Using Scent-Matching Dogs to Identify Individual Amur Tigers from Scats

Abstract: Scent-matching dogs have previously been used to identify caged individual Amur tigers (Panthera tigris altaica) by fecal material (scat), but this technique has not been tested in the wild. We tested the hypothesis that trained dogs can identify individual tigers by unique characteristics present in scat. To conduct this work, we used 5 dogs and 58 scats from 25 known individual tigers in independent trials. Dogs correctly selected matched test scats at an average rate of 87% (SE ± 1.4%, n = 521 trials). The average accuracy rates for 4 dogs increased to 98% (SE ± 1.6%, n = 86 sets of repeated-trials) using repeated-trial tests. Each of 5 dogs made correct choices better than expected by chance (dog 1 χ²₁ = 507.9, P ≤ 0.001; dog 2 χ²₁ = 882.1, P ≤ 0.001; dog 3 χ²₁ = 374.1, P ≤ 0.001; dog 4 χ²₁ = 379.2, P ≤ 0.001; and dog 5 χ²₁ = 103.9, P ≤ 0.001). Four dogs were able to match 11 scats deposited over a 4-year period from one tiger with an accuracy of 100% (n = 40 trails). This method may be a useful alternative to genetic analyses that are used in conjunction with scat-sampling schemes in studies for which DNA genotyping is impractical or ineffective. Used with mark—recapture surveys to estimate species abundance, scent-matching dogs have the potential of being important tools in the study of wild Amur tigers, as well as other wildlife species.     

Carbon stored in human settlements: the conterminous United States

Urban areas are home to more than half of the world's people, responsible for >70% of anthropogenic release of carbon dioxide and 76% of wood used for industrial purposes. By 2050 the proportion of the urban population is expected to increase to 70% worldwide. Despite fast rates of change and potential value for mitigation of carbon dioxide emissions, the organic carbon storage in human settlements has not been well quantified. Here, we show that human settlements can store as much carbon per unit area (23–42 kg C m⁻² urban areas and 7–16 kg C m⁻²exurban areas) as tropical forests, which have the highest carbon density of natural ecosystems (4–25 kg C m⁻²). By the year 2000 carbon storage attributed to human settlements of the conterminous United States was 18 Pg of carbon or 10% of its total land carbon storage. Sixty-four percent of this carbon was attributed to soil, 20% to vegetation, 11% to landfills, and 5% to buildings. To offset rising urban emissions of carbon, regional and national governments should consider how to protect or even to increase carbon storage of human-dominated landscapes. Rigorous studies addressing carbon budgets of human settlements and vulnerability of their carbon storage are needed.     

Storage and mobility of black carbon in permafrost soils of the forest tundra ecotone in Northern Siberia

Boreal permafrost soils store large amounts of organic carbon (OC). Parts of this carbon (C) might be black carbon (BC) generated during vegetation fires. Rising temperature and permafrost degradation is expected to have different consequences for OC and BC, because BC is considered to be a refractory subfraction of soil organic matter. To get some insight into stocks, variability, and characteristics of BC in permafrost soils, we estimated the benzene polycarboxylic acid (BPCA) method‐specific composition and storage of BC, i.e. BPCA‐BC, in a 0.44 km²‐sized catchment at the forest tundra ecotone in northern Siberia. Furthermore, we assessed the BPCA‐BC export with the stream draining the catchment. The catchment is composed of various landscape units with south‐southwest (SSW) exposed mineral soils characterized by thick active layer or lacking permafrost, north‐northeast (NNE) faced mineral soils with thin active layer, and permafrost‐affected raised bogs in plateau positions showing in part thermokarst formation. There were indications of vegetation fires at all landscape units. BC was ubiquitous in the catchment soils and BPCA‐BC amounted to 0.6–3.0% of OC. This corresponded to a BC storage of 22–3440 g m^?2. The relative contribution of BPCA‐BC to OC, as well as the absolute stocks of BPCA‐BC were largest in the intact bogs with a shallow active layer followed by mineral soils of the NNE aspects. In both landscape units, a large proportion of BPCA‐BC was stored within the permafrost. In contrast, mineral soils with thick active layer or lacking permafrost and organic soils subjected to thermokarst formation stored less BPCA‐BC. Permafrost is, hence, not only a crucial factor in the storage of OC but also of BC. In the stream water BPCA‐BC amounted on an average to 3.9% of OC, and a yearly export of 0.10 g BPCA‐BC m^?2 was calculated, most of it occurring during the period of snow melt with dominance of surface flow. This suggests that BC mobility in dissolved and colloidal phase is an important pathway of BC export from the catchment. Such a transport mechanism may explain the high BC concentrations found in sediments of the Arctic Ocean.     

ALPHA-FETOPROTEIN-MEDIATED TARGETING—A NEW STRATEGY TO OVERCOME MULTIDRUG RESISTANCE OF TUMOUR CELLSIN VITRO

The possibility of overcoming the multidrug resistance of human malignant cells by using doxorubicin conjugated to alpha-fetoprotein (AFP) was studied. It was shown that this type of antitumour drugs, penetrating the cell by receptor-mediated endocytosis with AFP as a vehicle, raises the sensitivity of the tumour cells that are resistant due to the expression of the multidrug resistance genemdr1. The sensitivity of antibiotic-resistant cell lines SKVLB (a human ovarian carcinoma) and MCF-7 AdrR (a human breast carcinoma) increased by 10- and 4-fold, respectively, when AFP-conjugated doxorubicin was used. The rationale of using human AFP-antitumour drug conjugates for the development of new chemotherapeutic approaches to cancer treatment is discussed.     

Intraspecific chromosomal and genetic polymorphism in Brassica napus L. detected by cytogenetic and molecular markers

The application of DNA intercalator 9-aminoacridine allowed us to increase the resolution of chromosome C-banding and DAPI-banding patterns and to investigate chromosomal polymorphism in karyotypes of seven spring and six winter rape varieties. It was shown that the pericentromeric and intercalary C-bands of most of the chromosomes in spring rape were smaller in size and less polymorphic than those of winter rape. More 26S and 5S rDNA sites were found in the winter rape karyotypes than the spring varieties. Separate or colocalized 26S and 5S rDNA sites were revealed on chromosomes 4, 5, 6, 8, 10, 14, 15, 16 and 18. Intervarietal and intravarietal polymorphism of the number and chromosomal localization of rDNA sites were detected. The generalized idiogram of chromosomes of 13 Brassica napus varieties with account of all possibilities of C-banding patterns as well as localization of 26S and 5S rDNA sites were constructed. Polymorphism of the examined molecular and cytogenetic markers as well as the heterozygosis level of FAE1.1 gene controlling erucic acid synthesis in rapeseed was higher in the winter varieties than in the spring ones. The obtained data were in a satisfactory agreement with increased tolerance to environmental stress conditions of winter rape.     

Identification of Microtubule-Organizing Centers in Interphase Melanophores of Xenopus Laevis Larvae In Vivo

The morphological characteristics of microtubule-organizing centers (MTOCs) in dermal interphase melanophores of Xenopus laevis larvae in vivo at 51-53 stages of development has been studied using immuno-stained semi-thick sections by fluorescent microscopy combined with computer image analysis. Computer image analysis of melanophores with aggregated and dispersed pigment granules, stained with the antibodies against the centrosome-specific component (CTR210) and tubulin, has revealed the presence of one main focus of microtubule convergence in the cell body, which coincides with the localization of the centrosome-specific antigen. An electron microscopy of those melanophores has shown that aggregation or dispersion of melanosomes is accompanied by changes in the morphological arrangement of the MTOC/centrosome. The centrosome in melanophores with dispersed pigment exhibits a conventional organization, and their melanosomes are situated in an immediate vicinity of the centrioles. In melanophores with aggregated pigment, MTOC is characterized by a three-zonal organization: the centrosome with centrioles, the centrosphere, and an outlying radial arrangement of microtubules and their associated inclusions. The centrosome in interphase melanophores is presumed to contain a pair of centrioles or numerous centrioles. Because of an inability of detecting additional MTOCs, it has been considered that an active MTOC in interphase melanophores of X. laevis is the centrosome. We assume that remaining intact microtubules in the cytoplasmic processes of mitotic melanophores (Rubina et al., 1999) derive either from the aster or the centrosome active at the interphase.     

Landscape controls of CH4 fluxes in a catchment of the forest tundra ecotone in northern Siberia

Terrestrial ecosystems in northern high latitudes exchange large amounts of methane (CH₄) with the atmosphere. Climate warming could have a great impact on CH₄ exchange, in particular in regions where degradation of permafrost is induced. In order to improve the understanding of the present and future methane dynamics in permafrost regions, we studied CH₄ fluxes of typical landscape structures in a small catchment in the forest tundra ecotone in northern Siberia. Gas fluxes were measured using a closed‐chamber technique from August to November 2003 and from August 2006 to July 2007 on tree‐covered mineral soils with and without permafrost, on a frozen bog plateau, and on a thermokarst pond. For areal integration of the CH₄ fluxes, we combined field observations and classification of functional landscape structures based on a high‐resolution Quickbird satellite image. All mineral soils were net sinks of atmospheric CH₄. The magnitude of annual CH₄ uptake was higher for soils without permafrost (1.19 kg CH₄ ha⁻¹ yr⁻¹) than for soils with permafrost (0.37 kg CH₄ ha⁻¹ yr⁻¹). In well‐drained soils, significant CH₄ uptake occurred even after the onset of ground frost. Bog plateaux, which stored large amounts of frozen organic carbon, were also a net sink of atmospheric CH₄ (0.38 kg CH₄ ha⁻¹ yr⁻¹). Thermokarst ponds, which developed from permafrost collapse in bog plateaux, were hot spots of CH₄ emission (approximately 200 kg CH₄ ha⁻¹ yr⁻¹). Despite the low area coverage of thermokarst ponds (only 2.1% of the total catchment area), emissions from these sites resulted in a mean catchment CH₄ emission of 3.8 kg CH₄ ha⁻¹ yr⁻¹. Export of dissolved CH₄ with stream water was insignificant. The results suggest that mineral soils and bog plateaux in this region will respond differently to increasing temperatures and associated permafrost degradation. Net uptake of atmospheric CH₄ in mineral soils is expected to gradually increase with increasing active layer depth and soil drainage. Changes in bog plateaux will probably be much more rapid and drastic. Permafrost collapse in frozen bog plateaux would result in high CH₄ emissions that act as positive feedback to climate warming.     

Characterization of ecosystem responses to climatic controls using artificial neural networks

Understanding and modeling ecosystem responses to their climatic controls is one of the major challenges for predicting the effects of global change. Usually, the responses are implemented in models as parameterized functional relationships of a fixed type. In contrast, the inductive approach presented here based on artificial neural networks (ANNs) allows the relationships to be extracted directly from the data. It has been developed to explore large, fragmentary, noisy, and multidimensional datasets, such as the carbon fluxes measured at the ecosystem level with the eddy covariance technique. To illustrate this, our approach has been systematically applied to the daytime carbon flux dataset of the deciduous broadleaf forest Hainich in Germany. The total explainable variability of the half‐hourly carbon fluxes from the driving climatic variables was 93.1%, showing the excellent data mining capability of the ANNs. Total photosynthetic photon flux density was identified as the dominant control of the daytime response, followed by the diffuse radiation. The vapor pressure deficit was the most important nonradiative control. From the ANNs, we were also able to deduce and visualize the dependencies and sensitivities of the response to its climatic controls. With respect to diffuse radiation, the daytime carbon response showed no saturation and the light use efficiency was three times greater for diffuse compared with direct radiation. However, with less potential radiation reaching the forest, the overall effect of diffuse radiation was slightly negative. The optimum uptake of carbon occurred at diffuse fractions between 30% and 40%. By identifying the hierarchy of the climatic controls of the ecosystem response as well as their multidimensional functional relationships, our inductive approach offers a direct interface to the data. This provides instant insight in the underlying ecosystem physiology and links the observational relationships to their representation in the modeling world.     

The Embryos Obtained from the Karyoplasts of Starfish Oocytes: Their Development and Sensitivity to Cytostatic Neurotransmitter Antagonists

Karyoplasts obtained from full-grown oocytes of the starfish Aphelasterias japonica have practically no cytoplams and are incapable of maturation. Karyoplasts of oocytes of starfishes Marthasterias glacialis and Acanthaster planci have the cytoplasm (10%–15% of the total karyoplast volume) and are often capable of maturation, fertilization and one or several cleavage divisions. The embryoskaryoplasts completely lose supersensitivity and retain usual sensitivity to cytostatic antagonists of neurotransmitters. The assumption is made that the incapability or limited capability of this embryos for development might be due to a deficiency of certain components of the "prenervous" neurotransmitter systems.