...PubMed Abstract: Retroviral capsid proteins are conserved structurally but assemble into different morphologies. The mature human immunodeficiency virus-1 (HIV-1) capsid is best described by a 'fullerene cone' model, in which hexamers of the capsid protein are linked to form a hexagonal surface lattice that is closed by incorporating 12 capsid-protein pentamers. HIV-1 capsid protein contains an amino-terminal domain (NTD) comprising seven α-helices and a β-hairpin, a carboxy-terminal domain (CTD) comprising four α-helices, and a flexible linker with a 310-helix connecting the two structural domains. Structures of the capsid-protein assembly units have been determined by X-ray crystallography; however, structural information regarding the assembled capsid and the contacts between the assembly units is incomplete. Here we report the cryo-electron microscopy structure of a tubular HIV-1 capsid-protein assembly at 8 Å resolution and the three-dimensional structure of a native HIV-1 core by cryo-electron tomography. The structure of the tubular assembly shows, at the three-fold interface, a three-helix bundle with critical hydrophobic interactions. Mutagenesis studies confirm that hydrophobic residues in the centre of the three-helix bundle are crucial for capsid assembly and stability, and for viral infectivity. The cryo-electron-microscopy structures enable modelling by large-scale molecular dynamics simulation, resulting in all-atom models for the hexamer-of-hexamer and pentamer-of-hexamer...
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...Challenges for DFT11 Current research12 Conclusions15 Introduction It has become an accepted fact that computational chemistry has become the partner to experimental chemistry. This is because computational experiments supplement real world experimental data very well. There are many systems in which there is no possible way of getting data about them, and so we must turn to computational methods. One example of this is looking at transition states, which in the real world may only exist for fractions of a second, however with the help of computational methods; we are able to investigate them easier, cheaper and quicker. There are many methods for computational chemistry experiments, however in this paper we will be focusing on how density functional theories (DFT) has impacted the chemistry community. The review will show how DFT started as an alternative to Schrodinger wave function methods, with simulated homogeneous electron gases, and moved on to be non-local, including other short and long range potentials and also combining empirical data to improve on the functionals. How DFT has its strengths and weaknesses and what is a challenge for DFT and a discussion on how to overcome these. We will then go on to look at more recent pieces of research and how they contribute to the wealth of information. Roots of DFT Density functional theory and computational chemistry in general has its roots starting with the work done by Erwin Schrödinger in 19261, which gave the equation...
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...insight commentary Virtual screening of chemical libraries Brian K. Shoichet Department of Pharmaceutical Chemistry, University of California, 600 16th Street, San Francisco, California 94143-2240, USA (e-mail: shoichet@cgl.ucsf.edu) Virtual screening uses computer-based methods to discover new ligands on the basis of biological structures. Although widely heralded in the 1970s and 1980s, the technique has since struggled to meet its initial promise, and drug discovery remains dominated by empirical screening. Recent successes in predicting new ligands and their receptor-bound structures, and better rates of ligand discovery compared to empirical screening, have re-ignited interest in virtual screening, which is now widely used in drug discovery, albeit on a more limited scale than empirical screening. T he dominant technique for the identification of new lead compounds in drug discovery is the physical screening of large libraries of chemicals against a biological target (high-throughput screening). An alternative approach, known as virtual screening, is to computationally screen large libraries of chemicals for compounds that complement targets of known structure, and experimentally test those that are predicted to bind well. Such receptor-based virtual screening faces several fundamental challenges, including sampling the various conformations of flexible molecules and calculating absolute binding energies in an aqueous environment. Nevertheless, the field has...
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...Solvation? To understand the process of solvation, the terms solute and solvent should be known. Solute can be described as a substance which dissolves in a solvent and solvent is the substance which dissolves a solute. When a solute starts to dissolves in a solvent a polarization is observed in the solute in response to the solvent polarization as mentioned in the figure. In addition, a reorientation is observed in the solvent molecule due to the charges in the solute as indicated in the figure. Hence, an interaction happens between the solute and solvent molecules and the solute molecules or ions are surrounded by the solvent molecules . This interaction and association can be referred as solvation.( http://www.chemistrydaily.com/chemistry/Solvation) Free Energy of Solvation The meaning of free energy solvation is, the change in free energy of a molecule leaving the gas phase and entering a condensed phase, and is denoted...
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...fasting; pilgrimage to Mecca; and alms Science: Science is the system of acquiring knowledge through use of the scientific method — that is, generating hypotheses and theories through observation and testing. Science is intimately linked with technology; technology is developed using scientific discoveries and science is reliant on technology to further its ideas. The goals of science are to learn more about the world and use this knowledge for the betterment of humankind, or for the destruction of mankind, whichever comes first. The term "science" originally referred to knowledge in general. However, it has been evolved to refer primarily to the natural sciences the study of the natural world and the fundamental laws of nature biology, chemistry, physics, etc. In its original usage, fields such as theology were called 'sciences', which seems strange to people only familiar with its contemporary usage. To make it even more confusing, science was originally derived from "natural philosophy". Science...
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...GEC 104 3 3 NATURAL WORLD at least 1 course from each box, 7-9 total credit hours 2 different course codes, at least 1 with a lab Life Sciences (3-4 credit hours) BIO 100* Biological Sciences for Educators (lab) BIO 101 Biology in Your World BIO 111* Understanding Bio Sys Through Inq. (lab only) BIO 121* General Biology I (lab) BMS 100 Concepts & Issues in the Life Sciences BMS 105 Concepts & Lab in the Life Sciences (lab) BMS 110* Intro to Biomedical Sciences (lab) BMS 111* Intro to Lab in Biomedical Sci (lab only) GLG 115 Life of the Past Physical Sciences (3-5 credit hours) AST 113 Modern Astronomy AST 114 Survey of Astronomy AST 115 Basic Astronomy (lab) CHM 107 Chemistry for the Citizen CHM 108* Chemistry for the Citizen Lab CHM 116* Fundamentals of Chemistry CHM 117* Fundamentals of Chemistry Lab GLG 110 Principles of Geology (lab) GLG 171 Environmental Geology GRY 135 Principles of Weather & Climate (lab) GRY 142 Introductory Physical Geography (lab) PHY 100 Survey of Physics (lab) PHY 101* Physics by Inquiry for Educators (lab) PHY 123* Introduction to Physics I (lab) PHY 203* Foundations of Physics I (lab) 4(3-3) 3(3-0) 1(0-2) 4(3-3) 4(4-0) 4(3-2) 4(3-2) 1(0-2) 3(3-0) 3(3-0) 4(4-0) 4(3-2) 3(3-0) 1(0-2) 4(4-0) 1(0-2) 4(3-2) 3(3-0) 4(3-2) 4(3-2) 4(3-2) 4(2-6) 4(3-2) 5(4-2) GEC 107 (no lab) GEC 106 (lab) HUMAN CULTURES 4 different course codes from these boxes Social & Behavioral Sciences (choose two, 6 credit hours) AGR 100 Food Security 3 ANT 125 Exploring...
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... Mathematics A 28 NB-36 Nighat Altaf 5 Molecular Physiology A 16 SCI 9 SCI 6 SCI 8 SCI 12 SCI 12 Tooba Mohtsham Asifa Kayani Saleha Mehboob Ayesha Aftab Gaitee Joshua 22-Oct-13 Basic Concepts of Environmental Sciences 24 5 A Data Handling and Atomic Spectroscopy 5 A 5 5 Electrical Instrumentation Human and Animal Behavior A A 9 9 12 7 Advanced Topics in Molecular BiologyA 7 7 Medical Biotechnology Plant Ecology A A 19 33 3 SCI 6 SCI R SCI 6 SCI 7 SCI 7 SCI 8 SCI8 Dr.Hooria Younas Dr. Amber Shehzadi Asifa Kayani Ayesha Roohi Saleha Mehboob Saima Mubeen Dr. Saleema Bashir 3 3 Cell Biology Molecular Biology A A 22 37 SCI 12 NB 15 Amna Younus Dr. Amber Shehzadi 1 Introduction to Inorganic Chemistry A 1 Basic Concept of Organic ChemistryA 1 Calculus I A 21 35 27 NB-9 SCI 12 NB-9 Rahila Tariq Ayesha Roohi Shumaila Waheed 23-Oct-13 Oxidation-Reduction Reactions & Chemical Energetics 7 A 4 Spectroscopic and Electro Analytical Techniques 5...
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...4506 Ind. Eng. Chem. Res. 2007, 46, 4506-4516 Assessment of Sustainability-Potential: Hierarchical Approach L. T. Fan,* Tengyan Zhang, Jiahong Liu, and John R. Schlup Department of Chemical Engineering, Kansas State UniVersity, Manhattan, Kansas 66506 Paul A. Seib Department of Grain Science and Industry, Kansas State UniVersity, Manhattan, Kansas 66506 Ferenc Friedler and Bontond Bertok Department of Computer Science, UniVersity of Pannonia, Veszprem, Egyetem u. 10, H-8200, Hungary ´ A hierarchical approach is proposed to estimate the sustainability-potential of a chemical process, based on any of the alternative synthetic routes. This novel notion of sustainability-potential is a generalization of the notion of profit-potential, the estimation of which renders it possible to screen out economically nonviable processes derived from the alternative synthetic routes at the earliest stage. At the outset of assessment, all the individual alternative synthetic routes are identified by the graph-theoretic method based on process graphs (P-graphs). Subsequently, the individual alternative synthetic routes are sequentially assessed in descending order of quantifiability, in terms of available energy (or exergy), dissipation, the possible profit, and the toxicity index, respectively. The efficacy of the approach is demonstrated for the manufacture of C2H3Cl. The approach can possibly be adapted for estimating the sustainability-potential to assess the alternative production...
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...Theoretical assessment of the mechanisms involved in the cholesterol biosynthesis from lanosterol A theoretical approach to describe the mechanisms of the isomerization and reduction of a double bond, involved in the lanosterol conversion to cholesterol was undertaken. Also, the 14α-demethylation and 4α-demethylation in this biosynthesis were studied, and some similarities were found between the two; however they are different and their mechanisms have not been explained yet. Ab initio calculations were performed in order to prove these mechanisms. Two different characteristics involved in this biosynthesis were explained, namely (i) the stability of each molecule during this reaction using total energy, hardness and dipole moment, and (ii) the explanation of proposed mechanisms [Steroid Biochemistry and Pharmacology, 1970, p. 57] of the two different reactions, using frontier orbitals and atomic charges. For this sequence of reactions, the hardness and dipole moment indicate the hydro-solubility of the molecules, which means that carrying properties change through cell membrane. It is possible to explain the reaction mechanisms using frontier molecular orbitals theory and the atomic charge. The localization of highest occupied molecular orbital, lowest unoccupied molecular orbital and the flow of atomic charge are in agreement with reported mechanisms [Steroids 8 (1966) 353; Medicinal Natural Products, 1997, p. 218; Biochemistry of Steroid Hormones, 1975. 1...
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...Introduction This paper will be discussing the information systems and software applications available for use in the accounting, marketing, and human resources departments that work within the constructs of an organization. It will discuss the selected applications, organizational departments, and how they relate to each other. In today’s business environment most if not all businesses rely heavily on computer technology, such as information systems and software applications. Many of these programs have made business faster, more reliable, and much more efficient than in the old days of everything being writen by hand written on paper by a person. Computer based business information systems are not the only form of information system, but keeping with the times computer information systems will be mainly discussed in this essay. A major player in software applications for human resources is PeopleSoft. The PeopleSoft application is designed to help with everyday production, find training tools, and locate documents. It also helps with business performance, and increased productivity due to its many features. The application has a vast number of features and updates including 200 industry specific updates. ("Oracle.com", 2011). Quick books, is a type of business accounting software. Quick books, is mostly used in the small business arena. It has a variety of accounting solutions such as, remote access, remote payroll and outsourcing, online banking and reconciliation...
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...Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications Computer Applications...
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...Answer the following questions very briefly (3-4 sentences) IN YOUR OWN WORDS. 1. What is crosstalk? How is it minimized in the case to the twisted pair of wire? My responses to this questions will essentially be generated from my own basic understanding of the reading materials that I found in the unit and this is the concept I had from the textbook that I have seen and researched about this topic that interpreted into my own words. so I have tried this two basic element clarification straight to the point which I understood: 1. Crosstalk refers to the picking up of electromagnetic signals from another adjacent wire by electromagnetic reason. 2. While a pair of wires is twisted together, the electromagnetic signals caused by the two wires eliminate each other as these are of opposing polarity. This serves to decrease the sensitivity of interruption to the nearby wires. 2. Why are two separate frequencies used for uplink and downlink transmission in case of satellite communication? my answer to this question as follows: Two part groups frequencies are used so that one cannot contend with the other and full duplex communication is possible. Also, the different idea is that the Power needed to transfer a signal is equal to the frequency of the signal. Plus more power demand more would be the power of the system. As there are constraints on the load that can be carried with the satellite, mainly downlinking frequency is lower than the up linking one. 3. What is the...
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...Sections Found Accounting Select CRN Subj Crse Sec Cmp Cred NR 21138 ACC 201 01 M 3.000 Title Fund of Financial Accounting Days Time TRU Instructor Date Location Attribute (MM/DD) 02/03-06/01 SBM 009 Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective Design Managmnt Major_Elective and Design Managmnt Minor_Elective and Economics Major_BAE_Elective and Eng'g Managmnt_Minor_Elective and MTH Major_Elective 09:00 Marian I. Mason am-09:50 (P) am NR 21139 ACC 201 02 M 3.000 Fund of Financial Accounting TRU Ronald D. 12:00 pm-12:50 Williams (P) pm 02/03-06/01 SBM 012 ...
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...Takako Hirokawa, Noah Finkelstein, and H. J. Lewandowski† Department of Physics, University of Colorado Boulder, Boulder, CO 80309 (Dated: March 4, 2014) In response to national calls to better align physics laboratory courses with the way physicists engage in research, we have developed an epistemology and expectations survey to assess how students perceive the nature of physics experiments in the contexts of laboratory courses and the professional research laboratory. The Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS) evaluates students’ shifts in epistemology and affect at the beginning and end of a semester. Also, at the end of the semester, the E-CLASS assesses students’ reflections on their course’s expectations for earning a good grade. By basing survey statements on widely embraced learning goals and common critiques of teaching labs, the E-CLASS serves as an assessment tool for lab courses across the undergraduate curriculum and as a tool for PER research. We present the development, evidence of validation, and initial formative assessment results from a sample that includes 45 classes at 20 institutions. We also discuss feedback from instructors and reflect on the challenges of large-scale online administration and distribution of results. I. INTRODUCTION Laboratory courses offer significant opportunities for engagement in the practices and core ideas of science. Laboratory course environments typically have apparatus, flexible...
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...Current Events in Business Research Proper research in business is vital to its success. This paper will discuss how well the article Computer Modelling and Simulation of Bakeries' Production Planning written and researched by Walid Barakat Hussein, Florian Mitzscherling Hecker, Thomas Martin Becker published in 2009. The article summarizes the efforts of bakeries selling ten different products using the ARENA computer simulation system to streamline production and prevent “bottle-necking”. The first step of effective business research is stating a clear purpose. The article starts out with an introduction that states businesses past troubles with understanding the “sequence of activities required to complete a process-whether fulfilling an order, producing a part, or servicing a customer,” (par 1) which is what the ARENA computer system is supposed to help with. Later in the introduction: “This research work presents a methodology of modeling and simulation of production system using Arena software simulation tool, in order to deal efficiently with the production procedures and processes, and propose an appropriate system structure that will operate according to given specifications,” (par 3). The introduction stated a very clear purpose, which helps those reading the article as well as following the first step of proper business research. The research process was thoroughly detailed and the design was thoroughly planned. In the method and case study section on the article...
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