64 research outputs found
Cooper-pair qubit and Cooper-pair electrometer in one device
An all-superconductor charge qubit enabling a radio-frequency readout of its
quantum state is described. The core element of the setup is a superconducting
loop which includes the single-Cooper-pair (Bloch) transistor. This circuit has
two functions: First, it operates as a charge qubit with magnetic control of
Josephson coupling and electrostatic control of the charge on the transistor
island. Secondly, it acts as the transducer of the rf electrometer, which
probes the qubit state by measuring the Josephson inductance of the transistor.
The evaluation of the basic parameters of this device shows its superiority
over the rf-SET-based qubit setup.Comment: 4 pages incl. 3 figues; the SQUID'2001 paper, to be published in
Physica
Effect of Morinda citrifolia (Noni)-Enriched Diet on Hepatic Heat Shock Protein and Lipid Metabolism-Related Genes in Heat Stressed Broiler Chickens
Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition [TN] at 24°C) and fed two diets (control vs. Noni) in a 2 × 2 factorial design. Feed intake and body weights were recorded, and blood and liver samples were collected at 2 h and 3 wk post-heat exposure. HS depressed feed intake, reduced body weight, and up-regulated the hepatic expression of heat shock protein HSP60, HSP70, HSP90, as well as key lipogenic proteins fatty acid synthase (FASN), acetyl co-A carboxylase alpha (ACCα), and ATP citrate lyase (ACLY). HS down-regulated the hepatic expression of lipoprotein lipase (LPL) and hepatic triacylglycerol lipase (LIPC), but up-regulated adipose triglyceride lipase (ATGL). Although it did not affect growth performance, Noni supplementation regulated the hepatic expression of lipogenic proteins in a time- and gene-specific manner. Prior to HS, Noni increased ACLY and FASN in acute and chronic experimental conditions, respectively. During acute HS, Noni increased ACCα, but reduced FASN and ACLY expression. Under chronic HS, Noni up-regulated ACCα and FASN but it down-regulated ACLY. In cells, HS exposure to 45°C for 2 hours down-regulated ACCα, FASN, and ACLY compared to TN exposure at 37°C. Treatment with quercetin, one bioactive ingredient in Noni, up-regulated the expression of ACCα, FASN, and ACLY under TN conditions, but it appeared to down-regulate ACCα and increase ACLY levels under HS exposure. In conclusion, our findings indicate that HS induces hepatic lipogenesis in chickens and this effect is probably mediated via HSPs. The modulation of hepatic heat-shock protein HSP expression suggests that Noni might be involved in modulating the stress response in chicken liver
Correlated transport of FQHE quasiparticles in a double-antidot system
We have calculated the linear conductance associated with tunneling of
individual quasiparticles of primary quantum Hall liquids with filling factors
through a system of two antidots in series. On-site Coulomb
interaction simulates the Fermi exclusion and makes the quasiparticle dynamics
similar to that of tunneling electrons. The liquid edges serve as the
quasiparticle reservoirs, and also create the dissipation mechanism for
tunneling between the antidots. In the regime of strong dissipation, the
conductance should exhibit resonant peaks of unusual form and a width
proportional to the quasiparticle interaction energy . In the weakly-damped
regime, the shape of the resonant conductance peaks reflects coherent tunnel
coupling of the antidots. The Luttinger-liquid singularity in the rates of
quasiparticle tunneling to/from the liquid edges manifests itself as an
additional weak resonant structure in the conductance curves.Comment: 9 pages including 5 figure
Coherent control of macroscopic quantum states in a single-Cooper-pair box
A small superconducting electrode (a single-Cooper-pair box) connected to a
reservoir via a Josephson junction constitutes an artificial two-level system,
in which two charge states that differ by 2e are coupled by tunneling of Cooper
pairs. Despite its macroscopic nature involving a large number of electrons,
the two-level system shows coherent superposition of the two charge states, and
has been suggested as a candidate for a qubit, i.e. a basic component of a
quantum computer. Here we report on time-domain observation of the coherent
quantum-state evolution in the two-level system by applying a short voltage
pulse that modifies the energies of the two levels nonadiabatically to control
the coherent evolution. The resulting state was probed by a tunneling current
through an additional probe junction. Our results demonstrate coherent
operation and measurement of a quantum state of a single two-level system, i.e.
a qubit, in a solid-state electronic device.Comment: 4 pages, 4 figures; to be published in Natur
Effect of Tyrosine on the Productivity of PC12 Cells by Measuring Extracellular ATP release
Given the challenge to “reverse-engineer the brain”, our group tried to address the problems of a lack of long term focus and attention span. Tyrosine was determined to aid in mental focus and brain productivity as it is a precursor to the neurotransmitter Dopamine. Given that Tyrosine is naturally occurring in the body, it is preferable to add to the body, whereas a substance like Adderall has negative effects, including increased heart rate that, over time, can cause cardiovascular damage. Drawing connections between in increase ATP and an increased ability to focus and perform under stress, extracellular ATP secretion of PC12 cells is measured using a luminometer. This research is novel and important as it attempts to find a way to increase the human brain’s ability to focus. Based on results, higher levels of tyrosine in the brain would lead to increase overall human cognitive function and productivit
Phytogenic Feed Additives Improve Broiler Feed Efficiency Via Modulation of Intermediary Lipid and Protein Metabolism-related Signaling Pathways
Diets enriched with phytogenic feed additives (PFA) such as AV/HGP/16 premix (AVHGP), Superliv concentrate premix (SCP), and bacteriostatic herbal growth promotor (BHGP) with essential oils have been shown to improve feed efficiency (FE) in broilers. This FE improvement was achieved via modulation of hypothalamic neuropeptides, which results despite feed intake reduction, in increased breast yield without changes in body weight compared to the control group. To gain further insights into the mode of action of these PFA, the present study aimed to determine the potential involvement of signaling pathways associated with lipid and protein metabolism. One day-old male Cobb 500 chicks were randomly assigned into 1 of 4 treatments, comprising 8 replicates per treatment in a completely randomized design. The dietary treatments included a basal diet (control) or 0.55 g/kg diet of AVHGP, SCP, or BHGP. The birds had ad libitum access to water and feed. On day 35, after blood sampling, the liver, abdominal adipose tissue (AT), and breast muscle samples were collected. The levels of phosphorylated mechanistic target of rapamycin (mTOR)Ser2481 as well as its levels of mRNA and those of its downstream mediator RPS6B1 were significantly upregulated in the muscle of the PFA-fed groups compared with the control group. In the liver, the phosphorylated levels of acetyl-CoA carboxylase alpha at Ser79, the rate-limiting enzyme in fat synthesis, was significantly induced in the PFA-fed groups compared with the control group, indicating a lower hepatic lipogenesis. The hepatic expression of hepatic triglyceride lipase (LIPC) and adipose triglyceride lipase (ATGL) was significantly upregulated in the AVHGP-fed group compared with the control group. These hepatic changes were accompanied by a significant downregulation of hepatic sterol regulatory element-binding protein cleavage activating protein in all the PFA groups and an upregulation of peroxisome proliferator-activated receptor alpha and gamma in the SCP-fed compared with the control group. In the AT, the mRNA abundances of ATGL and LIPC were significantly increased in both SCPand BHGP-fed birds compared with the control group. Together these data indicate that PFA improve FE via modulation of muscle mTOR pathway and hepatic lipolytic/lipogenic programs, thus, favoring muscle protein synthesis and lowering hepatic lipogenesis
Quantum blue reduces the severity of Woody Breast myopathy via modulation of oxygen homeostasis-related genes in broiler chickens
The incidence of woody breast (WB) is increasing on a global scale representing a significant welfare problem and economic burden to the poultry industry and for which there is no effective treatment due to its unknown etiology. In this study, using diffuse reflectance spectroscopy (DRS) coupled with iSTAT portable clinical analyzer, we provide evidence that the circulatory-and breast muscle-oxygen homeostasis is dysregulated (low oxygen and hemoglobin levels) in chickens with WB myopathy compared to healthy counterparts. Molecular analysis showed that blood hemoglobin subunit Mu (HBM), Zeta (HBZ), and hephaestin (HEPH) expression were significantly down regulated, however the expression of the subunit rho of hemoglobin beta (HBBR) was upregulated in chicken with WB compared to healthy counterparts. The breast muscle HBBR, HBE, HBZ, and hypoxia-inducible factor prolyl hydroxylase 2 (PHD2) mRNA abundances were significantly down regulated in WB compared to normal birds. The expression of HIF-1α at mRNA and protein levels was significantly induced in breasts of WB-affected compared to unaffected birds confirming a local hypoxic status. The phosphorylated levels of the upstream mediators AKT at Ser473 site, mTOR at Ser2481 site, and PI3K P85 at Tyr458 site, as well as their mRNA levels were significantly increased in breasts of WB-affected birds. In attempt to identify a nutritional strategy to reduce WB incidence, male broiler chicks were randomly distributed into 48 floor pens and subjected to six treatments: a nutrient adequate control group (PC), the PC supplemented with 0.3% myo-inositol, a negative control deficient in available P and Ca , the NC fed with quantum blue (QB) at 500, 1,000 or 2,000 FTU/kg of feed. Although QB-enriched diets did not affect growth performances (FCR and FE), it did reduce the severity of WB by 5% compared to the PC diet. This effect is mediated by reversing the expression profile of oxygen homeostasis-related genes; i.e. significant down regulation of HBBR and upregulation of HBM, HBZ, and HEPH in blood, as well as a significant upregulation of HBA1, HBBR, HBE, HBZ, and PHD2 in breast muscle compared to the positive control
Effect of standard and physiological cell culture temperatures on in vitro proliferation and differentiation of primary broiler chicken pectoralis major muscle satellite cells
Culture temperatures for broiler chicken cells are largely based on those optimized for mammalian species, although normal broiler body temperature is typically more than 3°C higher. The objective was to evaluate the effects of simulating broiler peripheral muscle temperature, 41°C, compared with standard temperature, 38°C, on the in vitro proliferation and differentiation of primary muscle-specific stem cells (satellite cells; SC) from the pectoralis major (PM) of broiler chickens. Primary SC cultures were isolated from the PM of 18-day-old Ross 708 × Yield Plus male broilers. SC were plated in triplicate, 1.8-cm2, gelatin-coated wells at 40,000 cells per well. Parallel plates were cultured at either 38°C or 41°C in separate incubators. At 48, 72, and 96 h post-plating, the culture wells were fixed and immunofluorescence-stained to determine the expression of the myogenic regulatory factors Pax7 and MyoD as well as evaluated for apoptosis using a TUNEL assay. After 168 h in culture, plates were immunofluorescence-stained to visualize myosin heavy chain and Pax7 expression and determine myotube characteristics and SC fusion. Population doubling times were not impacted by temperature (p ≥ 0.1148), but culturing broiler SC at 41°C for 96 h promoted a more rapid progression through myogenesis, while 38°C maintained primitive populations (p ≤ 0.0029). The proportion of apoptotic cells increased in primary SC cultured at 41°C (p ≤ 0.0273). Culturing at 41°C appeared to negatively impact fusion percentage (p < 0.0001) and tended to result in the formation of thinner myotubes (p = 0.061) without impacting the density of differentiated cells (p = 0.7551). These results indicate that culture temperature alters primary broiler PM SC myogenic kinetics and has important implications for future in vitro work as well as improving our understanding of how thermal manipulation can alter myogenesis patterns during broiler embryonic and post-hatch muscle growth
Quantum oscillations in two coupled charge qubits
Despite an apparent progress in implementing individual solid-state qubits,
there have been no experimental reports so far on multi-bit gates required for
building a real quantum computer. Here we report a new circuit comprising two
coupled charge qubits. Using a pulse technique, we coherently mix quantum
states and observe quantum oscillations whose spectrum reflects interaction
between the qubits. Our results demonstrate the feasibility of coupling of
multiple solid-state qubits and indicate the existence of entangled two-qubit
states.Comment: 4 pages, 4 figures, submitted to Natur
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