Temperature, water level and bathymetry of thermokarst lakes in the continuous permafrost zone of northern Siberia - Lena River Delta, Siberia

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop continuous stratification in summer for at least 1 month. The modeled vertical heat flux across the bottom sediment tends towards an annual mean of zero, with maximum downward fluxes of about 5 W/m**2 in summer and with heat released back into the water column at a rate of less than 1 W/m**2 during the ice-covered period. The lakes are shown to be efficient heat absorbers and effectively distribute the heat through mixing. Monthly bottom water temperatures during the ice-free period range up to 15 °C and are therefore higher than the associated monthly air or ground temperatures in the surrounding frozen permafrost landscape. The investigated lakes remain unfrozen at depth, with mean annual lake-bottom temperatures of between 2.7 and 4 °C.

Field measurements of the atmosphere, ocean, sea ice and sub-ice platelet layer at Atka Bay in 2013

Ice shelves strongly interact with coastal Antarctic sea ice and the associated ecosystem by creating conditions favourable to the formation of a sub-ice platelet layer. The close investigation of this phenomenon and its seasonal evolution remain a challenge due to logistical constraints and a lack of suitable methodology. In this study, we characterize the seasonal cycle of Antarctic fast ice adjacent to the Ekström Ice Shelf in the eastern Weddell Sea. We used a thermistor chain with the additional ability to record the temperature response induced by cyclic heating of resistors embedded in the chain. Vertical sea-ice temperature and heating profiles obtained daily between November 2012 and February 2014 were analyzed to determine sea-ice and snow evolution, and to calculate the basal energy budget. The residual heat flux translated into an ice-volume fraction in the platelet layer of 0.18 ± 0.09, which we reproduced by a independent model simulation and agrees with earlier results. Manual drillings revealed an average annual platelet-layer thickness increase of at least 4m, and an annual maximum thickness of 10m beneath second-year sea ice. The oceanic contribution dominated the total sea-ice production during the study, effectively accounting for up to 70% of second-year sea-ice growth. In summer, an oceanic heat flux of 21 W/m**2 led to a partial thinning of the platelet layer. Our results further show that the active heating method, in contrast to the acoustic sounding approach, is well suited to derive the fast-ice mass balance in regions influenced by ocean/ice-shelf interaction, as it allows sub-diurnal monitoring of the platelet-layer thickness.

Hydrological and meteorological records from the Vernagtferner Basin - Vernagtbach station, for the years 2002 to 2012

In November 2001, two separate Campbell loggers ("Meteologger" and "Hydrologger", both type CR23X) were installed at the Vernagtbach site in the Oetztal Alps, Austria (Latitude: 46.85; Longitude: 10.82; Elevation: 2640 m). On these loggers, 10-minutes centred averages for the meteorological data and 5-minutes centred averages for the hydrological data are recorded. The meteorological parameters comprise air temperature, humidity of the air, air pressure, four radiation components, wind direction and speed, precipitation and snow height. For air temperature, two records are published, recorded with a ventilated and an unventilated Pt-100 in a Stevenson screen; for precipitation, three time series are available: (I) the cumulative record of a weighing gauge for the whole year, (II) single events derived from (I), and (III) single events from a tipping bucket; (II) and (III) are only provided for the period 1, May to 31, October of each year. Wind records are also given with a time step of one hour, as only these records include several statistics of speed and direction. Hydrological parameters are recorded on the "Hydrologger", they comprise water stage, discharge, water temperature and electrolytic conductivity of the water. An identifying number gives the kind of instrument used in the water stage time series. Daily photographs of the glacier are provided and analysed with respect to precipitation type.

European Leaf Physiognomic Approach ELPA

Physiognomic traits of plant leaves such as size, shape or margin are decisively affected by the prevailing environmental conditions of the plant habitat. On the other hand, if a relationship between environment and leaf physiognomy can be shown to exist, vegetation represents a proxy for environmental conditions. This study investigates the relationship between physiognomic traits of leaves from European hardwood vegetation and environmental parameters in order to create a calibration dataset based on high resolution grid cell data. The leaf data are obtained from synthetic chorologic floras, the environmental data comprise climatic and ecologic data. The high resolution of the data allows for a detailed analysis of the spatial dependencies between the investigated parameters. The comparison of environmental parameters and leaf physiognomic characters reveals a clear correlation between temperature related parameters (e.g. mean annual temperature or ground frost frequency) and the expression of leaf characters (e.g. the type of leaf margin or the base of the lamina). Precipitation related parameters (e.g. mean annual precipitation), however, show no correlation with the leaf physiognomic composition of the vegetation. On the basis of these results, transfer functions for several environmental parameters are calculated from the leaf physiognomic composition of the extant vegetation. In a next step, a cluster analysis is applied to the dataset in order to identify "leaf physiognomic communities". Several of these are distinguished, characterised and subsequently used for vegetation classification. Concerning the leaf physiognomic diversity there are precise differences between each of these "leaf physiognomic classes". There is a clear increase of leaf physiognomic diversity with increasing variability of the environmental parameters: Northern vegetation types are characterised by a more or less homogeneous leaf physiognomic composition whereas southern vegetation types like the Mediterranean vegetation show a considerable higher leaf physiognomic diversity. Finally, the transfer functions are used to estimate palaeo-environmental parameters of three fossil European leaf assemblages from Late Oligocene and Middle Miocene. The results are compared with results obtained from other palaeo-environmental reconstructing methods. The estimates based on a direct linear ordination seem to be the most realistic ones, as they are highly consistent with the Coexistence Approach.

Continuous measurements at Schwingbachtal Studienlandschaft in the growing seasons 2013-2014

The recent development of in-situ monitoring devices, such as UV-spectrometers, makes the study of short-term stream chemistry variation relevant, especially the study of diurnal cycles, which are not yet fully understood. Our study is based on high-frequency data from an agricultural catchment (Studienlandschaft Schwingbachtal, Germany). We propose a novel approach, i.e. the combination of cluster analysis and Linear Discriminant Analysis, to mine from these data nitrate behavior patterns. As a result, we observe a seasonality of nitrate diurnal cycles, that differs from the most common cycle seasonality described in the literature, i.e. pre-dawn peaks in spring. Our cycles appear in summer and the maximum and minimum shift to a later time in late summer/autumn. This is observed both for water- and energy-limited years, thus potentially stressing the role of evapotranspiration. This concluding hypothesis on the role of evapotranspiration on nitrate stream concentration, which was obtained through data mining, broadens the perspective on the diurnal cycling of stream nitrate concentrations.

Organization of the Hox gene cluster in the grasshopper, Schistocerca gregaria

The conserved organization of the Hox genes throughout the animal kingdom has become one of the major paradigms of evolutionary developmental biology. We have examined the organization of the Hox genes of the grasshopper, Schistocerca gregaria. We find that the grasshopper Hox cluster is over 700 kb long, and is not split into equivalents of the Antennapedia complex and the bithorax complex of Drosophila melanogaster. SgDax and probably also Sgzen, the grasshopper homologues of fushi-tarazu (ftz) and Zerknüllt (zen), respectively, are also in the cluster, showing that the non-homeotic Antp-class genes, “accessory genes,” are an ancient feature of insect Hox clusters.

Interaction of the Hsp70 molecular chaperone, DnaK, with its cochaperone DnaJ

Chaperones of the Hsp70 family bind to unfolded or partially folded polypeptides to facilitate many cellular processes. ATP hydrolysis and substrate binding, the two key molecular activities of this chaperone, are modulated by the cochaperone DnaJ. By using both genetic and biochemical approaches, we provide evidence that DnaJ binds to at least two sites on the Escherichia coli Hsp70 family member DnaK: under the ATPase domain in a cleft between its two subdomains and at or near the pocket of substrate binding. The lower cleft of the ATPase domain is defined as a binding pocket for the J-domain because (i) a DnaK mutation located in this cleft (R167H) is an allele-specific suppressor of the binding defect of the DnaJ mutation, D35N and (ii) alanine substitution of two residues close to R167 in the crystal structure, N170A and T173A, significantly decrease DnaJ binding. A second binding determinant is likely to be in the substrate-binding domain because some DnaK mutations in the vicinity of the substrate-binding pocket are defective in either the affinity (G400D, G539D) or rate (D526N) of both peptide and DnaJ binding to DnaK. Binding of DnaJ may propagate conformational changes to the nearby ATPase catalytic center and substrate-binding sites as well as facilitate communication between these two domains to alter the molecular properties of Hsp70.

A Framework for Conceptualizing Psychologically Healthy Contemplative Practice.

In recent years contemplative practices such as Zen Buddhism and yoga have become increasingly utilized in the United States (Mann et al., 2001). The most visible contemplative practice in America today is the practice of yoga. According to a 2008 market study conducted by Yoga Journal, yoga was a 5.6 billion dollar industry in America in 2008. This market study also found that 15.8 million people, or 6.9% of American adults, practice yoga (Yoga Market Study, 2008). Zen Buddhism may be less visible than yoga in popular culture, yet its presence in the United States is substantial. While exact statistics are difficult to come by, Harvard University's Pluralism Project cites that the number of practicing Buddhists in America ranges from 2.4 to 4 million people, although it is unclear how many of these individuals practice Zen, or contemplative Buddhism (Pluralism Project Statistics, 2009). The popularity of Zen in America is further evidenced by the presence of Zen centers in most major cities. The sizeable and growing presence of Buddhism in America indicates a move towards the inclusion of contemplative practice in the cultural mainstream (Pluralism Project Statistics, 2009).

Japan, 1876 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: 府懸改正大日本全圖 : 全 [Fuken kaisei Dai Nihon zenzu : zen], Sekiguchi Bisho shu. It was published by Kobayashi Shinbē, Nakamura Nakamura Kumajirō in Meiji 9 [1876]. Scale: 1:100,000. Map in Japanese.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia North Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, administrative boundaries, shoreline features, and more. Includes 3 island insets: Hokkaidō, Ryūkyū shotō, and Ogasawara guntō; and 6 additional insets: Owari Nagoya, Rikuzen Sendai, Aki Hiroshima, and Higo Kumamoto.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.