Paleoecology grand challenge

Exactly 50 years ago, in 1964, a landmark article whose two-word title, “Strong inference,” revealed little and evoked plenty, appeared in the hallowed pages of Science (Platt, 1964). Simply stated, Platt's view of scientific research in its highest form proceeds through three steps: development of alternative hypotheses; design of crucial experiments to exclude one or more hypotheses; execution of careful studies to obtain clear-cut results. It was a powerful reminder of how problem solving can be performed, written in a style both informal and authoritative. In those days it was not unusual for the most prestigious scientific outlets to publish articles whose language seems to nowadays have been relegated to blog posts. Just seven years earlier, another Science paper had appeared with a whimsical title, “Biological clock in the unicorn” (Cole, 1957), addressing the excessive reliance on statistical analysis of cycles and correlations that was plaguing the biologists of the time. Among the many citable passages in either one of those articles, one may dwell on a segment in Platt's text: “Whether it is hand-waving or number-waving or equation-waving, a theory is not a theory unless it can be disproved. That is, unless it can be falsified by some possible experimental outcome.” Literal interpretations of such statements, especially when translated to all possible scientific research, are problematic, and Platt's impact is best described as “more an inspirational tract than the development of a formal scientific methodology” (Davis, 2006). It is in that vein that I decided to open this Grand Challenge editorial by evoking a paper from half a century earlier

Stem Circadian Phenology of Four Pine Species in Naturally Contrasting Climates from Sky-Island Forests of the Western USA

We identified intra-annual climatic drivers of stem water relationships and growth in foundation conifers at a subalpine site in the Great Basin Desert and at a montane site in the Mojave Desert (Nevada, USA). Sites were instrumented to represent naturally different levels of heat and drought stress as part of NevCAN (the Nevada Climate and ecohydrological Assessment Network). We analyzed three years (2013-2015) of sub-hourly dendrometer records for limber (Pinus flexilis) and bristlecone pine (Pinus longaeva) at the subalpine site, and for ponderosa (Pinus ponderosa) and pinyon pine (Pinus monophylla) at the montane site. Multiple logistic regression was used to identify relationships with environmental variables measured in-situ. At both sites, stem expansion occurred during the early morning and late afternoon, and irreversible stem increment was concentrated in the early morning hours. In subalpine species, stem growth started in late spring and continued until August, while at the montane site stem growth was episodic, peaking during summer monsoonal rainstorms. Circadian maximum and minimum stem size during the growing season were reversed during the dormant season at the colder/wetter subalpine site but not at the warmer/drier montane one. Knowledge of intra-annual tree-water relationships and stem growth helps understand how sky island forests grow under highly diverse climatic conditions, including severe drought and heat stress

Research poster: Eco-hydrological pathways inferred from stable isotopes in a Pinus ponderosa and Pinus monophylla woodland of the Sheep Range, southern Great Basin, USA

Research poste

Radiocarbon Analysis Confirms the Annual Nature of Sagebrush Growth Rings

In the Great Basin of North America, big sagebrush (Artemisia tridentata Nutt.) growth rings can be used to reconstruct environmental changes with annual resolution in areas where there is otherwise little such information available. We tested the annual nature of big sagebrush wood layers using accelerator mass spectrometry (AMS) radiocarbon dating. Four cross-sections from 3 sagebrush plants were collected near Ely, Nevada, USA, and analyzed using dendrochronological methods. Ten 14C measurements were then used to trace the location of the 1963–64 "bomb spike." Although the number of rings on each section did not exceed 60, crossdating was possible within a section and between sections. Years assigned to individual wood layers by means of crossdating aligned with their expected 14C values, matching the location of the 14C peak. This result confirmed the annual nature of growth rings formed by big sagebrush, and will facilitate the development of spatially explicit, well-replicated proxy records of environmental change, such as wildfire regimes, in Great Basin valleys

Virtual and Augmented Reality Therapy Framework for Phobia Treatment

Phobias are a common type of anxiety disorder that affects a great number of people. Treating phobias is not always straightforward and require a significant effort from both the patient and the therapist. In recent years, Virtual Reality Exposure Therapy and Augmented Reality Exposure Therapy have emerged to help in phobia treatments by using virtual content. However, most available systems are not free and require expensive hardware. In this paper, we present a free and open-source framework for phobia treatment, designed for both the therapist and the patient. A Virtual Reality scenario for acrophobia (fear of heights) and an Augmented Reality scenario for arachnophobia were developed for validation.XVI Workshop Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Virtual and Augmented Reality Therapy Framework for Phobia Treatment

Phobias are a common type of anxiety disorder that affects a great number of people. Treating phobias is not always straightforward and require a significant effort from both the patient and the therapist. In recent years, Virtual Reality Exposure Therapy and Augmented Reality Exposure Therapy have emerged to help in phobia treatments by using virtual content. However, most available systems are not free and require expensive hardware. In this paper, we present a free and open-source framework for phobia treatment, designed for both the therapist and the patient. A Virtual Reality scenario for acrophobia (fear of heights) and an Augmented Reality scenario for arachnophobia were developed for validation.XVI Workshop Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Long-term response of Torrey pine to coastal climate: precipitation, temperature, and fog

EXTRACT (SEE PDF FOR FULL ABSTRACT): Torrey pine (Pinus torreyana Parry ex Carr.) has one of the most limited geographical ranges and population size in the Pinus genus; it is present only on Santa Rosa Island and on the coast between San Diego and Del Mar, where our research was conducted. A 168-year chronology (1827-1994) was developed using 28 increment cores extracted from 15 living and 2 dead stranding trees at Torrey Pines State Reserve, San Diego, California. ... The spatial correlation with western North America winter and spring precipitation, as well as with published tree-ring chronologies, indicates a connection with the American Southwest. Global correlation maps with winter sea level pressure and sea surface temperature are consistent with the hypothesis that San Diego precipitation is affected by a southerly displaced North Pacific storm track and by warmer water farther south, both leading to higher transport of lower latitude moisture