Light curves and colours of the ejecta from Dimorphos after the DART impact

On 26 September 2022, the Double Asteroid Redirection Test (DART) spacecraft struck Dimorphos, a satellite of the asteroid 65803 Didymos1. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from roughly 8.8 to 17 min (refs. 2,3). Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen scientists' telescopes across the world. We find a maximum brightening of 2.29 ± 0.14 mag on impact. Didymos fades back to its pre-impact brightness over the course of 23.7 ± 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3-0.5% Dimorphos's mass depending on the dust size. We also observe a reddening of the ejecta on impact.

Maintaining study validity in a changing clinical environment

BACKGROUND

Nurse scientists who conduct intervention research in a variety of clinical settings find themselves facing numerous challenges posed by today's changing and sometimes complex health care environment. Maintaining study validity thus becomes a major focus of interventional research, but existing literature does not fully address challenges to study validity nor offer potential solutions.

OBJECTIVES

The purposes of this paper are to 1) discuss methodologic challenges to maintaining study validity of intervention research that is conducted in a changing clinical environment, and 2) share strategies for maximizing study validity.

METHODS

A recently completed intervention study is used as an example to discuss two specific areas that affected study validity, provide examples of selected threats to validity, and outline strategies used to minimize these threats.

RESULTS

Careful definition of goals, thoughtful decision making, and implementation of specific strategies to maintain study validity helped increased the rigor of the research.

CONCLUSIONS

Investigators conducting intervention research in changing clinical settings can reduce threats to study validity and increase design rigor by considering clinical realities (e.g., clinician-researcher role conflict) when making methodologic decisions, becoming familiar with the setting, and involving clinicians in the research.

Comparison of subjective sleep quality in patients with cancer and healthy subjects

PURPOSE/OBJECTIVES

To compare the subjective sleep quality of a group of patients with cancer undergoing treatment and a normative sample of healthy comparison subjects.

DESIGN

Secondary analysis of data from a single time point in a repeated measures descriptive-correlational study.

SAMPLE/SETTING

Convenience sample of 15 patients with cancer receiving antineoplastic therapy and admitted to a tertiary university medical center for fever or neutropenia and 52 healthy comparison subjects without sleep disturbances. Although both groups were of similar age, a higher percentage of men comprised the comparison group.

METHODS

Patients completed the Pittsburgh Sleep Quality Index (PSQI) on the first day of hospitalization to reflect their perceptions of sleep for the month prior to hospitalization. Healthy comparison subject scores on the PSQI were obtained from a published report outlining psychometric properties of the PSQI (Buysse, Reynolds, Monk, Berman, & Kupfer, 1989).

MAIN RESEARCH VARIABLES

Sleep latency, sleep duration, sleep efficiency, sleep disturbances, medication use, daytime dysfunction, and global sleep quality.

FINDINGS

Patients with cancer reported significantly poorer overall sleep quality accompanied by more daytime dysfunction. The incidence of specific sleep disturbances, such as snoring and dyspnea, was not different between the groups.

CONCLUSIONS

This small sample of patients reported significantly poorer sleep quality than an historical comparison group. Specific sleep disturbances commonly seen in the general population were not problematic for the patients with cancer. Limited sample size and use of an historical comparison group need to be considered in interpreting and applying these findings. Additional research is needed to further characterize the nature of sleep problems in patients with cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to assess sleep in their patients, including its impact on quality of life and functional status.

Acute oral pain and mucositis in bone marrow transplant and leukemia patients: data from a pilot study

The purposes of this prospective, repeated-measures descriptive pilot study were to describe patterns of acute oral pain and mucositis in patients receiving a bone marrow transplant or high-dose chemotherapy for leukemia, and to test procedures and instruments before initiating a larger intervention study. A nonprobability, purposive selection process was used to enroll 18 patients admitted to two acute care inpatient hospital units for bone marrow transplantation or leukemia therapy at a university health sciences center in the southeastern United States. Data were collected at baseline, then daily through patient interviews, oral examination, and chart review for at least 3 weeks or until discharge. Research variables were pain intensity, intolerable pain, verbal descriptors of pain, pain relief, and use of pain relief strategies (Pain Assessment Form), mucositis (erythema and ulceration) in eight anatomic locations of the oral cavity (Oral Mucositis Index), voice/talking (Oral Assessment Guide), and mood states (11-item Brief Profile of Mood States). Mild to moderate pain occurred in nearly 70% of patients and was described as "tender," "irritating," and "sore." Patients used pain medicines, mouth care, and mental and physical activities to relieve pain, and reported partial overall relief of pain. Mucositis was mild, with the tongue and buccal and labial mucosa most commonly affected with erythema and the buccal mucosa with ulceration. Voice/talking were only mildly impaired, and mood disturbance was mild. Patterns of pain, mucositis, and mood disturbance were consistent with each other and followed the trajectory described in previous research. Results suggest that nurses should continue to assess these symptoms vigorously and assist patients in selecting multiple management strategies. Research using repeated-measures designs in this acutely ill inpatient population is challenging and needs careful attention by researchers. The results have been used to improve the ongoing larger intervention study.

A comparison of characteristics of patients with completed stroke: those who achieve continence and those who do not

The purpose of this retrospective study was to compare the demographic, neurologic, and cognitive characteristics of patients with completed stroke who participated in a behavioral management program for urinary incontinence. The study sought to determine the differences between those patients who achieved continence by the time of discharge from the program and those who did not. A retrospective chart review that used the Functional Independence Measure (FIM) scores identified 75 subjects with urinary incontinence at the time of admission. Forty-two study subjects achieved continence after participating in a rehabilitation and bladder management program. Thirty-three study subjects remained incontinent despite participation in a rehabilitation and bladder management program. Incontinent subjects had more difficulty with orientation to time, memory, and problem solving. These areas of cognitive function appear to have a direct impact on the ability of the person with stroke to achieve continence.

Accessory function and properties of monocytes from healthy elderly humans for T lymphocyte responses to mitogen and antigen

The waning of cell-mediated immunity during aging has been attributed primarily to defects in T lymphocyte properties and functions. We assessed the potential contribution of accessory dysfunction of monocytes from the elderly on responses of T cells to phytohemagglutinin (PHA) and to tetanus toxoid after in vivo boosting. Accessory function of monocytes from the elderly subjects for T lymphocyte responses to tetanus toxoid was comparable to the young. Expression of the cytokines interleukin-1, interleukin-6 and tumor necrosis factor, the cell adhesion molecules ICAM-1 and LFA-3 and the class II major histocompatibility molecule HLA-DR by monocytes from the elderly and young subjects was similar. T lymphocytes from the elderly responded poorly to PHA. Monocytes from the elderly had a decreased accessory function for PHA-stimulated T cells from young, third donors. Thus, although many accessory properties of monocytes from the elderly are normal, the monocyte and T lymphocyte defects in the elderly for mitogen may represent interactive factors in cell-mediated immunity during aging.

The effects of lidocaine on intracranial hypertension

In head-injured adults sudden increases in intracranial pressure (ICP) frequently occur in response to noxious stimuli, such as endotracheal suctioning (ETS). Transient increased ICP may have potentially harmful effects upon head-injured patients. One intervention clinicians believe to be efficacious in blunting ICP response to ETS is administration of lidocaine hydrochloride. This article critiques studies that examined effects of lidocaine in attenuating the ICP response to suctioning and similar stimuli. The literature to date, while providing conflicting results, does demonstrate tentative support for the use of lidocaine prior to ETS as a means of attenuating a rise in ICP. Support was found for the intratracheal route of administration. Additionally when intratracheal lidocaine was coupled with muscle relaxants or other anesthetic agents administered at appropriate times prior to suctioning, large rises in ICP may be effectively blunted.

Is the hospital setting the place for teaching breast self-examination?

The purpose of this study was to investigate the effects of an instructional program for nurses educating them to teach breast self-examination (BSE) to hospitalized patients. Nurses' knowledge, attitudes, self-practice, and practice of teaching breast self-examination to patients were measured in a group who attended such a program and compared with those of a control group who did not attend. The researchers found that the instructional program increased nurses' teaching of BSE to their patients, but did not affect their own self-practice. Nurses' attitudes to teaching BSE were less favorable than for self-practice. Issues related to environments for teaching BSE are discussed.

Nurses' perspectives on the meaning of hope in patients with cancer: a qualitative study

This study focused on developing an understanding of the meaning of hope for patients with cancer by eliciting vivid descriptions of hopeful cancer patients from clinical nurse specialists. The qualitative methodology for this study was based on one form of grounded theory. An inductive approach was applied to the development of generalized knowledge about the concept of hope. A conceptual model of hope was derived from critical attributes of hope identified within descriptions of hopeful cancer patients. Six oncology clinical nurse specialists were interviewed about their clinical experience with patients with cancer who were hopeful. Interviews were documented through process recordings. Attributes of hope were isolated and coalesced into six subthemes: goal setting, positive personal attributes, future redefinition, meaning in life, peace, and energy. Thematic analysis was used to develop a conceptual model of hope. Energy emerged as a strand running through each of the six subthemes and served as a focal point in the description and model of hope. Each of the subthemes described a component of the process whereby energy was exchanged, transformed, or moved, resulting in the preservation or loss of hope. This study generates a new way of viewing the patient with cancer and suggests several approaches for fostering hope.