Effect of solar eclipse on the behavior of a captive group of chimpanzees (Pan troglodytes)

A captive group of chimpanzees, housed in an outdoor compound at the Yerkes Regional Primate Research Center, was observed during the annular solar eclipse of May 30, 1984. The behavior of each animal was recorded using an instantaneous scan-sampling technique (Altmann: Behaviour 49:227–265, 1974). Beginning 2 days prior to the eclipse and continuing through the day following the eclipse, data were collected from 1100 to 1300 hours daily. At 1214 hours on the day of the eclipse, when the sky began to darken and the temperature began to decrease, solitary females and females with infants moved to the top of a climbing structure. As the eclipse progressed, additional chimpanzees began to congregate on the climbing structure and to orient their bodies in the direction of the sun and moon. At 1223 hours, during the period of maximum eclipse, the animals continued to orient their bodies toward the sun and moon and to turn their faces upward. One juvenile stood upright and gestured in the direction of the sun and moon. Sunlight began to increase at 1225 hours, and as it became brighter, the animals began to descend from the climbing structure. The behaviors exhibited by the group during the period of maximum eclipse were not observed prior to or following the eclipse nor as darkness approached at normal, daily sunset. These data indicate that a solar eclipse, a rare and uncommon environmental event, can influence and modulate the behavior of chimpanzees.     

The orientation of the sandhopper <Emphasis Type="Italic">Talitrus saltator</Emphasis> during a partial solar eclipse

To acquire more information about the identification and use of the sun and other celestial cues in the sea–land orientation of the sandhopper Talitrus saltator, we carried out releases in a confined environment during a partial solar eclipse and at sunset. The sandhoppers were unable to identify the sun (86% covered) during the eclipse nor to use other celestial compass factors of orientation. This was probably due to the low level of light intensity (close to the minimum level for orientation recorded at sunset) and to the variations in intensity and pattern of skylight polarization.     

日偏食对乌鲁木齐空气可培养细菌群落的影响

利用自然沉降法采集2009年7月19日至24日日偏食前后乌鲁木齐空气微生物,以可培养法分析日偏食对其细菌群落组成的影响。结果如下：（1）细菌数量和种类均随日偏食临近而增多,当天达到峰值,随后减少。（2）所获81株细菌经测序及系统发育分析将其归为四个门,分别为放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),其中放线菌门为优势类群,占细菌总数的54%。（3）不同采样时间细菌群落组成的聚类分析显示,日偏食发生前日（21日）和当日（22日）空气细菌组成较为相似聚为一类,其余日期的聚为一类。（4）典型相关分析(Canonical Correlation Analysis, CCA)发现,放线菌门中菌株与绝大多数大气环境因子呈正相关性;变形菌门和厚壁菌门与大多数大气环境因子呈正相关性;而拟杆菌门中的菌株只与温度、风速和太阳风速度呈正相关。结果表明,日偏食会增加乌鲁木齐空气可培养细菌的数量和种类。     

In the shadow of the Moon,what type of solar eclipse will we see?

Solar eclipses occur several times a year, but most people will be lucky if they see one total solar eclipse in their lifetime. There are two upcoming total solar eclipses that can be seen from different parts of the United States (August 21, 2017 and April 8, 2024), and they provide teachers with an amazing opportunity to engage students with a remarkable astronomical event. We summarize the science behind eclipses and describe an inexpensive activity for students from third grade up through middle school that will let them use models to see the differences between total, annular, and partial solar eclipses. The activity lets students explore why, during a solar eclipse, people in different areas will see different types of eclipses. The activity can be used as a way to get students excited about astronomy and the upcoming eclipses. We also give ideas for ways that teachers can engage their students during the eclipses.     

European light dosimeter network (ELDONET): 1998 data

The European light dosimeter network of over 40 stations has been established in Europe and other continents equipped with three-channel filter dosimeters to measure solar radiation in three channels, UV-B (280–315 nm), UV-A (315–400 nm) and photosynthetically active radiation (PAR). The recorded data have been evaluated, and the monthly doses in all three channels show a strong latitudinal dependence from northern Sweden to the Canary Islands. There are a few remarkable exceptions such as the data recorded at the high mountain station on the Zugspitze (German Alps) and unequal doses at stations at comparable latitudes which indicate the impact of local weather conditions and mean sunshine hours. While generally peak values are recorded in the months of June and July, the UV-B maxima are shifted later into the year, which is due to the antagonistic functions of decreasing solar angles and increasing transparency of the atmosphere as the total column ozone decreases in the second half of the year for the Northern Hemisphere. This is supported by comparison with modelled total column ozone and satellite-based measurements. Also the ratios of UV-B:UV-A and UV-B:PAR as well as UV-A:PAR peak during the summer months, with the exception of the northernmost station at Abisko (north Sweden) where the UV-A:PAR ratio peaks in the winter months which is due to the specific photoclimatic conditions north of the polar circle. The penetration of solar radiation into the water column was found to strongly depend on the transparency of the water column. In Gran Canaria more than 10% of the surface UV-B penetrated to 4–5 m depth. The path of the solar eclipse on 11 August 1999 could be followed in several stations with different degrees of occlusion of the sun disk. Received in revised form: 12 May 2000 Electronic Publication     

Woody encroachment of grasslands: Near‐surface thermal implications assessed through the lens of an astronomical event

Temperature has long been understood as a fundamental condition that influences ecological patterns and processes. Heterogeneity in landscapes that is structured by ultimate (climate) and proximate (vegetation, topography, disturbance events, and land use) forces serve to shape thermal patterns across multiple spatio‐temporal scales. Thermal landscapes of grasslands are likely shifting as woody encroachment fragments these ecosystems and studies quantifying thermal fragmentation in grassland systems resulting from woody encroachment are lacking. We utilized the August 21st, 2017, solar eclipse to mimic a rapid sunrise/sunset event across a landscape characterized as a grassland to experimentally manipulate levels of solar radiation in the system. We then quantified changes in near‐surface temperatures resulting from changes in solar radiation levels during the eclipse. Temperatures were monitored across three grassland pastures in central Oklahoma that were characterized by different densities (low, medium, and high) of Juniperus virginiana to understand the impact of woody encroachment on diurnal temperature patterns and thermal heterogeneity in a grassland''s thermal landscape. The largest temperature range across sites that occurred during the eclipse was in the mixed grass vegetation. Similarly, the largest change in thermal heterogeneity occurred in the grassland with the lowest amount of woody encroachment. Thermal heterogeneity was lowest in the highly encroached grassland, which also experienced the lowest overall change in thermal heterogeneity during the eclipse. Time series models suggested that solar radiation was the most influential factor in predicting changes in thermal heterogeneity as opposed to ambient temperature alone. These results suggest that highly encroached grasslands may experience lower diurnal variability of temperatures at the cost of a decrease in the overall thermal heterogeneity of that landscape. It appears that fine‐scale spatio‐temporal thermal variation is largely driven by solar radiation, which can be influenced by vegetation heterogeneity inherent within a landscape.     

Microorganisms collected during a solar eclipse in India

A solar eclipse was observed in India on 24 October, 1995. It was a total eclipse in some parts of the country while it was partial in other parts. The effect of the total or partial eclipse on the airspora was investigated. Airspora play an important role in various phenomena on the earth. Martins rose bengal agar plates were exposed at Kalpi (total eclipse) and at Aurangabad (partial eclipse). Both the quantitative and qualitative variations in the airspora were observed during different phases of the eclipse. At both places the number of fungal colonies were higher during the pre- and post-eclipse phase. There was a decrease at contact phase, total/partial or diamond ring eclipse phase. Thus, very minor changes were observed during the eclipse period. Bacterial colonies were higher at the post-eclipse phase at Kalpi but were less at Aurangabad during this phase. At Kalpi 23 fungal species were recorded while at Aurangabad 31 were recorded. Most of the fungal species are organic matter decomposers, while some of them are known to cause allergies in humans and also cause plant diseases.Aspergillus species were dominant. BothA. fumigatus (causing allergy and asthma) andA. flavus (producing aflatoxin) were the dominant species and they showed a definite trend in their occurrence. This was related to wind velocity and temperature changes in the atmosphere.     

Acute skin sun damage in children and its consequences in adults

Children spend more time outdoors than adults and there is compelling evidence that childhood is a particularly vulnerable time for the photocarcinogenic effects of the sun. The negative effects of solar radiation are accumulated during the entire lifetime; however 80% of total lifetime sun exposure is taking place before the age of 18 years. Child skin is more sensitive than adult skin because natural defense mechanisms are not fully developed. A short exposure to midday sun will result in sunburns. Epidemiologic studies show a higher incidence of malignant melanoma in persons with a history of sunburns during childhood and adolescence. Sun exposure among infants and pre-school children is largely dependent on the discretion of adult care providers. Sun protective habits of mothers may predict the level of sun exposure in children. It is very important to transfer the knowledge and positive habits of proper sun protection to children. The purpose of sun-safety behavior is not to avoid outdoor activities, but rather to protect the skin from detrimental sun effects. Proper sun protection of children includes protection from excessive sun exposure, sunburns and other forms of skin damage caused by sun, which may lead to the future development of skin cancers. This paper reviews acute skin reactivity to sun in childhood and adolescence that causes damage in skin structure and function and produces undesirable chronic changes in adults.     

日偏食对乌鲁木齐空气微生物群落功能多样性的影响

为了了解日偏食对空气微生物群落碳代谢的影响,利用BIOLOG指纹图谱方法分析日偏食前后乌鲁木齐空气微生物群落碳代谢功能多样性的变化。结果表明,日偏食当天空气微生物的碳源代谢能力高于其他几天。微生物群落多样性指数方差分析显示,当天(2009年7月22日)Shannon-Wiener多样性指数最高;主成分分析表明对碳源利用起分异作用的主要是羧酸类物质。日偏食会影响乌鲁木齐空气微生物群落功能多样性。     

Effect of a total solar eclipse on the surface crowding of zooplankton in a freshwater lake ecosystem

Zooplankton surface crowding in a freshwater lake ecosystem during a total solar eclipse (maximum eclipse at 06:28:43 Indian Standard Time, 22 July 2009) was studied in relation to ambient physicochemical conditions and compared with the crowding that occurred during pre- and post-eclipse days. Rapid light attenuation on the eclipse day led to changes in zooplankton surface crowding, which manifested as alterations to community structure and statistical parameters. Zooplankton diversity and density varied depending on the day (either the pre-eclipse day, the eclipse day, or the post-eclipse day) and the sampling time considered. A total of 20 zooplankton species were recorded during the study. On the day of the eclipse, the highest zooplankton density in the surface water was recorded just after the end of totality at 06:30 IST. The populations of two adult cladoceran species (Alona rectangula rectangula and Chydorus sphaericus) were particularly prominent in the zooplankton, whereas rotifers were almost absent from the surface water during the eclipse. Rather than decreasing, the primary production of the phytoplankton increased on the day of the TSE compared to that seen on the control days. Comparatively high Lindeman’s efficiency values were observed during the eclipse, indicating particularly efficient utilization of photons in photosynthesis.     

Behavioural studies of freshwater fishes during a solar eclipse

Synopsis Effects of a total solar eclipse on fish have rarely been recorded. Three freshwater fish species — Amphipnous cuchia, Anabas testudineus and Colisa fasciata were studied during the past total solar eclipse on February 16, 1980. Behavioural studies pertaining chiefly to fish movement, fish breathing and colouration were made, and possible reasons for effects are discussed.     

Response of Cassava canopy to mid-day pseudo sunrise induced by solar eclipse

Variations in CO₂ concentration over a cassava canopy were measured during a solar eclipse at Thiruvananthapuram, India. The analysis presented attempts to differentiate between the eclipse effect and the possible effect of thick clouds, taking CO₂ as a proxy for photosynthesis. CO₂ and water vapor were measured at a rate of 10 Hz, and radiation at 1 Hz, together with other meteorological parameters. A rapid reduction in CO₂ observed post-peak eclipse, due apparently to intense photosynthesis, appears similar to what happens at daybreak/post-sunrise. The increase in CO₂ (4 ppm) during peak eclipse, with radiation levels falling below the photosynthesis cut-off for cassava, indicates domination of respiration due to the light-limiting conditions.     

Morpho‐anatomical and physiological differences between sun and shade leaves in Abies alba Mill. (Pinaceae,Coniferales): a combined approach

Morphology, anatomy and physiology of sun and shade leaves of Abies alba were investigated and major differences were identified, such as sun leaves being larger, containing a hypodermis and palisade parenchyma as well as possessing more stomata, while shade leaves exhibit a distinct leaf dimorphism. The large size of sun leaves and their arrangement crowded on the upper side of a plagiotropic shoot leads to self‐shading which is explainable as protection from high solar radiation and to reduce the transpiration via the lamina. Sun leaves furthermore contain a higher xanthophyll cycle pigment amount and Non‐Photochemical Quenching (NPQ) capacity, a lower amount of chlorophyll b and a total lower chlorophyll amount per leaf, as well as an increased electron transport rate and an increased photosynthesis light saturation intensity. However, sun leaves switch on their NPQ capacity at rather low light intensities, as exemplified by several parameters newly measured for conifers. Our holistic approach extends previous findings about sun and shade leaves in conifers and demonstrates that both leaf types of A. alba show structural and physiological remarkable similarities to their respective counterparts in angiosperms, but also possess unique characteristics allowing them to cope efficiently with their environmental constraints.     

Blue light controls solar tracking by flowers of an alpine plant

In at least 18 plant families, leaves or flowers can maintain a specific orientation with respect to diurnal movements of the sun. Previous work on heliotropic leaves has demonstrated that blue light (400–500nm) provides the cue for their tracking response. Floral heliotropism occurs in several families of arctic and alpine plants, but the spectral sensitivity of the response has not been studied previously. Moreover, no studies on the spectral sensitivity of any heliotropism have been conducted on wild plants growing in their natural habitat. Working under field conditions, we used coloured acrylic filters to determine whether heliotropism by flowers of the snow buttercup (Ranunculus adoneus) is responsive to broad-band blue or red light. Flowers were able to orient towards the sun under boxes made entirely of blue-transmitting filters and in red-transmitting boxes having a single blue side that faced the sun. In these treatments, solar tracking ability was not significantly different from that observed in adjacent control flowers. In contrast, the precision of solar orientation was significantly reduced in red-transmitting boxes and red boxes with a single blue side oriented away from the sun. In the early morning, flowers covered by red-transmitting boxes failed to orient in the direction of sunrise, suggesting that this floral response, unlike that seen in some heliotropic leaves, lacks a residual‘memory’ for previous solar movements.     

New option in photoprotection

All the people are exposed to solar ultraviolet radiation. Exposure to sun with living in an oxygen-rich atmosphere causes unwanted photodemage. Sunburned skin is a leading risk factor for melanoma and non-melanoma cancers. UV exposure causes immunosuppression via multiple mechanisms in the skin. In this review the main topic is to mention new or alternative ways of photoprotection. Sunscreens are commonly used as protection against sun damage. They reduce the penetration of damaging solar UV wavelengths in skin by reflecting or absorbing them. Sunscreens are very valuable, but they have limitations. They have to be used properly to gain the full effect (application a little while before UV exposure, at frequent time points and in adequate amounts). Also, they have the problem of photoinactivation, which is the degeneration of the UV-filter due to exposure to UV rays resulting in the loss of absorbing capacity. Products with immune protection factor contain DNA-repair enzymes and antioxidants that may reduce mutations and enable the immune system to combat photodamage. The use of antioxidants and polyphenols may exert an anti-aging effect by preventing and even reversing sun damage. Adequate photoprotection is essential to control photocarcinogenesis and photoaging.     

Measurements of secondary neutrons from cosmic radiation with a Bonner sphere spectrometer at 79°N

Air crew members and airline passengers are continuously exposed to cosmic radiation during their flights. Particles ejected by the sun during so-called solar particle events (SPEs) in periods of high solar activity can contribute to this exposure. In rare cases the dose from a single SPE might even exceed the annual dose limit of 1 mSv above which dose monitoring of air crews is legally required in Germany. Measurements performed by means of neutron monitors have already shown that the relative intensity of secondary neutrons from cosmic radiation is enhanced during an SPE, particularly at regions close to the magnetic poles of the Earth where shielding of the cosmic radiation by the geomagnetic field is low. Here we describe a Bonner sphere spectrometer installed at the Koldewey station at 79°N, i.e. about 1,000 km from the geographic North pole, which is designed to provide first experimental data on the time-dependent energy spectrum of neutrons produced in the atmosphere during an SPE. This will be important to calculate doses from these neutrons to air crew members. The system is described in detail and first results are shown that were obtained during quiet periods of sun activity.     

Moon and sun compasses in sandhoppers rely on two separate chronometric mechanisms

The relationship between the chronometric system of compensation for the apparent movement of the sun and that for the moon has been the subject of several, never proven, hypotheses. Our studies on sandhoppers have demonstrated that the chronometric mechanism of the moon compass is separate from that of the sun compass. They show (i) that a period of seven days in constant darkness has no influence on the capacity for orientation, either solar or lunar, and indicates the presence of one or more continuously operating timing mechanisms; (ii) that two different shifts in the light–dark phase have no effect on the chronometric mechanism of lunar orientation, but they do affect that of solar orientation; and (iii) that exposure to an artificial moon delayed by seven days with respect to the natural cycle causes the expected change in the mean direction of individuals tested under the natural moon, but not of those tested under the sun.     

Chorioretinal temperature increases from solar observation

Chorioretinal temperature increases produced by solar observations are computed digitally. The spectral characteristics of solar radiation and the spectral transmittances of the atmosphere, atmospheric water vapor and ocular media are considered. Image spread is employed in all calculations. The calculations are executed for a variety of observation angles, and the effects of pupil diameter, fixed filters and optical instruments are predicted. Temperature increases are also computed for solar eclipse observations by the appropriate superposition of unobscured solar disk solutions.