180 research outputs found
On Scaling Solutions with a Dissipative Fluid
We study the asymptotic behaviour of scaling solutions with a dissipative
fluid and we show that, contrary to recent claims, the existence of stable
accelerating attractor solution which solves the `energy' coincidence problem
depends crucially on the chosen equations of state for the thermodynamical
variables. We discuss two types of equations of state, one which contradicts
this claim, and one which supports it.Comment: 8 pages and 5 figures; to appear in Class. Quantum Gra
Determination of organic microcontaminants in agricultural soils irrigated with reclaimed wastewater: Target and suspect approaches
Plasticity induced by pairing brain stimulation with motor-related states only targets a subset of cortical neurones
Movement-related brain stimulation (MRBS) interventions associate endogenously generated movement-related brain states with external brain stimuli to induce targeted plastic changes in the motor cortex (M1) [[1], [2], [3], [4]]. These studies have emphasised the importance of the timing of stimulation relative to movement onset. However, none has examined whether the effects are specific to the cortical circuits activated by the stimuli.
The question arises because previous work has shown that different sets of inputs to corticospinal neurones can be activated using TMS. Stimulation with a posterior-anterior (PA) direction activates a set of neurones that have a shorter latency connection to corticospinal neurones than those activated with an anterior-posterior (AP) current [5]. Previous MRBS studies have paired movement onset with PA pulses [1]. The present work tests whether the after-effects of MRBS are specific to PA-sensitive neurones, or whether those activated by AP pulses are also affected.
Here we applied AP or PA TMS pulses applied just prior to the onset of volitional index finger movements in two experiments conducted on separate days in the same group of individuals [3]. Corticospinal excitability changes induced by these interventions were assessed using AP and PA TMS pulses in the effector muscle and in a control muscle
A Single Nucleotide Polymorphism in STK11 Influences Insulin Sensitivity and Metformin Efficacy in Hyperinsulinemic Girls With Androgen Excess
status: publishe
Plan de negocio para determinar la viabilidad de una tienda minorista digital para la venta de productos org?nicos y de primera necesidad
El E-commerce es un fen?meno que tom? gran impulso durante la pandemia COVID-19, ya que permiti? que las familias lograran adquirir bienes sin la necesidad de exponerse a contagiarse debido al m?nimo contacto f?sico que se requer?a por este canal. Asimismo, se viene presentando un fen?meno de cambios de h?bitos de los consumidores al preferir productos saludables org?nicos. El presente plan de negocio pretende determinar la viabilidad de crear un Marketplace para la venta y despacho de productos org?nicos y de primera necesidad en seis distritos de Lima Metropolitana: San Isidro, San Borja, Surquillo, Miraflores, Barranco y Santiago de Surco. Se desarroll? un an?lisis estrat?gico y se hizo investigaci?n de mercado con estudios cuantitativos. Adem?s se dise?aron los planes de marketing y comercial (describiendo estrategias de marca), un plan operativo (bas?ndonos en la atenci?n a tiempo y en la calidad de entrega cuidando de la huella de carbono), acompa?ado y soportado por un plan de Administracion y Recursos Humanos, para que finalmente concluyamos que el plan de negocio es econ?mica y financieramente viable y rentable para los accionistas
Predictions of SUSY Masses in the Minimal SUSY GUT
The MSSM distinguishes itself from other GUT's by a successful prediction of
many unrelated phenomena with a minimum number of parameters. Among them: a)
Unification of the couplings constants; b)Unification of the masses; c) Proton
decay; d) Electroweak symmetry breaking. A combined fit of the free parameters
in the MSSM to these low energy constraints shows that the MSSM model can
satisfy these constraints simultaneously. From the fitted parameters the masses
of the as yet unobserved superpartners of the SM particles are predicted. The
2nd order QCD coupling constant is required to be between 0.108 and 0.132. It
is shown that a top mass of GeV, as suggested recently by the CDF
Collaboration, constrains the mixing angle between the Higgs doublets in the
MSSM to: 1.2<\tb<5.5 at the 90% C.L.. The most probable value corresponds to
\tb = 1.56, which leads to a stop mass below the top mass. In this case the
stop production in collisions would contribute to the top signature.
This could be an explanation for the large effective cross section
observed by CDF.Comment: latex + eps fig IEKP-KA/94-0
In utero exposure to low doses of environmental pollutants disrupts fetal ovarian development in sheep
Epidemiological studies of the impact of environmental chemicals on reproductive health demonstrate consequences of exposure but establishing causative links requires animal models using ‘real life’ in utero exposures. We aimed to determine whether prolonged, low-dose, exposure of pregnant sheep to a mixture of environmental chemicals affects fetal ovarian development. Exposure of treated ewes (n = 7) to pollutants was maximized by surface application of processed sewage sludge to pasture. Control ewes (n = 10) were reared on pasture treated with inorganic fertilizer. Ovaries and blood were collected from fetuses (n = 15 control and n = 8 treated) on Day 110 of gestation for investigation of fetal endocrinology, ovarian follicle/oocyte numbers and ovarian proteome. Treated fetuses were 14% lighter than controls but fetal ovary weights were unchanged. Prolactin (48% lower) was the only measured hormone significantly affected by treatment. Treatment reduced numbers of growth differentiation factor (GDF9) and induced myeloid leukaemia cell differentiation protein (MCL1) positive oocytes by 25–26% and increased pro-apoptotic BAX by 65% and 42% of protein spots in the treated ovarian proteome were differently expressed compared with controls. Nineteen spots were identified and included proteins involved in gene expression/transcription, protein synthesis, phosphorylation and receptor activity. Fetal exposure to environmental chemicals, via the mother, significantly perturbs fetal ovarian development. If such effects are replicated in humans, premature menopause could be an outcome
Profiling Early Lung Immune Responses in the Mouse Model of Tuberculosis
Tuberculosis (TB) is caused by the intracellular bacteria Mycobacterium tuberculosis, and kills more than 1.5 million people every year worldwide. Immunity to TB is associated with the accumulation of IFNγ-producing T helper cell type 1 (Th1) in the lungs, activation of M.tuberculosis-infected macrophages and control of bacterial growth. However, very little is known regarding the early immune responses that mediate accumulation of activated Th1 cells in the M.tuberculosis-infected lungs. To define the induction of early immune mediators in the M.tuberculosis-infected lung, we performed mRNA profiling studies and characterized immune cells in M.tuberculosis-infected lungs at early stages of infection in the mouse model. Our data show that induction of mRNAs involved in the recognition of pathogens, expression of inflammatory cytokines, activation of APCs and generation of Th1 responses occurs between day 15 and day 21 post infection. The induction of these mRNAs coincides with cellular accumulation of Th1 cells and activation of myeloid cells in M.tuberculosis-infected lungs. Strikingly, we show the induction of mRNAs associated with Gr1+ cells, namely neutrophils and inflammatory monocytes, takes place on day 12 and coincides with cellular accumulation of Gr1+ cells in M.tuberculosis-infected lungs. Interestingly, in vivo depletion of Gr1+ neutrophils between days 10–15 results in decreased accumulation of Th1 cells on day 21 in M.tuberculosis-infected lungs without impacting overall protective outcomes. These data suggest that the recruitment of Gr1+ neutrophils is an early event that leads to production of chemokines that regulate the accumulation of Th1 cells in the M.tuberculosis-infected lungs
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