Rate of tree carbon accumulation increases continuously with tree size.

Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle--particularly net primary productivity and carbon storage--increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree's total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

Pain measurement: a comparison using horizontal and vertical visual analogue scales.

The McGill Pain Questionnaire (MPQ) is widely used in assessing a variety of pain problems. MPQ has been found to be sensitive enough to detect differences in pain relief and differences between acute and chronic pain. It requires, however, 5 to 10 minutes to administer. Because of this time factor, the Short-Form McGill Pain Questionnaire (SF-MPQ) was developed. A visual analogue scale (VAS) was not included in the original MPQ but is part of the SF-MPQ. Studies addressing the best way to present a VAS suggest that a vertical line is easier for patients to see; however, the VAS on the SF-MPQ is a horizontal line. This study examined the relationship between SF-MPQ scores with both the horizontal and vertical VAS.

The effects of foot reflexology on anxiety and pain in patients with breast and lung cancer.

PURPOSE/OBJECTIVES: To test the effects of foot reflexology on anxiety and pain in patients with breast and lung cancer. DESIGN: Quasi-experimental, pre/post, crossover. SETTING: A medical/oncology unit in a 314-bed hospital in the southeastern United States. SAMPLE: Twenty-three inpatients with breast or lung cancer. The majority of the sample were female, Caucasian, and 65 years or older; had 12 or fewer years of education and an annual income of $20,000 or more; and were receiving regularly scheduled opioids and adjuvant medications on the control and intervention day. METHODS: Procedures included an intervention condition (foot reflexology to both feet for 30 minutes total by a certified reflexologist) and a control condition for each patient (with at least a two-day break). No changes were made in patients' regular schedule or medications. MAIN RESEARCH VARIABLES: Anxiety and pain. FINDINGS: Following the foot reflexology intervention, patients with breast and lung cancer experienced a significant decrease in anxiety. One of three pain measures showed that patients with breast cancer experienced a significant decrease in pain. CONCLUSIONS: The significant decrease in anxiety observed in this sample of patients with breast and lung cancer following foot reflexology suggests that this may be a self-care approach to decrease anxiety in this patient population. IMPLICATIONS FOR NURSING PRACTICE: Professionals and lay people can be taught reflexology. Foot reflexology is an avenue for human touch, can be performed anywhere, requires no special equipment, is noninvasive, and does not interfere with patients' privacy.

Creative strategies for updating knowledge on sexually transmitted diseases.

Updating knowledge is important in maintaining effective nursing competency. The hectic pace of health care delivery in the 1990s does not always allow for attending day-long continuing education sessions. This article presents creative teaching-learning strategies that are self-paced, interesting, and less time intensive, designed to update nurses on sexually transmitted diseases.

A comparison of nurse and patient: perceptions of postsurgical pain.

In this study, the nurses' and patients' perceptions of a patient's postsurgical pain were compared. Responses to the McGill Pain Questionnaire, Present Pain Intensity (MPQ-PPI) and the Visual Analogue Scale (VAS) indicated that nurses scored patients lower on the average than patients scored themselves, both before pain medication and after pain relief. As expected, the scores on the MPQ-PPI and VAS were highly correlated, except for patients' scores before administration of medication.

New permanent endocardial atrial J lead: implantation techniques and clinical performance.

The potential benefits of pacing systems which restore A-V synchrony have long been recognized. However, availability of atrial leads which are easily implanted and which consistently perform well has been limited. A new version of the silicone rubber tined J leads is now available. Changes were made in the insulation material, conductor configuration, tine configuration, and a J memory coil was added. After over three years of use in 100 patients, we conclude that these leads are easier to implant than previous atrial leads, and that they demonstrate excellent clinical performance.