Abstract: Anthropogenic light is known or suspected to exert profound effects on many taxa, including birds. Documentation of bird aggregation around artificial light at night, as well as observations of bird reactions to strobe lights and lasers, suggests that light may both attract and repel birds, although this assumption has yet to be tested. These effects may cause immediate changes to bird movement, habitat selection and settlement, and ultimately alter bird distribution at large spatial scales. Global increases in the extent of anthropogenic light contribute to interest by wildlife managers and the public in managing light to reduce harm to birds, but there are no evidence syntheses of the multiple ways light affects birds to guide this effort. Existing reviews usually emphasize either bird aggregation or deterrence and do so for a specific context, such as aggregation at communication towers and deterrence from airports. We outline a protocol for a systematic map that collects and organizes evidence from the many contexts in which anthropogenic light is reported to affect bird movement, habitat selection, or distribution. Our map will provide an objective synthesis of the evidence that identifies subtopics that may support systematic review and knowledge gaps that could direct future research questions. These products will substantially advance an understanding of both patterns and processes associated with the responses of birds to anthropogenic light.

Abstract: Although selenium is known to be essential for reproductive function, studies have indicated the adverse effect with its prolonged use. The present study investigated the duration-related effect of selenium administrations on reproductive hormones and estrous cycle indices in adult female Wistar rats exposed to a model of light pollution using altered photoperiod (AP). Ninety-six cyclic female Wistar rats displaying 4-5 days' estrous cycle length (ECL) and weighing 148-152 g were randomly divided into short and long experimental cohorts consisting of six groups each and spanning for 1 and 8 weeks, respectively. Each consisted of control, high selenium dose (HSE), low selenium dose (LSE), AP, AP + HSE, and AP + LSE. The rats were orally administered high dose (150 mug/kg) and low dose (100 mug/kg) of sodium selenite once per day. The estrous cycle indices were monitored. Plasma levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E), progesterone (P), prolactin, E/P ratio, and histology of ovary and uterine horn were evaluated. The statistical analysis was performed using Statistical Package for the Social Sciences. In AP rats, HSE and LSE caused no significant effect on LH, E, P, and E/P ratio, ECL, estrus interval (EI), and estrous cycle ratio (ECR). The effect of HSE and LSE on LH, E, P, E/P ratio, and ECL showed no duration-dependent increase, but there was a duration-dependent increase in EI and ECR at low dose. The study indicated that administration of HSE of selenium improved reproductive function in photo-pollution-exposed rats irrespective of the duration of treatment.

Abstract: Currently, one of the most disputed hypotheses regarding breast cancer (BC) development is exposure to short wavelength artificial light at night (ALAN) as multiple studies suggest a possible link between them. This link is suggested to be mediated by nocturnal melatonin suppression that plays an integral role in circadian regulations including cell division. The objective of the research was to evaluate effects of 1 x 30 min/midnight ALAN (134 micro Wcm(-2), 460 nm) with or without nocturnal melatonin supplement on tumor development and epigenetic responses in 4T1 tumor-bearing BALB/c mice. Mice were monitored for body mass (Wb) and tumor volume for 3 weeks and thereafter urine samples were collected at regular intervals for determining daily rhythms of 6-sulfatoxymelatonin (6-SMT). Finally, mice were sacrificed and the tumor, lungs, liver, and spleen were excised for analyzing the total activity of DNA methyltransferases (DNMT) and global DNA methylation (GDM) levels. Mice exposed to ALAN significantly reduced 6-SMT levels and increased Wb, tumor volume, and lung metastasis compared with controls. These effects were diminished by melatonin. The DNMT activity and GDM levels showed tissue-specific response. The enzymatic activity and GDM levels were lower in tumor and liver and higher in spleen and lungs under ALAN compared with controls. Our results suggest that ALAN disrupts the melatonin rhythm and potentially leading to increased BC burden by affecting DNMT activity and GDM levels. These data may also be applicable to early detection and management of BC by monitoring melatonin and GDM levels as early biomarker of ALAN circadian disruption.