Quantum Probes for Ohmic Environments at Thermal Equilibrium

It is often the case that the environment of a quantum system may be described as a bath of oscillators with Ohmic density of states. In turn, the precise characterization of these classes of environments is a crucial tool to engineer decoherence or to tailor quantum information protocols. Recently, the use of quantum probes in characterizing Ohmic environments at zero-temperature has been discussed, showing that a single qubit provides precise estimation of the cutoff frequency. On the other hand, thermal noise often spoil quantum probing schemes, and for this reason we here extend the analysis to complex system at thermal equilibrium. In particular, we discuss the interplay between thermal fluctuations and time evolution in determining the precision {attainable by} quantum probes. Our results show that the presence of thermal fluctuations degrades the precision for low values of the cutoff frequency, i.e. values of the order $\omega_c \lesssim T$ (in natural units). For larger values of $\omega_c$ decoherence is mostly due to the structure of environment, rather than thermal fluctuations, such that quantum probing by a single qubit is still an effective estimation procedure.Comment: Entropy, special issue on Open Quantum Systems (OQS) for quantum technologies (S. Lorenzo and M. G. Palma, Eds

Monitoring Microtubule Mechanical Vibrations via Optomechanical Coupling

The possible disruption of a microtubule during mitosis can control the duplication of a cancer cell. Cancer detection and treatment may be possible based on the detection and control of microtubule mechanical oscillations in cells through external fields (e.g. electromagnetic or ultrasound). However, little is known about the dynamic (high-frequency) mechanical properties of microtubules. Here we propose to control the vibrations of a doubly clamped microtubule by tip electrodes and to detect its motion via the optomechanical coupling between the vibrational modes of the microtubule and an optical cavity. In the presence of a red-detuned strong pump laser, this coupling leads to optomechanical induced transparency of an optical probe field, which can be detected with state-of the art technology. The center frequency and linewidth of the transparency peak give the resonance frequency and damping rate of the microtubule respectively, while the height of the peak reveals information about the microtubule-cavity field coupling. Our method should yield new knowledge about the physical properties of microtubules, which will enhance our capability to design physical cancer treatment protocols as alternatives to chemotherapeutic drugs

Quantum probes for the cutoff frequency of Ohmic environments

Quantum probing consists of suitably exploiting a simple, small, and controllable quantum system to characterize a larger and more complex system. Here, we address the estimation of the cutoff frequency of the Ohmic spectral density of a harmonic reservoir by quantum probes. To this aim, we address the use of single-qubit and two-qubit systems and different kinds of coupling with the bath of oscillators. We assess the estimation precision by the quantum Fisher information of the sole quantum probe as well as the corresponding quantum signal-to-noise ratio. We prove that, for most of the values of the Ohmicity parameter, a simple probe such as a single qubit is already optimal for the precise estimation of the cutoff frequency. Indeed for those values, upon considering a two-qubit probe either in a Bell or in separable state, we do not find improvement to the estimation precision. However, we also showed that there exist few conditions where employing two qubits in a Bell state interacting with a common bath is more suitable for precisely estimating the cutoff frequency.Comment: 8 pages, 5 figures, 1 tabl

Numerical Modeling of Bistun Rock Slope Behavior in Grouting Using Discrete Element Method

The discrete element method is an established method for considering discontinuous deformation behavior of joint systems. This paper provides a description of this algorithm used to model coupled hydraulic and mechanical effects of joints on rock mass behavior. The paper also describes Bistun rock slope stability analysis using empirical (SMR) and numerical (D.E.) methods. The behavior of the rock slope and rock blocks containing Bistun epigraph in grouting and groundwater flow has successfully simulated using UDEC (Universal Distinct Element Code) program. Finally, results have been presented and discussed on slope stability condition and grouting pressure

Serum levels of vitamins A and D, and zinc in children with acute diarrhea: A cross-sectional study

Background: Diarrhea is a leading cause of mortality and morbidity during the early life period especially in developing countries. Micronutrients deficiencies have been proposed either as a risk factor or a consequence of diarrhea. Association studies highlight the relation of vitamins and minerals' deficiencies with acute diarrhea. In this regard we aimed to evaluate the status of vitamins A and D, and zinc serum levels in children with acute diarrhea. Methods: In this cross sectional study performed in a referral teaching hospital, we measured and compared baseline vitamin A, 25-hydroxy vitamin D (25(OH)D), and zinc serum levels in 25 children admitted with acute diarrhea and 25 other children who were admitted for undergoing elective surgeries. Results: 25-(OH)D levels were significantly lower in the diarrhea group (p=0.03). We were unable to demonstrate a significant difference in the levels of vitamin A and zinc between the case and control groups (p= 0.14 and p=0.07, respectively). Conclusion: We observed lower serum 25(OH)D levels in children with acute diarrhea. Whether this finding indicates a premorbid risk factor or simply a consequence of diarrhea needs further studies. Regardless of the cause and effect relationship, supplementation with vitamin D in acute diarrhea remains as a plausible consideration

Effect of Different Levels of Lavandula Stoechas Essence on Production Performance and Egg Quality of Laying Hens

The objective of this study was to evaluate the effects of different levels of Lavander stoechas essence on performance and egg quality of laying hens for 8 weeks. This experiment was conducted with 160 Hy-Line (W36) laying hens (30 wks of age), randomly divided into 4 experimental groups, 5 replicates and 8 birds per each (2 cages for each replicate and 4 birds in each cage). Treatments were control (without Lavander essence), and levels of 200, 400, and 600 ppm Lavander essence. All hens were provided the layer diets (2870 kcal/kg ME and 15.5 % CP) ad- libitum and received 16 h of light/ 8 h of dark. Performance parameters including egg weight and egg production were recorded daily and feed intake, feed conversion ratio (grams of feed:grams of egg) and egg quality were measured weekly. The following characteristics were recorded for the individual eggs: weight, shape index, eggshell breaking strength, shell thickness, yolk color, and Haugh unit. Levels of 200 and 400 ppm of Lavander essence showed a significant increase in production percentage and egg weight but these parameters decreased at level of 600 ppm. Feed intake was highest for control, 200 and 400 ppm essence dietary levels but level of 600 ppm showed significant decrease. Addition of essence to the diet had no effect on FCR. Shape index and Haugh unit were not significantly affected by the treatments. Higher yolk color score was observed in treatments containing Lavander essence in comparison with control (p<0.05). Levels of 200 and 400 ppm essence increased significantly egg shell quality including thickness, weight and shell breaking strength. The results showed that the addition of essences of Lavender up to 400 ppm increased production performance and improved egg quality

Investigation of Blood Parameters and Ovarian Morphology of Laying Hens Feeding Lavandula Stoechas Essence

The objective of this study was to evaluate the effects of different levels of Lavander stoechas essence on blood parameters and ovarian morphology of laying hens for 8 weeks. This experiment was conducted with 160 Hy-Line (W36) laying hens (30 wks of age) randomly divided into 4 experimental groups, 5 replicates and 8 birds per each (2 cages for each replicate and 4 birds in each cage). Treatments were control (without Lavander essence), and levels of 200, 400, and 600 ppm Lavander essence. All hens were provided the layer diets (2870 kcal/kg ME and 15.5 % CP) ad- libitum and received 16 h of light/ 8 h of dark. At the end of experiment, 2 birds of each replicate were randomly selected and blood samples were collected by brachial venipuncture. Serum was harvested by centrifugation and frozen for future analysis of plasma lipid. After that birds were killed by cervical dislocation for morphological assessments of ovaries. The weights of the oviduct, ovary, and stroma were recorded. The stroma weight comprised the ovarian tissue remaining after the large yellow follicles (LYF) were counted and removed. The number of small yellow follicles (SYF) and postovulatory follicles (POF) was recorded. Blood triglycerides, glucose and HDL were not affected by the treatments but by adding Lavender essence to the diet, cholesterol and LDL concentration decreased significantly in comparison with control diet (p<0.05). In addition, the levels of Lavander essence had no effect on the relative weight of the ovary, oviduct, stroma and number of SYF and POF. However, the levels of 200 and 400 ppm of Lavender caused significant increase of number and weight of LYF. The results showed that the addition of essence of Lavender up to 400 ppm increased weight and numbers of LYF