Population assessment without individual identification using camera-traps: a comparison of four methods

The use of camera traps to estimate population size when animals are not individually recognizable is gaining traction in the ecological literature, because of its applicability in population conservation and management. We estimated population size of synthetic animals with four camera trap sampling-based statistical models that do not rely on individual recognition. Using a realistic model of animal movement to generate synthetic data, we compared the random encounter model, the random encounter and staying time model, the association model and the time-to-event-model and we investigated the impact of violation of assumptions on the population size estimates. While under ideal conditions these models provide reliable population estimates, when synthetic animal movements were characterised by differences in speed (due to diverse behaviours such as locomotion, grazing and resting) none of the model provided both unbiased and precise density estimates. The random encounter model and the time-to-event-model provided pre- cise results but tended to overestimate population size, while the random encounter and staying time model was less precise and tended to underestimate population size. Lastly, the association model was unable to provide precise results. We found that each tested model was very sensitive to the method used to estimate the range of the field-of-view of camera traps. Density esti- mates from both random encounter model and time-to-event-model were also very sensitive to biases in the estimate of ani- mals’ speed. We provide guidelines on how to use these statistical models to get population size estimates that could be useful to wildlife managers and practitioners

Diamond detectors with electrodes graphitized by means of laser

In the last years there has been an increase of interest in diamond devices because of the promising applications in different field, such as high-energy physics, radiotherapy and biochemical applications. In particular, a new frontier is represented by the realization of full-carbon detectors characterized by graphite electrodes, which give to the devices considerable advantages like high radiation hardness, perfect mechanical adhesion and good charge collection properties. In this paper the manufacturing of full-carbon devices and their detection performances are illustrated and compared to a reference diamond detector characterized by traditional electrodes

Realization and characterization of graphitic contacts on diamond by means of laser

This work deals with the realization and characterization of integrated graphitic contacts on diamond by means of laser irradiation (graphitization), in order to obtain good quality ohmic electrodes for nuclear radiation detectors to be used in high energy physics experiments. Unlike the conventional method used for the electrode production, which requires numerous steps and very well controlled environmental conditions, this alternative technique presents many advantages: the contacts are realized in air at room temperature in a single step. In this study, the characteristics of several graphitic structures realized on a diamond surface by changing the radiation-matter interaction parameters have been evaluated in order to define the best experimental conditions to create graphitic electrodes with low resistivity. The obtained results are promising: contacts perfectly adherent, with good charge collection properties, stable and resistant to ionizing radiation

A comparison of small rodent assemblages after a 20 year interval in the Alps

Human-induced environmental alterations in the Alps may importantly affect small mammal species, but evidence in this sense is limited. We live-trapped small rodents in the Central-Eastern Italian Alps in three close-by habitat types (rocky scree, alpine grassland, and heath) at 2100 m a.s.l. during summer-fall, in 1997 and 2016. We compared small rodent assemblages through a Redundancy Detrended Analysis (RDA). In both surveys, we detected two specialist species, i.e., the common vole (Microtus arvalis) and the snow vole (Chionomys nivalis), and, unexpectedly, the forest generalist bank vole (Myodes glareolus). In 1997, grassland was mainly occupied by the common vole, while the bank vole and the snow vole were sympatric in the other habitats. In 2016, the snow vole was detected only in the scree, while other species did not show distribution changes. We discuss a series of hypotheses that might have driven the differences observed across decades, among which is a species-specific response to abiotic and biotic environmental alterations, with the alpine habitat specialist moving out of sub-optimal habitats. We encourage further research on this topic, e.g., via long-term longitudinal studies

The effect of light sensitizer localization on the stability of indocyanine green liposomes

Light triggered drug delivery systems offer attractive possibilities for sophisticated therapy, providing both temporal and spatial control of drug release. We have developed light triggered liposomes with clinically approved indocyanine green (ICG) as the light sensitizing compound. Amphiphilic ICG can be localized in different compartments of the liposomes, but the effect of its presence, on both triggered release and long term stability, has not been studied. In this work, we report that ICG localization has a significant effect on the properties of the liposomes. Polyethylene glycol (PEG) coating of the liposomes leads to binding and stabilization of the ICG molecules on the surface of the lipid bilayer. This formulation showed both good storage stability in buffer solution (at +4-37 degrees C) and adequate stability in serum and vitreous (at +37 degrees C). The combination of ICG within the lipid bilayer and PEG coating lead to poor stability at elevated temperatures of +22 degrees C and +37 degrees C. The mechanisms of the increased instability due to ICG insertion in the lipid bilayer was elucidated with molecular dynamics simulations. Significant PEG insertion into the bilayer was induced in the presence of ICG in the lipid bilayer. Finally, feasibility of freeze-drying as a long term storage method for the ICG liposomes was demonstrated. Overall, this is the first detailed study on the interactions of lipid bilayer, light sensitizer (ICG) and PEG coating on the liposome stability. The localization of the light triggering agent significantly alters the structure of the liposomes and it is important to consider these aspects in triggered drug delivery system design.Peer reviewe

Innovative metallic solutions for alpine ski bases

Ski manufacturers are interested in improving ski performance in terms of rapid sliding, excellent trajectory control, and reduced maintenance. A possible approach to achieve this goal is based on substitution of the base material, moving from the standard ultra-high-molecular-weight polyethylene to metallic solutions. Despite their elevated mechanical properties, however, metallic materials exhibit a poor sliding behavior, at least in their original manufacture condition. Although the interaction between the ski base and snow is still an open field, the authors investigated the relationship between ice friction and material hydrophobicity. The wettability behavior of surfaces can be managed by surface patterning techniques, among which laser surface texturing (LST) is a promising method, permitting surface feature modification from the micrometer- to millimeter-scale, and attractive for industrial applications. Herein, the tribological properties of two metallic materials are investigated and a process to reduce the sliding friction against snow is proposed. The LST is used to realize dimple patterning on the metallic surfaces, where the laser parameters are used to control the dimple geometry and surface wettability using untreated substrates as a reference condition. Finally, characterization using a prototype snow tribometer was performed to determine the friction coefficient and sliding performance of the laser-treated metallic surfaces

Incidence trends and risk factors of lung cancer in never smokers : Pooled analyses of seven cohorts

The trends in incidence of lung cancer in never smokers are unclear as well as the significance of risk factors. We studied time trends in the incidence and risk factors of lung cancer in never smokers in Finland in a large, pooled cohort. We pooled data from seven Finnish health cohorts from the period between 1972 and 2015 with 106 193 never smokers. The harmonised risk factors included education, alcohol consumption, physical activity, height and BMI. We retrieved incident lung cancers from the nation-wide Finnish Cancer Registry. We estimated average annual percent change (AAPC) and the effects of risk factors on cause-specific hazard ratios (HRs) of lung cancer using Poisson regression. We detected 47 lung cancers in never smoking men (n = 31 859) and 155 in never smoking women (n = 74 334). The AAPC of lung cancer incidence was -3.30% (95% confidence interval [CI]: -5.68% to -0.88%, P = .009) in never smoking men and 0.00% (95% CI: -1.57% to 1.60%, P = .996) in never smoking women. Of the five studied risk factors only greater height in women had a statistically significant increased risk of lung cancer (multivariate HR = 1.84, 95%CI: 1.08 to 3.12). It is plausible that tobacco control measures focused on working places have reduced passive smoking among men more than among women, which could explain the declining trend in lung cancer incidence in never smoker men but not in never smoker women. As tobacco control measures have not been targeted to domestic environments, it is likely that women's exposure to passive smoking has continued longer.Peer reviewe

Incidence trends and risk factors of lung cancer in never smokers : Pooled analyses of seven cohorts

The trends in incidence of lung cancer in never smokers are unclear as well as the significance of risk factors. We studied time trends in the incidence and risk factors of lung cancer in never smokers in Finland in a large, pooled cohort. We pooled data from seven Finnish health cohorts from the period between 1972 and 2015 with 106 193 never smokers. The harmonised risk factors included education, alcohol consumption, physical activity, height and BMI. We retrieved incident lung cancers from the nation-wide Finnish Cancer Registry. We estimated average annual percent change (AAPC) and the effects of risk factors on cause-specific hazard ratios (HRs) of lung cancer using Poisson regression. We detected 47 lung cancers in never smoking men (n = 31 859) and 155 in never smoking women (n = 74 334). The AAPC of lung cancer incidence was -3.30% (95% confidence interval [CI]: -5.68% to -0.88%, P = .009) in never smoking men and 0.00% (95% CI: -1.57% to 1.60%, P = .996) in never smoking women. Of the five studied risk factors only greater height in women had a statistically significant increased risk of lung cancer (multivariate HR = 1.84, 95%CI: 1.08 to 3.12). It is plausible that tobacco control measures focused on working places have reduced passive smoking among men more than among women, which could explain the declining trend in lung cancer incidence in never smoker men but not in never smoker women. As tobacco control measures have not been targeted to domestic environments, it is likely that women's exposure to passive smoking has continued longer.Peer reviewe

Pairwise association of key lifestyle factors and risk of colorectal cancer : a prospective pooled multicohort study

Background Several lifestyle factors are associated with an increased risk of colorectal cancer (CRC). Although lifestyle factors co-occur, in most previous studies these factors have been studied focusing upon a single risk factor or assuming independent effects between risk factors. Aim To examine the pairwise effects and interactions of smoking, alcohol consumption, physical inactivity, and body mass index (BMI) with risk of subsequent colorectal cancer (CRC). Methods and results We used METCA cohort data (pooled data from seven population-based Finnish health behavior survey studies during years 1972-2015) consisting of 171 063 women and men. Participants' smoking, alcohol consumption, physical inactivity and BMI measures were gathered, and participants were categorized into those exposed and those not exposed. The incidence of CRC was modeled by Poisson regression with main and interaction effects of key lifestyle factors. The cohort members were followed-up through register linkage to the Finnish Cancer Registry for first primary CRC case until the end of 2015. Follow-up time was 1715, 690 person years. The highest pairwise CRC risk was among male smokers who had overweight (BMI >= 25 kg/m(2)) (HR 1.75, 95% CI 1.36-2.26) and women who had overweight and consumed alcohol (HR 1.45, 95% CI 1.14-1.85). Overall, among men the association of lifestyle factors and CRC risk was stronger than among women. In men, both having overweight and being a smoker combined with any other adverse lifestyle factor increased CRC risk. Among women, elevated CRC risks were observed for those who were physically inactive and who consumed alcohol or had overweight. No statistically significant interactions were detected between pairs of lifestyle factors. Conclusions This study strengthens the evidence of overweight, smoking, and alcohol consumption as CRC risk factors. Substantial protective benefits in CRC risk can be achieved by preventing smoking, maintaining BMI toPeer reviewe