4,848 research outputs found
Robustness of Entanglement as a Resource
The robustness of multipartite entanglement of systems undergoing decoherence
is of central importance to the area of quantum information. Its
characterization depends however on the measure used to quantify entanglement
and on how one partitions the system. Here we show that the unambiguous
assessment of the robustness of multipartite entanglement is obtained by
considering the loss of functionality in terms of two communication tasks,
namely the splitting of information between many parties and the teleportation
of states.Comment: 11 pages, 5 figure
Decoupling the effect of mutant amyloid precursor protein (APP) from the effect of plaque on axonal transport dynamics in the living mouse brain: A correlation MRI-microscopy study
The parent protein for amyloid plaques, amyloid precursor protein (APP), mediates cargo‐motor attachments for intracellular transport. Axonal transport is decreased and the distal location of accumulation is altered in transgenic mice expressing human APP with the Swedish and Indiana mutations (APPSwInd) linked to Familial Alzheimer’s Disease, as detected by time‐lapse magnetic resonance imaging (MRI) of transport in living mouse brains (Bearer et al. 2017). Transport is also altered in brains of Down syndrome mice with 3 copies of APP gene. Questions now become whether expression of mutated APP effects transport dynamics independent of plaque, and do plaques alone contribute to transport defects? To address these we used the Tet‐Off system to decouple expression of APPSwInd from presence of plaques, and then studied transport using our MRI technique in three experimental groups of transgenic mice in which the timing and duration of APPSwInd expression, and thereby plaque formation, was altered with doxycycline: Group A (+ plaques, + APPSwInd); Group B (+ plaques, no APPSwInd), and group C (no plaques, + APPSwInd). Manganese‐enhanced MRI (MEMRI) allows us to perform cell biological experiments in live animals with T1‐weighted MRI in a Bruker 11.7T scanner (Medina et al 2016). Time‐lapse MR images were captured before and after stereotactic injection of Mn2+ (3‐5nL) into CA3 of the hippocampus at successive time‐points. Images of multiple individuals were aligned and processed with our automated computational pipeline (Medina et al. 2017) and statistical parametric mapping (SPM) performed. After MRI brains were harvested for
histopathology or biochemistry. Results show that within group between time‐point have altered
transport locations as well as diminished transport in all groups compared to wildtype (p<0.05 FDR n=
36). Preliminary ANOVA between‐group comparisons both by SPM and by region of interest
measurements of images support the visual impression that APPSwInd expression alone may
compromise transport. Groups A and B displayed plaques, but not C, and Western blots showed
APPSwInd expressed 3.2‐fold over normal at sacrifice in Groups A and C but not B, with Aβ detected only
in Groups A and B, where phospho‐tau was also present in dystrophic neurites surrounding plaques.
Cholinergic neurons that project to hippocampus from the medial septal nucleus were decreased in
Group C (p=0.0006 by ANOVA, n=15). Isolated hippocampal vesicles contained Mn2+, as well as Trk (NGF
receptor), Rab 5 and 7 (associated with transport vesicles), suggesting a distinct vesicle population is
affected by these APP mutations. These surprising results implicate mutated APPSwInd in transport
defects, separable from the effect of plaque
Witnessing microtubule-based transport in the living brain: Impact of the cargomotor receptor, amyloid precursor protein, and Alzheimer’s plaques
Most amyloid precursor protein (APP)-based Alzheimer’s models overexpress mutant human APP
resulting in Abeta plaques. Yet the relative contribution of this elevated APP and the presence of
plaques to neurodegeneration remains a big question. APP’s role as a cargo-motor receptor for axonal
transport suggests that overexpression might lead to increased transport. Indeed we showed that
transport is increased in Down’s syndrome and decreased in APP knockout mice. Hence transport may
be elevated in APP overexpressors and lead to either beneficial or deleterious consequences. Here we
use high field microMRI with Mn2+, an MR contrast agent useful as a track-tracer, to pose this cell
biological quest
ion within the whole living brains of wildtype and Alzheimer’s model mice. Injection of
Mn2+ into the CA3 region of the hippocampus results in measurable transport over time. Application of
3D unbiased whole brain image analysis detects all circuitry emanating from the hippocampus. By
driving APP Swe/Ind transgene expression with a tetracycline-sensitive promoter, APPSwe/Ind
expression can be decoupled from the presence of plaques with doxycycline (doxy). Three groups of
mice were studied: group ‘A’ (no doxy, +plaques, +APP); group ‘B’ (doxy at 8 days before sacrifice,
+plaques, no APP), and group ‘C’ (doxy prior to conception, and stopped 8 days before sacrifice, no
plaques, +APP). Images were captured before and sequentionally after Mn2+ injection into CA
3 (1, 7, 25
hr). Images were aligned and analyzed by statistical parametric mapping to identify differential
accumulation within the hippocampal projections. Histopathology revealed well-developed plaques in A
and B, and Western blots showed human APP expressed five-fold over WT in in A and C. Our preliminary
results show increased transport in A and C, with APP Swe/Ind expression when compared with B,
where expression is suppressed. Cholinergic neurons in the medial septal nucleus were decreased as
determined by anti-ChAT staining in Group C (p=0.0006 by one-way ANOVA, n=15). In conclusion, the
effects of elevated APP expression are separable from consequences of plaque, and each may
Developing a Model for Slow Hypoxic Injury and Vascular Degeneration in Amyloid Burdened Brains
The breakdown of neurovascular systems may play a crucial role in the pathogenesis of Alzheimer’s
disease. However whether this breakdown initiates a degenerative mechanism or is the consequence of
some other deleterious process remains unknown. We examined hippocampal pathology in double
transgenic mice overexpressing a human mutant gene encoding the amyloid precursor protein
(APPSwe/Ind) using a combination of histochemistry and stereologic techniques. Expression of
APPSwe/Ind in these mice is driven by a tetracycline-sensitive promoter. Tetracycline transcriptional
activator (tTA), the second transgene, is driven in turn by a CAM KIIa promoter that is only active in
neurons. Thus this double transgenic construct allows us to control expression of APPSwe/Ind with
doxycycline. Utilizing this characteristic, we created three distinct experimental groups: A, display abeta
plaque pathology and express APPSwe/Ind at time of sacrifice; B, display abeta plaque pathology but do
not express APPSwe/Ind at time of sacrifice; and C, do not display abeta plaque pathology but do
express APPSwe/Ind at time of sacrifice. Stereologic investigation revealed decreased hippocampal
volume in groups A(n=5) and B(n=5) when compared to group C(n=5) and age-matched wildtype (n=9)
Uniformidade de aplicação de água em um sistema de irrigação por gotejamento com duas fitas por fileira de planta.
O objetivo da pesquisa foi avaliar a uniformidade de emissão de água em um sistema de irrigação localizada com duas linhas laterais por fileira de planta. Os procedimentos experimentais foram conduzidos na propriedade hidroagrícola Fazenda Vale do Sol no município de Jequié-Bahia, no período de Março a Junho de 2011. A área experimental de 0,18ha era irrigada por sistema de irrigação localizada por gotejamento composto de duas linhas laterais por fileira de planta com gotejadores autocompensantes, de vazão 1,6 L.h-1 e pressão de 196 kPa. Foi aplicada a metodologia de Keller e Kermelli (1975) considerando três situações: as vazões da linha lateral a direita da fileira de planta, as vazões da linha lateral a esquerda da fileira de planta e a média das vazões entre estas posições. Os coeficientes de uniformidade em sua maioria, apresentaram valores classificados como excelentes sendo o valor médio entre todos de 90,15%; 93,10% e 94,13% para as situações a direita, esquerda e entre a média destas posições respectivamente
Inclusão do óleo essencial de alfavaca-cravo (Ocimum gratissimum) na dieta do tambaqui (Colossoma macropomum) para controle de monogenóides.
O objetivo deste estudo foi avaliar o emprego do óleo essencial de alfavaca-cravo na dieta do tambaqui para o controle de helmintos monogenóides.Resumo 0234
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