17 Cal.4th 229 (1998)
THE PEOPLE, Plaintiff and Respondent,
v.
SCOTT ALDEN WHITSON, Defendant and Appellant.
Docket No. S057262.
Supreme Court of California.
January 15, 1998.
*233 COUNSEL
Richard L. Schwartzberg, under appointment by the Supreme Court, for Defendant and Appellant.
Daniel E. Lungren, Attorney General, George Williamson, Chief Assistant Attorney General, Gary W. Schons, Assistant Attorney General, Esteban Hernandez, Janelle Marie Boustany and Karl T. Terp, Deputy Attorneys General, for Plaintiff and Respondent.
Michael R. Capizzi, District Attorney (Orange), Devallis Rutledge, Deputy District Attorney, Kent S. Scheidegger and Charles L. Hobson as Amici Curiae on behalf of Plaintiff and Respondent.
OPINION
GEORGE, C.J.
In 1994, defendant Scott Alden Whitson was convicted of two counts of second degree murder, arising out of a collision in which the motor vehicle he was driving ran through a red light and crashed into another car at a speed estimated to be in excess of seventy-five miles per hour, killing the other driver as well as one of defendant's passengers. (Pen. Code, § 187, subd. (a).)[1] A divided Court of Appeal reversed the convictions, concluding that the trial court erred in admitting into evidence (1) defendant's pretrial statements to police officers, because the statements had been obtained in violation of Miranda v. Arizona (1966) 384 U.S. 436 [86 S.Ct. 1602, 16 L.Ed.2d 694, 10 A.L.R.3d 974] (Miranda), and (2) evidence of defendant's poor driving record.
As we explain, we conclude the Court of Appeal erred in finding a violation of defendant's rights under Miranda, and further conclude that even if evidence of defendant's poor driving record erroneously was admitted at his trial, any error in this regard was not prejudicial. Accordingly, we reverse the judgment of the Court of Appeal.

*234 I

A
The prosecution's evidence at trial established that the crime arose out of the following facts. Shortly before midnight on June 11, 1993, Costa Mesa Police Department Motorcycle Officer Angelo Morgan observed a man running "full sprint" through the parking lot adjacent to a commercial building complex. When the officer made eye contact with the individual, Derick Romo, Romo abruptly changed direction and ran toward a Volkswagon Cabriolet (VW). The VW was backed into a parking space in a remote section of the parking lot, far from a fast-food restaurant  the only business open in that area at that late hour. Morgan observed Romo enter the VW, which immediately sped away, tires squealing and headlights off. Defendant was driving.
The VW entered the flow of traffic and sped through a red light at the intersection of Harbor and MacArthur Boulevards. After Morgan heard the sound of tires skidding (which he believed to be vehicles locking their brakes to avoid colliding with the VW), he activated his emergency lights and siren and pursued the VW. Morgan estimated the VW's speed to be 80 to 85 miles per hour.
As Morgan pursued the VW, defendant turned on the VW's headlights, maneuvered around two vehicles, then turned off the headlights. Morgan lost sight of the car as it entered the City of Fountain Valley. He turned off his motorcycle's lights and siren, sent a radio broadcast stating he had discontinued his pursuit, and began looking for the VW. Within a few minutes, a man on the sidewalk signaled the officer to report a serious accident at the nearby intersection of Ward and Slater Streets  located about two miles from the commercial parking lot where Morgan initially had observed the VW.
At the intersection mentioned, Morgan observed the scene of a "major injury accident" crash between the VW and an Acura sedan. An accident reconstruction expert estimated that the VW had hit the Acura at a 90-degree angle at a speed of approximately 77 miles per hour. (Lay witnesses estimated the VW's speed at 40-70 miles per hour.) There was no evidence indicating that either driver had braked or attempted to take evasive action, or that either vehicle had a mechanical problem that might have contributed to the collision. A pedestrian believed the driver of the VW had adequate time in which to stop prior to the collision, and testified that the VW was at least one and one-half blocks from the intersection of Ward and Slater Streets when the traffic light changed to red.
*235 Janice Diehm, the driver of the Acura, was killed. She bled to death as a result of blunt force trauma to her head and torso, the impact of the collision having fractured her neck, ribs, and pelvis. One of defendant's passengers, Romo, also bled to death, due to lacerations of the cerebrum, aorta, liver, and spleen; he also had suffered a fractured skull.[2]
An emergency medical technician found a metal "window punch" in defendant's sock. The punch can be used to break into vehicles. There was no evidence that defendant was under the influence of drugs or alcohol at the time of the collision.
Defendant was charged by information with having committed two counts of murder, arising from the deaths of Janice Diehm and Derick Romo, but not charged with having committed any offenses stemming from the injuries sustained by Royola Richards or Zacharia Antolin.
Over defense objection (based on Miranda), the prosecution introduced incriminating statements made by defendant to police officers in the course of three interviews conducted on the days immediately following the collision. This evidence, which revealed inconsistencies in defendant's version of relevant events and indicated defendant was aware of the risk that his driving posed to others, is more fully summarized in the discussion that follows (post, pp. 237-240).
Over defense objection, the prosecution also introduced evidence pertaining to defendant's driving record, establishing that defendant (1) attended traffic school in September 1990, (2) was involved in a traffic accident in October 1990 (for which police officers determined he was at fault for failing to yield the right of way), (3) received a citation for driving at an excessive speed in November 1990, and (4) was cited for failing to obey a posted sign in February 1992.
In response to the prosecution's case, the defense sought to establish that defendant was guilty of vehicular manslaughter, not murder. Toward this end, the defense presented a number of witnesses to establish that defendant was an individual of exceedingly limited mental capabilities who had difficulty functioning in stressful conditions, and thus could not have harbored *236 the "conscious disregard for human life" necessary to support a verdict of second degree murder based upon a theory of implied malice. (See, generally, People v. Nieto Benitez (1992) 4 Cal.4th 91, 102-104 [13 Cal. Rptr.2d 864, 840 P.2d 969]; People v. Protopappas (1988) 201 Cal. App.3d 152, 168 [246 Cal. Rptr. 915].)
Defendant was described by a psychologist retained by the defense as being "borderline retarded," based upon defendant's consistently poor performance on intelligence tests, in which he scored below the fifth percentile. Because of his mental limitations, defendant had been enrolled in special education classes since the third grade. By the 12th grade, defendant had a 6th grade reading level, and his spelling and mathematics capabilities were below that. He suffered from an attention-deficit problem that made it difficult for him to focus and organize his thoughts. He made four attempts to pass the driver's test before obtaining his driver's license. The defense psychologist opined that defendant did not think rationally or consistently, although on cross-examination the psychologist acknowledged that defendant was not incapable of fabricating a story to the police when that would serve his purpose.
Defendant's stepfather testified that when he and his wife visited defendant at the hospital at approximately 4:10 a.m. on June 12, 1993, a nurse was sewing the laceration on defendant's forehead, and defendant was covered with blood, was drifting in and out of consciousness, and did not immediately recognize them.
Defendant did not testify.
The prosecution did not offer any evidence in rebuttal.
After hearing the evidence and deliberating, the jury returned a verdict finding defendant guilty of two counts of second degree murder.

B
At a pretrial hearing, defendant moved to suppress statements that he made to investigating police officers at the hospital on three separate occasions shortly after the collision, and also moved to suppress evidence of his poor driving record. With regard to the pretrial statements to the officers, defendant contended that at no time during those interviews did he knowingly, intelligently, and voluntarily waive his right to an attorney, and that therefore his statements were inadmissible under the principles set forth in Miranda. He also objected to the prosecution's intended introduction of *237 evidence of his poor driving record on the grounds that such evidence was irrelevant and, if relevant, was unduly prejudicial. (See Evid. Code, §§ 210, 352.)
In response to defendant's motion, the prosecutor called two witnesses to establish that defendant understood and validly waived his rights under Miranda. Defendant thereafter called three witnesses. The pretrial testimony of these five witnesses is summarized below.
The first prosecution witness, Tustin Police Officer Joseph Thornton, testified that on December 26, 1992, approximately six months prior to the occurrence of the collision in the present case, he responded to a request for police assistance (in connection with an alleged shoplifting incident) at a Mervyn's store located in the City of Tustin. When Thornton arrived at the Mervyn's security office, he encountered defendant and interviewed him. Prior to the interview, Thornton advised defendant of his rights under Miranda. Thornton testified that defendant did not appear confused by any of the questions posed to him during the officer's reading of the Miranda advisements, that defendant affirmatively responded that he understood each of his rights as they were read to him, and that defendant thereafter expressed his willingness to be interviewed by the police.[3]
The prosecution's second witness, Fountain Valley Police Officer Christopher Andrews, testified that he interviewed defendant at approximately 2:45 a.m. on June 12, 1993, about three hours after the VW driven by defendant collided with the Acura. Andrews conducted the interview in the emergency room of the University of California at Irvine Medical Center. Two other officers were present. Andrews testified that he advised defendant of his rights under Miranda, adding, "You understand you don't have to talk to me if you don't want to." Andrews did not request an "express" waiver of defendant's rights under Miranda, but instead asked whether defendant "understood" the rights. According to Andrews, defendant responded in a "normal" and "clear" voice that he understood his Miranda rights, after which Andrews began to question defendant. At no time did defendant request the presence of an attorney or indicate a desire not to speak with the officer.
Andrews testified that his interview with defendant lasted approximately 10 minutes, during which time defendant explained that just prior to the collision, he was driving "Derick [Romo]'s" vehicle with 2 friends, and that for some unknown reason they were chased by a Hispanic male, approximately 25 years of age, driving a red Cadillac. After the officer informed *238 defendant that he disbelieved defendant's story, defendant agreed to "cut out the bullshit." He thereafter told the officer that after parking the VW, Romo had left the vehicle to steal a car stereo. At some point, Romo returned, exclaiming, "Let's go. Let's get out of here." Defendant drove away, and someone on a motorcycle began to chase the vehicle. Defendant tried to elude the motorcycle, not knowing the driver was a police officer, and denied hearing the motorcycle's siren or seeing its red and blue lights. Defendant believed he was traveling approximately 60 miles per hour. He was unsure whether he had run any red lights, but admitted that he might have done so. He acknowledged that it was a "stupid" thing to try to steal the stereo. Andrews testified that during the interview, defendant did not say anything  or make any sounds  indicating he was in considerable pain. The interview was not tape-recorded.
The second interview also took place in the hospital, at approximately 7:50 p.m. on the same day, and was conducted by Fountain Valley Police Sergeant Larry Griswold, who was accompanied by Officer Andrews and a sheriff's deputy. According to Andrews, Griswold readvised defendant of his rights under Miranda and asked defendant whether he understood them. Defendant responded affirmatively and did not request an attorney or appear confused. During the interview, which lasted approximately 30 minutes, defendant reiterated the version of events he had given previously, adding that he was "[s]cared of the guy chasing me [on the motorcycle]." Defendant also acknowledged that approximately five seconds before the collision, he feared that the VW might crash. He again denied being aware that a law enforcement officer was driving the motorcycle, adding that he would have pulled over had he known. Defendant's answers were "normal, clear and loud," and he did not appear to be in any pain (except at one point when Griswold inadvertently bumped into defendant's bed).
Although Griswold and Andrews each possessed concealed tape recorders during the second interview of defendant, Griswold's malfunctioned and Andrews's tape contained many gaps  including a gap at the point when defendant was advised under Miranda. According to Andrews, the gaps were the result of his having hidden the tape recorder inside a pocket of his jeans; he testified that when he moved about the room, he inadvertently switched the "pause" button on and off.
The third interview took place at the hospital, at approximately 2:00 p.m., on June 21, 1993, nine days after the collision. Andrews, again accompanied by Griswold and a sheriff's deputy, readvised defendant of his Miranda rights and asked him whether he understood those rights. It is undisputed that defendant responded affirmatively. Andrews then asked, "OK, and *239 having your rights in mind do you want to answer a few questions for me?" It is undisputed that defendant again responded affirmatively.
During the interview, the officers asked defendant to reiterate his version of the relevant events. Defendant replied that Romo had left the VW, then returned to the vehicle "like Speedy Gonzalez," telling defendant, "Let's go, let's get out of here." Defendant drove through the intersection of Harbor and MacArthur Boulevards, believing the light to be green. Defendant acknowledged that a motorcycle chased him, but stated that during the pursuit he believed the driver of the motorcycle intended to shoot at the VW. When asked, "Did you realize it was kind of dangerous?," defendant replied, "Yes, I did." The following colloquy then ensued:
"Officer: What do you think made you keep going?
"Defendant: Being egged on.
"Officer: OK, I think so too. But you have to tell me about that 'cause I wasn't in the car.
"Defendant: Derick's going `Fuckin' go, fuckin' go man!'
"Officer: Just Derick? You knew how dangerous it was, but your friend is just making you keep going? ... Why? Tell me ... what was so strong about him about telling you to keep going?
"Defendant: Just the tone of his voice.
"Officer: How scared were you?
"Defendant: I shit my pants.
"Officer: Because....
"Defendant: ... afraid I'm going to kill someone or hurt someone else...."
When asked about the Cadillac that he had described in the first interview, defendant admitted there had been no Cadillac. Andrews testified defendant's answers were responsive, "clear and loud," and that except for one point in the interview, defendant did not appear to be in any considerable pain. The interview was tape-recorded by Griswold and Andrews.
The parties stipulated that (1) a blood sample taken from defendant at approximately 5:00 a.m., June 12, 1993, was analyzed and determined to be *240 negative for alcohol and drugs, and (2) defendant possessed a California driver's license at the time of the collision.
The prosecution contended it was entitled to introduce evidence pertaining to defendant's driving record. This evidence established that defendant (1) had attended traffic school in September 1990, (2) was involved in a traffic accident in October 1990, for which he was found by police officers to have been the party at fault for failing to yield the right of way, (3) received a citation for driving with excessive speed in November 1990, and (4) was cited for failing to obey a posted sign in February 1992. The prosecution urged that such evidence tended to establish defendant's "subjective awareness of the rules of the road and the dangers involved."
In response to the prosecution's arguments at the pretrial hearing, the defense introduced the testimony of defendant's stepfather, Ronald Wahl, who stated that he and defendant's mother arrived at the hospital at approximately 4:10 a.m. on June 12, 1993 (more than one hour after defendant's initial interview with Officer Andrews). Wahl testified that defendant was "drifting in and out" and took several minutes to recognize Wahl. At the time, a nurse was sewing the cut on defendant's forehead, and, according to Wahl, defendant "had blood all over him." Defendant's voice was neither loud nor clear, and his answers were nonresponsive. Wahl testified that his stepson told him he was in pain, and that "you could see that he was in pain."
The defense also introduced the testimony of Arnold Purisch, a clinical psychologist, who interviewed defendant in December 1993 and February 1994. He characterized defendant "as having anywhere between a mentally retarded to borderline intelligence."
Finally, the defense introduced the testimony of Gianna Scannell, a surgeon who examined defendant shortly after he arrived at the hospital following the collision. Scannell testified that defendant stated at that time that he did not remember the collision.
As noted, defendant sought to suppress his pretrial statements on the basis that he had not knowingly, intelligently, and voluntarily waived his rights under Miranda. He contended that during his initial interview with police officers after the collision, he was incapable of making a free or rational choice due to his injuries and because he was "functionally retarded." During subsequent interviews with the police, he was in pain and had been administered various prescription drugs. Defendant's position was that the "totality of the circumstances" (see In re Cameron (1968) 68 Cal.2d 487, 498 *241 [67 Cal. Rptr. 529, 439 P.2d 633]) weighed against the admissibility of his pretrial statements.
The trial court found that with regard to each of defendant's three pretrial statements, the prosecution had presented uncontradicted testimony that law enforcement officers had advised defendant of his rights under Miranda. Accordingly, the court found that defendant had been so advised. Turning to the question whether defendant had waived his Miranda rights, the court opined: "I think the law is such that you do not have to expressly ask for a waiver, if from all the facts, it appears that the defendant was aware of his Miranda rights and then started responding to questions where there's no coercion or duress." Finally, the trial court rejected defendant's argument that his low intelligence, the pain and trauma from the collision, and defendant's medicated condition at various points during his hospital stay combined to establish that his waiver of his Miranda rights was not knowing or intelligent. Rather, based upon the totality of the circumstances, the court found that "defendant was ... well in control of his faculties and responsive to the questions," and that the waiver was valid. Accordingly, the court ruled that the statements were admissible.
The trial court further found that the evidence of defendant's poor driving record was relevant (Evid. Code, § 210), not unduly prejudicial (Evid. Code, § 352), and therefore admissible.

C
At trial, Officer Andrews and Sergeant Griswold testified for the prosecution in a manner consistent with the version of the events offered by Andrews at the pretrial hearing. Officer Andrews testified that he recited the Miranda advisements to defendant during their first interview after the accident, and that defendant appeared to be alert and responsive to questions. Sergeant Griswold testified similarly regarding defendant's apparent comprehension of the Miranda advisements given to him during the second and third interviews, and defendant's willingness to answer the officers' questions. Griswold also recounted defendant's inconsistent versions of relevant events. The prosecution played the tapes of the second and third interviews, and the jury was provided transcripts of those tapes.
The prosecution also introduced the evidence of defendant's poor driving record that had been considered at the pretrial hearing.
The testimony of defendant's mother established his learning difficulties. His stepfather testified regarding defendant's semiconscious condition in the *242 hospital at approximately 4:10 a.m. on June 12, 1993, and (on cross-examination) regarding defendant's general reluctance to operate a motor vehicle at unsafe speeds. Defendant's high school special education teacher testified regarding defendant's "attention deficit syndrome" and poor academic performance in school. On cross-examination, the teacher stated his belief that defendant was "possibly borderline retarded." A psychologist testified that defendant experienced difficulty in organizing his thoughts and functioning under stressful situations but that defendant was not so mentally limited as to be unable to lie or fabricate a story.
The jury was instructed with a panoply of standard and special instructions, none of which are challenged here. On the second day of deliberations, the jury found defendant guilty of having committed the second degree murders of Janice Diehm and Derick Romo.

D
Following defendant's convictions, he appealed, contending that the trial court committed reversible error in admitting his pretrial statements to the police officers and in admitting evidence of his poor driving record.
The Court of Appeal majority agreed with defendant's position on the Miranda issue, holding that "a combination of factors convinces us this defendant did not waive his Miranda rights when he spoke to police.... The failure to get an express waiver in this case is one factor that convinces us defendant did not effectively waive his rights. [¶] The most important circumstance here is, of course, defendant's mental impairment and physical condition at the time of his interviews. The evidence on [this] point was essentially undisputed: Defendant is borderline retarded and incapable of making decisions in stressful situations.... At the time of each interview, this mentally impaired defendant, who was severely injured (and must have been in pain or drugged or both) was in a room alone with three other officers, where he was interrogated. We cannot conclude this defendant made a competent or rational `decision' to waive his rights under these stressful conditions.... [¶] Moreover, defendant was not criminally sophisticated.... [¶].... Defendant's statements provided important evidence of his state of mind (subjective appreciation of the risk) at the time of the crash. Reversal is required." (Original italics.)
With regard to the admission of evidence of defendant's poor driving record, the Court of Appeal reasoned: "Evidence defendant had previously been convicted of speeding and failing to yield or obey a posted sign, without anything additional showing similarity between the previous and *243 present offenses, did not tend to prove defendant knew his conduct endangered life. There was, for example, no evidence defendant had caused or threatened injury to anyone in the prior incidents. It cannot be rationally argued that everyone who speeds or violates a posted sign necessarily appreciates his conduct threatens human life under all circumstances. [¶] ... [¶] ... [N]othing here reflects intention, as opposed to inattention. Admission of this evidence was error and not harmless. The evidence suggested defendant was an unsafe or negligent driver, more culpable than one with a flawless driving record, and thus encouraged a leap from manslaughter to murder. With no evidence defendant's prior conduct was in any way similar to his present misconduct, such a leap was illogical, unwarranted, and undoubtedly prejudicial. (People v. Watson (1956) 46 Cal.2d 818, 836 [299 P.2d 243].)"
Writing in dissent, Justice Sonenshine observed that her colleagues had assumed the role of "an extraordinary trier of fact" in reversing the trial court's ruling that defendant validly had waived his rights under Miranda. Justice Sonenshine opined that it was for the trial court to determine whether defendant was unable to knowingly and intelligently waive his Miranda rights, adding: "Indeed, the evidence was conflicting as to Whitson's intellectual capabilities (he was smart enough to pass his driver's test and sophisticated enough to fabricate events to police). I would remand the matter to the trial court for it to reconcile the facts and decide whether Whitson was capable of rendering a knowing and intelligent waiver.
"I would also uphold the admission of Whitson's prior citations for speeding and failing to yield. Although the majority claims there is `no evidence defendant's prior conduct was in any way similar to his present misconduct,' the facts clearly reveal Whitson speeded and failed to yield before broadsiding Diehm's car. My colleagues also overlook the citations were not used to prove a common plan or identity, which require a high degree of similarity between the uncharged act and the charged offense, but to show Whitson's intent, which requires `[t]he least degree of similarity[.]' (People v. Ewoldt (1994) 7 Cal.4th 380, 402 [27 Cal. Rptr.2d 646, 867 P.2d 757].)
"As for the prejudicial effect of the evidence, there was little risk the jury would be inclined to punish Whitson for the driving violations, because he had already been cited for the infractions. (See People v. Ewoldt, supra, 7 Cal.4th at p. 405.) Moreover, the citations were not unduly remote or anywhere near as inflammatory as the testimony concerning the charged offenses. (Ibid.) Thus, there was no abuse of discretion in admitting evidence of Whitson's past driving record."

*244 II
(1a) In reviewing the judgment rendered by the Court of Appeal, we begin with the question whether the trial court erred in admitting evidence of defendant's pretrial statements made to police officers during the three interviews conducted after the collision. In analyzing this issue, we consider whether defendant voluntarily, knowingly, and intelligently waived his Miranda rights.[4]
(2) In Miranda, supra, 384 U.S. 436, the United States Supreme Court addressed the admissibility of statements obtained from an individual who is subjected to custodial police interrogation, and set forth certain procedures to assure that the individual is accorded his privilege under the Fifth Amendment to the federal Constitution not to be compelled to incriminate himself. The high court held: "[W]hen an individual is taken into custody or otherwise deprived of his freedom by the authorities in any significant way and is subjected to questioning, the privilege against self-incrimination is jeopardized. Procedural safeguards must be employed to protect the privilege, and unless other fully effective means are adopted to notify the person of his right of silence and to assure that the exercise of the right will be scrupulously honored, the following measures are required. He must be warned prior to any questioning that he has the right to remain silent, that anything he says can be used against him in a court of law, that he has the right to the presence of an attorney, and that if he cannot afford an attorney one will be appointed for him prior to any questioning if he so desires. Opportunity to exercise these rights must be afforded to him throughout the interrogation. (3) After such warnings have been given, and such opportunity afforded him, the individual may knowingly and intelligently waive these rights and agree to answer questions or make a statement. But unless and until such warnings and waiver are demonstrated by the prosecution at trial, no evidence obtained as a result of interrogation can be used against him." (384 U.S. at pp. 478-479 [86 S.Ct. at p. 1630], italics added, fn. omitted.) The high court in Miranda also held that "a valid waiver will not be presumed simply from the silence of the accused after warnings are given or *245 simply from the fact that a confession was in fact eventually obtained." (Id. at p. 475 [86 S.Ct. at p. 1628].)[5]
In explaining the basis for its decision, the court in Miranda held: "For those unaware of the [right to remain silent], the warning is needed simply to make them aware of it  the threshold requirement for an intelligent decision as to its exercise." (384 U.S. at p. 468 [86 S.Ct. at p. 1624].) Likewise, the warning that anything said can and will be used against the individual "is needed in order to make him aware not only of the [Fifth Amendment] privilege, but also of the consequences of forgoing it. It is only through an awareness of these consequences that there can be any assurance of real understanding and intelligent exercise of the privilege." (Id. at p. 469 [86 S.Ct. at p. 1625]; see also Colorado v. Spring (1987) 479 U.S. 564, 574 [107 S.Ct. 851, 857-858, 93 L.Ed.2d 954] ["The Miranda warnings ensure that a waiver of [the Fifth Amendment privilege against self-incrimination] is knowing and intelligent by requiring that the suspect be fully advised of this constitutional privilege, including the critical advice that whatever he chooses to say may be used as evidence against him."].)
(1b) In the present case, the prosecution presented evidence that the investigating police officers advised defendant of his Miranda rights at each of the three interviews. On each one of these occasions, defendant affirmatively told the interviewing officers that he understood those rights. Defendant did not appear to be under the influence of drugs, and his answers were responsive to the questions asked of him. The defense offered no evidence to the contrary. The sole issue before us regarding the admissibility of the statements made by defendant in these interviews is whether the trial court properly found that defendant validly waived his rights under Miranda. To resolve this question, we are guided by well-established case law.
In North Carolina v. Butler (1979) 441 U.S. 369 [99 S.Ct. 1755, 60 L.Ed.2d 286] (Butler), the United States Supreme Court addressed the question whether an express waiver of Miranda rights invariably is required in order for there to be a valid waiver. In Butler, the prosecution produced evidence of incriminating statements made by the defendant to Federal *246 Bureau of Investigation agents shortly after his arrest. After advising the defendant of his Miranda rights, and determining that he had an 11th grade education and was literate, the agents provided him with an "Advice of Rights" form, which he read. When asked whether he understood his rights, defendant replied that he did. He refused to sign the form, however, instead declaring, "I will talk to you but I am not signing any form." He thereafter made inculpatory statements. At no time did the defendant request the presence of counsel or attempt to terminate the agents' questioning. The trial court denied the defendant's motion to suppress the statements, and defendant ultimately was found guilty of the charges against him, but the North Carolina Supreme Court reversed the judgment on the ground that the defendant's waiver had not been "specifically made" after the Miranda warnings were given. (441 U.S. at pp. 369-372 [99 S.Ct. at pp. 1755-1757].)
(4) In reversing the judgment rendered by the North Carolina Supreme Court, the United States Supreme Court held in Butler: "An express written or oral statement of waiver of the right to remain silent or of the right to counsel is usually strong proof of the validity of that waiver, but it is not inevitably either necessary or sufficient to establish waiver. The question is not one of form, but rather whether the defendant in fact knowingly and voluntarily waived the rights delineated in the Miranda case. As was unequivocally said in Miranda, mere silence is not enough. That does not mean that the defendant's silence, coupled with an understanding of his rights and a course of conduct indicating waiver, may never support a conclusion that a defendant has waived his rights. The courts must presume that a defendant did not waive his rights; the prosecution's burden is great; but in at least some cases waiver can be clearly inferred from the actions and words of the person interrogated." (441 U.S. at p. 373 [99 S.Ct. at p. 1757], italics added, fn. omitted.) The high court in Butler added that "the question of waiver must be determined on `the particular facts and circumstances surrounding that case, including the background, experience, and conduct of the accused.'" (441 U.S. at pp. 374-375 [99 S.Ct. at p. 1758], quoting Johnson v. Zerbst (1938) 304 U.S. 458, 464 [58 S.Ct. 1019, 1023, 82 L.Ed. 1461, 146 A.L.R. 357].)
Shortly after its decision in Butler, the United States Supreme Court in Fare v. Michael C. (1979) 442 U.S. 707 [99 S.Ct. 2560, 61 L.Ed.2d 197] (Fare) again discussed the proper method of analyzing whether a valid waiver of Miranda rights has occurred. Fare involved a juvenile's request, made while undergoing custodial interrogation, to see his probation officer. In reversing a judgment rendered by this court (which had concluded that the defendant's request represented a per se invocation of his Fifth Amendment rights as set forth in Miranda), the court held: "[T]he determination whether *247 statements obtained during custodial interrogation are admissible against the accused is to be made upon an inquiry into the totality of the circumstances surrounding the interrogation, to ascertain whether the accused in fact knowingly and voluntarily decided to forgo his rights to remain silent and to have the assistance of counsel. [Citation.] [¶] This totality-of-the-circumstances approach is adequate to determine whether there has been a waiver.... The totality approach permits  indeed, it mandates  inquiry into all the circumstances surrounding the interrogation." (442 U.S. at pp. 724-725 [99 S.Ct. at pp. 2571-2572].) In following this approach, the court in Fare concluded there was "no indication that [the defendant] was of insufficient intelligence to understand the rights he was waiving, or what the consequences of that waiver would be." (442 U.S. at p. 726 [99 S.Ct. at p. 2572].)
(5) In Moran v. Burbine (1986) 475 U.S. 412 [106 S.Ct. 1135, 89 L.Ed.2d 410] (Moran), a case involving the defendant's execution of a written form acknowledging his right to the presence of an attorney and explicitly declining counsel before giving a statement to the police, the United States Supreme Court made clear that in order to determine whether a defendant voluntarily, knowingly, and intelligently has waived his Miranda rights, a court analyzing the question must consider two distinct components: "First, the relinquishment of the right must have been voluntary in the sense that it was the product of a free and deliberate choice rather than intimidation, coercion, or deception. Second, the waiver must have been made with a full awareness of both the nature of the right being abandoned and the consequences of the decision to abandon it. Only if the `totality of the circumstances surrounding the interrogation' reveals both an uncoerced choice and the requisite level of comprehension may a court properly conclude that the Miranda rights have been waived. [Citations.] [¶] ... [¶] ... Once it is determined that a suspect's decision not to rely on his rights was uncoerced, that he at all times knew he could stand mute and request a lawyer, and that he was aware of the State's intention to use his statements to secure a conviction, the analysis is complete and the waiver is valid as a matter of law." (475 U.S. at pp. 421, 422-423 [106 S.Ct. at p. 1141], fn. omitted.)
California law involving the implied waiver of a defendant's Miranda rights is in accord with the federal case authorities cited above. (See People v. Medina (1995) 11 Cal.4th 694, 752 [47 Cal. Rptr.2d 165, 906 P.2d 2]; see also People v. Sully (1991) 53 Cal.3d 1195, 1233 [283 Cal. Rptr. 144, 812 P.2d 163] [the defendant impliedly waived his Miranda rights when, after having been admonished of those rights, he responded affirmatively that he understood them and gave a tape-recorded statement to a detective]; People v. Davis (1981) 29 Cal.3d 814, 823-826 [176 Cal. Rptr. 521, 633 P.2d 186] *248 [implied waiver upheld where the defendant, a 16-year-old minor, was advised of his Miranda rights and responded that he understood them, and thereafter made statements to investigating police officers that led to his arrest]; People v. Johnson (1969) 70 Cal.2d 541, 558 [75 Cal. Rptr. 401, 450 P.2d 865, 43 A.L.R.3d 366], disapproved on another point in People v. DeVaughn (1977) 18 Cal.3d 889, 899, fn. 8 [135 Cal. Rptr. 786, 558 P.2d 872] ["Once the defendant has been informed of his [Miranda] rights, and indicates that he understands those rights, it would seem that his choosing to speak and not requesting a lawyer is sufficient evidence that he knows of his rights and chooses not to exercise them."]; People v. Nitschmann (1995) 35 Cal. App.4th 677, 680-683 [41 Cal. Rptr.2d 325] [upholding a finding of an implied waiver where no evidence was presented that the defendant was confused, misled, or reluctant to speak about the incident].)
As noted, in this case the trial court, after hearing the testimony of witnesses called by both parties, found that defendant voluntarily and knowingly had waived his Miranda rights. (6) In People v. Wash (1993) 6 Cal.4th 215, 235-236 [24 Cal. Rptr.2d 421, 861 P.2d 1107], we discussed the proper role of an appellate court in reviewing such a trial court ruling: "In considering a claim that a statement or confession is inadmissible because it was obtained in violation of a defendant's rights under Miranda v. Arizona, supra, 384 U.S. 436, we accept the trial court's resolution of disputed facts and inferences, and its evaluation of credibility, if supported by substantial evidence. (People v. Kelly (1990) 51 Cal.3d 931, 947 [275 Cal. Rptr. 160, 800 P.2d 516].) Although we independently determine whether, from the undisputed facts and those properly found by the trial court, the challenged statements were illegally obtained (ibid.), we `"give great weight to the considered conclusions" of a lower court that has previously reviewed the same evidence.' (People v. Jennings (1988) 46 Cal.3d 963, 979 [251 Cal. Rptr. 278, 760 P.2d 475], quoting Miller v. Fenton (1985) 474 U.S. 104, 112 [106 S.Ct. 445, 88 L.Ed.2d 405, 412]; accord, People v. Kelly, supra, 51 Cal.3d at p. 947.) Because the crimes in this case occurred after the addition of section 28, subdivision (d) to article I of the California Constitution, the voluntariness of defendant's waiver and confession must be established by a preponderance of the evidence. (People v. Markham (1989) 49 Cal.3d 63 [260 Cal. Rptr. 273, 775 P.2d 1042].)" (People v. Wash, supra, 6 Cal.4th 215, 235-236; see also Colorado v. Connelly (1986) 479 U.S. 157, 168 [107 S.Ct. 515, 522, 93 L.Ed.2d 473] ["[T]he State need prove waiver only by a preponderance of the evidence."].)
(1c) With these principles in mind, we consider the evidence and the trial court's ruling in this case. On the question of the voluntariness of the waiver, the record is devoid of any suggestion that the police resorted to *249 physical or psychological pressure to elicit statements from defendant. To the contrary, defendant's willingness to speak with the officers is readily apparent from his responses. He was not worn down by improper interrogation tactics, lengthy questioning, or trickery or deceit. (See generally, Moran, supra, 475 U.S. at pp. 421-424 [106 S.Ct. at pp. 1140-1142]; People v. Samayoa (1997) 15 Cal.4th 795, 828-831 [64 Cal. Rptr.2d 400, 938 P.2d 2] [defendant's comment to police that he did not want his statement tape-recorded held to be insufficient to support his motion that statement was involuntarily made].) He was not induced to provide his statements by improper promises. The voluntariness of the waiver therefore is clear. (See Colorado v. Connelly, supra, 479 U.S. at p. 164 [107 S.Ct. at p. 520] ["Absent police conduct causally related to the confession, there is simply no basis for concluding that any state actor has deprived a criminal defendant of due process of law." (Fn. omitted.)]; Fare, supra, 442 U.S. at pp. 726-727 [99 S.Ct. at pp. 2572-2573]; Moran, supra, 475 U.S. at pp. 421-422 [106 S.Ct. at pp. 1140-1141].)
We next turn to the second component of the analysis, which focuses on whether defendant was aware of the rights he was abandoning and of the consequences of his decision to do so. Although defendant was seriously injured in the collision, there was no direct evidence that during any of his interviews with the police, his judgment was clouded or otherwise impaired by pain, medications, or surgical procedures. The police officers testified, without contradiction, that defendant's answers were clear and responsive. The tape recordings and transcripts of the second and third interviews support this view. Although the defense presented evidence that raised questions regarding defendant's condition when he first was questioned by the officers at 2:45 a.m.  the testimony of a physician that, shortly after arriving at the hospital, defendant informed the physician that he (defendant) was unable to remember the accident, and the testimony of defendant's stepfather describing him as disoriented and barely conscious when they visited him at approximately 4:10 a.m. that morning  on this record the trial court properly could find, on the basis of the evidence presented by the prosecution, that, at each interview, defendant was aware of his rights and knowingly waived them.
Although defendant possessed relatively low intelligence, he was sufficiently intelligent to pass a driver's test, and to attempt to deceive officers by claiming initially that he was chased not by a motorcyclist, but by someone driving a Cadillac. He acknowledged the stupidity of Romo's plan to steal a car stereo. After being advised of his Miranda rights at the outset of each interview, defendant affirmatively indicated that he understood these rights (of which he had been advised during another encounter with the police *250 approximately half a year earlier). As was true with regard to the defendant in Fare, supra, 442 U.S. 707, 726 [99 S.Ct. 2560, 2572], there was no evidence that defendant in the present case lacked sufficient intelligence to understand those rights or the consequences of his waiver. In addition to reading defendant the Miranda advisements before interviewing him for the first time, Officer Andrews added, "You understand you don't have to talk to me if you don't want to." At no time did defendant request the presence of an attorney, or indicate that he wished to terminate the questioning.
In light of the foregoing evidence, we conclude that the record before us amply supports the trial court's ruling. Although the police officers did not obtain an express waiver of defendant's Miranda rights, decisions of the United States Supreme Court and of this court have held that such an express waiver is not required where a defendant's actions make clear that a waiver is intended. (See, e.g., Butler, supra, 441 U.S. 369, 374-375 [99 S.Ct. 1755, 1758-1759]; People v. Medina, supra, 11 Cal.4th 694, 752; People v. Johnson, supra, 70 Cal.2d 541, 556-558.) In Davis v. United States (1994) 512 U.S. 452, 460-461 [114 S.Ct. 2350, 2356, 129 L.Ed.2d 362], the high court held: "A suspect who knowingly and voluntarily waives his right to counsel after having that right explained to him has indicated his willingness to deal with the police unassisted. Although Edwards [v. Arizona (1981) 451 U.S. 477 [101 S.Ct. 1880, 68 L.Ed.2d 378]] provides an additional protection  if a suspect subsequently requests an attorney, questioning must cease  it is one that must be affirmatively invoked by the suspect." (See also Terrovona v. Kincheloe (9th Cir.1990) 912 F.2d 1176, 1180 [where the defendant gave detectives no indication that he wished to remain silent, instead offering an alibi, an implied waiver of his Miranda rights was held to be valid].) Our independent review of the evidence, including the tapes and transcripts of the interrogations introduced at trial (People v. Ashmus (1991) 54 Cal.3d 932, 969-970 [2 Cal. Rptr.2d 112, 820 P.2d 214]), leads us to conclude that the trial court's ruling was sound and that defendant voluntarily and knowingly waived his Fifth Amendment rights. In finding otherwise, the Court of Appeal erred.

III
(7) As noted, in addition to concluding that the trial court erred in admitting defendant's pretrial statements, the Court of Appeal concluded that the trial court also erred in admitting evidence of defendant's poor driving record and of his attendance at traffic school. The Court of Appeal further held that the erroneous admission of this evidence was prejudicial. The People take issue with the Court of Appeal's conclusions, maintaining that the evidence properly was admitted and, in any event, was not prejudicial. As we shall explain, we need not determine whether the evidence *251 relating to defendant's driving record and attendance at traffic school properly was admitted, because even if we were to assume the trial court erred in allowing the prosecution to introduce such evidence, any error could not have been prejudicial under the applicable standard. (See People v. Watson (1956) 46 Cal.2d 818, 836 [299 P.2d 243].)
Under Watson, the erroneous admission of evidence of defendant's driving record and attendance at traffic school would constitute reversible error only if a reasonable probability exists that the jury would have reached a different result had this evidence been excluded. (See People v. Watson, supra, 46 Cal.2d 818, 836; People v. Scheid (1997) 16 Cal.4th 1, 21 [65 Cal. Rptr.2d 348, 939 P.2d 748].) In the present case, the prosecution introduced the evidence relating to defendant's poor driving record and attendance at traffic school in order to support its claim that, at the time of the collision, defendant subjectively was aware of the serious risk of death posed by his reckless driving. Even without the evidence of defendant's poor driving record, however, there was strong evidence establishing that defendant was aware of the serious risks from his dangerous driving  including, most significantly, his explicit admission, in one of his pretrial statements to the police, that he realized that his driving on the night in question was dangerous and that while driving he was "afraid I'm going to kill someone or hurt someone else."
In addition to the foregoing express admission by defendant of his awareness of the danger to life posed by his driving, the evidence before the jury concerning the circumstances leading up to the collision strongly supports a finding of such awareness. As we have seen, the evidence indicates that in an attempt to evade a pursuing police officer, defendant sped through one red light causing other vehicles to screech to a halt to avoid a collision, drove at excessive speed with his vehicle's headlights off (briefly turning the lights on to maneuver around vehicles in front of him), and finally entered the intersection where the collision occurred against a red light and at a grossly excessive speed  broadsiding another vehicle.
Although the Court of Appeal suggested that "nothing here reflects intention, as opposed to inattention," in our view the evidence related above, particularly defendant's admission that while driving he was "afraid [he was] going to kill someone or hurt someone else," makes it clear there is no reasonable probability the jury's verdict would have been different even if the evidence of defendant's driving record or attendance at traffic school had been excluded. Accordingly, we conclude that the Court of Appeal erred in finding that any error in admitting this evidence was prejudicial.

*252 IV
For the reasons discussed above, the judgment of the Court of Appeal is reversed.
Mosk, J., Kennard, J., Baxter, J., Werdegar, J., Chin, J., and Brown, J., concurred.
NOTES
[1]  Unless otherwise specified, subsequent statutory references are to the Penal Code.
[2]  Defendant's other passenger, Zacharia Antolin, suffered traumatic brain injury, hemorrhage, and various fractures. Defendant suffered a fractured pelvis and a cut on his forehead that required stitches. The comparatively minor nature of defendant's injuries was attributed to the operation of the driver's-side airbag in the VW.

Janice Diehm's passenger, Royola Richards, was brought to a hospital in a coma. She was found to have multiple system trauma with massive head injuries, skull fractures, and extremity fractures. She was hospitalized for several weeks, and thereafter was placed in a rehabilitation program for several months.
[3]  At oral argument before this court, counsel for defendant conceded that defendant had waived his Miranda rights in connection with the alleged shoplifting incident.
[4]  As we explain, a waiver may be express or implied; the People contend that both forms of waiver are found in the present case. Because the People failed to properly preserve the express waiver issue, however (raising it for the first time in a petition for rehearing filed in the Court of Appeal), we need not and do not address it. (People v. Crowson (1983) 33 Cal.3d 623, 628 [190 Cal. Rptr. 165, 660 P.2d 389].) Our analysis instead will focus on whether defendant impliedly waived his Miranda rights.
[5]  The record is unclear as to exactly when defendant was placed under arrest. The People never have challenged defendant's assertion that the second and third interviews conducted by police officers while defendant was immobilized in the hospital were "custodial interrogations" for purposes of Miranda. As to the first interview, the People contend that defendant was not in custody. We need not address the People's contention, because the interviewing officers assumed defendant was entitled to be advised under Miranda, and the evidence was uncontroverted that, in fact, the officers so admonished defendant. (See Duckworth v. Eagan (1989) 492 U.S. 195, 203 [109 S.Ct. 2875, 2880, 106 L.Ed.2d 166]; Oregon v. Mathiason (1977) 429 U.S. 492, 495 [97 S.Ct. 711, 714, 50 L.Ed.2d 714].)


/*
   PURPOSE: (Matrix subtraction)

   ASSUMPTIONS AND LIMITATIONS: ((3x3 Matrix implementation))

   PROGRAMMERS: (((Les Quiocho) (NASA/Johnson Space Center) (Jan 1990) (v1.0) (Init Release))) */

#include "trick/trick_math.h"

void dm_sub(double diff[3][3],  /* Out: Difference of the two matrices */
            double mat1[3][3],  /* In: Matrix 1 */
            double mat2[3][3])
{                                      /* In: Matrix 2 */
    diff[0][0] = mat1[0][0] - mat2[0][0];
    diff[0][1] = mat1[0][1] - mat2[0][1];
    diff[0][2] = mat1[0][2] - mat2[0][2];

    diff[1][0] = mat1[1][0] - mat2[1][0];
    diff[1][1] = mat1[1][1] - mat2[1][1];
    diff[1][2] = mat1[1][2] - mat2[1][2];

    diff[2][0] = mat1[2][0] - mat2[2][0];
    diff[2][1] = mat1[2][1] - mat2[2][1];
    diff[2][2] = mat1[2][2] - mat2[2][2];

    return;
}


Cyclopropylmescaline

Cyclopropylmescaline (CPM or 4-cyclopropylmethoxy-3,5-dimethoxyphenethylamine) is a lesser-known psychedelic drug. CPM was first synthesized by Alexander Shulgin. In his book PiHKAL, the dosage range is listed as 60–80 mg and the duration listed as 12–18 hours. CPM produces closed-eye imagery, visuals, and fantasies.  It also causes enhancement of music.  Very little data exists about the pharmacological properties, metabolism, and toxicity of CPM.

See also
 Phenethylamine
 Psychedelics, dissociatives and deliriants

References

Category:Psychedelic phenethylamines
Category:Mescalines
Category:Cyclopropanes


This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Please enable Javascript to watch this video

SAN DIEGO – Months after President Donald Trump's campaign promise to build a “big beautiful wall,” construction of eight border wall prototypes began Tuesday just east of the Otay Mesa border crossing.

"We are committed to securing our border and that includes constructing border walls. Our multi-pronged strategy to ensure the safety and security of the American people includes barriers, infrastructure, technology and people,” said U.S. Customs and Border Protection Acting Deputy Commissioner Ronald Vitiello. “Moving forward with the prototypes enables us to continue to incorporate all the tools necessary to secure our border."

All eight prototypes will be between 18 and 30 feet high. Four will be made of concrete, while the other four will be constructed of alternate or “other materials,” CBP officials said.

The top designs for a concrete wall came from four companies: Caddell Construction Co (DE), LLC, of Montgomery, Alabama; Fisher Sand & Gravel Co., DBA Fisher Industries, of Tempe, Arizona; Texas Sterling Construction Co., of Houston, Texas; W. G. Yates & Sons Construction Company, of Philadelphia, Mississippi.

The prototypes will "help us create a 'design standard' for operational walls," CBP said. "The new designs would be added to our menu of existing designs, and allow us to tailor a specific wall design to the unique demands of individual areas of the border."

The money for the process came from $20 million that Congress authorized the Department of Homeland Security to pull from other places in the budget earlier this year. Congress has not yet authorized any further money to actually build new miles of wall.

Each prototype award will be worth roughly $400,000 to $500,000, Vitiello said.

Prototypes were selected "based on their abilities to meet the requirements in the proposal," he said in August, and once the prototypes are built, they will be evaluated for their effectiveness in a real-world environment. CBP could ultimately use all or none of the wall types along the border, Vitiello said, in addition to existing bollard fence designs that are used on the "immediate border."

Vitiello emphasized that CBP is looking for a "more holistic view" on border security, including cameras, sensors and an enforcement zone in the wall plan. Vitiello showed diagrams of plans for border solutions in both urban and rural areas, which included a "see-through" design, usually a bollard fence, along the immediate border, a zone for enforcement, and then a secondary barrier with the cameras and sensors. The concrete proposals are largely for that secondary barrier, Vitiello said.

"All those things have to be combined in the proper mix to make it work," Vitiello said, saying each location will be evaluated for the different options.

The prototypes are expected to take about 30 days to complete and the evaluation process will take roughly three months.


function [textonObjHist, textonBgHist, colorObjHist, colorBgHist] = ...
    computeColorAndTextonHistograms(img, objMask, filterBank, clusterCenters, ...
    nbColorBins, indActiveLab)
% Computes color and texton histograms, for both object and background
%
% ----------
% Jean-Francois Lalonde

% compute texton map
textonMap = textonify(img, filterBank, clusterCenters);

% compute object and background distributions
textonObjHist = histc(textonMap(objMask), 1:1000);
textonBgHist = histc(textonMap(~objMask), 1:1000);

imgLab = rgb2lab(img);
imgLabVec = reshape(imgLab, size(imgLab,1)*size(imgLab,2), size(imgLab,3));

% compute color distributions
colorObjHist = myHistoND(imgLabVec(objMask, :), nbColorBins, [0 -100 -100], [100 100 100]);
colorObjHist = colorObjHist(indActiveLab);
colorBgHist = myHistoND(imgLabVec(~objMask, :), nbColorBins, [0 -100 -100], [100 100 100]);
colorBgHist = colorBgHist(indActiveLab);


---
abstract: 'Using the negativity as an entanglement measure, we investigate the possible amount of remotely prepared entanglement. For two identical isotropic states on two-qudit systems 12 and 34, we calculate the average amount of entanglement remotely distributed on the system 13 by joint measurement on the system 24, and show that the remote preparation of entanglement by the generalized Bell-measurement is optimal among rank-one measurements if the isotropic states have a certain fidelity with a maximally entangled state in higher dimensional quantum systems, or if the fidelity of the isotropic states is greater than a certain value depending on the dimension. In addition, we construct a measurement better than the generalized Bell-measurement with respect to the remote preparation of entanglement when the isotropic states have small fidelity.'
author:
- Soojoon Lee
title: Bound on remote preparation of entanglement from isotropic states
---

Introduction
============

Entanglement provides us with a novel correlation between two or more parties, which cannot be explained by any classical theories. In addition, the correlation can be successfully applied to quantum communication, which seems to be classically impossible. Thus entanglement shared between several parties has been considered as one of the most significant resources in quantum information processing including quantum teleportation [@BBCJPW] and quantum key distribution [@BB84; @Ekert91; @B92].

In order to perform a faithful quantum communication procedure in a given quantum network, first of all, it should be required to prepare sufficient entanglement shared between desired parties. As a generalization of entanglement swapping [@ZZHE; @ZHWZ; @BVK], there exists a process to remotely distribute entanglement between different parties [@GS; @Gour; @KL; @LKS], which is here called the [*remote preparation of entanglement*]{} (RPE).

One of the simplest cases of the RPE is as follows (see FIG. \[Fig:RPE\]): Assume that Alice (system 2), Bob (system 4) and the supplier Sapna (systems 1 and 3) share an initial state $\rho^{12}\otimes\rho^{34}\in{\mbox{$\mathcal{B}$}}({\mbox{$\mathcal{H}$}}_1\otimes{\mbox{$\mathcal{H}$}}_2\otimes{\mbox{$\mathcal{H}$}}_3\otimes{\mbox{$\mathcal{H}$}}_4)$, and Sapna performs a joint measurement on systems 1 and 3. Then entanglement can be probabilistically shared between Alice and Bob.

![\[Fig:RPE\] A simple example of remote preparation of entanglement.](RPE.eps){width=".9\linewidth"}

It has been known [@GS; @Gour; @KL; @LKS] that the possible average amount of the shared entanglement is bounded by the product of entanglement amounts of $\rho^{12}$ and $\rho^{34}$. In particular, if $\rho^{12}$ and $\rho^{34}$ are two-qubit states then the bound can be shown in terms of the [*concurrence*]{} ${\mbox{$\mathcal{C}$}}$ [@Wootters] as follows [@GS]: $$\sum_{j=1}^s Q_j {\mbox{$\mathcal{C}$}}(\sigma^{24}_j)
\le{\mbox{$\mathcal{C}$}}(\rho^{12}){\mbox{$\mathcal{C}$}}(\rho^{34}),
\label{eq:GS}$$ where $Q_j$ is the probability of the resulting state $\sigma^{24}_j$ on subsystems 24 after the joint measurement on subsystems 13, and ${\mbox{$\mathcal{C}$}}(\rho^{12})$, ${\mbox{$\mathcal{C}$}}(\rho^{34})$ and ${\mbox{$\mathcal{C}$}}(\sigma^{24}_j)$ are the concurrence of $\rho^{12}$, $\rho^{34}$ and $\sigma^{24}_j$, respectively.

However, we remark that the maximal average amount of entanglement by the RPE cannot generally attain to the bound, the product of entanglement amounts of the two states. Especially, for two-qubit states $\rho^{12}$ and $\rho^{34}$, there does not in general exist a measurement to saturate the inequality (\[eq:GS\]).

We note that if we can discover a measurement to achieve the maximal average amount of entanglement by the RPE in a given quantum network then we can learn how faithful quantum communication can be performed in the quantum network, and this can be also employed in constituting a quantum network for a desired level of quantum communication. On this account, it may be more important to calculate the maximal average amount of entanglement obtainable by the RPE or to find out the optimal measurement for the RPE than to acquire a constant bound in a given quantum network.

In order to evaluate amount of entanglement, we need an entanglement quantification. Since the negativity is one of the most computable measures of entanglement among several entanglement quantifications, we here deal with the [*negativity*]{} ${\mbox{$\mathcal{N}$}}$ [@LKPL; @VW; @LCOK], which is defined as $${\mbox{$\mathcal{N}$}}(\rho)\equiv \frac{\left\|\rho^{\Gamma}\right\|-1}{d-1}
\label{eq:negativity}$$ for a two-qudit state $\rho$, where $\left\|\cdot\right\|$ is the trace norm, and $\Gamma$ is the partial transposition. Moreover, since the negativity is an entanglement monotone [@LKPL; @VW; @LCOK], it can be regarded as a good measure of entanglement, even though the bound entanglement with positive partial transposition [@Horodecki1; @Horodeckis2] cannot be detected by the negativity.

In this paper, we investigate the possible amount of entanglement by the RPE in terms of the negativity, and show that, given two identical isotropic states as initial states, the RPE by the generalized Bell-measurement is optimal among rank-one measurements if the isotropic states have a certain fidelity with a maximally entangled state in higher dimensional quantum systems, or if the fidelity of the isotropic states is greater than a certain value depending on the dimension of quantum systems. In addition, we show that there exists a measurement better than the generalized Bell-measurement with respect to the RPE when the isotropic states have small fidelity.

Remote preparation of entanglement and the generalized Bell-measurement
=======================================================================

In this section, we show that the generalized Bell-measurement among rank-one measurements is an optimal measurement for the RPE presented in FIG. \[Fig:RPE\], provided that two identical isotropic states with a certain fidelity are initial states.

Let $$\begin{aligned}
\rho_F
&=& F{{\left| \phi_d \right\rangle}}{{\left\langle \phi_d \right|}}
+ \frac{1-F}{d^2-1} \left(I\otimes I - {{\left| \phi_d \right\rangle}}{{\left\langle \phi_d \right|}}\right)\nonumber\\
&=& F\Phi_d
+ \frac{1-F}{d^2-1} \left({\mbox{$\mathcal{I}$}}- \Phi_d\right)
\label{eq:isotropic}\end{aligned}$$ be the isotropic state with fidelity $F$ in the two-qudit system, where ${{\left| \phi_d \right\rangle}}=\sum_{j=0}^{d-1}{{\left| jj \right\rangle}}/\sqrt{d}$ is a maximally entangled state in the two-qudit system, $I$ is the $d$-dimensional identity operator, $\Phi_d={{\left| \phi_d \right\rangle}}{{\left\langle \phi_d \right|}}$ and ${\mbox{$\mathcal{I}$}}=I\otimes I$. We note that the isotropic states form a generic class of two-qudit states, to which any arbitrary two-qudit state can be transformed via local quantum operations and classical communication, and moreover it is not difficult to analyze their amounts of entanglement computed by the negativity. Hence quantum networks consisting of the isotropic states are here dealt with.

We consider $\rho_{F}^{12}\otimes \rho_{F}^{34}$ as an initial state. For the sake of convenience, we let $a=(1-F)/(d^2-1)$ and $b=(d^2F-1)/(d^2-1)$. Then it is clear that $d^2a+b=1$, and $\rho_{F}^{12}\otimes \rho_{F}^{34}$ becomes $$\begin{aligned}
\varrho&\equiv&\rho_{F}^{12}\otimes \rho_{F}^{34}\nonumber\\
&=&
\left(a {\mbox{$\mathcal{I}$}}^{12} + b\Phi_d^{12}\right)
\otimes
\left(a {\mbox{$\mathcal{I}$}}^{34} + b\Phi_d^{34}\right).
\label{eq:rho_F0}\end{aligned}$$

We now suppose that a rank-one measurement on subsystems 13 is performed, and let ${{\left| \psi \right\rangle}}{{\left\langle \psi \right|}}$ be a measurement operator of the rank-one measurement. Due to the symmetry of isotropic states over local unitary operations, without loss of generality, we may assume that $${{\left| \psi \right\rangle}}=\sum_{j=0}^{d-1}\sqrt{\lambda_j}{{\left| jj \right\rangle}}=\sum_{j=0}^{R-1}\sqrt{\lambda_j}{{\left| jj \right\rangle}},
\label{eq:general_psi}$$ where $1\ge \lambda_0\ge\lambda_1\ge\cdots\ge\lambda_{R-1}> 0$, and $\lambda_{R}=\lambda_{R+1}=\cdots=\lambda_{d-1}=0$. It follows from straightforward calculations that $$\begin{aligned}
 ^{13}{{\left\langle \psi \right|}}\varrho{{\left| \psi \right\rangle}}^{13}
&=&
a^2 {\mbox{$\mathcal{I}$}}^{24}
+\frac{b^2}{d^2}\sum_{i,j=0}^{R-1}\sqrt{\lambda_i\lambda_j}{{\left| ii \right\rangle}}^{24}{{\left\langle jj \right|}}
\nonumber\\
&&+
\frac{ab}{d}\left(
\Lambda_R\otimes I
+I\otimes \Lambda_R\right)^{24},
\label{eq:rho_F2}\end{aligned}$$ where $$\Lambda_R=\sum_{j=0}^{R-1}\lambda_j{{\left| j \right\rangle}}{{\left\langle j \right|}}.
\label{eq:Lambda_r}$$ Then ${\mbox{$\mathrm{tr}$}}{{\left\langle \psi \right|}}\varrho{{\left| \psi \right\rangle}}=d^2a^2+b^2/d^2+2ab=1/d^2$. Thus, the probability to obtain one measurement outcome after the rank-one measurement is $1/d^2$, and the resulting state $\rho_\psi$ in subsystems 24 after the measurement becomes $$\begin{aligned}
\rho_\psi
&\equiv& d^2\cdot ^{13}{{\left\langle \psi \right|}}\varrho{{\left| \psi \right\rangle}}^{13}\nonumber \\
&=&
d^2a^2 {\mbox{$\mathcal{I}$}}^{24}
+b^2\sum_{i,j=0}^{R-1}\sqrt{\lambda_i\lambda_j}{{\left| ii \right\rangle}}^{24}{{\left\langle jj \right|}}
\nonumber\\
&&+
dab\left(
\Lambda_R\otimes I
+I\otimes \Lambda_R\right)^{24}.
\label{eq:rho_F3}\end{aligned}$$

We note that $A\otimes B{{\left| \phi_d \right\rangle}}=I\otimes BA^T{{\left| \phi_d \right\rangle}}$ for any operators $A$ and $B$ on the $d$-dimensional quantum system. Hence, it can be clearly shown that one outcome after performing an arbitrary rank-one measurement on subsystems 13 is always obtained with probability $1/d^2$, and it can be also shown that the resultant state in subsystems 24 is equivalent to the state $\rho_\psi$ up to local unitary operations, if the pure state corresponding to the measurement outcome has the same Schmidt coefficients as those of the state ${{\left| \psi \right\rangle}}$.

We now take into account the partial transpose on subsystem 4. Then the partial transpose of $\rho_\psi$ is $$\begin{aligned}
\rho_\psi^\Gamma
&=&
d^2a^2 {\mbox{$\mathcal{I}$}}^{24}
+b^2\sum_{i,j=0}^{R-1}\sqrt{\lambda_i\lambda_j}{{\left| ij \right\rangle}}^{24}{{\left\langle ji \right|}}
\nonumber\\
&&+
dab\left(
\Lambda_R\otimes I
+I\otimes \Lambda_R\right)^{24}.
\label{eq:rho_F4}\end{aligned}$$ Thus, for each $0\le k\le d-1$, we have $$\rho_\psi^\Gamma{{\left| kk \right\rangle}}=\left(d^2 a^2+(b^2+2dab)\lambda_k\right){{\left| kk \right\rangle}}.
\label{eq:PT_eigenii}$$ For each $0\le k<l\le d-1$, let ${{\left| \psi_{kl}^{\pm} \right\rangle}}=({{\left| kl \right\rangle}}\pm{{\left| lk \right\rangle}})/\sqrt{2}$, then we also have $$\rho_\psi^\Gamma{{\left| \psi_{kl}^{\pm} \right\rangle}}=
\left(d^2 a^2+dab(\lambda_k+\lambda_l)\pm
b^2\sqrt{\lambda_k\lambda_l}\right){{\left| \psi_{kl}^{\pm} \right\rangle}}.
\label{eq:PT_eigenijp}$$

It follows from Eqs. (\[eq:PT\_eigenii\]) and (\[eq:PT\_eigenijp\]) that ${{\left| kk \right\rangle}}$’s and ${{\left| \psi_{kl}^{\pm} \right\rangle}}$’s are eigenvectors of $\rho_\psi$, and form an orthonormal basis for the two-qudit system. Hence, we can obtain that the negativity of $\rho_\psi$, ${\mbox{$\mathcal{N}$}}(\rho_\psi)$, is $$\frac{2}{d-1}\sum_{k<l< R}
\max\left\{0, b^2\sqrt{\lambda_k\lambda_l}-d^2 a^2-dab(\lambda_k+\lambda_l)\right\},
\label{eq:negativity_rho_psi}$$ which is less than or equal to $$\frac{2}{d-1}\sum_{k<l< R}
\max\left\{0, (b^2-2dab)\sqrt{\lambda_k\lambda_l}-d^2 a^2\right\}.
\label{eq:final}$$ It is clear that Eq. (\[eq:final\]) becomes $$\frac{2}{d-1}\sum_{(k,l)\in \mathcal{J}_\psi}
\left((b^2-2dab)\sqrt{\lambda_k\lambda_l}-d^2 a^2\right),
\label{eq:final2}$$ where $\mathcal{J}_\psi$ is the set of all ordered pairs $(k,l)$ such that $k<l< R$ and $(b^2-2dab)\sqrt{\lambda_k\lambda_l}\ge d^2 a^2$.

Since $a=(1-F)/(d^2-1)$ and $b=(d^2F-1)/(d^2-1)$, it can be shown that if $d$ is sufficiently large to satisfy $$b^2-2dab\ge 2(R-1) d^2 a^2
\label{eq:R_condition}$$ then $$\begin{aligned}
{\mbox{$\mathcal{N}$}}(\rho_\psi)
&\le&\frac{R-1}{d-1}\left(b^2-2dab-Rd^2 a^2\right)
\nonumber\\
&=&(b^2-2dab){\mbox{$\mathcal{N}$}}\left(\Phi_R\right)-\frac{R(R-1)}{d-1}d^2 a^2
\nonumber\\
&=&{\mbox{$\mathcal{N}$}}(\rho_{\phi_R}).
\label{eq:final_ineq}\end{aligned}$$ Furthermore, it can be also shown that if the dimension $d$ is large enough to satisfy $$b^2-2dab\ge (R+d-1)d^2 a^2
\label{eq:d_condition}$$ then $$\frac{R-1}{d-1}\left(b^2-2dab-Rd^2 a^2\right)
\label{eq:N(rho_{phi_R}}$$ is less than or equal to $$b^2-2dab-d^3 a^2,
\label{eq:N(rho_{phi_d}}$$ that is, the inequality ${\mbox{$\mathcal{N}$}}(\rho_{\phi_R})\le{\mbox{$\mathcal{N}$}}(\rho_{\phi_d})$ holds. Thus, we obtain that if the dimension $d$ is sufficiently large such that $$b^2-2dab\ge 2(d-1)d^2 a^2
\label{eq:d_final_condition}$$ then $${\mbox{$\mathcal{N}$}}(\rho_\psi)\le {\mbox{$\mathcal{N}$}}(\rho_{\phi_d})
\label{eq:optimal_ineq}$$ for any state ${{\left| \psi \right\rangle}}$. Hence, it can be obtained that, given a rank-one measurement of subsystem 13 with measurement operators $\{{{\left| \psi_j \right\rangle}}{{\left\langle \psi_j \right|}}\}$ on the state $\varrho$, if the inequality (\[eq:d\_final\_condition\]) holds then $$\sum_j p(\psi_j) {\mbox{$\mathcal{N}$}}(\rho_{\psi_j})\le \sum_{s,t} p(\phi_{st}){\mbox{$\mathcal{N}$}}(\rho_{\phi_{st}}),
\label{eq:average_optimal}$$ where $\rho_{\psi_j}$’s are the resultant states on subsystem 24 after the rank-one measurement, $p(\zeta)$ is the probability to obtain $\zeta$ as a measurement outcome, and ${{\left| \phi_{st} \right\rangle}}=I\otimes X^sZ^t{{\left| \phi_d \right\rangle}}$ with the generalized Pauli operators $X$ and $Z$ are the two-qudit generalized Bell states, since $p(\psi_j)=p(\phi_{st})=1/d^2$ and ${\mbox{$\mathcal{N}$}}(\rho_{\psi_j})\le{\mbox{$\mathcal{N}$}}(\rho_{\phi_d})={\mbox{$\mathcal{N}$}}(\rho_{\phi_{st}})$.

We remark that the left-hand side and the right-hand side in the inequality (\[eq:average\_optimal\]) represent the average amount of entanglement of the resultant states after the rank-one measurement and after the generalized Bell measurement, respectively. This implies that, under the condition in the inequality (\[eq:d\_final\_condition\]), the generalized Bell measurement is optimal among rank-one measurements with respect to the RPE.

In addition, the inequality (\[eq:average\_optimal\]) also holds if $F$ is more than a certain value depending on the dimension so that $$F\ge \frac{1+3d-d^2+(d^2-1)\sqrt{2d-1}}{d(d^2+2)},
\label{eq:F_condition}$$ since the inequality (\[eq:F\_condition\]) is equivalent to the inequality (\[eq:d\_final\_condition\]). Therefore, we can obtain the following theorem.

\[Thm:main\] Assume that the initial states are two identical isotropic states in the two-qudit quantum system. Then the RPE by the generalized Bell-measurement is optimal among rank-one measurements if the dimension of the quantum system is large enough to satisfy the inequality (\[eq:F\_condition\]), or if the isotropic states have fidelity more than a certain value depending on the dimension as seen in the inequality (\[eq:F\_condition\]).

We remark that for almost all initial states in higher dimensional quantum systems, the RPE by the generalized Bell-measurement is optimal, since the right-hand side in the inequality (\[eq:F\_condition\]) tends to zero as the dimension $d$ goes to the infinity.

Measurements better than the generalized Bell-measurement
=========================================================

In this section, we show that there exists a measurement to give higher entanglement than the generalized Bell-measurement for the RPE when the two identical isotropic states as initial states have small fidelity.

Three-dimensional quantum systems
---------------------------------

In this subsection, we assume that $d=3$. Let $\omega_3=\exp(2\pi\mathrm{i}/3)$ with $\mathrm{i}=\sqrt{-1}$, and consider a measurement whose measurement operators are ${{\left| \psi_{kl}^{\pm} \right\rangle}}{{\left\langle \psi_{kl}^{\pm} \right|}}$ for $0\le k<l \le 2$ and ${{\left| \phi_{3}^{s} \right\rangle}}{{\left\langle \phi_{3}^{s} \right|}}$ for $0\le s\le 2$, where $${{\left| \phi_{3}^{s} \right\rangle}}\equiv \sum_{j=0}^2 \omega_3^{sj}{{\left| jj \right\rangle}}.
\label{eq:phi_3k}$$ Then it can be easily shown that the measurement is a rank-one projective measurement, and it can be also shown that ${\mbox{$\mathcal{N}$}}\left(\rho_{\psi_{kl}^{\pm}}\right)$ is more than ${\mbox{$\mathcal{N}$}}\left(\rho_{\phi_3}\right)$ for $$\frac{7+8\sqrt{3}}{39}< F < \frac{1+8\sqrt{5}}{33},
\label{eq:example_F_ineq_3d}$$ as seen in FIG. \[Fig:3d\].

It follows that if the given isotropic states have fidelity $F$ satisfying the inequality (\[eq:example\_F\_ineq\_3d\]) then the RPE by this measurement provides higher entanglement than the RPE by the generalized Bell-measurement in terms of the negativity.

$d$-dimensional quantum systems
-------------------------------

In this subsection, we generalize the example in the three-dimensional case. Let $\omega_d=\exp(2\pi\mathrm{i}/d)$, and consider a measurement whose measurement operators are ${{\left| \psi_{kl}^{\pm} \right\rangle}}{{\left\langle \psi_{kl}^{\pm} \right|}}$ for $0\le k<l \le d-1$ and ${{\left| \phi_{d}^{s} \right\rangle}}{{\left\langle \phi_{d}^{s} \right|}}$ for $0\le s\le d-1$, where $${{\left| \phi_{d}^{s} \right\rangle}}\equiv \sum_{j=0}^{d-1} \omega_d^{sj}{{\left| jj \right\rangle}}.
\label{eq:phi_dk}$$ Then, as in the three-dimensional case, the measurement is also a rank-one projective measurement.

It follows from tedious but straightforward calculations that if the fidelity $F$ of the initial isotropic states satisfies the following inequality $$\frac{1-d+d^2+(d^2-1)\sqrt{3}}{d(d^2+2d-2)}
<F<
\frac{1+(d^2-1)\sqrt{d+2}}{d(d^2+d-1)},
\label{eq:example_F_ineq_general}$$ then the measurement gives higher amount of entanglement than the generalized Bell-measurement for the RPE.

From the two previous subsections, we have the following theorem.

\[Thm:example\] There exists a measurement such that the RPE by the measurement has larger average amount of entanglement than the RPE by the generalized Bell-measurement.

Summary
=======

We have investigated the possible amount of entanglement by the RPE in terms of the negativity, and have shown that, given two identical isotropic states as initial states, the RPE by the generalized Bell-measurement is optimal among rank-one measurements if the isotropic states have a certain fidelity with a maximally entangled state in higher dimensional quantum systems, or if the fidelity of the isotropic states is greater than a certain value depending on the dimension of the quantum systems.

On the other hand, we have shown that there exists a measurement better than the generalized Bell-measurement with respect to the RPE when the isotropic states have small fidelity.

[0]{}

C.H. Bennett, G. Brassard, C. Crépeau, R. Jozsa, A. Peres and W.K. Wootters, Phys. Rev. Lett. [**70**]{}, 1895 (1993).

C.H. Bennett and G. Brassard, in [*Proceeding of the IEEE International Conference on Computers, Systems and Signal Processing, Bangalore, India* ]{} (IEEE, New York, 1984), pp. 175–179; IBM Tech. Discl. Bull. [**28**]{}, 3153 (1985).

A.K. Ekert, Phys. Rev. Lett. **67**, 661 (1991).

C.H. Bennett, Phys. Rev. Lett. **68**, 3121 (1992).

M. Żukowski, A. Zeilinger, M.A. Horne and A.K. Ekert, Phys. Rev. Lett. **71**, 4287 (1993).

A. Zeilinger, M.A. Horne, H. Weinfurter and M. Żukowski, Phys. Rev. Lett. **78**, 3031 (1997).

S. Bose, V. Vedral and P.L. Knight, Phys. Rev. A **57**, 822 (1998).

G. Gour and B. C. Sanders, Phys. Rev. Lett. [**93**]{}, 260501 (2004).

G. Gour, Phys. Rev. A [**71**]{}, 012318 (2005).

J.S. Kim and S. Lee, J. Phys. A: Math. Theor. [**43**]{}, 385305 (2010).

S. Lee, J.S. Kim and B.C. Sanders, Phys. Lett. A [**375**]{}, 411 (2011).

W.K. Wootters, Phys. Rev. Lett. [**80**]{}, 2245 (1998).

J. Lee, M. S. Kim, Y. J. Park and S. Lee, J. Mod. Opt. [**47**]{}, 2151 (2000).

G. Vidal and R. F. Werner, Phys. Rev. A [**65**]{}, 032314 (2002).

S. Lee, D. P. Chi, S. D. Oh and J. Kim, Phys. Rev. A [**68**]{}, 062304 (2003).

P. Horodecki, Phys. Lett. A [**232**]{}, 333 (1997).

M. Horodecki, P. Horodecki and R. Horodecki, Phys. Rev. Lett. [**80**]{}, 5239 (1998).


Browse Work-Life Balance Articles

Nurses hear it all: The good, the bad, and the (very, very!) ugly. From pushy patients to bossy doctors, nurses handle it all with grace. But there are some things that can get under the most tolerant nurse’s skin. NursingLink staff members talked to health care professionals, one another and (of course!) nurses to find out what phrases or questions were ...

You don’t get to choose your patients. So your relationship with them can range anywhere from “match made in heaven” to “your worst nightmare.” Any appointment can be a potentially difficult situation, mainly because when patients come to see you, they’re probably already anxious. They may be concerned about what’s ailing them, be uncomfortable with the sterile atmosphere, or have a ...

"Constant attention by a good nurse may be just as important as a major operation by a surgeon." - Dag Hammarskjold Continue to Next Quote Submitted by nurseaisha [page] "The trained nurse has become one of the great blessings of humanity, taking a place beside the physician and the priest." - William Osler Continue to Next Quote Submitted by BlueGrassNurse [page] ...

A good quote can lift you up when you're feeling blue. It can inspire you to reach your goals. It can even make you laugh out loud. NursingLink members shared some of their favorites and we'd like to share some of ours. As a nurse (or aspiring nurse!), you probably face obstacles every day - whether it's helping a patient overcome ...

Nurses impact lives every day. But once in a while, a nurse comes along who touches the lives of the world, and not just her patients. These women went above and beyond for the field of nursing. They served in wars, broke down racial barriers, and campaigned for women's rights. They have become role models for women everywhere, not just nurses. ...

Telecommuting provides an attractive option for nurses seeking flexibility and work/life balance. Many large companies hire nurses to work from home doing a variety of jobs. Here's a look at three options: triage (also called telehealth), medical transcription and case management. Telehealth Over the past three years, McKesson Health Solutions, a health care services and IT provider, has increased its at-home ...

No matter how many years of experience you have under your belt, there are certain things medical professionals should never do. Not only are the things on this list pushing the ethical envelope, they could also be damaging to your career. As a medical professional, the public views you as someone knowledgeable, compassionate and authoritative. You should be proud of ...

If you've ever treated a "frequent flyer" patient with a case of "Nintendo thumb" or "Avatar blues," you may be familiar with this list of 40 humorous nursing lingo terms. Courtesy of our Scrubs Magazine readers and SlangRN.com we present these slang terms nurses use and wonder, what are some more? Scroll to the bottom to submit your favorites! 1. Frequent ...

Question: What involves lots of blood, guts, and gore, can be extremely scary at times, and requires a costume? Answer: Why, nursing, of course! Halloween and nursing go hand in hand. After all, they involve a lot of the same things: blood, guts, terrifying outfits. We've rounded up the best nursing horror stories straight from the trenches and just in ...

[photo:123611] Hospitals can be crazy places. From ambulances rushing in patients and nurses shouting vitals to security having to deal with frantic family members, you may blink and find you miss an important moment. But for many health care professionals, hospitals are their second home. With all the different departments and types of health care workers in hospitals, it’s not ...

Some of us are night owls. Others, early birds. Apparently, based on your chronotype, you will be more naturally alert earlier or later in the day. And your type may dictate when and for how long you sleep. But while a natural variance in sleep patterns is natural, it appears that the early bird is indeed the more coveted of ...

Are you gearing up for your summer vacation, but aren't sure which direction to go? When it comes to vacationing in the U.S., each city is unique. Which city is the best travel destination for a hard-working nurse? We have rated 25 cities for vacationing by examining what each has to offer. Our criteria • We looked at the average ...

It’s that time again – food, family feuds, festivities, and fussing over what to get everyone you know. No wonder we’re a little stressed out! NursingLink can’t help you get along with your brother-in-law, but we can give you tips on what to buy for the nurses in your life. And forget cutesy angel trinkets or mugs donned with nursing catch-phrases. ...

[photo:38098] Donna Cardillo, RN Donna Cardillo, RN has been referred to as the ‘guru’ of career development for nurses. Donna is a professional keynote speaker, author, consultant, and coach. Her accomplished career combines over 20 years of clinical, managerial and business experience, not to mention her stint as a professional singer. Donna’s clinical experience includes emergency and psychiatric nursing. *Donna's ...

You've heard them before: patient complaints, whining doctors, and every excuse in the book. You joke about them with fellow nurses, recount them with your friends and significant others, and roll your eyes as you hear the same phrase for the millionth time. Nursing is a crazy profession in which no one shift is quite like any other. But through it ...

Happy new year, nurses! Time for a fresh start; a clean slate is just what we need. A new year means new resolutions, and new things in store for the future. Our friends at Scrubs magazine have put together this fun list of predictions based on your astrological sign. What's your astrological forecast? FIND OUT! Sign: Aries Sign: Libra Sign: ...

Editor's note: To commemorate National Boss Day (October 16th), Scrubs sent out a missive to nurses asking: "What makes your boss great?" One particularly enthusiastic nurse not only responded immediately, she and a colleague developed a list of wonderful things their manager does that wins universal adoration from her unit. Terri Engelman, LPN wrote, "I just talked with my co worker ...

Let's face it ladies. The fight’s not fair in the hospital. We may be picking away at the salary gap but we still only earn 77 cents to every man’s dollar, according to the U.S. Census Bureau. And despite filling more seats at nursing school, fewer than 3 percent of Fortune 1000 CEOs are women. So how does bias run rampant ...

2010 was a crazy year for the healthcare industry. From healthcare scandals, technological advancements, disease outbreaks, hot industry news, and health warnings, healthcare made headlines almost daily! We've put together some of the most notable healthcare stories in 2010. Check 'em out and add your own! THE LIST: 10. Japanese Nurse Robot 5. Daily Pill Lowers AIDS Risk 9. Social Media ...

Happy Nurse’s week to all my fellow nurses out there! This is the week to celebrate our growth, accomplishments and the impact we have made on the health of the entire nation. One thing that has bugged me about his week is how nurses have been kind of lost in the shuffle of the whole thing and it is now about ...


Possible Cause of Bee Die-Off Is Found - jamesbressi
http://www.nytimes.com/2010/10/07/science/07bees.html

======
jacquesm
The paper:

[http://www.plosone.org/article/info:doi/10.1371/journal.pone...](http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013181)

~~~
moshezadka
Thanks! The article was long on CSI-style antics and short on actual science.

------
jemfinch
Entomologists don't do bee autopsies, they do bee necropsies. The only animal
that can be autopsied is a human. </pedant>

~~~
omaranto
The definition I had heard for autopsy was "examination of a cadaver to
attempt to determine the cause of it's death". I guess you're saying that's
wrong. What's the proper definition? I'm guessing it does have something to do
with examining cadavers but there are restrictions. Is the restriction that
the cadaver be human? Or that both the examiner and cadaver be human? Or
possibly that both cadaver and examiner be intelligent creatures of the same
kind in some sense (that's what "auto" sort of sounds like to me)?

~~~
davidw
Dict/wordnet says cadaver is "the dead body of a human being", so if an
autopsy only deals with cadavers, then it's only people, I suppose.

------
mian2zi3
How funny. Twenty years ago I worked for a summer for that guy at the
University of Montana grinding up bees and writing data collection/analysis
software.

edit: One of the projects I worked on looked at to what extent bees aggregated
environmental pollutants into the hive. To prepare the bee samples for mass
spectrometer, we ground them up, mixed them with aqua regia (mixture of nitric
and hydrochloric acids) in a nonreactive teflon container (a teflon bombs) and
then microwaved them! Science is awesome. One of the bombs exploded once and
the acid gutted the inside of the microwave.

------
nfriedly
The last I had heard, researchers believed that cell phones were at least
partially to blame, but the article doesn't seem to mention it at all. Does
anybody know if that has been disproved?

~~~
JulianMorrison
From the article: "suspected culprits ranged from pesticides to genetically
modified food".

Q. What do pesticides, GM food and mobile phones have in common?

A. Technophobic nature-romanticists hate them.

Those things are just the "usual suspects". They get blamed for anything.

~~~
ahi
<http://en.wikipedia.org/wiki/Pesticide_%28toxic_to_bees%29>

I haven't read GMO as a possible culprit, but I have seen monoculture, made
possible by pesticides and GMOs, as a possibility. Industrial agriculture is
rather sterile, not really providing a balanced diet for bees (or us for that
matter). The cell phone thing is just batty though.

------
rflrob
Skimming through the paper (
[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013181)
), I don't know that the mass spectrometry they did really required a
military-academia connection, as the article seems to imply. While the
machines certainly aren't everywhere, I would imagine that there are quite a
few in the hands of researchers who aren't paid by the DoD.

~~~
jacquesm
This bit might have something to do with that:

> using a new software system developed by the military for analyzing proteins

and in the paper:

> with data processing and statistical analysis by the US Army Night Vision
> Laboratory

So while not strictly speaking necessary (because knowledge can be
transferred) the mass-spectrometers are not the whole story here.

------
jared314
I thought they figured that out at least a year ago. I guess it was just a
hypothesis then.

~~~
jeromec
Was it the same cause of a double-whammy virus teamed up with a fungus?

~~~
bosch
I was going to post the same thing as the poster above you as I heard about
this last year, but I wasn't sure if it was the combo or not. I know it
involved fungus for sure though.

~~~
jeromec
I see... from the article:

 _Research at the University of California, San Francisco, had already
identified the fungus as part of the problem. And several RNA-based viruses
had been detected as well. But the Army/Montana team, using a new software
system developed by the military for analyzing proteins, uncovered a new DNA-
based virus, and established a linkage to the fungus, called N. ceranae._

Maybe this is what the OP refers to. Thanks.

------
code_duck
Very much a 'symptoms and not the causes' analysis. This doesn't really answer
anything. It's like finding out a virus causes AIDS and not noticing it's
spread through frequent promiscuous sexual contact.

What they should be reporting on is: if this is dietary in some way, what has
changed the diets of bees? Why are they catching this disease now, and not 20
years ago? What has been changing regarding the environment of bees?

~~~
davidw
> This doesn't really answer anything

Yes, it does; it tells us what is actually killing the bees. We didn't even
really know that with any certainty before hand. You're correct that there are
some important "why"'s, and "how"'s that aren't known, but one thing at a
time.

~~~
code_duck
Not determining the root causes of why the bees are actually experiencing this
plague is like thinking aspirin cures someone with chronic headaches.

~~~
davidw
You can't get to the root cause or find a cure without first finding the
cause, can you?

~~~
code_duck
Sure. But what I'm saying is that finding the pathogen is not finding the
'cause', it's more like a symptom. I would have preferred if the article and
headline took that attitude. That's all.

------
jashmenn
Checkout Michael Schacker's book 'A Spring Without Bees.' Though it is a bit
one-sided, he makes a compelling case for the pesticide Imidacloprid (IMD)
being a significant factor in the honey-bee decline (I don't have it on hand,
but I think he cites a study that shows that IMD "intoxicates" bees at as low
as 6 ppb).

French beekeepers have been saying it was IMD for years and even though the
"official" studies (from Bayer, the manufacturer of IMD) say there is no
negative effect on bees.

That said, since the French banned IMD in 1999 (for use on sunflowers and
other crops) they've seen a decline in CCD.

I'm a part of a few online beekeeping groups and the general feeling about
this NYT article is that yes, probably a fungus + virus is what is killing the
bees, but why are they weakened to such a point that it is spreading so
disastrously? And here pesticides, migratory stress (i.e. driving them all
around the country to pollenate crops), feeding them large amounts of hfcs,
and general overwork all seem to play a part in weakening colonies.

~~~
geebme
I became a beekeeper the end of August when I collected a swarm on the end of
our block. I've since become keenly aware of the extent to which beekeeping
has become "commercialized". Ignoring (external) factors like pesticides,
etc., pollination activities subject them to intense pressures (monoculture,
hive movement, sick bees from remote geographies, etc.). Varroa, for example,
is pretty much endemic in hives throughout the US after having been
"introduced" in the late 80s.

The University of Minnesota, known for the Minnesota Hygienic line, instructs
fledgling beekeepers to follow a "two-year" plan. The first year involves lots
of chemical treatments (routine use of "nasty" chemicals is now the norm in
the hive), the second year more chemicals and (hopefully) lots of honey. After
two years? Kill the hive.

The end-game in all of this seems unsustainable (highly-evolved diseases and
highly-chemical-dependent hives). I've been trying to work out a better plan
for myself: one that does not tolerate chemical treatments (but is willing to
let weak hives die), works with the bees, and fosters reproduction of thriving
stock. I'd appreciate any resources you'd be able to share to aid in this.

------
bcl
I don't think you need a login for the printable page -
[http://www.nytimes.com/2010/10/07/science/07bees.html?_r=1&#...</a>

~~~
turnersauce
Unfortunately, it still asks for a login.

~~~
d_r
BugMeNot to the rescue!

<http://www.bugmenot.com/view/nytimes.com>

------
earl
I worked in a wetlab or for a bioinformatics company writing software for 4
years. One of the things that completely shocked me when I started working
there, and I think most people don't appreciate, is that taking a liquid and
figuring out what proteins are in there is a very hard thing to do. Then the
next step -- how much does my sample have of the things I've identified -- is
also hard to do. Doing either of them inexpensively is harder still. People
still work hard on those two questions today, and there is still room for
significant innovation around those two questions.

Also, CSI style science, where you drop a sample into the magic machine and an
answer pops out is... nonsense. These are some of the most finicky machines
you've ever encountered -- you always end up doing baselining / calibration
runs, etc. Often they involve skilled lab work to set up, calibrate, run, and
determine whether answers are significant.

~~~
abalashov
I always had my suspicions about those machines they show on "House," where a
vial of serum or blood is popped into the machine and out comes a printed
checklist of tests run and positive or negative results.

It seems very doubtful that something like a rapid ELISA test for HIV can be
done within a machine, in combination with many other tests.

~~~
zeugma
It does exist : [http://www.bio-
rad.com/evportal/evolutionPortal.portal?_nfpb...](http://www.bio-
rad.com/evportal/evolutionPortal.portal?_nfpb=true&_pageLabel=productsPage&catID=a82cd166-67ca-4696-91a8-a98a550936f2)

------
pitdesi
[http://articles.sfgate.com/2007-10-14/living/17265958_1_cali...](http://articles.sfgate.com/2007-10-14/living/17265958_1_california-
almonds-almond-growers-almond-trees) Great article on Almonds and Bees in case
you weren't aware... over 50% of the bees in the US are shipped to California
during growing season... pretty crazy. Wonder what the impact will be on
almond prices.