Comparison of the Efficiency of Traditional and Industrial Milk Production Units in Khuzestan Province

One of the most important measures, in order to increase animal products and reduce imports, is the industrialization of animal husbandry units, specially the dairy cattle. The condition of milk production would be improved by this industrialization, which is in the direction of increasing the efficiency of milk production units. The purpose of this study is calculate , the efficiency of the traditional and industrial milk production units of Khuzestan province in 2011. The method of research was causal comparative. Data envelope analysis, in both forms of constant and variable return to scale, was used to calculate the types of efficiency. The needed information of industrial and traditional cattle houses was gained using capitation and random sampling from 384 production units, respectively. According to the results, the rate of total efficiency among the milk producers of traditional and industrial milk production units of Khuzestan is significantly different. In addition, the size of cattle house, manger`s level of education and experience, having a secondary job, animal`s race, and the production method are factors affecting the efficiency of units

Dependence of the Martian radiation environment on atmospheric depth: Modeling and measurement

The energetic particle environment on the Martian surface is influenced by solar and heliospheric modulation and changes in the local atmospheric pressure (or column depth). The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory rover Curiosity on the surface of Mars has been measuring this effect for over four Earth years (about two Martian years). The anticorrelation between the recorded surface Galactic Cosmic Ray-induced dose rates and pressure changes has been investigated by Rafkin et al. (2014) and the long-term solar modulation has also been empirically analyzed and modeled by Guo et al. (2015). This paper employs the newly updated HZETRN2015 code to model the Martian atmospheric shielding effect on the accumulated dose rates and the change of this effect under different solar modulation and atmospheric conditions. The modeled results are compared with the most up-to-date (from 14 August 2012 to 29 June 2016) observations of the RAD instrument on the surface of Mars. Both model and measurements agree reasonably well and show the atmospheric shielding effect under weak solar modulation conditions and the decline of this effect as solar modulation becomes stronger. This result is important for better risk estimations of future human explorations to Mars under different heliospheric and Martian atmospheric conditions

A Deterministic Computational Procedure for Space Environment Electron Transport

A deterministic computational procedure for describing the transport of electrons in condensed media is formulated to simulate the effects and exposures from spectral distributions typical of electrons trapped in planetary magnetic fields. The primary purpose for developing the procedure is to provide a means of rapidly performing numerous repetitive transport calculations essential for electron radiation exposure assessments for complex space structures. The present code utilizes well-established theoretical representations to describe the relevant interactions and transport processes. A combined mean free path and average trajectory approach is used in the transport formalism. For typical space environment spectra, several favorable comparisons with Monte Carlo calculations are made which have indicated that accuracy is not compromised at the expense of the computational speed

A Deterministic Transport Code for Space Environment Electrons

A deterministic computational procedure has been developed to describe transport of space environment electrons in various shield media. This code is an upgrade and extension of an earlier electron code. Whereas the former code was formulated on the basis of parametric functions derived from limited laboratory data, the present code utilizes well established theoretical representations to describe the relevant interactions and transport processes. The shield material specification has been made more general, as have the pertinent cross sections. A combined mean free path and average trajectory approach has been used in the transport formalism. Comparisons with Monte Carlo calculations are presented

Black Hole solutions in Einstein-Maxwell-Yang-Mills-Gauss-Bonnet Theory

We consider Maxwell and Yang-Mills (YM) fields together, interacting through gravity both in Einstein and Gauss-Bonnet (GB) theories. For this purpose we choose two different sets of Maxwell and metric ansaetze. In our first ansatz, asymptotically for $r\to 0$ (and $N>4$) the Maxwell field dominants over the YM field. In the other asymptotic region, $r\to \infty$, however, the YM field becomes dominant. For N=3 and N=4, where the GB term is absent, we recover the well-known Ba\U{f1}ados-Teitelboim-Zanelli (BTZ) and Reissner-Nordstr\U{f6}m (RN) metrics, respectively. The second ansatz corresponds to the case of constant radius function for $S^{N-2}$ part in the metric. This leads to the Bertotti-Robinson (BR) type solutions in the underlying theory.Comment: 20 pages, 5 figures, to be published in JCA

Issues In Space Radiation Protection: Galactic Cosmic Rays

When shielding from cosmic heavy ions, one is faced with limited knowledge about the physical properties and biological responses of these radiations. Herein, the current health is discussed in terms of conventional protection practice and a test biological response model. The impact of biological response on optimum materials selection for cosmic ray shielding is presented in terms of the transmission characteristics of the shield material. Although liquid hydrogen is an optimum shield material, evaluation of the effectiveness of polymeric structural materials must await improvement in our knowledge of both the biological response and the nuclear processes

Threshold meson production and cosmic ray transport

An interesting accident of nature is that the peak of the cosmic ray spectrum, for both protons and heavier nuclei, occurs near the pion production threshold. The Boltzmann transport equation contains a term which is the cosmic ray flux multiplied by the cross section. Therefore when considering pion and kaon production from proton-proton reactions, small cross sections at low energy can be as important as larger cross sections at higher energy. This is also true for subthreshold kaon production in nuclear collisions, but not for subthreshold pion production.Comment: 9 pages, 1 figur

Nephroprotective activity of naringin against chemical-induced toxicity and renal ischemia/reperfusion injury: A review

Objective: The kidney is well-known as the vital organ which is responsible for maintaining body homeostasis and secretion of toxic metabolites. Renal injury is accompanied by oxidative stress which results in cellular apoptosis, lipid peroxidation, and reduction of antioxidant levels. Plant extracts and their phytoconstituents, owing to free radical scavenging properties, seem to be valuable against modern synthetic and chemical drugs. Naringin is a flavonoid present in citrus fruits with pharmacologic effects including antioxidant, anti-inflammatory, and antiapoptotic properties. This review summarizes the renoprotective effects of naringin and discusses mechanisms of its action against renal injury. Materials and Methods: For this paper, original subject-related articles published up to October 2020 have been reviewed in the databases, including PubMed, Scopus, and Web of Science, and Google Scholar. Results: Naringin increases antioxidant enzyme activity, and glutathione content, reduces lipid peroxidation and inhibits inflammatory cytokines. In the molecular investigation, naringin activates the Nrf-2 signaling, prevents apoptosis signaling, and inhibits the autophagy pathway. Besides, naringin could protect the kidney through modulating microRNA-10a in the kidney tissue in an acute kidney injury model. Conclusion: This review recommends that naringin can be considered a promising candidate to treat kidney dysfunction induced by oxidative stress in the future

Restoration of the Renin-Angiotensin System Balance Is a Part of the Effect of Fasting on Cardiovascular Rejuvenation: Role of Age and Fasting Models

Intermittent fasting (IF) is an intervention that can be beneficial for health span and mitigate the risk of developing age-related cardiovascular diseases; however, the involved mechanisms are not well understood. The present study investigated the effects of IF regimens on the plasma level of angiotensin II (Ang II), and the expression of Ang II receptors (AT1aR and AT2R) and angiotensin-converting enzyme 2 (ACE2) in the heart and aorta of male, 3-, 12-, and 24-month-old Wistar rats fed ad libitum (AL), fed ad libitum and fasted 1 day per week (FW), or fasted every other day (EOD) for 3 months. Aging was associated with high circulating levels of Ang II, high level of AT1aR protein expression in the heart and aorta, and low level of AT2R protein expression in the heart and aorta. Both FW and EOD decreased Ang II levels (p < 0.01, p < 0.001) and AT1aR protein expression in the heart (p < 0.01, p < 0.001) and aorta (p < 0.001) of old rats. Both FW and EOD increased the expression of AT2R protein in the heart (p < 0.05 and p < 0.001, respectively). However, only EOD increased the expression of AT2R protein (p < 0.05) in the aorta. In the old group, both the FW and EOD regimens induced a significant increase in the expression of ACE2 protein in the heart (p < 0.01, p < 0.001 vs. age-matched AL group, respectively). The results suggest that a part of the recovery effect of fasting on cardiovascular system in old rats is mediated through restoration of the balance of renin-angiotensin system. © Copyright 2020, Mary Ann Liebert, Inc., publishers