<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0034-7426</journal-id>
<journal-title><![CDATA[Revista Colombiana de Matemáticas]]></journal-title>
<abbrev-journal-title><![CDATA[Rev.colomb.mat.]]></abbrev-journal-title>
<issn>0034-7426</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional de Colombia y Sociedad Colombiana de Matemáticas]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0034-74262007000300004</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Existence and uniqueness of a positive]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[PADRÓN]]></surname>
<given-names><![CDATA[VÍCTOR]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Normandale Community College Department of Mathematics ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>USA</country>
</aff>
<pub-date pub-type="pub">
<day>29</day>
<month>10</month>
<year>2007</year>
</pub-date>
<pub-date pub-type="epub">
<day>29</day>
<month>10</month>
<year>2007</year>
</pub-date>
<volume>41</volume>
<fpage>189</fpage>
<lpage>195</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0034-74262007000300004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0034-74262007000300004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0034-74262007000300004&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[We prove the existence and uniqueness of a positive solution to a logistic system of differential difference equations that arises as a population model for a single species which is composed of several habitats connected by linear migration rates. Our proof is based on the proof of a similar result for a reaction-advection-diffusion equation.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[En este artículo probamos la existencia y unicidad de una solución positiva a un sistema logístico de ecuaciones diferenciales y de diferencias finitas que surge como un modelo de la población de una especie localizada en un conjunto discreto de habitats interconectados por tasas lineales de migración. Nuestra prueba está basada en la prueba de un resultado similar para ecuaciones de reacción-advección-difusión.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Monotone matrices]]></kwd>
<kwd lng="en"><![CDATA[irreducible matrix]]></kwd>
<kwd lng="en"><![CDATA[maximum principle]]></kwd>
<kwd lng="en"><![CDATA[Matrices monótonas]]></kwd>
<kwd lng="en"><![CDATA[matriz irreducible]]></kwd>
<kwd lng="en"><![CDATA[principio máximo]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[   <font face="verdana" size="2">      <p><b><font size="4">    <center>Existence and uniqueness of a positive</center></font></b></p>      <center>V&Iacute;CTOR PADR&Oacute;N<sup>1</sup></center>    <br> <sup>1</sup> Department of Mathematics, Normandale Community College, USA. E-mail: <a href="mailto:victor.padron@normandale.edu"> victor.padron@normandale.edu </a></center>  <hr size=1>      <p><b>    <center>Abstract</center></b></p>      <p align="justify"> We prove the existence and uniqueness of a positive solution to a logistic system of differential difference equations that arises as a population model for a single species which is composed of several habitats connected by linear migration rates. Our proof is based on the proof of a similar result for a reaction-advection-diffusion equation. </p>      <p><b>Key words:</b> Monotone matrices, irreducible matrix, maximum principle.</p>  <hr size=1> <i>2000 Mathematics Subject Classification: Primary: 34A34. Secondary: 92D25.</i> <hr size=1>      <p><b>    ]]></body>
<body><![CDATA[<center>Resumen</center></b></p>      <p align="justify"> En este art&iacute;culo probamos la existencia y unicidad de una soluci&oacute;n positiva a un sistema log&iacute;stico de ecuaciones diferenciales y de diferencias finitas que surge como un modelo de la poblaci&oacute;n de una especie localizada en un conjunto discreto de habitats interconectados por tasas lineales de migraci&oacute;n. Nuestra prueba est&aacute; basada en la prueba de un resultado similar para ecuaciones de reacci&oacute;n-advecci&oacute;n-difusi&oacute;n. </p>      <p><b>Palabras clave:</b> Matrices mon&oacute;tonas, matriz irreducible, principio m&aacute;ximo.</p>  <hr size=1>      <p>Texto completo disponible en <a href="pdf/rcm/v41s1/v41s1a04.pdf">PDF</a></p>  <hr size=1>      <p><b><font size="3">References</font></b></p>      <!-- ref --><p> 1 J. ARINO, J. R. DAVIS, D. HARLEY, R. JORDAN, J. M. MILLER & P. VAN DEN DRIESSCHE, A multi-species model with spatial dynamics, <i>Mathematical Medicine and Biology</i> 22 (2005), 129-142. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000018&pid=S0034-7426200700030000400001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 2 R. S. CANTRELL & C. COSNER, <i>Spatial Ecology Via Reaction-diffusion Equations</i>, Wiley, Chichestewr West Sussex UK, 2003. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000019&pid=S0034-7426200700030000400002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 3 V. PADR&Oacute;N & M. C. TREVISAN, Effect of aggregating behavior on population recovery on a set of habitat islands, <i>Math. Biosc.</i> 165 (2000) 1, 63-78. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000020&pid=S0034-7426200700030000400003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 4 V. PADR&Oacute;N & M. C. TREVISAN, Environmentally induced dispersal under heterogeneous logistic growth, <i>Math. Biosc.</i> 199 (2006), 160-174. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000021&pid=S0034-7426200700030000400004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 5 H. SMITH, <i>Monotone Dynamical Systems: An Introduction to the Theory of Competitive and Cooperative Systems</i>, American Mathematical Society, SURV/41, 1995. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000022&pid=S0034-7426200700030000400005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 6 G. STOYAN, Maximum principles for monotone matrices, <i>Lin. Alg. Appl.</i> 78 (1986), 147-161. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000023&pid=S0034-7426200700030000400006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p> 7 P. F. VERHULST, Notice sur la loi que la population suit dans son accroissement, <i>Corr. Math. et Phys.</i> 10 (1838), 113-121. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000024&pid=S0034-7426200700030000400007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
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