Elevated Light Levels Research Articles

N6-benzyladenine (BAP)-Based Seed Preconditioning Enhances the Shoot Regeneration of Seedling-Derived Explants for Subsequent Indirect Gene Transfer in Soybeans (Glycine max [L.] Merrill.)

This study evaluated the effects of N6-benzyladenine (BAP) seed preconditioning and seedling-derived explants on in vitro plant regeneration potential in soybeans (Glycine max [L.] Merrill.). The findings showed that seed preconditioning with 2.55 mg/L BAP prior to germination significantly influenced seedling establishment and the development of shoots, shoot elongation, and rooting on MS media supplemented with BAP and TDZ, compared to the negative (MS-NC) and positive (MS-NP) controls. The results also showed significant differences based on the genotypes, with Dundee recording 91.0% germination over a minimum of 5 days, compared to 74.2% with Peking, followed by 87.5% and 80.0% overall shoot induction frequency in these genotypes, respectively. Regenerated shoots were successfully elongated on MS medium supplemented with 0.5 mg/L BAP plus 0.6 mg/L GA3 and rooted on hormone-free medium, for 3‒4 weeks, and then hardened in the acclimatization growth room under elevated light levels. Overall, this study revealed that BAP preconditioning of seeds enhances the frequency of bud initiation and shoot proliferation, mostly in whole-seedling and cotyledonary node explants subcultured on MS-E and MS-A media supplemented with BAP in combination with TDZ.

A comparison of optophysiological biomarkers of photoreceptor stress and phototoxicity in BALB/cJ, B6 (Cg)-Tyrc-2J/J, and C57Bl/6J mouse strains.

Ophthalmic imaging instruments, including the confocal scanning laser ophthalmoscope and spectral-domain optical coherence tomography system, originally intended for revealing ocular microstructures in the human eye, have been deployed by vision researchers to evaluate the eyes of numerous small and large animal species for more than two decades. In this study, we have used these two instruments to obtain imaging data sequentially from the retinas of three prominent, widely used experimental mouse models to document changes induced by two contrasting vivarium lighting conditions. Mice studied include albino BALB/cJ and B6(Cg)-Tyrc-2J/J and pigmented C57Bl/6J. Mice were reared under dim light conditions until ~8 weeks of age where they underwent baseline imaging. Following, mice were returned to the dim vivarium or relocated to the top rack cage position in a standard vivarium. Mice were then followed for several months by ocular imaging to catalog the retinal dynamics as a function of long-term dim vs. elevated, standard vivarium lighting exposure levels. Upon exposure to elevated light levels, B6(Cg)-Tyrc-2J/J underwent similar changes as BALB/cJ in regard to photoreceptor outer segment shortening, photoreceptor layer proximal aspect hyperreflective changes, and the development of retinal infoldings and autofluorescent sub-retinal inflammatory monocyte infiltrate. Noteworthy, however, is that infoldings and infiltrate occurred at a slower rate of progression in B6(Cg)-Tyrc-2J/J vs. BALB/cJ. The photoreceptor outer nuclear layer thickness of BALB/cJ degenerated steadily following elevated light onset. In contrast, B6(Cg)-Tyrc-2J/J degeneration was unremarkable for many weeks before experiencing a noticeable change in the rate of degeneration that was concomitant with a plateau and decreasing trend in number of retinal infoldings and monocyte infiltrate. Pathological changes in C57Bl/6J mice were unremarkable for all imaging biomarkers assessed with exception to autofluorescent sub-retinal inflammatory monocyte infiltrate, which showed significant accumulation in dim vs. elevated light exposed mice following ~1 year of observation. These data were evaluated using Spearman's correlation and Predictive Power Score matrices to determine the best imaging optophysiological biomarkers for indicating vivarium light stress and light-induced photoreceptor degeneration. This study suggests that changes in proximal aspect hyperreflectivity, outer segment shortening, retinal infoldings and autofluorescent sub-retinal inflammatory monocyte infiltrate are excellent indicators of light stress and light-induced degeneration in albino B6(Cg)-Tyrc-2J/J and BALB/cJ mouse strains.

Response of Posidonia oceanica (L.) Delile and Its Associated N2 Fixers to Different Combinations of Temperature and Light Levels

The increasing occurrence of heat waves and water turbidity are threats to the persistence of seagrass meadows. Their effects on the productivity of seagrasses and the functioning of their associated microorganisms have not been studied extensively. The purpose of this study is to assess the effects of different light levels and temperatures onPosidonia oceanica; the endemic seagrass species in the Mediterranean Sea, and their N2-fixing community, which contributes importantly to the nitrogen requirements and high productivity of the plants. Aquarium experiments were conducted in winter, when the plants are more vulnerable to changes in temperature, subjecting them to short-term exposures to an ambient (15.5°C) and elevated temperatures (ambient+5.5°C), and at limited (13 μmol photons m−2s−1) and saturating light conditions (124 μmol photons m−2s−1). Primary production, chlorophyll content, reactive oxygen species production, polyphenols content, thenifHgene expression, N2fixation, and alkaline phosphatase activities were measured in different plant tissues. Plants incubated at ambient temperature and high light exhibited an enhanced total chlorophyll production. Significantly higher gross and net primary production rates were also recorded under ambient temperature and high light conditions, which were approximately two-fold compared to the rest of the treatments. The oxidative stress analyses revealed an increased production of reactive oxygen species in young leaves incubated at ambient temperature and saturating light, while the polyphenols content in top leaves was considerably higher under elevated temperatures. In contrast, the N2fixation and alkaline phosphatase rates were significantly higher under elevated temperature and low light levels. The presence of the N2-fixing phylotypes UCYN-A, -B, and -C was detected through genetic analyses, with UCYN-B demonstrating the highestnifHgene transcription levels at elevated temperatures. These findings emphasize the significant role of irradiance on the productivity ofP. oceanicaand the temperature dependence of the N2fixation process in winter.

Spring Accumulation Rates in North Atlantic Phytoplankton Communities Linked to Alterations in the Balance Between Division and Loss.

For nearly a century, phytoplankton spring blooms have largely been explained in the context of abiotic factors regulating cellular division rates (e.g., mixed-layer light levels). However, the accumulation of new phytoplankton biomass represents a mismatch between phytoplankton division and mortality rates. The balance between division and loss, therefore, has important implications for marine food webs and biogeochemical cycles. A large fraction of phytoplankton mortality is due to the combination of microzooplankton grazing and viral lysis, however, broad scale simultaneous measurements of these mortality processes are scarce. We applied the modified dilution assay along a West-to-East diagonal transect in the North Atlantic during spring. Our results demonstrate positive accumulation rates with losses dominated by microzooplankton grazing. Considering the dynamic light environment phytoplankton experience in the mixed surface layer, particularly in the spring, we tested the potential for incubation light conditions to affect observed rates. Incubations acted as short-term ‘light’ perturbations experiments, in which deeply mixed communities are exposed to elevated light levels. These “light perturbations” increased phytoplankton division rates and resulted in proportional changes in phytoplankton biomass while having no significant effect on mortality rates. These results provide experimental evidence for the Disturbance-Recovery Hypothesis, supporting the tenet that biomass accumulation rates co-vary with the specific rate of change in division.

Artificial nightlight alters the predator–prey dynamics of an apex carnivore

Artificial nightlight is increasingly recognized as an important environmental disturbance that influences the habitats and fitness of numerous species. However, its effects on wide‐ranging vertebrates and their interactions remain unclear. Light pollution has the potential to amplify land‐use change, and as such, answering the question of how this sensory stimulant affects behavior and habitat use of species valued for their ecological roles and economic impacts is critical for conservation and land‐use planning. Here, we combined satellite‐derived estimates of light pollution, with GPS‐data from cougars Puma concolor (n = 56), mule deer Odocoileus hemionus (n = 263) and locations of cougar‐killed deer (n = 1562 carcasses), to assess the effects of light exposure on mammal behavior and predator–prey relationships across wildland–urban gradients in the southwestern United States. Our results indicate that deer used the anthropogenic environments to access forage and were more active at night than their wildland conspecifics. Despite higher nightlight levels, cougars killed deer at the wildland–urban interface, but hunted them in the relatively darkest locations. Light had the greatest effect of all covariates on where cougars killed deer at the wildland–urban interface. Both species exhibited functional responses to light pollution at fine scales; individual cougars and deer with less light exposure increasingly avoided illuminated areas when exposed to greater radiance, whereas deer living in the wildland–urban interface selected elevated light levels. We conclude that integrating estimates of light pollution into ecological studies provides crucial insights into how the dynamic human footprint can alter animal behavior and ecosystem function across spatial scales.

Levels of the TNF-Related Cytokine LIGHT Increase in Hospitalized COVID-19 Patients with Cytokine Release Syndrome and ARDS.

Many coronavirus disease 2019 (COVID-19) patients demonstrate lethal respiratory complications caused by cytokine release syndrome (CRS). Multiple cytokines have been implicated in CRS, but levels of tumor necrosis factor superfamily 14 (TNFSF14) (LIGHT) have not been previously measured in this setting. In this study, we observed significantly elevated serum LIGHT levels in hospitalized COVID-19 patients compared to healthy age- and gender-matched control patients. The assay detected bioavailable LIGHT unbound to the inhibitor Decoy receptor-3 (DcR3). Bioavailable LIGHT levels were elevated in patients both on and off ventilatory support, with a trend toward higher levels in patients requiring mechanical ventilation. In hospitalized patients over the age of 60, who exhibited a mortality rate of 82%, LIGHT levels were significantly higher (P = 0.0209) in those who died than in survivors. As previously reported, interleukin 6 (IL-6) levels were also elevated in these patients, with significantly (P = 0.0076) higher levels observed in patients who died than in survivors, paralleling the LIGHT levels. Although attempts to block IL-6 binding to its receptor have shown limited success in COVID-19 CRS, neutralization of LIGHT may prove to be more effective owing to its more central role in regulating antiviral immune responses. The findings presented here demonstrate that LIGHT is a cytokine which may play an important role in COVID-19 patients presenting with acute respiratory distress syndrome (ARDS) and CRS and suggest that LIGHT neutralization may be beneficial to COVID-19 patients.

Nocturnal singing by diurnal birds in a temperate region of central Europe

Most bird species sing by day, with two distinct peaks of vocal activity—around sunrise and sunset. However, even typically diurnal birds also sing during at night what is for them an atypical part of the day. To date, the mechanism and function(s) of such behaviour remain unclear across bird taxa. In our study we focused on night singing by diurnal birds in two different types of environments—forests and open areas in eastern Poland. We examined: (1) which diurnal species sing at night (defined as the period between astronomical dusk and dawn); (2) how intensively different species vocalise at night; and (3) whether the occurrence of nocturnal singing by diurnal birds depends on the type of environment. To do this, we used autonomous sound recorders to record soundscapes in 27 points located in open habitats and 27 points located in forests. At each location the recorder continuously collected data for an entire day during the breeding season, from one hour before dawn to 10 AM the next day. All night songs were classified to their species of origin via manual spectrogram scanning. We recorded 88 bird species in total (12 orders, 32 families), of which 24 species (7 orders, 15 families) sang at night. Night singing was observed significantly more often in open areas than in forests. The frequency and intensity of night singing was species-specific and ranged from occasional singing to regular and intense singing. We hypothesise that elevated light levels have a crucial influence on night singing, but that the effect of light may also be modified by environmental factors (e.g., predator pressure).

Seawall as salmon habitat: Eco-engineering improves the distribution and foraging of juvenile Pacific salmon

Urban nearshore ecosystems are built environments that differ structurally and functionally from the natural ecosystems they replace. Eco-engineering offers the ability to enhance these ecosystems by reducing the impacts of shoreline modification. Recent studies have linked shoreline armoring and pier shade—common features of modified shorelines—to lower foraging rates, altered distribution patterns, and increased predation risk for juvenile salmon. The 2017 replacement of the Elliott Bay seawall in Seattle, WA, USA incorporated novel eco-engineering design elements, including glass light penetrating surfaces (LPS) in overwater structures, an elevated seafloor, and textured substrates in the seawall face to enhance nearshore habitat for juvenile Pacific salmon (Oncorhynchus spp.) migrating from natal streams to the ocean. To examine the effectiveness of seawall eco-engineering, we used snorkel surveys to assess changes in juvenile salmon spatial distribution and foraging patterns during peak outmigration (March–August), and measured ambient light penetration before and after seawall replacement. Overall, we found that juvenile salmon were distributed more evenly across a spatial mosaic of habitats following eco-engineering. LPS enhanced ambient light penetration in nearshore under-pier habitats, and juvenile salmon use of these habitats increased concurrently. Salmon densities under piers tended to be greatest at low tides, indicating that light availability may mediate selective habitat use. Feeding rates at sites immediately adjacent to the seawall increased both between and under piers following habitat enhancement. Our findings suggest that the elevated light levels facilitated by LPS, in concert with physical enhancements that provided more complex shallow water habitat, temper the negative effects of pier shade and shoreline armoring on juvenile salmon.

Combined effects of nocturnal exposure to artificial light and habitat complexity on fish foraging

Due to the widespread use of artificial light, freshwater ecosystems in urban areas at night are often subjected to light of intensities exceeding that of the moonlight. Nocturnal dim light could modify fish behaviour and benefit visual predators because of enhanced foraging success compared to dark nights. However, effects of nocturnal light could be mitigated by the presence of structured habitats providing refuges for prey. We tested in laboratory experiments whether nocturnal light of low intensity (2 lx) increases foraging efficiency of the Eurasian perch (Perca fluviatilis) on invertebrate prey (Gammarus fossarum). The tests were conducted at dusk and night under two light regimes: natural cycle with dark nights and disturbed cycle with artificially illuminated nights, in habitats differing in structural complexity: sand and woody debris. We found that nocturnal illumination significantly enhanced the consumption of gammarids by fish compared to dark nights. In addition, the perch was as effective predator in illuminated nights (2 lx) as at dusk (10 lx). Woody debris provided an effective refuge only in combination with undisturbed darkness, but not in illuminated nights. Our results suggest that nocturnal illumination in aquatic ecosystems may contribute to significant reductions in invertebrate population sizes through fish predation. The loss of darkness reduces the possibility of using shelters by invertebrates and hence the effects of elevated light levels at night could not be mitigated by an increased habitat complexity.

Environmental heterogeneity alters mate choice behavior for multimodal signals

Animals frequently experience changes in their environment, including diel and seasonal shifts in abiotic and biotic factors. In addition to physiological and morphological changes, animals alter their behavior in response to environmental variation. This study examined the impacts of heterogeneous environments on mating behaviors. We examined both male and female tungara frog phonotactic responses to multimodal (audiovisual) and unimodal (acoustic) stimuli. We altered aspects of the physical environment by changing substrate (terrestrial and aquatic) and ambient light levels. Females demonstrated a similar preference for the audiovisual stimulus regardless of substrate but decreased latency to choose in an aquatic environment. When ambient light levels were increased (relative to darker control), females reversed their preference, avoiding the multimodal stimulus, but the latency to choose was unchanged. Males demonstrated no preference for the multimodal signal on either substrate, but like females, male latency was reduced in an aquatic environment. Different environments carry their own associated costs, including varying levels of predation risk. Increased light levels and an aquatic environment likely carry higher predation risk and therefore should lead to changes in female and male responses. Interestingly, these two environments do not cause uniform changes in female responses. The addition of an aquatic environment led to a reduction in latency, whereas an increase in ambient light levels induced a change in female mate preference. These findings demonstrate the importance of the environment on mating responses to multimodal signals. Responses to conspecific mating signals (e.g., mate preferences) have often been assumed to be static. In this study, we tested responses of both male and female tungara frogs to a multimodal (visual + vocal) advertisement signal under varying environmental conditions. Elevated light levels changed female responses to mating signals. When both sexes were required to swim, rather than walk to a signal, their choices did not change. They did respond faster, however. These results indicate that measuring the strength of sexual selection should be considered as a function of both innate preferences and the environmental conditions experienced by the animals.

Juveniles of the Atlantic coral, Favia fragum (Esper, 1797) do not invest energy to maintain calcification under ocean acidification

Ocean acidification (OA) threatens coral reef ecosystems by slowing calcification and enhancing dissolution of calcifying organisms and sediments. Nevertheless, multiple factors have been shown to modulate OA's impact on calcification, including the nutritional status of the coral host. In three separate experiments, we exposed juveniles of the Atlantic golf ball coral, Favia fragum, to elevated CO2 and varied nutritional (light or feeding) conditions. Juveniles reared from planulae larvae were significantly larger and produced more CaCO3 when fed, regardless of CO2 level. However, corals subjected to elevated CO2 produced less CaCO3 per mm2 regardless of feeding condition. Additionally, unfed corals reared under elevated light levels exhibited lower chlorophyll a and higher total lipid content, but light had no significant effect on coral calcification. Conversely, elevated CO2 had a significant, negative affect on calcification, regardless of light condition but no detectable effect on physiological tissue parameters. Our results indicate that the sensitivity of juvenile F. fragum calcification to OA was neither modulated by light nor by feeding, despite physiological indications of enhanced nutritional status. This suggests that corals do not necessarily divert energy to maintain calcification under high CO2, even when they have the energetic resources to do so.

Stability testing of silver nanodisc suspensions for solar applications

In solar and optical applications, nanofluids can be exposed to intense light, high temperature, and variable pH levels. Over time these forces can destabilize particle suspensions by altering particle morphology, breaking functional groups, and inducing agglomeration. Since UV exposure has been a critical unknown for nanoparticle suspension stability in solar and optical applications, a modified ISO standard UV accelerated lifetime test method was developed and applied herein. Aqueous formulations of protective silica shells over silver nanodiscs (relative to unprotected silver) were investigated as indicative non-spherical nanoparticles that might be expected to survive these perturbations. As such, the dispersion stability of these suspensions was investigated before and after exposure to elevated temperature, UV light, and pH levels. Dispersion stability was determined using a few techniques – changes in spectral transmission, zeta potential, and particle size distribution via nanoparticle tracking analysis. A protective shell of silica deposited via a modified Stöber (using tetraethyl-orthosilicate – TEOS) method was found to provide stability against temperature, UV, and pH exposure, whereas uncoated silver nanoparticles or those with a shell grown using a sodium silicate silica source were considered relatively unstable. The TEOS silica shells also exhibited a beneficial UV curing effect, which can be explained by increased crosslinking throughout UV exposure.

Nocturnal courtship, copulation, and egg-laying in the western grebe (Aechmophorus occidentalis) and Clark’s grebe (Aechmophorus clarkii)

Grebes (Podicipedidae) are primarily diurnal although migration occurs at night and some species forage opportunistically at night. We used motion-activated cameras to study nocturnal reproductive activities of the western grebe, Aechmophorus occidentalis, and Clark’s grebe, Aechmophorus clarkii, at Clear Lake, California, USA, during 2014–2016. During 9283 h of monitoring, 19.4% of rushing displays (n = 75) and 8.4% of copulations (n = 435), plus two weed dancing displays and four instances of egg-laying, occurred at night. Nocturnal copulation and egg-laying often occurred on empty, recently abandoned nests, but some incubating pairs of grebes also copulated at night. Nocturnal reproductive activities occurred more frequently at nests attached to submergent vegetation in open water far from shore when water levels were low than on nests attached to emergent vegetation close to shore when water levels were high, probably due to a reduced risk of predation by nocturnal mammals farther from shore. Nocturnal reproductive activities were not in response to elevated light levels at night, daylight disturbances, diurnal predation, high temperatures on hot days, or sexual interference during daylight. Instead, grebes attempted to increase mating investment and minimize parental investment by exploiting recently abandoned nests at night, and perhaps by undertaking extrapair copulations under the cover of darkness, but some pairs of grebes may simply extended routine reproductive activities into the night. Reproductive activities are probably limited at night by the need to feed during daylight and sleep at night, and by the increased risk of predation by mammals at night. Given the high costs of construction and maintenance of floating nests and the obvious benefit of quickly exploiting abandoned nests, nocturnal reproductive activities may occur more frequently in grebes and other waterbirds using floating nests than in other groups of birds whose reproductive activities occur mostly during daylight.

Elevated light levels reduce hemlock woolly adelgid infestation and improve carbon balance of infested eastern hemlock seedlings

The rapid loss of eastern hemlock (Tsuga canadensis) due to infestation with hemlock woolly adelgid (Adelges tsugae, HWA) has greatly altered structure and function of eastern forests. Numerous control strategies including local pesticide use and biocontrol with predator beetles have been implemented with considerable cost and varying success. Silviculture treatments that increase incident light on surviving hemlock trees to reduce infestation and ameliorate carbon starvation have been proposed as another possible conservation strategy, yet no controlled studies have evaluated the coupled plant-insect responses to increased light. We conducted a nursery experiment on artificially infested eastern hemlock seedlings under varying levels of ambient light, ranging from 0 to 90% shade. We measured HWA infestation (ovisac density), short- and long-term indicators of carbon balance (leaf chlorophyll fluorescence, net photosynthesis, total nonstructural carbohydrate content, and shoot growth), and nutrition (leaf N content). We hypothesized that higher light would result in reduced HWA densities, higher C assimilation rates, and improved tissue non-structural carbohydrate balance; and these effects would ameliorate the effects of infestation on C balance and lead to improved seedling growth. HWA density decreased with increasing light, and was highest in the 90% shade treatments. However, photosystem II efficiency and net assimilation were also lower under the higher light treatment. Despite tradeoffs between reduced infestation and reduced leaf function from higher light, and little variation in sugar content among treatments, both leaf and root starch content and seedling growth were higher under the higher light treatment. Increasing light levels improves long-term carbon balance for hemlock seedlings in the presence of HWA. Although hemlock typically occurs in deeply shaded forests, our results suggest that silvicultural treatments such as forest thinning that increase light exposure may reduce HWA abundance and lead to better tree C balance, and may be an effective component of large-scale conservation and restoration strategies.

Artificial light at night disrupts sleep in female great tits (Parus major) during the nestling period, and is followed by a sleep rebound

Artificial light at night has been linked to a wide variety of physiological and behavioural consequences in humans and animals. Given that little is known about the impact of light pollution on sleep in wild animals, we tested how experimentally elevated light levels affected sleep behaviour of female songbirds rearing 10 day old chicks. Using a within-subject design, individual sleep behaviour was observed over three consecutive nights in great tits (Parus major), with females sleeping in a natural dark situation on the first and third night, whereas on the second night they were exposed to a light-emitting diode (1.6 lux). Artificial light in the nest box dramatically and significantly affected sleep behaviour, causing females to fall asleep later (95 min; while entry time was unaffected), wake up earlier (74 min) and sleep less (56%). Females spent a greater proportion of the night awake and the frequency of their sleep bouts decreased, while the length of their sleep bouts remained equal. Artificial light also increased begging of chicks at night, which may have contributed to the sleep disruption in females or vice versa. The night following the light treatment, females slept 25% more compared to the first night, which was mainly achieved by increasing the frequency of sleep bouts. Although there was a consistent pattern in how artificial light affected sleep, there was also large among-individual variation in how strongly females were affected. When comparing current results with a similar experiment during winter, our results highlight differences in effects between seasons and underscore the importance of studying light pollution during different seasons. Our study shows that light pollution may have a significant impact on sleep behaviour in free-living animals during the reproductive season, which may provide a potential mechanism by which artificial light affects fitness.

Elevated light levels in schools have a protective effect on myopia.

To determine whether elevated light levels in classrooms in rural areas can protect school-age children from myopia onset or myopia progression. A total of 317 subjects from 1713 eligible students aged six to 14 in four schools located in northeast China participated in the study. Students received a comprehensive eye examination including cycloplegic refraction and ocular biometry, which included axial length (AL), anterior chamber depth (ACD), and corneal curvature (CC) measurement, and completed a questionnaire. The intervention arm included 178 students in two schools with rebuilt elevated lighting systems and the control arm included 139 students in which lighting systems were unchanged. Results for the two arms were compared with a Wilcoxon rank sum test, a chi-squared test or a t-test, as appropriate. Factors that might help explain any differences were explored with multivariate linear regression analysis. The median average illuminance of blackboards and desks and uniformity of desk lighting were significantly improved, however, the uniformity of blackboard lighting declined after intervention. At baseline, the mean refraction, AL, CC, ACD and myopia prevalence between the two arms were not significantly different. After 1 year, compared with the control arm the intervention arm had a lower incidence of new myopia onset (4% vs 10%; p = 0.029), a smaller decrease in refractive error among no myopic subjects (-0.25 dioptre [D] vs -0.47 D; p = 0.001), and shorter axial growth for both non-myopic (0.13 vs 0.18 mm; p = 0.023) and myopic subjects (0.20 vs 0.27 mm; p = 0.0001). Multivariate linear regression analysis showed the intervention program, lower hyperopic baseline refraction, lower father's education level, longer time sleeping and less time in screen-viewing activities were associated with less refractive shift in the direction of myopia in non-myopic children. For myopic subjects, myopia progression was significantly associated with family income only. The intervention program and older age had a protective effect on axial growth for both myopic and non-myopic subjects. The father's education level and sleep duration were significantly associated with axial growth in non-myopic children. Elevated light levels in classrooms have a significant effect on myopia onset, decreases in refraction, and axial growth; if the findings of lighting intervention are reproduced in future studies, the ambient light levels in schools should be improved.

Association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students

To explore the association between elevated light levels in classrooms and change in vision acuity among elementary and secondary students. A total of 4 elementary (grade 1-5) and secondary (grade 7-8) schools in urban and rural areas in Sujiatun, Shenyang, China were selected by cluster sampling as experimental schools, and lighting systems have been rebuilt to improve the ambient light levels in 56 classrooms in November 2012. The control schools were chosen for the comparable academic burden and adjacent location to experimental schools, 4 schools in all. Cluster sampling of all students in the selected schools as the subjects was carried out. A total of 2 092 students were chosen as experimental group and 1 595 students were in the control group. The luxmeter was used to measure illuminance of classrooms in two groups at baseline, and intervention for 1 month, respectively.Students in both groups were underwent 3 times for vision acuity examination by standard logarithmic visual acuity chart at baseline, intervention for 6 month and intervention for 1 year, respectively. The light levels of desk and blackboard in two groups were compared by Wilcoxon test. Multivariate analysis of covariance with repeated measures was performed to assess three vision acuity results between groups. After intervention, the average illuminance of desk (117.5 vs 532.5 lx, Z = -5.38, P < 0.001) and blackboard (75.6 vs 423.5 lx, Z = -5.38, P < 0.001) and uniformity of desk (Z = -4.28, P < 0.001) with new lighting were improved significantly than that with old lighting, however the uniformity of blackboard was lower than baseline significantly (0.64 vs 0.70, Z = -2.34, P = 0.019). The average scores of vision acuity in students at baseline, intervention for 6 month and intervention for 1 year were 4.87 ± 0.23, 4.84 ± 0.25 and 4.85 ± 0.23 in experimental group, and 4.88 ± 0.22, 4.84 ± 0.25 and 4.81 ± 0.27 in control group, respectively. The significant differences between groups were found and F values were 1.41, 0.13, 19.99, P values were 0.235,0.724, <0.001. At last the average vision acuity in experimental group were significantly better than that in control group either among elementary (4.90 ± 0.20) vs (4.87 ± 0.21) score, F = 13.61, P < 0.001 or secondary students (4.73 ± 0.28) vs (4.68 ± 0.32) score, F = 14.25, P < 0.001. Visual acuity loss could be decreased in students with elevated light levels which may slow the response to myopiagenic stimuli for eyes, therefore the ambient light levels of blackboard and desk in classroom should be improved.

Prediction of coral bleaching in the Florida Keys using remotely sensed data

Shallow water tropical coral reefs may bleach due to extremes in a variety of environmental factors. Of particular concern have been temperature, ultraviolet radiation, and photosynthetically available radiation. Satellite observation systems allow synoptic-scale monitoring of coral environments that can be used to investigate the effects of such environmental parameters. Recent advancements in algorithm development for new satellite data products have made it possible to include light availability in such monitoring. Long-term satellite data (2000–2013), in combination with in situ bleaching surveys (N = 3,334; spanning 2003–2012), were used to identify the environmental factors contributing to bleaching of Florida reef tract corals. Stepwise multiple linear regression supports the conclusion that elevated sea surface temperature (SST; partial R adj 2 = 0.13; p < 0.001) and high visible light levels reaching the benthos (partial R adj 2 = 0.06; p < 0.001) each independently contributed to coral bleaching. The effect of SST was modulated by significant interactions with wind speed (partial R adj 2 = 0.03; p < 0.001) and ultraviolet benthic available light (partial R adj 2 = 0.01; p = 0.022). These relationships were combined via canonical analysis of principal coordinates to create a predictive model of coral reef bleaching for the region. This model predicted ‘severe bleaching’ and ‘no bleaching’ conditions with 69 and 57 % classification success, respectively. This was approximately 2.5 times greater than that predicted by chance and shows improvement over similar models created using only temperature data. The results enhance the understanding of the factors contributing to coral bleaching and allow for weekly assessment of historical and current bleaching stress.

Elevated Involved Light Chains Discordant to the Increase of the Involved Heavy Chains Identifies a Subset of Multiple Myeloma Patients with Worse Outcome

INTRODUCTIONElevated free chain level (FLC) levels were found to be associated with adverse outcomes in patients with newly diagnosed multiple myeloma (NDMM), reflecting either a high burden of disease at presentation, and/or the higher incidence of renal failure and unfavorable cytogenetics. An alternative explanation is that patients presenting with increased light chain level combined with “discordant” elevation of the involved heavy chain (HC) may represent greater clonal heterogeneity, which is also associated with adverse outcomes. In this study we compared the prognostic importance of elevated FLC levels; concordant vs discordant to involved HC level, in NDMM patients treated with bortezomib- based induction.METHODSWe reviewed data of consecutive patients with newly diagnosed multiple myeloma who received first line bortezomib-based therapy, between January 1st 2007 and January 31st 2014 in three participating centers in Greece and Israel. We included only patients with a measurable disease. We defined a dominating light chain clone (HiLC) as Kappa or Lambda levels ≥1000 mg/L and involved heavy chain levels (M protein as measured by protein electrophoresis) < 2.5 gr/L ; a Heavy chain dominating disease (HiHC) as heavy chain levels ≥2.5 gr/L and light chain < 1000 mg/L; elevation of both heavy and light chain (BiC) as both light chain levels ≥1000 mg/L and heavy chain levels ≥2.5 gr/L; low expression disease (Lo) included all patients not meeting the previous criteria. We compared groups in respects to baseline characteristics, response, overall survival (OS) and progression free survival (PFS).RESULTSWe included in the analysis 295 patients (27% HiLC, 31.5% HiHC, 23% BiC, 18.5% Lo). HiLC patients had more often ISS-3 (53% HiLC, 27% HiHC, 44% BiC, 20% Lo, p<0.0001). High risk cytogenetic abnormalities were most common in patients with BiC (30% HiLC, 39% HiHC, 46% BiC, 20% Lo, p=0.05). Notably, t(4:14) was more frequent in HiHC and BiC patients compared to HiLC and Lo patients (28% & 17% vs. 3% and 6%, respectively, p=0.005).High levels of paraprotein or free light chains were associated with higher levels of bone marrow plasmacytosis above 60% (more than 55% of patients in BiC, HiHC, HiLC, vs 27% in Lo, p<0.0001) and higher rates of anemia (more than 40% had Hb<10g/dL in BiC, HiHC, HiLC vs 15%, in Lo, p<0.0001). HiLC patients were characterized by higher rates of renal failure (Cr>2mg/dL in 49% HiLC, 7% HiHC, 26% BiC, 13% Lo, p<0.0001 ) and higher levels of beta2microglobulin (mean B2M g/L 9.2 in HiLC, 6.0 in BiC, 4.6 in HiHC, 3.8 in Lo, p<0.0001).There was no difference in overall response rate between the groups (p=0.5), however, HiLC patients had a higher rate of progression or death during induction (13% HiLC, 3% HiHC, 8% BiC, 4% Lo, p=0.004) and a significantly shorter OS compared to other patients (52 months vs. not reached, HiLC vs.BiC, HiHC, Lo, p=0.014. Fig 1). Both HiLC and BiC patients had a shorter PFS compared to HiHC and Lo patients (16/15 vs. 28/29 months for BiC/HiLC vs. HiHC/Lo respectively, p<0.0001. Fig 2). In multivariate analysis controlling for patient features (age, sex, performance status) and disease features (plasmacytosis in bone marrow, skeletal disease and extramedullary disease), HiLC and BiC status retained independent statistical significance for shorter PFS, and HiLC for shorter OS.ConclusionsOur analysis confirmed the adverse prognosis of elevated light chain levels in patients with NDMM, which was associated with a shortened PFS. Patients with predominantly elevated light chain levels, discordant to the increase in the involved HC, were also found to have shorter survival. This group of patients may represent a different, more aggressive category, possibly reflecting greater clonal heterogeneity, in which light chain escape could be the trigger to the development of clinically significant myeloma. Further studies are needed to confirm this hypothesis and investigate this patient subgroup. [Display omitted] DisclosuresDimopoulos:Celgene: Consultancy, Honoraria.

Light levels, refractive development, and myopia – A speculative review

Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may be involved, providing additional activation of retinal dopaminergic pathways.