Outdoor artificial light at night and risk of early-onset dementia: A case-control study in the Modena population, Northern Italy

Background Dementia is a neurological syndrome characterized by severe cognitive impairment with functional impact on everyday life. It can be classified as young onset dementia (EOD) in case of symptom onset before 65, and late onset dementia (LOD). The purpose of this study is to assess the risk of dementia due to light pollution, and specifically outdoor artificial light at night (LAN). Methods Using a case-control design, we enrolled dementia patients newly-diagnosed in the province of Modena in the period 2017–2019 and a referent population from their caregivers. We geo-referenced the address of residence on the date of recruitment, provided it was stable for the previous five years. We assessed LAN exposure through 2015 nighttime luminance satellite images from the Visible Infrared Imaging Radiometer Suite (VIIRS). Using a logistic regression model adjusted for age, sex, and education, we calculated the risk of dementia associated with increasing LAN exposure, namely using <10 nW/cm2/sr as reference and considering ≥10-<40 nW/cm2/sr intermediate and ≥40 nW/cm2/sr high exposure, respectively We also implemented non-linear assessment using a spline regression model. Results We recruited 58 EOD cases, 34 LOD cases and 54 controls. Average LAN exposure levels overlapped for EOD cases and controls, while LOD cases showed higher levels. Compared with the lowest exposure, the risk of EOD associated with LAN was higher in the intermediate exposure (OR = 1.36, 95% CI 0.54–3.39), but not in the high exposure category (OR = 1.04, 95% CI 0.32–3.34). In contrast, the risk of LOD was positively associated with LAN exposure, with ORs of 2.58 (95% CI 0.26–25.97) and 3.50 (95% CI 0.32–38.87) in the intermediate and high exposure categories, respectively. The spline regression analysis showed substantial lack of association between LAN and EOD, while almost linear although highly imprecise association emerged for LOD. Conclusions Although the precision of the estimates was affected by the limited sample size and the study design did not allow us to exclude the presence of residual confounding, these results suggest a possible role of LAN in the etiology of dementia, particularly of its late-onset form

Standard test methods for rating of solar reflectance of built-up surfaces and potential use of satellite remote sensors

More and more attention is being paid to the solar reflectance of built-up surfaces due to its influence on the summer heating of buildings and urban areas and the consequent effects on energy needs for air conditioning, as well as on the peak load of the electric grid. Several standard test methods are available for measuring solar reflectance in the laboratory or in the field, based on different devices and approaches. A convergence of some methods has been achieved by rating programs in the U.S. and, more recently, in Europe and other areas. However, laboratory or field measurements are impractical for characterizing a large number of urban surfaces—whether it is for identifying critical issues, developing policies, or verifying compliance with building requirements. In this regard, satellite remote sensors have recently become available, through which it is possible to estimate the reflectance of roof and pavement surfaces thanks to a spatial resolution that is suitable for identifying and characterizing individual built-up surfaces. In the present paper, the most-used standard test methods for rating of solar reflectance are reviewed. Subsequently, some publicly accessible satellite sensors are examined, through which comparable measurements could be obtained

Identification of SUHI in Urban Areas by Remote Sensing Data and Mitigation Hypothesis through Solar Reflective Materials

The urban heat island (UHI) is an increasingly widespread phenomenon of concern to the wellbeing and the health of populations living in urban environments. The SUHI (Surface UHI) is directly related to UHI and influences its extension and intensity. Satellite images in the thermal infrared spectral region can be used to identify and study the SUHI. In this work, Landsat 8 TIR images were acquired to study the SUHI of a medium-sized municipality of the Po valley in the northern part of Italy. An additional Worldview 3 satellite image was used to classify the study area and retrieve the surface albedo of building roofs. Using the Local Climate Zone approach, existing roof materials were virtually replaced by solar reflective materials, and the mitigation potential of the SUHI and the UHI was quantified. This virtual scenario shows a decrease in the overheating of building roofs with respect to the ambient temperature of up to 33% compared to the current situation in the industrial areas. Focusing on UHI intensity, the air temperature decrease could be up to 0.5◦C

The role of the ATPase inhibitor factor 1 (IF(1)) in cancer cells adaptation to hypoxia and anoxia

The physiological role of the mitochondrial ATP synthase complex is to generate ATP through oxidative phosphorylation. Indeed, the enzyme can reverse its activity and hydrolyze ATP under ischemic conditions, as shown in isolated mitochondria and in mammalian heart and liver. However, what occurs when cancer cells experience hypoxia or anoxia has not been well explored. In the present study, we investigated the bioenergetics of cancer cells under hypoxic/anoxic conditions with particular emphasis on ATP synthase, and the conditions driving it to work in reverse. In this context, we further examined the role exerted by its endogenous inhibitor factor, IF1, that it is overexpressed in cancer cells. Metabolic and bioenergetic analysis of cancer cells exposed to severe hypoxia (down to 0.1% O2) unexpectedly showed that \u394\u3c8m is preserved independently of the presence of IF1 and that ATP synthase still phosphorylates ADP though at a much lower rate than in normoxia. However, when we induced an anoxia-mimicking condition by collapsing \u394\u3bc\u397+ with the FCCP uncoupler, the IF1-silenced clones only reversed the ATP synthase activity hydrolyzing ATP in order to reconstitute the electrochemical proton gradient. Notably, in cancer cells IF1 overexpression fully prevents ATP synthase hydrolytic activity activation under uncoupling conditions. Therefore, our results suggest that IF1 overexpression promotes cancer cells survival under temporary anoxic conditions by preserving cellular ATP despite mitochondria dysfunction

Hypoxia decreases ROS level in human fibroblasts

We have previously demonstrated that cells adapt to hypoxia using different metabolic reprogramming mechanisms depending on metabolism. We now investigate how the different adapting mechanisms affect reactive oxygen species (ROS) levels, and how ROS levels and cellular metabolism are linked. We show that when skin fibroblasts grew under short-term hypoxia (1% oxygen tension) ROS level markedly decreased (-50%) whatever substrate was available to the cells. Indeed, cellular ROS level linearly and directly decreased with oxygen tension. However, these relationships cannot explain the progressive ROS level decrease observed after prolonged cells hypoxia exposure. In glucose-enriched medium reduced mitochondrial mass and greater fragmentation are observed, both clear-cut indications of mitophagy suggesting that this is responsible for cellular ROS level decrease. Otherwise, in glucose-free medium exposure to prolonged hypoxia resulted in only minor mass reduction, but significantly enhanced expression of antioxidant enzymes. Interestingly, cellular ROS levels were lower in glucose-free compared to glucose-enriched medium under either normoxic or hypoxic conditions. Taken together, these findings reveal that in primary human fibroblasts hypoxia induces a decline in ROS and that different metabolism-dependent mechanisms contribute it, besides the major oxygen concentration decrease. In addition, the present data support the notion that metabolisms generating fewer ROS are associated with lower HIF-1α stabilization

Hypoxia Decreases ROS level in human fibroblasts

We have previously demonstrated that cells adapt to hypoxia using different metabolic reprogramming mechanisms depending on metabolism. We now investigate how the different adapting mechanisms affect reactive oxygen species (ROS) levels, and how ROS levels and cellular metabolism are linked. We show that when skin fibroblasts grew under short-term hypoxia (1% oxygen tension) ROS level markedly decreased (-50%) whatever substrate was available to the cells. Indeed, cellular ROS level linearly and directly decreased with oxygen tension. However, these relationships cannot explain the progressive ROS level decrease observed after prolonged cells hypoxia exposure. In glucose-enriched medium reduced mitochondrial mass and greater fragmentation are observed, both clear-cut indications of mitophagy suggesting that this is responsible for cellular ROS level decrease. Otherwise, in glucose-free medium exposure to prolonged hypoxia resulted in only minor mass reduction, but significantly enhanced expression of antioxidant enzymes. Interestingly, cellular ROS levels were lower in glucose-free compared to glucose-enriched medium under either normoxic or hypoxic conditions. Taken together, these findings reveal that in primary human fibroblasts hypoxia induces a decline in ROS and that different metabolism-dependent mechanisms contribute it, besides the major oxygen concentration decrease. In addition, the present data support the notion that metabolisms generating fewer ROS are associated with lower HIF-1α stabilization

Photogrammetry and Remote Sensing for the identification and characterization of trees in urban areas

For the last few decades, there have been a lot of studies recognising the significant roles of the urban trees as a high-quality carbon sink. This work is a preliminary study about how remote sensing and photogrammetry could be useful tools to identify urban trees for the purpose of Carbon Storage (CS) computation in urban areas. Our first study area is a typical urban park located in Sassuolo, a municipality in the northern part of Italy in the so-called "Pianura Padana". We measured the tree Height (H) and the Diameter at Breast Height (DBH), required for the calibration of the CS, based on the tree allometry during the field data collection along with the constructing a 3D model through the photogrammetric approach. A high-resolution WorldView (WV) 3 satellite image of the same area, was classified using an object-oriented approach to count the number of trees varied with different species. This preliminary study will enhance the possibilities of the application of these approaches in case of the larger urban areas to ascertain the accuracy of the tree CS calibration