was the proximate cause of Jason’s infection. See Lamb, 1 F.3d at 1187 (citing Boeing Co. v. Shipman, 411 F.2d 365, 374-75 (5th Cir.1969) (en banc)). The only portion of Armour’s insufficient causation argument that merits discussion is the allegation that the statistical probabilities derived from the epidemiological studies, as analyzed by Dr. Robinson, were not scientifically valid and thus could not be used to determine the time or source of Jason’s infection. Upon careful review of Dr. Robinson’s testimony, there is no question that several of his statements, viewed in isolation, were statistically invalid and, as such, that the district court should not have admitted them. See Daubert v. Merrell Dow Pharmaceuticals, Inc., — U.S. -, -, 113 S.Ct. 2786, 2796, 125 L.Ed.2d 469 (1993) (<HOLDING>). In many other instances, however, Dr.
holding that the district court did not err in relying on hearsay evidence where the government offered reasons why its hearsay evidence had indicia of reliability and the court considered the reliability of the evidence in deciding the weight to give the hearsay evidence holding a proffer of testimony is required to preserve the issue of whether testimony was properly excluded by the trial judge and an appellate court will not consider error alleged in the exclusion of testimony unless the record on appeal shows fairly what the excluded testimony would have been holding that the trial court must screen experts evidence to ensure its reliability by conducting a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid  and properly can be applied to the facts in issue holding that the appellants failure to provide a transcript of the proceedings was fatal to its claims because without a record of the trial proceedings the appellate court can not sic properly resolve the underlying factual issues so as to conclude that the trial courts judgment is not supported by the evidence or by an alternative theory holding that an experts opinion must be based on facts in evidence or within his or her knowledge and that the admission of an experts opinion is reviewed for an abuse of discretion