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

A combined optimization–simulation approach for modified outside-in boarding under COVID-19 regulations including limited baggage compartment capacities

The timely handling of passengers is critical to efficient airport and airline operations. The pandemic requirements mandate adapted process designs and handling procedures to maintain and improve operational performance. Passenger activities in the confined aircraft cabin must be evaluated to potential virus transmission, and boarding procedures should be designed to minimize the negative impact on passengers and operations. In our approach, we generate an optimized seat allocation that considers passengers’ physical activities when they store their hand luggage items in the overhead compartment. We proposed a mixed-integer programming formulation including the concept of shedding rates to determine and minimize the risk of virus transmission by solving the NP-hard seat assignment problem. We are improving the already efficient outside-in boarding, where passengers in the window seat board first and passengers in the aisle seat board last, taking into account COVID-19 regulations and the limited capacity of overhead compartments. To demonstrate and evaluate the improvements achieved in aircraft boarding, a stochastic agent-based model is used in which three operational scenarios with seat occupancy of 50%, 66%, and 80% are implemented. With our optimization approach, the average boarding time and the transmission risk are significantly reduced already for the general case, i.e., when no specific boarding order is specified (random boarding). If the already efficient outside-in boarding is used as a reference, the boarding time can be reduced by more than 30% by applying our approach, while keeping the transmission risk at the lowest level

Extreme bendability of DNA double helix due to bending asymmetry

Experimental data of the DNA cyclization (J-factor) at short length scales, as a way to study the elastic behavior of tightly bent DNA, exceed the theoretical expectation based on the wormlike chain (WLC) model by several orders of magnitude. Here, we propose that asymmetric bending rigidity of the double helix in the groove direction can be responsible for extreme bendability of DNA at short length scales and it also facilitates DNA loop formation at these lengths. To account for the bending asymmetry, we consider the asymmetric elastic rod (AER) model which has been introduced and parametrized in an earlier study (B. Eslami-Mossallam and M. Ejtehadi, Phys. Rev. E 80, 011919 (2009)). Exploiting a coarse grained representation of DNA molecule at base pair (bp) level, and using the Monte Carlo simulation method in combination with the umbrella sampling technique, we calculate the loop formation probability of DNA in the AER model. We show that, for DNA molecule has a larger J-factor compared to the WLC model which is in excellent agreement with recent experimental data.Comment: 8 pages, 9 figure

Understanding Intention Toward Animal Welfare Between Iranian Stockperson

Although conventional livestock farming has been successful at production and cost-benefits rate however, besides these successes, modern livestock system, also, created ethical, social and environmental challenge. In other words, it is really unsuccessful at the issues of environmentally friendly production, animal health and animal welfare. In this situation, organic livestock has been introduced as an alternative for conventional livestock. Organic livestock is guided by a set of fundamental goals and ideas. Providing animal welfare can be related to some overall goals for organic. As such understanding how different actors perceive it is a precondition for the successful improvement of animal welfare. To our knowledge, no studies undertake to investigate stockmen’s intention toward animal welfare in Iran and MENA region. As such, the aim of this study is to investigate the intention of stockmen regarding importance and necessity of animal welfare at Sirjan County in Kerman province in the middle of Iran through a psychological perspective. Therefore, 100 industrial stockmen through simple random sampling were selected who, as we assume, will be the key stakeholders, and will contribute to the animal welfare in Iran. Data were analyzed using the SPSS. The results through a multiple regression revealed that attitude toward animal welfare, moral norm, control perceived behaviour and outcome expectations were predictor of stockmen’ intention toward animal welfare. The findings of this study provided preliminary data toward improvement of animal welfare between Iranian stockmen

Nota preliminare sulle indagini archeologiche presso la grotta “Mora di Cavorso”

Si presentano i dati relativi allo scavo archeologico eseguito per il recupero di reperti umani segnalati nel 2003 presso la grotta Mora Cavorso a Jenne (Rm). Si tratta di varie centiania di ossa umane, fauna e materiale archeologico datati al Neolitico antico e probabilmente relativi a una serie di sepolture intenzionali sconvolte in antico

Meta-Cognitive Strategies and Nursing Students’ Achievement

In the information era in which there is an increasing and rapid information change, education system needs to enable students to solve the problems of real world with their acquired skills. Metacognition is essential for successful learning and students can learn and use it to improve their performance. This paper was an attempt to investigate the reliability of meta-cognitive awareness inventory that is generated by Schraw and Dennison (1994) and its correlation with nursing students’ achievement in Iran. The design adopted for this study was a descriptive correlation design. To this end, 40 female university students majoring in nursing were selected as the sample. Pediatric nursing performance was measured using a test which included higher and lower order questions. The results indicated that (a) the questionnaire has acceptable internal consistency, with a Cronbach alpha coefficient of .74, (b) there was a strong, positive correlation between the two variables, r = .729, n = 40,

The macrostructure of milk lipids: the fat globules

The aim of this review article is to summarize the information available related to milk fat globules (MFGs) in order to highlight their contribution to the nutritional and technological characteristics of milk and dairy products. The macrostructure of milk lipids is composed of globules made up of triglycerides with different melting points, enveloped by a biological membrane from the mammary epithelial cell. In milks of different animal species, there are different sized MFGs, ranging from diameters of less than 0.2 μm to a maximum of 15 μm. The average diameter and the number of globules are affected by endogenous, physiological and exogenous factors. The size of the globules in turn affects the qualitative characteristics of milk and cheese. In addition, the average diameter of the globules and their surface that is exposed to the digestive system affect fat digestibility in different ways. Finally, the components of the milk fat globule membranes have been shown to take part in the secretion process of globules and to have a beneficial effect on human health. In conclusion, by acting on factors influencing the dimensions of the fat globules and by increasing the content of the milk membrane could help adapt milk production to specific consumer targets and improve milk nutritional properties