Qualitative results of a benchmarking process in logistics areas between companies operating in Argentina are presented. A description of the main logistics processes reengineered by these companies is done and some inferences are taken from the study. The companies are finally analyzed according to another benchmarking process generated in Michigan State University, which leads to a discussion on how companies can be characterized as world class in emerging countries.

ResumenEste artículo es un caso de estudio sobre el modelado de la estructura de toma de decisiones de la cadena de suministro de una embotelladora en México. Al modelar las cadenas de suministro de esta manera, es posible identificar las políticas gerenciales y los flujos de informacion que introducen y amplifican distorsiones en la demanda. En la segunda parte de este artículo, utilizamos dos escenarios para analizar posibles modificaciones en las políticas de dirección. Este trabajo ilustra no sólo una innovadora forma de estudiar el efecto látigo, o una forma distinta de modelar las cadenas de suministro usando los principios de dinámica de sistemas, sino que también establece una relación entre la estructura de información, las políticas de los gerentes y las distorsiones en la cadena de suministro.Descriptores: Dinámica de sistemas, cadenas de suministro, caso de estudio, efecto látigo. Abstract This is a case study about the mod el ling of a sup ply chain de ci sion struc ture of a Mex i can bot tling com pany. We find that by mod el ling the in for ma tion and de ci sion struc ture of sup ply chains, it is pos si ble to iden tify man a ge rial pol i cies and in for ma tion flows that dis tort and am plify mar ket de mand sig nals. In the sec ond part of the pa per we use two sce nar ios to ana lyse var i ous changes in pol i cies. This pa per il lus trate not only an in no va tive form to study the Bull whip Ef fect nor only a dif fer ent way to model sup ply chains us ing Sys tem Dy nam ics, but also it es tab lishes a re la tion ship be tween in for ma tion struc tures, de ci sions rules, and de mand dis tor tion in sup ply chains. Key words: Sys tem dy nam ics, sup ply chain man age ment, case study, bull whip ef fect. Intro duc tionThe study of sup ply chain dy nam ics is about compa nies op er at ing man u fac tur ing sup ply chains of mul ti ple ech e lons sub ject to lim ited pro duc tion and dis tri bu tion ca pac i ties. At each ech e lon, opera tion man ag ers re ceive or ders from a down stream ech e lon and try to ful fil them by tak ing two de cisions: ship ping from avail able in ven tory, and ordering more prod ucts to the ech e lon up stream. Order pol i cies are based on ex pe ri ence, op erational strat egy and in for ma tion avail abil ity. Order ful fil ment is con strained by pro duc tion ca pac ity, trans por ta tion ca pac ity and in ven tory avail abil ity. Sup ply chain sys tems have mainly two time de lays: 1 Por razones de confidencialidad, los datos referidos en este artículo (a excepción de los públicos) han sido modificados. Por tanto, este modelo no refleja forzosamente la realidad del negocio en cuestión. Sin embargo, sentimos que esas modificaciones no afectan la validez científica de la investigación.

Giant cell arteritis (GCA), also known as temporal arteritis is the most common of the systemic vasculitides. It occurs in individuals older than 50 years of age and peaks in incidence in the seventh decade. The gold standard for diagnosis of GCA is temporal artery biopsy (TABx) which will show transmural inflammation, but a negative biopsy does not rule out the disease. We present a case of a 66-year-old male with a classic clinical presentation of temporal arteritis with a normal erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and negative bilateral temporal artery biopsies. He was discharged on prednisone. Ten days later, he unilaterally stopped his corticosteroid treatment leading to a recurrence of symptoms and conversion to seropositivity (ESR negative and CRP positive). The objective of this article is to point out that the diagnosis of temporal arteritis is clinical and is not discarded by a negative TABx. Patients with classic clinical manifestations of temporal arteritis but with a negative TABx should be treated aggressively.

Guillain-Barré syndrome after Pfizer and Astra-Zeneca vaccinations against COVID-19 has been previously reported in the literature. The objective of this study was to report the first case of Guillain-Barré following the COVID-19 vaccination with the Johnson & Johnson COVID-19 vaccine. We report the case of a 53-yearold female who presented to the Emergency Department complaining of bilateral lower extremity weakness, paresthesias, and gait difficulties 14 days after having received the Johnson & Johnson COVID-19 vaccination. MRI of the lumbar spine with and without contrast revealed enhancement of the cauda equina nerve roots suggestive of acute inflammatory demyelinating polyradiculoneuropathy. Cerebrospinal fluid (CSF) analysis reported mildly elevated protein low white blood cells (WBCs). Ganglioside (GM1 and GQ1b) antibodies were reported as negative. After intravenous immunoglobulin (IVIg), the patient had significant improvement in her weakness and paresthesia and was discharged home. The case was reported to the Centers for Disease Control and Prevention (CDC) Vaccine Adverse Event Reporting System. Guillain-Barré syndrome after COVID-19 immunization remains a rare complication. A clear mechanism of disease has not been clarified; however, it is believed that there could be some type of molecular mimicry between the spike glycoprotein produced with the help of the vaccines and proteins in the myelin sheath.