Mood states and academic performance in the objective structured clinical examination. The mediating effect of self-efficacy

BACKGROUND

The role of self-efficacy on academic outcomes in clinical simulation evaluations is well-known. However, no previous studies have reported the mediating effect of self-efficacy in the link between mood state and academic performance in the Objective Structured Clinical Examination (OSCE).

OBJECTIVES

This study explores the following aims: i) to determine the effects of mood states on academic performance; ii) to assess the effect of mood states on self-efficacy; and iii) to analyze whether self-efficacy mediates the relationship between mood state and academic performance in the OSCE.

DESIGN

This quantitative and cross-sectional study received Institutional Review Board approval.

SETTINGS

A private university in Santiago, Chile.

PARTICIPANTS

A convenience sample of 117 nursing students from fourth and sixth semester.

METHODS

Data were collected using two questionnaires (the short version of the Profile of Mood State, and the General Self-Efficacy Scale), and the objective structured clinical examination in adult medical-surgical nursing and pediatric nursing courses.

RESULTS

Mood state has a significant effect on self-efficacy β = -0.068 p = .001. There was, however, no significant relationship between mood and academic performance (= - 0.004 p = .114). Similarly, Sobel's test indicated a non-significant mediation effect for self-efficacy-0.000544; 95 %; CI (-0.00256, 0.00148) p = .597.

CONCLUSIONS

The results of this study improve the understanding of students' self-efficacy and academic performance. Further investigation regarding the use of the self-efficacy construct as a mediating variable in different high-stakes evaluations and in students with varying training levels is needed.

Cross-Cultural Adaptation and Psychometric Evaluation of Condom Use Self-Efficacy Scale in Chilean College Students

Background and Purpose: Limited culturally relevant condom self-efficacy measures have been adapted for use with Chilean college students. This study aims to culturally adapt and measure the psychometric properties of the Condom Use Self-Efficacy Scale (CUSES) by use in college students in Chile. Methods: This cross-sectional study was carried out in six stages: (a) authorization from original authors, (b) translation, (c) back translation, (d) analysis of equivalences, (e) content analysis, and (f) exploratory factor analysis and reliability assessment. Results: Of the 460 college students who completed the Chilean CUSES (Ch-CUSES), 73.9% were women and 99% were single with a mean age of 20.5. Total scale Cronbach's alpha was 0.845, and factor analysis demonstrated six dimensions with 59.1% of the total variance. The factor loading scores of 21 items ranged between 0.515 and 0.921. Conclusions: Ch-CUSES shows good psychometric properties for assessing self-efficacy for condom use in Chilean college students.

Learner-centred teaching in a non-learner-centred world: An interpretive phenomenological study of the lived experience of clinical nursing faculty

BACKGROUND

With the growing complexities in the contemporary health care system, there is a challenge of preparing nurses for the practice demands. To this end, learner-centred teaching has emerged in many nursing curricula in Canada and evidence indicates its effectiveness in developing the essential practice skills in nursing students. It is important to examine the experience of the clinical faculty members who implement learner-centred teaching, as doing so would provide an insight to the factors that may hinder the implementation of learner-centred teaching in the practice settings.

OBJECTIVE

This phenomenological study aimed to address two research questions: what does learner-centred teaching mean to clinical nurse faculty? What is the lived experience of clinical nursing faculty who incorporate learner-centred teaching?

METHODS

Ten clinical nurse faculty members who had at least two years of clinical teaching experience volunteered to participate in the study. Data were collected using a semi-structured interview guide and audio recorder. Additional data sources included a demographic survey and a reflective journal.

RESULTS

Multiple sub-themes emerged from this study from which three significant themes were consolidated: diversity of meanings, facilitators of LCT, and barriers to LCT. However, an overarching theme of "learner-centred teaching in a non-learner-centred world" was coined from participants' accounts of their experiences of barriers in incorporating LCT in the practice settings.

CONCLUSION

A collaborative effort between faculty and the stakeholders is paramount to a successful implementation of learner-centred teaching in practice settings.

Graduate Students’ Experiences: Developing Self-efficacy

The nurse educator shortage continues without an increase in the numbers of graduate prepared nurses. Studies identified challenges in recruitment of nursing graduate students. No studies explore the experiences of nurses during graduate education. The framework used was Bandura’s self-efficacy theory. The population for this study included 15 nurse educators with a master’s or doctoral degree currently teaching in an undergraduate or graduate program in a western Canadian city. In semi-structured interviews, participants shared their experiences. Two themes emerged from the data: i) the hurdles of learning and ii) being a graduate student. The purpose of this article is to report the findings of faculty members’ experiences as graduate students. Understanding these experiences will help graduate faculty understand how graduate students develop self-efficacy throughout their graduate programs. Moreover, findings of this study will help graduate students succeed in a graduate program. Finally, issues related to recruitment and retention are addressed.

Sexual selection uncouples the evolution of brain and body size in pinnipeds

The size of the vertebrate brain is shaped by a variety of selective forces. Although larger brains (correcting for body size) are thought to confer fitness advantages, energetic limitations of this costly organ may lead to trade-offs, for example as recently suggested between sexual traits and neural tissue. Here, we examine the patterns of selection on male and female brain size in pinnipeds, a group where the strength of sexual selection differs markedly among species and between the sexes. Relative brain size was negatively associated with the intensity of sexual selection in males but not females. However, analyses of the rates of body and brain size evolution showed that this apparent trade-off between sexual selection and brain mass is driven by selection for increasing body mass rather than by an actual reduction in male brain size. Our results suggest that sexual selection has important effects on the allometric relationships of neural development.

Foot care education in patients with diabetes at low risk of complications: a consensus statement

AIMS

To define and agree a practical educational framework for delivery by all healthcare professionals managing patients with diabetes, particularly those at low risk of developing foot complications.

METHODS

A consensus meeting of a multidisciplinary expert panel. Prior to the meeting, relevant clinical papers were disseminated to the panel for review. The consensus was largely based upon the experts' clinical experience and judgement.

RESULTS

Four main health behaviours were identified for those at low risk of developing foot complications, namely: control of blood glucose levels; attendance at annual foot screening examination; reporting of any changes in foot health immediately; and the engagement in a simple daily foot care routine.

CONCLUSION

There is currently little evidence-based literature to support specific foot care practices. Patients with diabetes at low risk of developing complications should be encouraged to undertake a basic foot care regimen to reduce their likelihood of developing complications.

The impact of rabbit haemorrhagic disease on wild rabbit (Oryctolagus cuniculus) populations in Queensland

Rabbit haemorrhagic disease virus (RHDV) escaped from quarantine facilities on Wardang Island in September 1995 and spread through South Australia to Queensland by December 1995. To determine the impact of this biological control agent on wild rabbit populations in Queensland, shot sample and spotlight count data were collected at six sites. RHDV spread across Queensland from the south-west to the east at a rate of at least 91 km month–1 between October 1995 and October 1996. The initial impact on rabbit density appeared highly variable, with an increase of 81% (255 ± 79 (s.e.) to 385 ± 73 rabbits km–2) at one site and a decrease of 83% (129 ± 27 to 22 ± 18 rabbits km–2) at another during the first outbreak. However, after 30 months of RHDV activity, counts were at least 90% below counts conducted before RHDV arrived. Using a population model to account for environmental conditions, the mean suppression of rabbit density caused by rabbit haemorrhagic disease (RHD) was estimated to be 74% (ranging from 43% to 94% between sites). No outbreaks were observed when the density of susceptible rabbits was lower than 12 km–2. Where rabbit density remains low for long periods RHDV may not persist. This is perhaps most likely to occur in the isolated populations towards the northern edge of the range of rabbits in Australia. RHDV may have to be reintroduced into these populations. Further south in areas more suitable for rabbits, RHDV is more likely to persist, resulting in a high density of immune rabbits. In such areas conventional control techniques may be more important to enhance the influence of RHD.

Corrigendum to: The impact of rabbit haemorrhagic disease on wild rabbit (Oryctolagus cuniculus) populations in Queensland

Rabbit haemorrhagic disease virus (RHDV) escaped from quarantine facilities on Wardang Island in September 1995 and spread through South Australia to Queensland by December 1995. To determine the impact of this biological control agent on wild rabbit populations in Queensland, shot sample and spotlight count data were collected at six sites. RHDV spread across Queensland from the south-west to the east at a rate of at least 91 km month–1 between October 1995 and October 1996. The initial impact on rabbit density appeared highly variable, with an increase of 81% (255 ± 79 (s.e.) to 385 ± 73 rabbits km–2) at one site and a decrease of 83% (129 ± 27 to 22 ± 18 rabbits km–2) at another during the first outbreak. However, after 30 months of RHDV activity, counts were at least 90% below counts conducted before RHDV arrived. Using a population model to account for environmental conditions, the mean suppression of rabbit density caused by rabbit haemorrhagic disease (RHD) was estimated to be 74% (ranging from 43% to 94% between sites). No outbreaks were observed when the density of susceptible rabbits was lower than 12 km–2. Where rabbit density remains low for long periods RHDV may not persist. This is perhaps most likely to occur in the isolated populations towards the northern edge of the range of rabbits in Australia. RHDV may have to be reintroduced into these populations. Further south in areas more suitable for rabbits, RHDV is more likely to persist, resulting in a high density of immune rabbits. In such areas conventional control techniques may be more important to enhance the influence of RHD.

Developing alternative devices to the long-term urinary catheter for draining urine from the bladder

The self-retaining urinary catheter is used for long-term drainage of urine from the bladder only as a last resort because of serious associated complications, yet it remains a routine method for managing older and disabled patients with loss of bladder control. Blockage of the catheter from calcified deposits within its lumen is a common occurrence, obstructing the passage of urine and causing an urgent, unpredictable problem for patients, carers and the nursing staff. The need for further research on the subject has been recognized for many years. The SuPort Project aimed to develop an alternative suprapubic urine collection system. This report outlines the approach adopted towards the design and selection of the novel device, the production problems that ensued and the small clinical trial of a modified prototype.

Urinary catheter 'deflation cuff' formation: clinical audit and quantitative in vitro analysis

OBJECTIVE

To investigate reports from district nursing staff of difficulty in removing long-term urinary catheters (LTCs) because of the formation of a 'cuff' on deflating the self-retaining balloon.

PATIENTS AND METHODS

Problems experienced by district nurses when removing urethral and suprapubic LTCs were audited, noting the type of problem, the catheter and any action taken. Quantitative in vitro studies were conducted on the deflated self-retaining balloons after incubating a similar range of catheters in saline at 37 degrees C for 6 weeks, using suprapubic profilometry to assess the resistance to withdrawal (retention force).

RESULTS

Questionnaires were returned on 154 patients with LTCs; 56% had urethral and 44% suprapubic catheters. The catheters were hydrogel-coated (83%), all-silicone (13%) and PTFE-coated (3%). Twenty-two (14%) of the sample reported problems with catheter removal in the previous year, including 15 (68%) with all-silicone catheters and 15 (68%) with suprapubic catheters; cuff formation was noted in 60%. In the laboratory, 10 of the balloons formed a 'cuff' on deflation, but there was great variability in the effect this had on the retention force, with values of 0.5-3 N for different catheters.

CONCLUSIONS

Most problems with catheter removal involved all-silicone and suprapubic catheters. Suprapubic profilometry confirmed increased resistance to withdrawal by formation of a 'cuff' on deflation of the balloon of all-silicone catheters. These results suggest that the first choice of catheter material for long-term urethral and suprapubic use should be hydrogel-coated latex.

Urinary free cortisol and sleep under baseline and stressed conditions in healthy senior women: effects of estrogen replacement therapy

The purpose of this study was to examine the effects of a mild 24-h stress (indwelling IV catheter) on cortisol and sleep in postmenopausal women, and to evaluate differences due to estrogen replacement therapy (ERT) status. This study, conducted in the General Clinical Research Center at the University of Washington Medical Center, examined sleep, cortisol and sleep-cortisol relationships in both baseline and stress conditions, and compared women on ERT with women not on ERT. Forty-two women (age=69.6 +/- 6.2 years [SD]), of whom 20 were on ERT, participated. Urinary free cortisol (UFC) levels and sleep polysomnography were measured over both 24-baseline and stress condition. Sleep was impaired in the stress condition for both groups; mean UFC levels were higher, sleep efficiency and minutes of stages 2, 3 and 4 sleep were reduced, and morning risetime was earlier in the stress than baseline condition. For the combined groups, age-controlled correlations between 24-h UFC and sleep were significant in both conditions: at baseline, UFC levels were associated with earlier time of rising and less REM sleep, and under stress with reduced sleep efficiency, there was reduced minutes of stages 2, 3, 4 sleep, reduced REM sleep, and an earlier risetime. The pattern of negative significant correlations between UFC and sleep/sleep timing remained when plasma estrogen was statistically controlled; however, when groups were examined separately, the significant negative UFC-sleep relationships were confined to the non ERT group. Elevated 24-h UFC is associated with impaired sleep and earlier awakening in older women not on ERT, but not in women on ERT.

The Mini-Cog: receiver operating characteristics with expert and naïve raters

BACKGROUND

As elderly populations grow, dementia detection in the community is increasingly needed. Existing screens are largely unused because of time and training requirements. We developed the Mini-Cog, a brief dementia screen with high sensitivity, specificity, and acceptability. Here we describe the development of its scoring algorithm, its receiver operating characteristics (ROC), and the generalizability of its clock drawing scoring system.

SAMPLE AND METHODS

A total of 249 multi-lingual older adults were examined. Scores on the three-item recall task and the clock drawing task (CDT-CERAD version) were combined to create an optimal algorithm. Receiver operating characteristics for seven alternatives were compared with those of the MMSE and the CASI using expert raters. To assess the CDT scoring generalizability, 20 naïve raters, without explicit instructions or prior CDT exposure, scored 80 randomly selected clocks as "normal" or "abnormal" (20 from each of four CERAD categories).

RESULTS

An algorithm maximizing sensitivity and correct diagnosis was defined. Its ROC compared favorably with those of the MMSE and CASI. CDT concordance between naïve and trained raters was >98% for normal, moderately and severely impaired clocks, but lower (60%) for mildly impaired clocks. Recalculation of the Mini-Cog's performance, assuming that naïve raters would score all mildly impaired CDTs in the full sample as normal, retained high sensitivity (97%) and specificity (95%).

CONCLUSION

The Mini-Cog algorithm performs well with simple clock scoring techniques. The results suggest that the Mini-Cog may be used successfully by relatively untrained raters as a first-stage dementia screen. Further research is needed to characterize the Mini-Cog's utility when population dementia prevalences are low.

The mini-cog: a cognitive 'vital signs' measure for dementia screening in multi-lingual elderly

OBJECTIVES

The Mini-Cog, a composite of three-item recall and clock drawing, was developed as a brief test for discriminating demented from non-demented persons in a community sample of culturally, linguistically, and educationally heterogeneous older adults.

SUBJECTS

All 129 who met criteria for probable dementia based on informant interviews and 120 with no history of cognitive decline were included; 124 were non-English speakers.

METHODS

Sensitivity, specificity, and diagnostic value of the Mini-Cog were compared with those of the Mini-Mental State Exam (MMSE) and Cognitive Abilities Screening Instrument (CASI).

RESULTS

The Mini-Cog had the highest sensitivity (99%) and correctly classified the greatest percentage (96%) of subjects. Moreover, its diagnostic value was not influenced by education or language, while that of the CASI was adversely influenced by low education, and both education and language compromised the diagnostic value of the MMSE. Administration time for the Mini-Cog was 3 minutes vs 7 minutes for the MMSE.

CONCLUSIONS

The Mini-Cog required minimal language interpretation and training to administer, and no test forms of scoring modifications were needed to compensate for the extensive linguistic and educational heterogeneity of the sample. Validation in clinical and population-based samples is warranted, as its brevity and ease of administration suggest that the Mini-Cog might be readily incorporated into general practice and senior care settings as a routine 'cognitive vital signs' measure.

The Clock Drawing Test: utility for dementia detection in multiethnic elders

BACKGROUND

Disproportionate increases in dementia morbidity in ethnic minorities challenge established screening methodologies because of language and culture barriers, varying access to health services, and a relative paucity of cross-cultural data validating their use. Simple screening techniques adapted to a range of health and social service settings would accelerate dementia detection and social and health services planning for demented minority elders.

METHODS

The effectiveness of the Clock Drawing Test (CDT) for dementia detection was compared with that of the Mini-Mental State Examination (MMSE) and the Cognitive Abilities Screening Instrument (CASI) in community-dwelling elders of diverse linguistic, ethnic, and educational backgrounds. Subjects (N = 295) were tested at home in their native languages (English, n = 141; another language, n = 154). An informant-based clinical dementia history and functional severity index derived from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) protocols were used to classify subjects as probably demented (n = 170), and probably not demented (n = 125).

RESULTS

All tests were significantly affected by education (p < .001) but not by primary language (p > .05). Sensitivities and specificities for probable dementia were 82% and 92%, respectively, for the CDT; 92% and 92% for the MMSE; and 93% and 97% for the CASI for subjects completing each test. However, in poorly educated non-English speakers, the CDT detected demented subjects with higher sensitivity than the two longer instruments (sensitivity and specificity 85% and 94% for the CDT, 46% and 100% for the MMSE, and 75% and 95% for the CASI). Moreover less information was lost due to noncompletion of the CDT than the MMSE or CASI (severe dementia or refusal: CDT 8%, MMSE 12%, and CASI 16%).

CONCLUSIONS

Overall, the CDT may be as effective as the MMSE or CASI as a first-level dementia screen for clinical use in multiethnic, multilingual samples of older adults. Its brevity (1-5 minutes), minimal language requirements, high acceptability, and lack of dependence on specialized testing materials are well adapted for screening of non-English-speaking elderly persons in settings where bilingual interpreters are not readily available and screening time is at a premium.

Relationship of cues to assessed infant pain level

Cues that 46 pediatric nurses with a BS in Nursing reported as key to their pain assessments of 88 videotaped infants, ages 0 to 12 months, are identified. Frequencies with which these cues were used for infants of different ages and the relationships between key cues and assessed levels of pain are described. Greater pain was strongly associated with tears, stiff posture, guarding, and fisting. Greater pain was moderately associated with inadequate type or dosage of analgesia, more recent surgery, inconsolability, difficult to distract, does not focus on surroundings, frown, grimace, wrinkled face, flushed face, pain cry, and increased arousal in response to touch of sore area. Internurse variability in cue use was sizable. Most of the often-used cues had weak or no association with assessed pain level. Only consolability, pain cry, grimace, and stiff posture were frequently used and correlated > .51 with assessed level of pain.

Rearing paradigm in a nonhuman primate affects response to beta-CCE challenge

Two groups of socially housed rhesus monkeys were raised under conditions differing in the degree of control or mastery over appetitive stimuli (food, water, and treats) in the 1st year of life. At age 18-24 months, a benzodiazepine receptor inverse agonist, beta-carboline-3-carboxylic acid ethyl ester (beta-CCE), was administered to both social groups to investigate the effects of differential rearing on the response to a putative anxiogenic drug. In both groups beta-CCE was followed by behavioral activation with a profile suggesting increases in aggression rather than fear or anxiety. A group by drug analysis revealed that the increase in aggression was observed predominantly in the subjects reared with mastery during the 1st year. Plasma cortisol increased in both groups, but its increase was greater in the yoked subjects. These results suggest that early experience with controllability may have long term consequences which can be revealed by challenge with beta-CCE.

Altruistic interference shown by the alpha-female of a captive troop of rhesus monkeys

Interferences in aggressive disputes were recorded in a captive troop of rhesus monkeys (Macaca mulatta) comprising 19 mature females, 2 mature males and 12 immatures. The top ranking animal - the oldest female, Alpha, 23 years of age - was the only one who consistently interfered in favor of victims, never of aggressors. This protective, dispute-breaking strategy was distinguished by the following facts: None of the supported monkeys shared genes with Alpha; Alpha had no preference for aiding particular individuals; Alpha's high-risk interference (against aggressors) was never reciprocated; and (4) there was no evidence that Alpha's strategy aimed at the improvement of dominance standing. It was concluded that Alpha's behavior may represent an example of altruism.

Medical interpreting for hearing-impaired patients

Medical interpreting for deaf patients is a new dimension of the medical field. Medical interpreting allows for the fast, accurate, and complete exchange of medical information between medical professionals and their deaf patients. The exchange of accurate medical information is critical to the early diagnosis and treatment of medical problems.

Swelling of Vulcanized Rubbers in Binary Solvent Mixtures

The single-liquid approximation has been applied to the data of Bristow on ternary systems containing benzene and cyclohexane with one of the rubbers, natural, SBR, or butyl. Satisfactory fits are obtained with a constant value of the interaction constant between the two solvents χ12 which differs markedly, however, from the value obtained by measurements on the binary solvent mixture.

Crosslink Formation during Aging of Natural Rubber Vulcanizates

The effect of antioxidant on the crosslinking reaction occurring during the oxidation of sulphur vulcanizates of natural rubber was investigated by using both continuous and intermittent stress relaxation measurements. Similarly, by means of continuous stress relaxation and equilibrium swelling measurements the cross-linking reaction in vacuum was followed. The presence of antioxidant or removal of air reduced considerably both continuous and intermittent relaxation and also the difference between them, which measures the crosslinking. The crosslink formation must therefore form part of the sequence of oxidative reactions.

The Cyclization of Natural Rubber

The resinification of natural rubber by acid catalysts has been investigated since the beginnings in 1937 of interest in the chemical reactivity of rubber. During the reaction there is a partial loss in unsaturation but no change in the empirical formula of the rubber, C5H8. No general agreement exists on the decrease in unsaturation, values from 40 to 90% of the original having been quoted. (see PDF for diagram) The reduction in the number of double bonds has been attributed to an intramolecular bond formation leading to formation of cyclic structures. D'Ianni, Naples, Marsh, and Zarney have suggested the generally favored structure I, formed by reaction between pairs of adjacent isoprene units of the rubber chain. Van Veersen on the other hand, has proposed the more highly condensed polycyclic structure II. with the cyclization proceeding along the chain to involve a number of adjacent isoprene groups.

Statistical Treatments of Rubber Structure

Chemical reactions are random in nature and can therefore be subjected to mathematical analyses based on probability theory. This is a particularly necessary approach to polymer structure in which the effect of chance inherent in the reactions is preserved in physical form and therefore much attention has been given to deductions from such treatments. It is the purpose of this paper to review the results of those investigations which have particular application to rubbery high polymers. Some emphasis will be given to the authors' view that experimental testing of the derived expressions is still far from being satisfactory and that the subject in spite of the effort expended is still only at its beginning. Consideration of details of polymer structure is not merely an academic exercise. The properties of raw rubbers are highly dependent on polymer chain length and for many important ones such as viscosity, either in solution or in the melt, the dependence is not simply linear. Unless linear dependence on the number of molecules and their size does apply, an average value of molecular weight is insufficient to characterize a rubber sample in respect of the property considered and further knowledge of the distribution of molecular weights among the rubber molecules is required. The properties of rubbers are also markedly influenced by the occurrence of branching in the polymer chains; the insolubility and elasticity conferred by vulcanization are the results of the formation of complex branched structures which have been the subjects for statistical treatments.

Stress Relaxation during the Photoxidation of Peroxide Crosslinked Rubber

The chemical reactions involved in the thermal and photochemical aging of natural rubber vulcanizates are largely unknown. Experimental difficulties have precluded direct chemical investigation owing to the insolubility of the crosslinked networks and the small extent of reaction required for a great deterioration in physical properties. Accordingly recourse has been made to physical measurement. Tobolsky et al. (e.g. Ref. (1)) have shown that the relaxation in stress on holding a rubber strip at constant extension during aging is a convenient experimental measure capable of interpretation in terms of network breakdown. In photochemical studies the opacity of conventional sulfur vulcanizates provides a further complication. In the present work, the stress relaxation technique has been used in a study of the degradation by 365 mµ radiation of the comparatively transparent and chemically simple rubber networks obtained after crosslinking by organic peroxides.

Stress Relaxation during the Thermal Oxidation of Vulcanized Natural Rubber

The photoinitiated oxidative aging of peroxide vulcanized natural rubber (which contains only carbon-carbon cross-links) was found by stress relaxation measurements to be autocatalytic and to be sensitive to the presence of free radical retarders and catalysts. Similar behavior would be expected in thermal aging. However, earlier work in these laboratories indicated that the thermal aging of peroxide vulcanizates was not autocatalytic. Because of this discrepancy the stress relaxation of peroxide vulcanizates at elevated temperatures has now been reinvestigated and the study has been extended to include also the aging of the other types of networks which are produced on vulcanization by tetramethylthiuram disulfide in the absence of sulfur, by sulfenamide-sulfur, and by sulfur alone.

Aging of Natural Rubber Vulcanizates in the Presence of Dithiocarbamates

The thermal and photochemical aging of extracted dicumyl peroxide-, TMTD (sulfurless)- and santocure-vulcanized rubber, in presence of a number of metal and alkylammonium dithiocarbamates, has been investigated by measurements of stress relaxation. The dithiocarbamates have a considerable protective action upon the degradation of peroxide- and TMTD-vulcanizates, but they accelerate stress decay in santocure-accelerated vulcanizates. The reasons for this behavior are discussed. It is suggested that the excellent aging properties of unextracted TMTD vulcanizates are due to the presence of zinc dimethyldithiocarbamate formed during vulcanization.