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Creating a climate for critical thinking in the preceptorship experience.

The impact of the learning climate on students' ability to think critically during preceptorship cannot be underestimated. The success of students in learning to think critically rests largely with the tone set by preceptors and staff (Myrick 1998). Students must be led gently into the active role of discussing, dialoguing, and problem solving (Meyers 1986). They watch very carefully how respectfully preceptors and staff field their comments, quickly notice nonverbal cues that indicate how open, approachable and supportive the preceptors and the staff are to their questions and contributions, and then discern how valued they are as colleagues. When preceptors genuinely value, support, and work with students in the practice setting and staff accept them as part of the team, a climate that is conducive to learning and critical thinking is established. This is due to the fact that students feel safe enough to question, to challenge and be challenged, and to be creative in their problem solving. The purpose of this paper is threefold: a) to identify key factors in the preceptorship experience that contribute to the creation of a climate that is conductive to critical thinking; b) to provide important insights into the role of the preceptor and the staff within that context; and c) to discuss how nursing faculty can more actively contribute to ensuring that such a learning climate is achieved in the preceptorship experience.

Education, Nursing↗

Cities as harbingers of climate change: common ragweed, urbanization, and public health.

BACKGROUND: Although controlled laboratory experiments have been conducted to demonstrate the sensitivity of allergenic pollen production to future climatic change (ie, increased CO(2) and temperature), no in situ data are available. OBJECTIVE: The purpose of this investigation was to assess, under realistic conditions, the impact of climatic change on pollen production of common ragweed, a ubiquitous weed occurring in disturbed sites and the principal source of pollen associated with seasonal allergenic rhinitis. METHODS: We used an existing temperature/CO(2) gradient between urban and rural areas to examine the quantitative and qualitative aspects of ragweed growth and pollen production. RESULTS: For 2000 and 2001, average daily (24-hour) values of CO(2) concentration and air temperature within an urban environment were 30% to 31% and 1.8 degrees to 2.0 degrees C (3.4 degrees to 3.6 degrees F) higher than those at a rural site. This result is consistent with most global change scenarios. Ragweed grew faster, flowered earlier, and produced significantly greater above-ground biomass and ragweed pollen at urban locations than at rural locations. CONCLUSIONS: Here we show that 2 aspects of future global environmental change, air temperature and atmospheric CO(2), are already significantly higher in urban relative to rural areas. In general, we show that regional urbanization-induced temperature/CO(2) increases similar to those associated with projected global climatic change might already have public health consequences; we suggest that urbanization, per se, might provide a low-cost alternative to current experimental methods evaluating plant responses to climate change.

Allergens↗

Organizational climate, staffing, and safety equipment as predictors of needlestick injuries and near-misses in hospital nurses.

BACKGROUND: Recently passed federal legislation requires institutions to adopt safety equipment to prevent needlesticks, but there is little empirical evidence of the effectiveness of specific types of safety devices or the contribution of safety devices to reducing needlesticks relative to the contributions of staffing, organizational climate, and clinicians' experience. METHOD: In 1998, 2287 medical-surgical unit nurses in 22 US hospitals were surveyed in regard to staffing and organizational climate in their hospitals and about patient and nurse outcomes, including needlestick injuries. Hospitals provided information about available protective devices at the time of the survey. Relationships between nurse and hospital characteristics and protective equipment and the likelihood of needlestick injuries and near-miss incidents were examined. RESULTS: Poor organizational climate and high workloads were associated with 50% to 2-fold increases in the likelihood of needlestick injuries and near-misses to hospital nurses. Capless-valve secondary intravenous set systems and use of any type of protective equipment for IV starts or blood draws were associated with 20% to 30% lowered risks of both event types. CONCLUSIONS: Nurse staffing and organizational climate are key determinants of needlestick risk and must be considered with the adoption of safety equipment to effectively reduce sharps injuries.

Accidents, Occupational↗

Climate change impacts are sensitive to the concentration stabilization path.

Analysis of policies to achieve the long-term objective of the United Nations Framework Convention on Climate Change, stabilizing concentrations of greenhouse gases at levels that avoid "dangerous" climate changes, must discriminate among the infinite number of emission and concentration trajectories that yield the same final concentration. Considerable attention has been devoted to path-dependent mitigation costs, generally for CO2 alone, but not to the differential climate change impacts implied by alternative trajectories. Here, we derive pathways leading to stabilization of equivalent CO2 concentration (including radiative forcing effects of all significant trace gases and aerosols) with a range of transient behavior before stabilization, including temporary overshoot of the final value. We compare resulting climate changes to the sensitivity of representative geophysical and ecological systems. Based on the limited available information, some physical and ecological systems appear to be quite sensitive to the details of the approach to stabilization. The likelihood of occurrence of impacts that might be considered dangerous increases under trajectories that delay emissions reduction or overshoot the final concentration.

Journal Article↗

A climate-change risk analysis for world ecosystems.

We quantify the risks of climate-induced changes in key ecosystem processes during the 21st century by forcing a dynamic global vegetation model with multiple scenarios from 16 climate models and mapping the proportions of model runs showing forest/nonforest shifts or exceedance of natural variability in wildfire frequency and freshwater supply. Our analysis does not assign probabilities to scenarios or weights to models. Instead, we consider distribution of outcomes within three sets of model runs grouped by the amount of global warming they simulate: <2 degrees C (including simulations in which atmospheric composition is held constant, i.e., in which the only climate change is due to greenhouse gases already emitted), 2-3 degrees C, and >3 degrees C. High risk of forest loss is shown for Eurasia, eastern China, Canada, Central America, and Amazonia, with forest extensions into the Arctic and semiarid savannas; more frequent wildfire in Amazonia, the far north, and many semiarid regions; more runoff north of 50 degrees N and in tropical Africa and northwestern South America; and less runoff in West Africa, Central America, southern Europe, and the eastern U.S. Substantially larger areas are affected for global warming >3 degrees C than for <2 degrees C; some features appear only at higher warming levels. A land carbon sink of approximately 1 Pg of C per yr is simulated for the late 20th century, but for >3 degrees C this sink converts to a carbon source during the 21st century (implying a positive climate feedback) in 44% of cases. The risks continue increasing over the following 200 years, even with atmospheric composition held constant.

Atmosphere↗

Pronounced climatic variations in Alaska during the last two millennia.

Paired oxygen-isotopic analyses of abiotic carbonate and benthic-ostracode shells from lake sediments provide a continuous quantitative record of growing-season temperature for the past 2000 years in the northwestern foothills of the Alaska Range. This record reveals three time intervals of comparable warmth: anno Domini (A.D.) 0-300, 850-1200, and post-1800, the latter two of which correspond to the Medieval Climatic Anomaly and climatic amelioration after the end of the Little Ice Age. The Little Ice Age culminated at A.D. 1700, when the climate was approximately 1.7 degrees C colder than at present. A marked climatic cooling also occurred around A.D. 600, coinciding with extensive glacial advances in Alaska. Comparisons of this temperature record with ostracode trace-element ratios (Mg/Ca, Sr/Ca) further suggest that colder periods were wetter and vice versa during the past 2000 years.

Journal Article↗

Predicting the effects of climate change on avian life-history traits.

Across North America, tree swallows have advanced their mean date of clutch initiation (lay date) by approximately 9 days over the past 30 years, apparently in response to climate change. In a sample of 2,881 nest records collected by the lay public from 1959 to 1991, we examined whether clutch size has also responded to climate change. We found that clutch size is strongly related to lay date, both within and among years, and there has been no significant temporal variation in the slopes or intercepts of the clutch-size/lay-date regressions. As a consequence, we expected increases in clutch size with advancement in lay date; however, we detected no such trend over time. The distributions of egg-laying dates were more constricted in the warmest (and earliest) years, suggesting that changes in mean clutch size might be constrained by changes in the distribution of laying dates. If spring temperatures continue to increase, we predict further reductions of variance in laying dates and relatively small increases in clutch size. Such constraints on life-history variation probably are common and need to be considered when modeling the effects of climate change on reproduction in natural populations. Predicting the long-term effects of constraints and interpreting changes in life-history traits require a better understanding of both adaptive and demographic effects of climate change.

Animals↗

Soot climate forcing via snow and ice albedos.

Plausible estimates for the effect of soot on snow and ice albedos (1.5% in the Arctic and 3% in Northern Hemisphere land areas) yield a climate forcing of +0.3 W/m(2) in the Northern Hemisphere. The "efficacy" of this forcing is approximately 2, i.e., for a given forcing it is twice as effective as CO(2) in altering global surface air temperature. This indirect soot forcing may have contributed to global warming of the past century, including the trend toward early springs in the Northern Hemisphere, thinning Arctic sea ice, and melting land ice and permafrost. If, as we suggest, melting ice and sea level rise define the level of dangerous anthropogenic interference with the climate system, then reducing soot emissions, thus restoring snow albedos to pristine high values, would have the double benefit of reducing global warming and raising the global temperature level at which dangerous anthropogenic interference occurs. However, soot contributions to climate change do not alter the conclusion that anthropogenic greenhouse gases have been the main cause of recent global warming and will be the predominant climate forcing in the future.

Journal Article↗

Tree rings, carbon dioxide, and climatic change.

Tree rings have been used in various applications to reconstruct past climates as well as to assess the effects of recent climatic and environmental change on tree growth. In this paper we briefly review two ways that tree rings provide information about climate change and CO2: (i) in determining whether recent warming during the period of instrumental observations is unusual relative to prior centuries to millennia, and thus might be related to increasing greenhouse gases; and (ii) in evaluating whether enhanced radial growth has taken place in recent decades that appears to be unexplained by climate and might instead be due to increasing atmospheric CO2 or other nutrient fertilization. It is found that a number of tree-ring studies from temperature-sensitive settings indicate unusual recent warming, although there are also exceptions at certain sites. The present tree-ring evidence for a possible CO2 fertilization effect under natural environmental conditions appears to be very limited.

Journal Article↗

Models for stochastic climate prediction.

There has been a recent burst of activity in the atmosphere/ocean sciences community in utilizing stable linear Langevin stochastic models for the unresolved degree of freedom in stochastic climate prediction. Here several idealized models for stochastic climate modeling are introduced and analyzed through unambiguous mathematical theory. This analysis demonstrates the potential need for more sophisticated models beyond stable linear Langevin equations. The new phenomena include the emergence of both unstable linear Langevin stochastic models for the climate mean and the need to incorporate both suitable nonlinear effects and multiplicative noise in stochastic models under appropriate circumstances. The strategy for stochastic climate modeling that emerges from this analysis is illustrated on an idealized example involving truncated barotropic flow on a beta-plane with topography and a mean flow. In this example, the effect of the original 57 degrees of freedom is well represented by a theoretically predicted stochastic model with only 3 degrees of freedom.

Journal Article↗

Airborne minerals and related aerosol particles: effects on climate and the environment.

Aerosol particles are ubiquitous in the troposphere and exert an important influence on global climate and the environment. They affect climate through scattering, transmission, and absorption of radiation as well as by acting as nuclei for cloud formation. A significant fraction of the aerosol particle burden consists of minerals, and most of the remainder- whether natural or anthropogenic-consists of materials that can be studied by the same methods as are used for fine-grained minerals. Our emphasis is on the study and character of the individual particles. Sulfate particles are the main cooling agents among aerosols; we found that in the remote oceanic atmosphere a significant fraction is aggregated with soot, a material that can diminish the cooling effect of sulfate. Our results suggest oxidization of SO2 may have occurred on soot surfaces, implying that even in the remote marine troposphere soot provided nuclei for heterogeneous sulfate formation. Sea salt is the dominant aerosol species (by mass) above the oceans. In addition to being important light scatterers and contributors to cloud condensation nuclei, sea-salt particles also provide large surface areas for heterogeneous atmospheric reactions. Minerals comprise the dominant mass fraction of the atmospheric aerosol burden. As all geologists know, they are a highly heterogeneous mixture. However, among atmospheric scientists they are commonly treated as a fairly uniform group, and one whose interaction with radiation is widely assumed to be unpredictable. Given their abundances, large total surface areas, and reactivities, their role in influencing climate will require increased attention as climate models are refined.

Journal Article↗

Can ozone depletion and global warming interact to produce rapid climate change?

The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate trends during the past few decades is marked by rapid cooling and ozone depletion in the polar lower stratosphere of both hemispheres, coupled with an increasing strength of the wintertime westerly polar vortex and a poleward shift of the westerly wind belt at the earth's surface. Annular modes of variability are fundamentally a result of internal dynamical feedbacks within the climate system, and as such can show a large response to rather modest external forcing. The dynamics and thermodynamics of these modes are such that strong synergistic interactions between stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible for the pronounced changes in tropospheric and stratospheric climate observed during the past few decades. If these trends continue, they could have important implications for the climate of the 21st century.

Journal Article↗

Peer relationships in adolescent competitive soccer: associations to perceived motivational climate, achievement goals and perfectionism.

The aim of this study was to examine the relationship between the perceived motivational climate, achievement goals, perfectionism and indices of peer relationships in a sample of young male and female Norwegian soccer players. The sample consisted of 1719 experienced soccer players (1231 males, 488 females) aged 12-19 years (mean = 14.9 years) participating in the Norway Cup international youth soccer competition. The players responded to a questionnaire measuring perceived peer acceptance and quality of friendship in soccer, perceived motivational climate, achievement goals and perfectionism in soccer. Canonical correlation analyses revealed that young female players who perceived the motivational climate as predominantly mastery oriented, and who were moderately task oriented and scored negatively on maladaptive perfectionism, reported better relations with their peers in soccer. Constructive peer relations were evident in that they scored positively on companionship with their best friend in soccer; they perceived this friend as being loyal and allowing of free discussion, and they reported being socially accepted by their peers in soccer. Mirroring these findings, young male players who perceived the motivational climate as predominantly performance oriented, who had a moderately negative score on task orientation but a quite strong positive score on maladaptive perfectionism, reported negative relationships with peers in terms of these aspects. They also reported being in conflict with their best soccer friend. The findings suggest that the qualities of motivation have a systematic relationship with peer acceptance and the quality of friendship in male and female youth soccer.

Achievement↗

Uncertainty requirements in radiative forcing of climate change.

The continuing increase in atmospheric carbon dioxide (CO2) makes it essential that climate sensitivity, the equilibrium change in global mean surface temperature that would result from a given radiative forcing, be quantified with known uncertainty. Present estimates are quite uncertain, 3 +/- 1.5 K for doubling of CO2. Model studies examining climate response to forcing by greenhouse gases and aerosols exhibit large differences in sensitivities and imposed aerosol forcings that raise questions regarding claims of their having reproduced observed large-scale changes in surface temperature over the 20th century. Present uncertainty in forcing, caused largely by uncertainty in forcing by aerosols, precludes meaningful model evaluation by comparison with observed global temperature change or empirical determination of climate sensitivity. Uncertainty in aerosol forcing must be reduced at least three-fold for uncertainty in climate sensitivity to be meaningfully reduced and bounded.

Aerosols↗

A model for simulating the effects of changing climate on the functioning and structure of the boreal forest ecosystem: an approach based on object-oriented design.

We have developed a forest ecosystem model to assess the effects of climate change on the functioning and structure of boreal coniferous forests assuming that temperature and precipitation are the major variables of the niche occupied by a tree species. We specified weather patterns to a level representing the time constant of different physiological and ecological processes relevant to the survival, growth and death of trees. We thereby coupled the long-term dynamics of the forest ecosystem with climate through physiological mechanisms such as photosynthesis and respiration in terms of energy flow through the ecosystem. The hydrological and nutrient cycles couple the dynamics of the forest ecosystem with climate change through soil processes, which represent the thermal and hydraulic properties of the soil, and the decomposition of litter and humus with mineralization of nutrients. Simulations for southern Finland (62 degrees N) indicated that an increase in temperature of 5 degrees C over one hundred years could reduce soil water in Scots pine-dominated forest ecosystems. At the same time, the temperature increase could enhance photosynthesis up to 6-8% under current CO(2) concentrations (330 ppm) and up to 8-10% under elevated CO(2) concentrations (660 ppm). Because the elevated temperature and CO(2) concentration caused an increase in respiration (12-14% more than under the current climate), total stem production increased only up to 4% with a 5 degrees C increase in temperature and up to 6% when temperature and atmospheric CO(2) concentration were increased simultaneously. Because transpiration only increased up to 5% in response to elevated temperature and CO(2) concentration, the water use efficiency of Scots-pine dominated forest ecosystems increased up to 3%, particularly during the late rotation.

Journal Article↗

Offsetting changes in biomass allocation and photosynthesis in ponderosa pine (Pinus ponderosa) in response to climate change.

We examined the effect of climate on aboveground biomass allocation of ponderosa pine (Pinus ponderosa) by measuring trees in disjunct forest stands growing on the same substrate at high-elevation montane sites and low-elevation desert sites. Climatic differences between the sites were comparable to the difference between present and future climates of interior North America that is expected to result from a doubling of atmospheric CO(2) concentration. Relative to the montane populations, the desert populations allocated a greater proportion of biomass to sapwood (functional xylem) at the expense of foliage. The leaf/sapwood area ratio and percent of aboveground biomass in sapwood for trees of the same height were 0.201 m(2) cm(-2) and 58% for montane trees and 0.104 m(2) cm(-2) and 71% for desert trees. In a phytotron experiment, increases in net photosynthesis and net assimilation rate for seedlings grown under future conditions of high CO(2) and temperature were offset by a decrease in leaf area ratio. As was observed for large trees at different elevations, increased temperatures caused an increase in biomass allocation to stem in the phytotron seedlings. Thus, CO(2)- and temperature-driven shifts in biomass allocation negated the effect on growth of the CO(2)-driven increase in carbon assimilation rate. Our data from the controlled growth chamber and field experiments suggest that future climate conditions, including elevated atmospheric CO(2), may not stimulate growth and productivity of ponderosa pine.

Journal Article↗

Modeling productivity and transpiration of Pinus radiata: climatic effects.

Climatic effects on annual net carbon gain, stem biomass and annual transpiration were simulated for Pinus radiata D. Don at Canberra and Mt. Gambier. Simulations were conducted with an existing process-based forest growth model (BIOMASS, Model 1) and with a modified version of the BIOMASS model (Model 2) in which response functions for carbon assimilation and leaf conductance were replaced with those derived from field gas exchange data collected at Mt. Gambier. Simulated carbon gain was compared with a published report stating that mean annual stem volume increment (MAI) at Mt. Gambier was 1.8 times greater than at Canberra and that the difference could be the result solely of differences in climate. Regional differences in climate resulted in a 20% greater simulated annual transpiration at Canberra than at Mt. Gambier but only small differences in simulated productivity, indicating that climatic differences did not account for the reported differences in productivity. With Model 1, simulated annual net carbon gain and annual increase in stem biomass were greater at Canberra than at Mt. Gambier, whereas Model 2 indicated a similar annual net carbon gain and annual stem biomass increase in both regions.

Journal Article↗

Developing adaptive forest management strategies to cope with climate change.

Numerous investigations have indicated that projected climate change will impact strongly on forest growth and composition. To adapt managed forests to changing environmental conditions it may be necessary to modify traditional forest management strategies. An extended version of a forest gap model was applied to a managed forest district in northeastern Germany. The model was initialized with forest inventory data and run using routines devised to simulate three management scenarios: (1) maximized timber production, (2) climatically well-adapted forest composition, and (3) maximized tree species diversity. The strategies were compared with a baseline scenario of traditional management without any response to climate change. The comparisons were based on simulated wood production and species composition after 110 years of development. The results underline the important influence that management strategies have on forest growth. Forest management may adopt a variety of strategies to respond to the expected changes in climate. Process-oriented forest gap models can aid in the assessment of these strategies.

Journal Article↗