Surface composition of Hyperion

Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25-26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high- and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus.

Randomized, controlled trials as minimal risk: an ethical analysis

OBJECTIVE

We aim to clarify the circumstances in which randomized, controlled trials should be designated as minimal risk, allowing institutional review boards to approve their conduct with a waiver of informed consent if obtaining informed consent is not feasible.

METHODS

An ethical analysis of the minimal risk standard as applied to randomized, controlled trials was conducted.

CONCLUSIONS

In determining whether an randomized, controlled trial should be designated as minimal risk, the potential sources of risk that must be considered are as follows: physical risk from study treatments, the loss of individualized care, risk from nontherapeutic components of the research protocol, and the psychological impact of participation, particularly if the research takes place without informed consent in an emergency setting. The risks of research participation should be considered in comparison with the risk of nonparticipation; e.g., the risks specific to research participation should be considered separately from the risks inherent in treatment of the potential research participant's underling condition. Participation in an randomized, controlled trial may pose no more than minimal risk when: 1) genuine clinical equipoise exists; 2) all of the treatment options included in the research study fall within the current standard of care; 3) there is no currently available treatment with a more favorable risk-benefit profile than the treatments included in the study; 4) the nontherapeutic components of the research are safely under the minimal risk threshold; and 5) the research protocol provides sufficient latitude for treating physicians to individualize care when appropriate. The potential for research participation to have a negative psychological impact on participants or their families should be considered in risk assessment. The requirement for informed consent should only be waived to the extent necessary, and opportunities for the research participant or surrogate to decide whether to participate in the research should be maximized.

Reforming the Oversight of Multi-Site Clinical Research: A Review of Two Possible Solutions

The current system for the ethical oversight of clinical research suffers from structural, procedural, and performance assessment problems. Initially conceived primarily to handle local investigator-initiated single-site studies, the system of institutionally-based committee review has become progressively more inefficient given the increased prevalence of commercially or federally sponsored multi-center trials. To date, proposed solutions do not adequately address these problems. Beginning with a review of these structural, procedural, and performance assessment problems, this article will then consider two proposals for addressing these deficiencies: (a) regional ethics organizations; and (b) IRBNet, a newly developed web-based program for cooperative IRB review. The strengths and weaknesses of these two approaches will be evaluated in light of recent experience with centralized review. The proposal to establish a system of regional ethics organizations presents a comprehensive approach to many of the problems faced by the current system. However, IRBNet offers an immediate and feasible solution to many of the problems faced by the review of multi-site clinical studies.

Ethical challenges in neonatal research: Summary report of the ethics group of the newborn drug development initiative

BACKGROUND

The Newborn Drug Development Initiative (NDDI) was established to address the lack of substantive data supporting efficacy and safety of drugs in the neonate.

OBJECTIVE

This commentary summarizes some of the ethical issues involved in neonatal drug development.

METHODS

At the NDDI workshop held March 29 and 30, 2004, in Baltimore, Maryland, members of the Ethics Group were dispersed among the subspecialty groups before convening to discuss common ethical themes. The Ethics Group then met together to identify and discuss those ethical themes that were both important and shared among the groups. These themes are discussed and illustrated with the other NDDI group reports. This workshop was cosponsored by the National Institute of Child Health and Human Development and the US Food and Drug Administration.

RESULTS

Neonatal drug research is scientifically and ethically necessary to establish the efficacy and safety of drugs widely used in newborn medicine. However, research involving neonates must be carefully designed to balance potential risks and benefits, with consideration given to the component analysis of risk. The protocols proposed by the NDDI groups would be considered greater than minimal risk and offering prospect for direct benefit, thus adhering to the Department of Health and Human Services' pediatric research regulations (Subpart D). The NDDI groups all proposed randomized controlled clinical trials, with careful attention to scientifically and ethically appropriate control groups. Multiple regulatory bodies have affirmed that in the absence of proven effective treatment or when a proven treatment offers marginal benefits, study designs with placebo controls are ethical. Obtaining parental permission is a complex issue, with a paucity of evidence describing the feasibility of informed and voluntary consent under conditions of duress and a short therapeutic window. The Subpart D regulations offer sufficient protection to critically ill neonates. The application of the revised Subpart B regulations would restrict the use of a waiver of consent for minimal risk research and for emergency research, and would not allow research that offers no direct benefit and no more than a minor increase over minimal risk.

CONCLUSIONS

Multisite collaboration involving standards of care and institutional review board procedures may be important for establishing scientific and ethical consistency. Ongoing dialogue among researchers, clinicians, parents, and other interested parties is essential to promoting ethically and scientifically sound neonatal clinical research.

Is a "wage-payment" model for research participation appropriate for children?

OBJECTIVE

Our goal was to evaluate the applicability of a "wage-payment" model to inducements for children to participate in research.

SUBJECTS AND METHODS

We interviewed 42 children and adolescents between the ages of 4 and 16 years who had diabetes, asthma, seizures, or no chronic medical condition. The interview explored hypothetical participation decisions for up to 4 research scenarios. To evaluate factors that would influence children and adolescents' decision-making for research participation, we probed for the impact of monetary and other incentives. The interviews were transcribed and coded for specific themes related to money or other rewards and incentives.

RESULTS

Older children, mainly those >9 years of age, showed an appreciation for the role and value of money through (a) an accurate concept of the material value of money in society or (b) asking for a realistic amount of money in exchange for their research participation. Younger children, primarily those <9 years of age, showed an inability to appreciate the role and value of money by: (a) asking for excessive monetary amounts that bore no relationship to the sum warranted by participation; (b) having no concept of what that money could buy; (c) not comprehending the meaning of a wage as earning a reward for working; or (d) justifying proposed amounts with reasons unrelated to the time and effort involved.

CONCLUSIONS

An age-appropriate token of appreciation as an inducement for research participation is appropriate for the younger child who is <9 years old, because they generally have an inadequate understanding of the value of money and, therefore, the meaning of a wage. A wage-payment model for compensating older children (>9 years of age) and adolescents for the time and effort of research participation is appropriate because they generally understand the meaning and value of a wage.

A paradigm for inpatient resuscitation research with an exception from informed consent

OBJECTIVE

Resuscitation research with an exception from informed consent (EFIC) has not been reported in the inpatient or pediatric setting, and little practical information exists to guide application of EFIC regulations to inpatient or pediatric research. The objective of this study was to assess the feasibility of conducting inpatient pediatric resuscitation research with EFIC using handouts to communicate with parents of potential participants and to determine how many parents would likely allow their child to participate in such research.

DESIGN

Verbal questionnaire.

SETTING

Pediatric intensive care units.

PARTICIPANTS

Parents of pediatric intensive care unit patients.

INTERVENTIONS

Three one-page handouts described proposed studies; version 1 described a trial of a new medication given during cardiac arrest, and versions 2a and 2b described of a trial of induced hypothermia, with version 2a in paragraph format and version 2b in bullet format. We asked parents of pediatric intensive care unit patients to review the handouts, and then we administered a verbal questionnaire to assess parental reactions to the handouts and to determine how many parents would allow their child to participate.

MEASUREMENTS AND MAIN RESULTS

One or both parents of 91 patients were asked to participate; 100% agreed. Sixty-three percent said they would likely allow their child to participate in resuscitation research with EFIC if they were given a prospective opportunity to opt out. Parents who reviewed version 2b (bullet format) were more likely than parents who reviewed version 2a (paragraph format) to say that they would let their child participate. Parents were more supportive of a trial of induced hypothermia than of a trial of a new medication given during cardiopulmonary resuscitation. Parents endorsed conducting the community consultation process for inpatient resuscitation research with families and healthcare providers of critically ill patients.

CONCLUSIONS

Inpatient pediatric resuscitation research is feasible using handouts to inform parents of a study and provide a prospective opportunity to opt out. Succinct, bullet-format handouts will yield higher participation rates than paragraph-format handouts.

A developmental approach to child assent for nontherapeutic research

The question of when and how to obtain child assent for nontherapeutic research has received increasing attention in recent years. Although child assent and parent permission are grounded in the principle of respect for persons, assent is often understood from the more narrow principle of respect for autonomy. When viewed in this way, "assent" is frequently conflated with "consent," and children are held to a higher standard than what might be sufficient for meaningful involvement in decision-making about research participation. When nested within the requirement for parental permission, child assent functions as a way to promote children's moral growth and developing autonomy, rather than as an autonomous decision. A developmental approach to child assent is necessary to understand how children can be meaningfully involved in decision-making about research participation across development. This approach suggests that the content and process of child assent should be allowed to vary across development. In addition, a developmental approach requires that future research employ longitudinal designs, examine the developmental mechanisms underlying age variations in child assent, and attend to both cognitive and noncognitive variables that may influence the assent process as children mature.

Variation in standards of research compensation and child assent practices: a comparison of 69 institutional review board-approved informed permission and assent forms for 3 multicenter pediatric clinical trials

OBJECTIVE

To systematically compare standards for compensation and child participant assent in informed permission, assent, and consent forms (IP-A-CFs) approved by 55 local institutional review boards (IRBs) reviewing 3 standardized multicenter research protocols.

METHOD

Sixty-nine principal investigators participating in any of 3 national, multicenter clinical trials submitted standardized research protocols for their trials to their local IRBs for approval. Copies of the subsequently IRB-approved IP-A-CFs were then forwarded to an academic clinical research organization. This collection of IRB-approved forms allowed for a quasiexperimental retrospective evaluation of the variation in informed permission, assent, and consent standards operationalized by the local IRBs.

RESULTS

Standards for compensation and child participant assent varied substantially across 69 IRB-approved IP-A-CFs. Among the 48 IP-A-CFs offering compensation, monetary compensation was offered by 33 as reimbursement for travel, parking, or food expenses, whereas monetary or material compensation was offered by 22 for subject inconvenience and by 13 for subject time. Compensation ranged widely within and across studies (study 1, $180-1425; study 2, $0-500; and study 3, $0-100). Regarding child participant assent, among the 57 IP-A-CFs that included a form of assent documentation, 33 included a line for assent on the informed permission or consent form, whereas 35 included a separate form written in simplified language. Of the IP-A-CFs that stipulated the documentation of assent, 31 specified > or =1 age ranges for obtaining assent. Informed permission or consent forms were addressed either to parents or child participants.

CONCLUSION

In response to identical clinical trial protocols, local IRBs generate IP-A-CFs that vary considerably regarding compensation and child participant assent.

An open letter to institutional review boards considering Northfield Laboratories' PolyHeme trial

At the time of this writing, a widely publicized, waived-consent trial is underway. Sponsored by Northfield Laboratories, Inc. (Evanston, IL) the trial is intended to evaluate the emergency use of PolyHeme, an oxygen-carrying resuscitative fluid that might prevent deaths from uncontrolled bleeding. The protocol allows patients in hemorrhagic shock to be randomized between PolyHeme and saline in the field and, still without consent, randomized between PolyHeme and blood after arrival at an emergency department. The Federal regulations that govern the waiver of consent restrict its applicability to circumstances where proven, satisfactory treatments are unavailable. Blood-the standard treatment for hemorrhagic shock-is not available in ambulances but is available in hospitals. The authors argue that the in-hospital stage of the study fails to meet ethical and regulatory standards.

Weighing the risks of G-CSF administration, leukopheresis, and standard marrow harvest: ethical and safety considerations for normal pediatric hematopoietic cell donors

BACKGROUND

Granulocyte colony stimulating factor (G-CSF) is used for collection of hematopoietic cells in most adult and a smaller but significant percentage of pediatric normal donor harvests. Short and long-term risks of G-CSF administration and leukopheresis are not well understood in the pediatric population.

PROCEDURE

Literature review including observations from the IBMTR, NMDP, EBMT, German Donor Registry, and the authors' work.

RESULTS

G-CSF causes temporary discomfort in a minority of younger donors. Rare serious side effects of G-CSF have yet to be reported in children. To date, an increase in hematological malignancies after short-term G-CSF use has not been detected in adult donors and no cases have been reported in children. Reported complications of leukopheresis in children are rare and minor, but donors <20 kg may be exposed to allogeneic blood products. Pediatric aged donors vary widely in their ability to assent or consent to the risks of a donation procedure. There are key regulations and ethical imperitives, which must be addressed in deciding which donation procedures are appropriate for minors.

CONCLUSIONS

While short term administration of G-CSF and leukopheresis appear to be safe and effective procedures when used to assist in collection of a hematopoietic cell graft from a normal pediatric donor, institutions adding or substituting one or both of these procedures for standard marrow donation must decide whether the donor should be considered a research subject, and if so, whether the new procedures are a minor increase over minimal risk. Because these procedures are being performed on and off study at many pediatric centers, a comprehensive study addressing donor safety could help clarify risks of rare adverse events.

Composition and Physical Properties of Enceladus' Surface

Observations of Saturn's satellite Enceladus using Cassini's Visual and Infrared Mapping Spectrometer instrument were obtained during three flybys of Enceladus in 2005. Enceladus' surface is composed mostly of nearly pure water ice except near its south pole, where there are light organics, CO2, and amorphous and crystalline water ice, particularly in the region dubbed the "tiger stripes." An upper limit of 5 precipitable nanometers is derived for CO in the atmospheric column above Enceladus, and 2% for NH3 in global surface deposits. Upper limits of 140 kelvin (for a filled pixel) are derived for the temperatures in the tiger stripes.

Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan

Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar (ref. 1) and, similar to the Earth, N2 is the main component of the atmosphere. Methane is the second most important component, but it is photodissociated on a timescale of 10(7) years (ref. 3). This short timescale has led to the suggestion that Titan may possess a surface or subsurface reservoir of hydrocarbons to replenish the atmosphere. Here we report near-infrared images of Titan obtained on 26 October 2004 by the Cassini spacecraft. The images show that a widespread methane ocean does not exist; subtle albedo variations instead suggest topographical variations, as would be expected for a more solid (perhaps icy) surface. We also find a circular structure approximately 30 km in diameter that does not resemble any features seen on other icy satellites. We propose that the structure is a dome formed by upwelling icy plumes that release methane into Titan's atmosphere.

What factors are important to parents making decisions about neonatal research?

BACKGROUND

Although parents of neonates with congenital heart disease are often asked permission for their neonates to participate in research studies, little is known about the factors parents consider when making these decisions.

OBJECTIVE

To determine the reasons for parents' decisions about participation in research studies.

METHODS

Qualitative analysis of the unsolicited comments of 34 parents regarding reasons for agreeing or declining to participate in research studies. Parents' comments were offered spontaneously during interviews about clinical care decisions for neonates with congenital heart disease.

RESULTS

Parents cited five types of reason for or against permitting their newborn to participate in research studies: societal benefit (n = 18), individual benefit for their infant (n = 16), risk of study participation (n = 10), perception that participation posed no harm (n = 9), and anti-experimentation views (n = 4).

CONCLUSION

Addressing parental decision making in the light of these reasons could enhance the parental permission process for parents of critically ill neonates.

Compositional maps of Saturn's moon Phoebe from imaging spectroscopy

The origin of Phoebe, which is the outermost large satellite of Saturn, is of particular interest because its inclined, retrograde orbit suggests that it was gravitationally captured by Saturn, having accreted outside the region of the solar nebula in which Saturn formed. By contrast, Saturn's regular satellites (with prograde, low-inclination, circular orbits) probably accreted within the sub-nebula in which Saturn itself formed. Here we report imaging spectroscopy of Phoebe resulting from the Cassini-Huygens spacecraft encounter on 11 June 2004. We mapped ferrous-iron-bearing minerals, bound water, trapped CO2, probable phyllosilicates, organics, nitriles and cyanide compounds. Detection of these compounds on Phoebe makes it one of the most compositionally diverse objects yet observed in our Solar System. It is likely that Phoebe's surface contains primitive materials from the outer Solar System, indicating a surface of cometary origin.