Causes and consequences of past and projected Scandinavian summer temperatures, 500-2100 AD

Tree rings dominate millennium-long temperature reconstructions and many records originate from Scandinavia, an area for which the relative roles of external forcing and internal variation on climatic changes are, however, not yet fully understood. Here we compile 1,179 series of maximum latewood density measurements from 25 conifer sites in northern Scandinavia, establish a suite of 36 subset chronologies, and analyse their climate signal. A new reconstruction for the 1483–2006 period correlates at 0.80 with June–August temperatures back to 1860. Summer cooling during the early 17th century and peak warming in the 1930s translate into a decadal amplitude of 2.9°C, which agrees with existing Scandinavian tree-ring proxies. Climate model simulations reveal similar amounts of mid to low frequency variability, suggesting that internal ocean-atmosphere feedbacks likely influenced Scandinavian temperatures more than external forcing. Projected 21st century warming under the SRES A2 scenario would, however, exceed the reconstructed temperature envelope of the past 1,500 years.

The Uses of Violence: An Examination of some Cross-Cutting Issues

A general theory of violence may only be possible in the sense of a meta-theoretical framework, As such it should comprise a parsimonious set of general mechanisms that operate across various manifestations of violence. In order to identify such mechanisms, a general theory of violence needs to equally consider all manifestations of violence, in all societies, and at all times. Departing from this assumption this paper argues that three theoretical approaches may be combined in a non-contradictory way to understand violence as goal-directed instrumental behaviour: a theory of the judgment and decision-making processes operating in the situations that give rise to violence; a theory of the evolutionary processes that have resulted in universal cognitive and emotional mechanisms associated with violence; and a theory of the way in which social institutions structure violence by selectively enhancing its effectiveness for some purposes (i.e legitimate use of force) and controlling other types of violence (i.e crime). To illustrate the potential use of such a perspective the paper then examines some general mechanisms that may explain many different types of violence. In particular, it examines how the mechanisms of moralistic aggression (Trivers) and moral disengagement (Bandura) may account for many different types of violence.

The adaptive power of the present: Perceptions of past, present, and future life satisfaction across the life span

Despite remarkable stability of life satisfaction across the life span, it may be adaptive to perceive change in life satisfaction. We shed new light on this topic with data from 766 individuals from three age groups and past, present, and future life satisfaction perceptions across the life span. On average, participants were most satisfied with their current life. When looking back, satisfaction increased from past to present, and when looking ahead, satisfaction decreased into the future. Trajectories were best fitted with a curvilinear growth model. Neuroticism and extraversion predicted the level of trajectories, but none of the Big Five predicted the slope. We conclude that humans have an adaptive capacity to perceive the present life as being the best possible.

Lake sediments as archives of recurrence rates and intensities of past flood events

Palaeoflood hydrology is an expanding field as the damage potential of flood and flood-related processes are increasing with the population density and the value of the infrastructure. Assessing the risk of these hazards in mountainous terrain requires knowledge about the frequency and severness of such events in the past. A wide range of methods is employed using diverse biologic, geomorphic or geologic evidences to track past flood events. Impact of floods are studied and dated on alluvial fans and cones using for example the growth disturbance of trees (Stoffel and Bollschweiler 2008; Schneuwly-Bollschweiler and Stoffel 2012: this volume) or stratigraphic layers deposited by debris flows, allowing to reconstruct past flood frequencies (Bardou et~al. 2003). Further downstream, the classical approach of palaeoflood hydrology (Kochel and Baker 1982) utilizes geomorphic indicators such as overbank sediments, silt lines and erosion features of floods along a river (e.g. Benito and Thorndycraft 2005). Fine-grained sediment settles out of the river suspension in eddies or backwater areas, where the flow velocity of the river is reduced. Records of these deposits at different elevations across a river’s profile can be used to assess the discharge of the past floods. This approach of palaeoflood hydrology studies was successfully applied in several river catchments (e.g. Ely et al. 1993; Macklin and Lewin 2003; O’Connor et al. 1994; Sheffer et al. 2003; Thorndycraft et al. 2005; Thorndycraft and Benito 2006). All these different reconstruction methods have their own advantages and disadvantages, but often these studies have a limited time coverage and the records are potentially incomplete due to lateral limits of depositional areas and due to the erosional power of fluvial processes that remove previously deposited flood witnesses. Here, we present a method that follows the sediment particle transported by a flood event to its final sink: the lacustrine basin.

Characteristics and experiences of past participants in the Texas Peer Assistance Program for Nurses

There are nearly 200,000 licensed practicing nurses in the state of Texas, representing one-tenth of the nations' workforce. The prevalence of substance abuse among nurses is estimated to range between six and 20 percent in this professional group.^ Since March 1987, the Texas Peer Assistance Program for Nurses (TPAPN) has offered intervention, education, support and monitoring to nurses in Texas whose practice has become impaired due to substance abuse and/or mental illness. Since then approximately 44 percent of nurses who voluntarily signed participation agreements successfully completed the program; fifty-six percent have not. One determinant of completion for those nurses identified as chemically dependent is abstinence from mood altering substances. Other helping professions report higher rates of abstinence two years following treatment.^ The purpose of this study was to investigate the relationship between relapse, demographics, treatment variables, work setting, "stress" indicators and support factors for nurses who participated in TPAPN. A questionnaire was mailed to 1000 randomly selected nurses who had signed agreements since 1987 and were no longer active in the program. More than 41% of the questionnaires were returned undeliverable.^ Recipients of the questionnaire were known only to TPAPN, never to the investigator. All information was received anonymously except when the participant chose to sign the questionnaire. A cover letter explaining the study and inviting participation was enclosed. Completion and return of the questionnaire was considered consent to participate.^ Findings demonstrated a significant relationship between relapse and opiates as the drug of choice for past participants in the Texas Peer Assistance Program for Nurses. Significant associations were found among factors such as control at work, support, physical complaints, job security, self-esteem and employment in this sample. Respondents shared copious written comments about their experiences in TPAPN. These data were analyzed using qualitative methods and compared with similar studies of recovering nurses. Further research with nurses whose practice has been affected by abuse of chemical and mental illness is warranted. ^

A 2600-year record of past polycyclic aromatic hydrocarbons (PAHs) deposition at Holzmaar (Eifel, Germany)

Polycyclic aromatic hydrocarbons (PAHs) are a proxy for climate- and human-related historical fire activity which has rarely been used beyond 1800 AD. We explored the concentration and composition patterns of PAHs together with other proxies (charcoal, C, N, S, δ13C, δ15N, and δ34S) in a sediment core of Holzmaar as indicators of variations in climate and anthropogenic activity over the past 2600 years. The concentrations of pyrogenic PAHs remained low (< 500 ng g− 1) from the pre-Roman Iron Age (600 BC) until the first significant increases to ca. 1000–1800 ng g− 1 between 1700 and 1750 AD related to regional iron production. The highest increases in pyrogenic PAH concentrations occurred with industrialization peaking in the 1960s. PAH concentrations in most recent sediments decreased to pre-industrial levels because of emission control measures and the switch from coal to oil and gas as major fuel sources. Fluxes of PAHs (mg km− 2 yr− 1) increased in the order Migration Period and Early Middle Ages < pre-Roman Iron Ages < Roman era < High Middle Ages and Renaissance < pre-industrial modern period < industrial modern period. The changes of PAHs fluxes in pre-industrial times parallel known changes in local, regional and continental anthropogenic activity and climatic variations or their interactions across these historical periods. Perylene, a mainly biologically produced compound, was the dominant PAH in pre-industrial times. The Migration Period and the Early Middle Ages witnessed the most profound and simultaneous changes to the sedimentary organic matter properties in the past 2600 years including the lowest PAH fluxes because of reduced human activity and more negative δ13C and δ15N values probably in response to colder and wetter conditions.