MEMORANDUM OPINION AND JUDGMENT ON APPEAL

INBODY, Chief Judge.

INTRODUCTION

Jacqueline Larsen, special administrator of the estate of and wife of Edward Lee Larsen (Edward), appeals the order of the district court for Douglas County granting Union Pacific Railroad Company's (UP) motion in limine and motion for summary judgment.

STATEMENT OF FACTS

Edward was employed by UP as a railroad conductor on a route from Council Bluffs to Sioux City, Iowa. On October 25, 2003, Edward went on duty at 11:45 p.m. to take a train on this route. Edward finished his shift at approximately 4 a.m. on October 26. Edward returned to duty at 6:15 p.m. that same day, at which time Edward and his partner created the next train by joining locomotives with two sets of railcars. Edward was driven in a contract vehicle to the yard office to retrieve the necessary documents to allow the train to be on the mainline track. Edward's partner indicated that at no time had Edward indicated that he was feeling ill or that anything was wrong, but after waiting 30 minutes for Edward to return, his partner tried to contact him numerous times. At 7:30 p.m., Edward was found on the ground in the yard office and medical dispatch was called. Edward was pronounced dead at a local hospital.

On October 26, 2005, Larsen brought an action in district court alleging that UP was negligent and in violation of the Federal Employers' Liability Act and Hours of Service Act by failing to provide Edward the necessary tools to safely perform his duties; requiring Edward to work beyond his physical capabilities; and failing to provide adequate time for rest and recovery. Larsen requested a judgment against UP for punitive and exemplary damages, attorney fees and costs, and any other relief deemed proper by the district court.

During the pendency of the proceedings, three separate depositions were taken of Dr. David Randall Pritza, Edward's cardiologist, the latter two of which were taken in response to affidavits submitted by Dr. Pritza. The affidavits of Dr. Pritza were drafted on February 16, 2007; May 6, 2008; and March 11, 2009. The first two affidavits were submitted at prior summary judgment proceedings held by the assigned district court judge, who later recused himself. We will further discuss the contents of the affidavits and depositions as necessary in the analysis below. In January 2008, UP filed a motion for summary judgment alleging that no genuine issue of material fact existed and a motion in limine to exclude the testimony of Dr. Pritza at trial. The two motions came before the district court in May 2009. UP submitted the affidavits of the UP manager of train operations, a UP engineer, and Dr. Kevin Crowe. The depositions of Dr. Pritza were offered and received into evidence without objection for purposes of the motion in limine. Larsen also attempted to submit a third affidavit of Dr. Pritza, but UP objected to the submission of the affidavit on the basis that the affidavit did not comply with notice requirements, lack of foundation, and speculation. The affidavit submitted to the court was not signed by Dr. Pritza. Several days later, a signed copy of the affidavit was filed with the district court and can be found in the transcript.

The district court took the issue of the affidavit, exhibit 18, in addition to both motions, under advisement and, on July 24, 2009, issued an order excluding the testimony of Dr. Pritza at trial, denying the admission of Dr. Pritza's third affidavit, granting UP's motion for summary judgment, and dismissing the case entirely. On July 31, Larsen filed a motion for a new trial, which we will treat as a motion to alter or amend, which was also denied by the district court. See Vesely v. National Travelers Life Co., 12 Neb.App. 622, 682 N.W.2d 713 (2004) (motion for new trial can be treated as motion to alter or amend following motion for summary judgment). Larsen has timely appealed to this court.

ASSIGNMENTS OF ERROR

Larsen assigns that the district court erred by failing to admit exhibit 18, the affidavit of Dr. Pritza; failing to accord her a second hearing on the motion for summary judgment in order to receive exhibit 18; not allowing Dr. Pritza to testify; and granting UP's motion for summary judgment. Larsen also assigns that the district court erred by failing to grant her motion for a new trial, but has failed to argue the assignment, and as such, we will not address this assignment of error. See In re Interest of Hope L. et al., 278 Neb. 869, 775 N.W.2d 384 (2009) (in order to be considered by appellate court, alleged error much be both specifically assigned and specifically argued in brief of party asserting error).

STANDARD OF REVIEW

In proceedings where the Nebraska rules of evidence apply, the admission of evidence is controlled by rule and not by judicial discretion, except where judicial discretion is a factor involved in assessing admissibility. Epp v. Lauby, 271 Neb. 640, 715 N.W.2d 501 (2006). A trial court's ruling in receiving or excluding an expert's testimony which is otherwise relevant will be reversed only when there has been an abuse of discretion. Id. An abuse of discretion occurs when a trial court's decision is based upon reasons that are untenable or unreasonable or if its action is clearly against justice or conscience, reason, and evidence. Id.

Summary judgment is proper when the pleadings and evidence admitted at the hearing disclose no genuine issue regarding any material fact or the ultimate inferences that may be drawn from those facts and that the moving party is entitled to judgment as a matter of law. In reviewing a summary judgment, we view the evidence in the light most favorable to the party against whom the judgment is granted and give such party the benefit of all reasonable inferences deducible from the evidence. Erickson v. U-Haul Internal, 274 Neb. 236, 738 N.W.2d 453 (2007).

ANALYSIS

District Court's Denial of Exhibit 18 and Second Hearing on UP's Motion for Summary Judgment.

Larsen first argues that the district court erred by refusing to admit Dr. Pritza's third affidavit, exhibit 18, submitted at the hearing on the motion for summary judgment and motion in limine. This hearing was held on May 15, 2009, during which time Larsen offered the unsigned affidavit of Dr. Pritza and requested 7 days to file the affidavit; UP objected to the submission of the unsigned affidavit on the basis of notice requirements, procedural issues, foundation, and speculation.

According to Neb. Rev. Stat. § 25-1241 (Reissue 2008), an affidavit is a "written declaration under oath, made without notice to the adverse party." Furthermore, Neb. Rev. Stat. § 25-1332 (Reissue 2008) requires that the adverse party must serve opposing affidavits prior to the date of the hearing. See, Medley v. Davis, 247 Neb. 611, 529 N.W.2d 58 (1995); Barelmann v. Fox, 239 Neb. 771, 478 N.W.2d 548 (1992). Thus, Larsen failed to comply with either § 25-1241 or § 25-1332, and the district court properly excluded the affidavit.

However, Larsen argues that the district court should have granted her a second hearing on the motion for summary judgment "if it determined it was necessary to allow it to receive [e]xhibit 18." Brief for appellant at 3. Essentially, Larsen argues that the district court should have afforded her an opportunity to cure the defect of the affidavit. Without affording Larsen such an opportunity, she claims that she was unfairly prejudiced.

Neb. Rev. Stat. § 25-1335 (Reissue 1995) does provide a safeguard against a possible premature grant of summary judgment. Medley v. Davis, supra; Wachtel v. Beer, 229 Neb. 392, 427 N.W.2d 56 (1988). In such an instance, the party opposing the summary judgment may by affidavit show a reasonable excuse or good cause why the party is presently unable to offer evidence essential to justify opposition to the motion for summary judgment. Id.

Larsen's contentions center on the following comment made by the district court regarding the submission of Dr. Pritza's unsigned affidavit: "THE COURT: I haven't even seen it. I suppose once it's produced why don't you produce a copy to counsel and if we need to have another hearing we can do that. I'll show that you object to it. I don't even know what it is yet."

At the hearing, Larsen did not request a continuance, but merely requested that she be given 7 days to file a properly drafted affidavit, which the district court took under advisement as indicated in its aforementioned comment. In her brief, Larsen directs us to an affidavit of her counsel which was attached to the unsigned affidavit of Dr. Pritza as evidence of good cause shown why she was unable to offer evidence essential to justify opposition to the motion for summary judgment. The problem with the affidavit of Larsen's counsel is that it was not mentioned at the hearing. Larsen did not offer the affidavit of counsel, nor was it received or taken under advisement by the district court. Therefore, we will not consider the affidavit of Larsen's counsel and find that Larsen did not show good cause for her failure to secure Dr. Pritza's signed affidavit prior to the hearing.

Under these circumstances, we cannot say that the district court abused its discretion by excluding Dr. Pritza's affidavit and by not granting a second hearing in order for Larsen to submit a properly signed affidavit. These two assignments of error are without merit.

Expert Testimony.

Larsen argues the district court erred in granting UP's motion in limine to exclude the testimony of Dr. Pritza at trial.

An expert's opinion is ordinarily admissible under Neb. Rev. Stat. § 27-702 (Reissue 2008) if the witness (1) qualifies as an expert, (2) has an opinion that will assist the trier of fact, (3) states his or her opinion, and (4) is prepared to disclose the basis of that opinion on cross-examination. Smith v. Colorado Organ Recovery Sys., 269 Neb. 578, 694 N.W.2d 610 (2005); Robb v. Robb, 268 Neb. 694, 687 N.W.2d 195 (2004). Under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L. Ed. 2d 469 (1993), and Schafersman v. Agland Coop, 262 Neb. 215, 631 N.W.2d 862 (2001), the trial court acts as a gatekeeper to ensure the evidentiary relevance and reliability of an expert's opinion. Epp v. Lauby, 271 Neb. 640, 715 N.W.2d 501 (2006).

From a careful review of the record, it is clear that neither party disputes Dr. Pritza's qualifications to testify as an expert in the area of cardiology and as Edward's treating physician; therefore, let us first address the testimony given by Dr. Pritza in more detail through a review of the contents of the various depositions and affidavits submitted. The first deposition taken of Dr. Pritza occurred on February 16, 2007. Dr. Pritza first treated Edward in 1998, who was then 47, for congestive heart failure. Edward was diagnosed with cardiomyopathy, a weakening of the heart muscle, which Dr. Pritza believed to be a result of a virus or alcoholism. At that time, Edward was placed on medical therapy to restrengthen the heart muscle and ordered to stop smoking and drinking alcohol.

Dr. Pritza found that Edward had several risk factors for the development of cardiovascular disease, such as smoking, diabetes, a family history of heart transplant, and high blood pressure. In 1999, Edward was hospitalized and had surgery on his heart to determine whether he had any blockages during which it was discovered that one of the arteries had a 95 to 99 percent blockage and a stent was placed in the artery. Shortly after the procedure, Edward was back to work full time and Dr. Pritza opined there was no reason why he should not have been employed in his position at that time.

Dr. Pritza continued to see Edward about every 6 months and testified that Edward was not following his recommendations and had been placed on medical therapy for diabetes. Dr. Pritza indicated that Edward had not been exercising but found that his stamina at work remained good. In February 2002, Dr. Pritza reported that Edward had been experiencing a shortness of breath and fluid retention, both symptoms of congestive heart failure. Edward was hospitalized and treated with intravenous diuretics.

In May 2003, approximately 5 months prior to Edward's death, Dr. Pritza indicated that Edward had been taking additional diuretics to ease the symptoms of the congestive heart failure due to his unsuccessful attempts to watch his salt and calorie intake. However, Dr. Pritza testified that Edward's blood pressure was low, he had quit smoking, and he had been taking his medications on a regular basis. Dr. Pritza testified that there was no reason why Edward should not work, only that he needed to change his dietary management. Dr. Pritza testified that he could not, with a reasonable degree of medical probability, opine the cause of Edward's death which occurred in October 2003, only that he could speculate what might have happened:

Dr. Pritza testified that at no time did he tell Edward that he should quit or cut back his employment because he was able to do the job. Dr. Pritza testified that he did not know in what capacity Edward was employed with the railroad or what his duties were, only that he had knowledge of the railroad generally from his own family involvement. Dr. Pritza further testified that it would be "pure speculation" for him to testify about what might have caused Edward's irregular heartbeat.

On March 3, 2008, Dr. Pritza submitted an affidavit to the court, in which he states,

In response to this affidavit, a second deposition of Dr. Pritza was taken on May 6, 2008. Dr. Pritza again testified about his history with Edward in the same fashion as indicated in the first deposition. Dr. Pritza testified that he did not restrict Edward's work at anytime because he felt Edward was able to complete those duties. Dr. Pritza testified that the February 2002 appointment is when he first diagnosed him with congestive heart failure, but he did not restrict Edward's work duties, and that later that year, Edward's health began to improve. Dr. Pritza testified that in May 2003, Edward's cardiomyopathy was stable and he was taking medications for diabetes, blood pressure, diuretics, and cholesterol. Dr. Pritza testified that he never told Edward he could not or should not work as a conductor at UP or that he should lighten his duties. Dr. Pritza stated, "Up through May 20th, last time I saw him in the office in 2003, I felt that it was safe for him to continue to work. There was nothing in his health condition that would have said a concern to me." Dr. Pritza testified that he did not know what, if anything, had occurred between May and October and could not comment about that timeframe. Dr. Pritza further stated:

On September 5, 2008, a second affidavit of Dr. Pritza was submitted to the court in which he sets forth the same testimony as set forth above in his first affidavit. Dr. Pritza further set forth that it was his opinion that "stress, increased physical labor, long hours and other job duties" of a conductor contributed to and were a cause of Edward's fatal arrhythmia, but not the cause of cardiomyopathy. Dr. Pritza further stated that no work restrictions were placed on Edward in May 2003, because it was safe for him to work at that time.

A third and final deposition of Dr. Pritza was then taken on March 11, 2009. Dr. Pritza testified that none of his testimony from the previous depositions had changed. Dr. Pritza testified that he had no knowledge of any particular change in Edward's duties after their last appointment in May 2003, and he reiterated again that he felt Edward could still work as he had previously done. Dr. Pritza testified that the arrhythmia Edward suffered could have occurred at anytime. When asked to give an opinion as to whether Edward's employment played any role in the development of his cardiomyopathy and cardiac artery disease, Dr. Pritza testified:

In its order excluding Dr. Pritza's testimony at trial and granting UP's motion for summary judgment, the district court found that Dr. Pritza's opinions were not supported by his testimony and were "inconsistent at best, calling for speculation and are speculative and unsupported by the evidence."

Larsen argues that any apparent contradictions in Dr. Pritza's causation opinions should have been addressed through cross-examination at trial and not through summary judgment.

A nonparty witness' changed testimony, even if made without reasonable explanation and in order to meet the exigencies of pending litigation is a factor to be considered by the jury when determining the weight and credibility to be given to the witness testimony. Ketteler v. Daniel, 251 Neb. 287, 556 N.W.2d 623 (1996). See, also, State v. Osborn, 241 Neb. 424, 490 N.W.2d 160 (1992); State v. Robertson, 223 Neb. 825, 394 N.W.2d 635 (1986).

Clearly in this case, Dr. Pritza's testimony has changed, and it has done so without a reasonable explanation and in order to meet the exigencies of pending litigation, i.e., the motion for summary judgment. This change in testimony results in a genuine issue of material fact regarding whether Edward's employment with UP was a cause of his death. Therefore, the testimony of Dr. Pritza at trial should not have been excluded, and we find that the district court abused its discretion by excluding the testimony.

Summary Judgment.

Larsen also argues that the district court erred in granting UP's motion for summary judgment. Reviewing the evidence offered at the hearing in a light most favorable to Larsen and giving Larsen the benefit of all reasonable inferences deducible from the evidence, we find that there is a genuine issue of material fact regarding causation, the district court erred in granting summary judgment, and the matter should have proceeded to trial. Therefore, we reverse the decision of the district court granting summary judgment in favor of UP and remand the matter back to the district court for further proceedings.

CONCLUSION

In sum, we find that the district court did not abuse its discretion in excluding Dr. Pritza's third affidavit, exhibit 18, and in not affording Larsen a second hearing to cure the defect in the affidavit. However, we find that the district court did abuse its discretion by excluding the testimony of Dr. Pritza at trial and granting UP's motion for summary judgment. Therefore, we reverse, and remand for further proceedings consistent with this opinion.

AFFIRMED IN PART, AND IN PART REVERSED AND REMANDED FOR FURTHER PROCEEDINGS.