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le (4m59s)

2.2. Genes: from Mendel to molecular biology

The notion of gene emerged withthe works of Gregor Mendel. Mendel studied the inheritance on some traits like the shape of pea plant seeds,through generations. He stated the famous laws of inheritance which, by the way, were rediscovered 50 years later. The important thing here tounderline is that these concepts of inheritance of genes and so on were very abstract. No physical supports ofthese genes were clarified. So, it's something which appearedlater through molecular biology. We now know that genes are thoseregions of DNA which code the information used by the cell to produce proteins. And, this is what Francis Crick stated as the central dogma of molecular biology. One gene ...
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le (5m0s)

5.4. The UPGMA algorithm

We know how to fill an array with the values of the distances between sequences, pairs of sequences which are available in the file. This array of distances will be the input of our algorithm for reconstructing phylogenetic trees. The name of this algorithm israther complicated but the method itself is rather simple,too simple indeed. We will see that. The name standsfor Unweighted Pair Group Method with Arithmetic Mean, wewill understand these terms along the presentationof the algorithm. The algorithm starts withan array of distances. Let's take this very simpleexample, it implies seven species and here we have the values of thedistances between these different sequences associated with a species. As you ...
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le (5m11s)

1.5. Counting nucleotides

In this session, don't panic. We will design our first algorithm. This algorithm is forcounting nucleotides. The idea here is that as an input,you have a sequence of nucleotides, of bases, of letters, of characters which ends with a star symbol, here. And, you want to count the number of A,C, G and T, and then the frequencies. To write an algorithm in thispseudo code language, you need first to declare on which objector variables you will work. Here, we declare severalinteger variables. What does it mean integer variables? That is a variable, the value of which can be an integer: 1, 2, 3, minus 9 and so on. So, integer ...
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Label UNT Clip pédagogique

le (5m13s)

Remediation - Vecteurs position, vitesses et accélérations décrits en coordonnées cartésiennes et polaires - VIDEO 17-accélération en coordonnées polaires partie 2

... vecteur accélération non nulle.Cet élément de remédiation permet d'expliquer cette réponse.Etant donné que les positions, vitesses et accélérations sont décrits par des vecteurs,nous rappellerons quelques propriétés utiles sur la façon de se repérer dans...
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le (5m14s)

3.2. A simple algorithm for gene prediction

Based on the principle we statedin the last session, we will now write in pseudo code a firstalgorithm for locating genes on a bacterial genome. Remember first how this algorithm should work, we first need to find two consecutive stop triplets in the same phase, same phase meansthe number of letters between these two stop triplets might bea multiple of three so that this sequence here can be divided into triplets. This is called an open reading frame. Once we have an open reading framewe look for the start triplet which is situated leftmost onthe open reading frame and we declare, we make the hypothesis that thisis a coding ...
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le (5m17s)

5.1. The tree of life

Welcome to this fifth and last week of our course on genomes and algorithms that is the computer analysis of genetic information. During this week, we will firstsee what phylogenetic trees are and how we can reconstruct these trees from the available data. Then to conclude this week and this course, we will present an overview, a larger overview of bioinformatic algorithms and we will conclude on the application of bioinformatics at least in the microbial world. So first the tree of life, we have already seen that due to the ideas of Darwin, we know that species evolve and the evolution of these species canbe seen as a ...
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