lett ; 107(4): 041801, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21866992

RESUMO

The T2K experiment observes indications of ν(µ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.

11.
Zentralbl Chir ; 129(4): 282-4, 2004 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-15354249

RESUMO

A simple technique by twisting the thread in clockwise or counter clockwise direction before tightening the suture can help to produce a regular vascular suture line. In a blinded experiment with 60 vascular anastomosis it was proved that the time needed for suture can be reduced by 15%, and that traumatic touch with surgical instruments can be diminished by 63%.


Assuntos
Técnicas de Sutura , Anastomose Cirúrgica , Animais , Aorta/cirurgia , Prótese Vascular , Interpretação Estatística de Dados , Polietilenotereftalatos , Polipropilenos , Suínos , Fatores de Tempo
12.
Phys Rev Lett ; 92(13): 133007, 2004 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-15089605

RESUMO

The metastable a(1)[(3)Sigma(+)] state of PbO has been suggested as a suitable system in which to search for the electric dipole moment of the electron. We report here the development of experimental techniques allowing high-sensitivity measurements of Zeeman and Stark effects in this system, similar to those required for such a search. We observe Zeeman quantum beats in fluorescence from a vapor cell of PbO, with shot-noise limited extraction of the quantum beat frequencies, high counting rates, and long coherence times. We argue that improvement in sensitivity to the electron electric dipole moment by at least 2 orders of magnitude appears possible using these techniques.

13.
Surg Endosc ; 14(4): 367-71, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10790557

RESUMO

BACKGROUND: According to the literature, the number of port-site metastases in laparoscopic surgery varies considerably depending on the type of gas used for the pneumoperitoneum. In order to investigate this observation we studied the changes in blood, subcutaneous, and intra-abdominal pH during laparoscopy with helium, CO(2) and room air in a rat model. In addition, we looked at the influence of intra-abdominal pressure and duration of pneumoperitoneum on the pH during the laparoscopy. METHODS: pH was measured by tonometry, intra-abdominally and subcutaneously. A pH electrode was additionally placed into the subcutaneous tissue and the results compared to those measured by tonometry. Blood samples were taken from a catheter in the carotid artery. The intra-abdominal pressure was 0, 3, 6, 9 mm Hg for 30 min in each case. We investigated the effect of pneumoperitoneum with CO(2), helium and air in randomized groups of 5 rats. In an additional series the pressure was held constant at 3 mm Hg and the pH was measured every 30 min. RESULTS: Due to the different absorption capacity of the peritoneum, laparoscopy with CO(2) decreases the subcutaneous pH from 7.35 to 6.81. Blood pH is reduced from 7.37 to 7.17 and the intra-abdominal pH from 7.35 to 6.24. Other, less absorbable gases induce smaller changes of blood and subcutaneous pH (only 10% of CO(2)). In a variance analysis the p value is less than 0.001. The influence of duration of laparoscopy (30 min vs. 90 min) on the subcutaneous pH is less compared to the influence of intra-abdominal pressure (0, 3, 6, 9 mm Hg). CONCLUSIONS: Depending on the type of gas (CO(2), air, helium) used for laparoscopy blood, subcutaneous and intra-abdominal pH are influenced differently. Because lower pH is known to impair local defense mechanisms, these results may be one explanation for the higher incidence of port-site metastasis in laparoscopy with CO(2) than with other gases, as reported in the literature.


Assuntos
Abdome/fisiologia , Sangue/metabolismo , Gases/administração & dosagem , Laparoscopia , Pneumoperitônio Artificial/métodos , Pressão , Pele/metabolismo , Tecido Adiposo/metabolismo , Ar , Animais , Dióxido de Carbono/administração & dosagem , Hélio/administração & dosagem , Concentração de Íons de Hidrogênio , Laparoscopia/métodos , Masculino , Monitorização Intraoperatória , Ratos , Ratos Wistar , Fatores de Tempo
14.
Surg Endosc ; 14(11): 1082-4, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11116425

RESUMO

BACKGROUND: We devised a safe and simple method of liver resection with a wire loop in a small animal model. Herein the method is evaluated and combined with a tumor model for further immunological, oncological, and laparoscopic research. METHODS: With the aid of a wire loop and an adapted electric generator, a liver lobe resection can be performed through three trocars (first trocar: camera; second and third trocars: instruments). This operative procedure was evaluated in 10 rats (group 1). In a second group of ACI rats, a Morris hepatoma (1 mm(3)) was induced. After 11 days, a liver lobe resection was performed. One week after the resection an autopsy and a histological examination were performed in all animals. RESULTS: Ten ACI rats underwent laparoscopic liver resection to evaluate the operative technique with the wire loop (group 1). All rats returned to normal feeding and activity on the 1st postoperative day. There were no deaths. At autopsy, the resection area was inconspicuous, without any sign of hematoma or bilioma. In the second group, 10 days after tumor induction, the induced hepatoma was increased (1 cm(3)) and localized in the left liver lobe. In all rats, the liver lobe was resected without touching or laceration of the tumor. At autopsy, the resection area was inconspicuous. No tumors were found in the histological workup of liver and lungs. CONCLUSION: This model of laparoscopic liver resection in the rat allows a safe and simple liver lobectomy, including a total tumor resection. It should also facilitate basic oncological, immunological, and laparoscopic research.


Assuntos
Hepatectomia/métodos , Laparoscopia/métodos , Anestesia , Anestésicos Dissociativos , Animais , Hepatectomia/instrumentação , Ketamina , Laparoscópios , Neoplasias Hepáticas Experimentais/cirurgia , Masculino , Transplante de Neoplasias , Ratos , Ratos Endogâmicos ACI , Organismos Livres de Patógenos Específicos , Instrumentos Cirúrgicos , Xilazina
15.
Berl Munch Tierarztl Wochenschr ; 113(11-12): 423-30, 2000.
Artigo em Alemão | MEDLINE | ID: mdl-11153221

RESUMO

Comparative studies on the prevalence of infections caused by Coxiella burnetii (C. burnetii) and Chlamydia were carried out with 592 cattle older than 2 years and 234 cattle younger than 2 years. Of these 477 originated from 24 dairy herds with considerable fertility problems (positive herds) and 349 from 14 dairy herds without major fertility problems (control herds). For the direct detection of these pathogens in the genitals capture ELISAs were employed, for the demonstration of antibodies the complement fixation test (CFT). Direct detection of C. burnetii and Chlamydia single as well as mixed infection revealed significant higher values for cattle from positive herds compared with those from the control herds. Animals revealing insemination ratios of > or = 2 showed significantly more frequent excretion of Chlamydia via the genitals and antibodies against C. burnetii than cattle with an insemination ratio of < 2. Investigations of cows which had had an abortion showed no indications of significantly more frequent C. burnetii or chlamydial infections. Inseminated but non-pregnant cows excreted significantly more C. burnetii and Chlamydia than pregnant cows. Clinical signs of endometritis were associated with an enhanced excretion of Chlamydia. Animals younger than 2 years excreted significantly more frequently C. burnetii but not Chlamydia via the genitals than animals older than 2 years. Indirect test showed results vice versa.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Infecções por Chlamydia/veterinária , Febre Q/veterinária , Aborto Animal/epidemiologia , Aborto Animal/microbiologia , Animais , Bovinos , Infecções por Chlamydia/epidemiologia , Coxiella burnetii , Feminino , Alemanha/epidemiologia , Infertilidade Feminina/epidemiologia , Infertilidade Feminina/microbiologia , Infertilidade Feminina/veterinária , Inseminação Artificial/veterinária , Masculino , Gravidez , Prevalência , Febre Q/epidemiologia
16.
Surg Endosc ; 12(7): 963-7, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9632871

RESUMO

METHODS: In order to evaluate the stress and immunological response to laparoscopic and conventional colon resection we operated on male Wistar rats (350-380 g), performing either laparoscopic (n = 15) or open colon resection (n = 15). A third group (n = 10) underwent anesthesia only. Immediately before and after surgery as well as 1 and 7 days postoperatively a 1 ml sample of blood was taken from the retrobulbar veinous plexus. Stress (corticosterone) and immune parameters (neopterin and interleukin [IL] 1-beta) were measured. Furthermore, the body weight as a parameter of postoperative recovery was monitored. RESULTS: The analysis of variance showed significant differences between the three groups over a period of 1 week (p < 0.0001 for corticosterone, p = 0.0854 for IL 1-beta, p = 0. 0045 for neopterin). Additionally in a t-test significant differences were found between the laparoscopic and conventional group with regard to corticosterone (p = 0.08), to neopterin (p = 0. 045), and to IL 1-beta (p = 0.0043) at the end of the operation. One week after the operation the stress and immune parameters were back to normal levels in each group except IL 1-beta, but the recovery indicated by body weight was different according to the kind of the applied operative procedure: 7 days postoperatively the rats lost 5. 99% of their body weight after open surgery and only 2.4% after laparoscopic surgery. After anesthesia only the body weight increased by about 4.8%. CONCLUSION: Laparoscopic colon resection alters the stress and immune system of healthy rats less than open colon resection. This observation is confirmed by the quicker recovery in laparoscopically operated rats.


Assuntos
Colectomia/métodos , Corticosterona/sangue , Interleucina-1/sangue , Laparoscopia , Estresse Fisiológico/sangue , Animais , Modelos Animais de Doenças , Estudos de Avaliação como Assunto , Masculino , Estudos Prospectivos , Radioimunoensaio , Distribuição Aleatória , Ratos , Ratos Wistar
17.
Complement Ther Nurs Midwifery ; 3(6): 152-5, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9511643

RESUMO

Despite its popularity on mainland Europe, particularly in Germany and Switzerland, anthroposophical medicine remains relatively unknown in the UK. Joanna Trevelyan takes a closer look at this truly holistic form of medicine, and asks Frances Bay, one of the founders of the Anthroposophical Nurses Association in Great Britain, what it can offer nurses.


Assuntos
Medicina Antroposófica , Enfermagem Holística , Sociedades de Enfermagem , Europa (Continente) , Humanos , Descrição de Cargo , Reino Unido
18.
Complement Ther Nurs Midwifery ; 1(2): 34-6, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9456705

RESUMO

In this article, the author explores some of the issues involved if nurses wish to incorporate complementary therapies into their role. Amongst others, questions are raised concerning the compatibility of complementary therapies with current health care provision in hospital and community. Aspects of accountability, education and research are touched upon. No answers are offered, leaving readers to draw their own conclusions how best to overcome some of the obstacles mentioned.


Assuntos
Terapias Complementares , Empatia , Enfermagem Holística/normas , Humanos , Responsabilidade Social
19.
Experientia ; 32(5): 560-2, 1976 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-1278292

RESUMO

Changing the L:D intensity ratio of a synchronizing dark regime leads to characteristic modulations of the activity pattern of Chiroptera species. These modulations fit the predictions of WEVER'S oscillator model.


Assuntos
Ciclos de Atividade , Quirópteros/fisiologia , Ritmo Circadiano , Animais , Escuridão , Luz , Modelos Biológicos
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