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1.
Phys Rev Lett ; 128(13): 132501, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426696

RESUMO

We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.

2.
Phys Rev Lett ; 125(11): 112502, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32976004

RESUMO

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}→0) where they should be most reliable.

3.
Phys Rev Lett ; 111(14): 141803, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-24152148

RESUMO

The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 µA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in ep scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p)(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of Q(W)(p)(SM)=0.0710±0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be Q(W)(n)(PVES+APV)=-0.975±0.010.

4.
J Dev Orig Health Dis ; 4(6): 491-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24924228

RESUMO

An infant's early developmental environment plays a pivotal role in the programming of its physiological phenotype. The identification of the factors in the maternal environment that mediate the effects of maternal obesity and diet is essential to the development of clinical intervention strategies. Maternal hyperglycaemia, hyperinsulinaemia, hypertriglyceridaemia, hyperleptinaemia and altered inflammatory cytokines concentrations are potentially important predictive factors of her future offspring's susceptibility to metabolic disease. Using a diet-induced obese mouse model, we have investigated which of these maternal factors could induce adverse metabolic programming in the offspring. Female C57Bl/6 mice were fed either laboratory chow (10% fat) or high fat diet (42% fat) for 10 weeks before mating and throughout gestation. At day 18 of pregnancy, maternal body weight, body composition and glucose tolerance were measured, as well as plasma insulin, adiponectin, RBP4, leptin, resistin and the inflammatory cytokines (IL6, IL10, IL12, IL1ß, IFNγ, KC, TNF-α). At day 18 of pregnancy, high fat-fed dams were significantly heavier than the chow dams and had increased fat mass. High fat-fed dams had higher 5 h fasting blood glucose than chow dams and elevated plasma insulin. Although the obese dams had both reduced plasma adiponectin and resistin levels compared with lean dams, their plasma IL6, IL10 and IFNγ levels were all increased. High fat feeding in pregnancy leads to altered plasma concentrations of both adipokines and adipocytokines in the dam that may directly pass to the fetus and affect their development.

5.
Int J Obes (Lond) ; 36(8): 1040-6, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22124449

RESUMO

BACKGROUND: Pups of normally nourished dams that are cross-fostered after birth to dams fed a low-protein (8% by weight) diet (postnatal low protein (PLP)) grow slower during the suckling period and remain small and lean throughout adulthood. At weaning, they have increased expression in the arcuate nucleus (ARC) of the hypothalamus of the orexigenic neuropeptide Y (NPY) and decreased expression of pro-opiomelanocortin, the precursor of anorexigenic melanocortins. OBJECTIVES AND METHODS: We investigated, using third ventricle administration, whether 3-month-old male PLP rats display altered sensitivity to leptin with respect to food intake, NPY and the melanocortin 3/4-receptor agonist MTII, and using in situ hybridization or laser capture microdissection of the ARC followed by RT-PCR, whether the differences observed were associated with changes in the hypothalamic expression of NPY or the leptin receptor, NPY receptors and melanocortin receptors. RESULTS: PLP rats were smaller and had reduced percentage body fat content and plasma leptin concentration compared with control rats. Leptin (5 µg) reduced food intake over 0-48 h more in PLP than control rats (P<0.05). Submaximal doses of NPY increased the food intake less in PLP rats than in controls, whereas submaximal doses of MTII reduced the food intake more in PLP rats. Maximal responses did not differ between PLP and control rats. Leptin and melanocortin-3 receptor (MC3R) expression were increased in both ARC and ventromedial hypothalamic nuclei in PLP animals compared with the controls. MC4R, NPY Y1R, Y5R and NPY expression were unchanged. CONCLUSION: Postnatal undernourishment results in food intake in adult rats being more sensitive to reduction by leptin and melanocortins, and less sensitive to stimulation by NPY. We propose that this contributes to increased leptin sensitivity and resistance to obesity. Increased expression of ObRb and MC3R may partly explain these findings but other downstream mechanisms must also be involved.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Núcleo Arqueado do Hipotálamo/patologia , Leptina/metabolismo , Neuropeptídeo Y/metabolismo , Obesidade/genética , Receptor Tipo 3 de Melanocortina/metabolismo , Magreza/genética , Animais , Núcleo Arqueado do Hipotálamo/fisiologia , Peso Corporal/genética , Suscetibilidade a Doenças , Ingestão de Alimentos , Regulação da Expressão Gênica , Leptina/farmacologia , Masculino , Neuropeptídeo Y/farmacologia , Obesidade/metabolismo , Ratos , Ratos Wistar , Magreza/metabolismo , Fatores de Tempo , Aumento de Peso/genética
6.
Manag Care Q ; 7(2): 43-50, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10537639

RESUMO

Many believe that successful companies beyond the year 2000 will all need to operate as learning organizations. Stimulating this vision have been Dr. Peter Senge of the Massachusetts Institute of Technology and Dr. James Milojkovic of Stanford University. As a learning organization, all members of a company will learn more about other parts of the organization and more about essential processes such as: helping each other learn, sharing, cooperating, leading, and participating in organizational decisions. This learning together will change existing stratifications, such as "bosses make decisions and employees implement the decisions without being consulted." A learning organization is a group of very different people who work together closely; bosses learn to treat each person as a responsible adult and hourly employees learn to participate in decisions. Learning organizations have a strong commitment to continual change. Each participant is expected to personally learn and grow. Everyone is expected to be open and share information, all while being tactful. The question that is continually before everyone in the company is "how can we do better?"


Assuntos
Aprendizagem , Cultura Organizacional , Inovação Organizacional , Tomada de Decisões Gerenciais , Humanos , Liderança , Objetivos Organizacionais , Gestão da Qualidade Total , Estados Unidos
7.
Environ Monit Assess ; 36(3): 217-28, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24197778

RESUMO

The use of chloride as a tracer for soil water investigations is discussed. Limitations with laboratory based soil core and field based sampling are considered with respect to the poor suitability of the data for rigorous assessment of mechanistic models. Investigation of water movement in soil has been restricted by limitations in spatial and temporal sampling. Fine resolution sampling generates large numbers of samples which cause problems with post sampling laboratory analysis. This paper describes a field-based system for the analysis of chloride in soil water. There are three component parts to the system, (i) a custom sampling sub-system comprising of ceramic cup suction samplers and sample traps, (ii) a sample routing sub-system to channel sample to (iii) a sample analysis sub-system utilizing a flow injection method for sample analysis using a custom built photo-diode detector. The three sub-systems were controlled by a suitably equipped personal computer. A calibration procedure is described with a third order polynomial equation derived to convert millivolt response from the detector into chloride concentration. Field and laboratory data from a tracer experiment are presented and discussed, and it is concluded that the system is well suited to field-based applications. Finally it is noted that the photo-detector is suitable for colourimetric analysis of any tracer with suitable chemical determination.

8.
Ir J Med Sci ; 162(7): 256-7, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8407264

RESUMO

A 52 year old man developed progressive painful swelling of both calves and difficulty walking. Physical examination showed asymmetrical localised swelling with induration and tenderness on palpation. Peripheral blood eosinophilia was noted. Biopsy of deep fascia and muscle showed typical features of eosinophilic fasciitis. He was treated with non-steroidal anti-inflammatory drugs and intensive physiotherapy. The clinical features had completely resolved six months later.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Eosinofilia/terapia , Fasciite/terapia , Modalidades de Fisioterapia , Terapia Combinada , Eosinofilia/complicações , Fasciite/complicações , Humanos , Perna (Membro) , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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