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131.
Nina Vasiljevic Nadja V. Morf Josef Senn Sílvia PrezEspona Federica Mattucci Nadia Mucci Gaia MooreJones Simone Roberto Rolando Pisano Adelgunde Kratzer Rob Ogden 《Ecology and evolution》2022,12(2)
In the early 1800s, the European roe deer (Capreolus capreolus) was probably extirpated from Switzerland, due to overhunting and deforestation. After a federal law was enacted in 1875 to protect lactating females and young, and limiting the hunting season, the roe deer successfully recovered and recolonized Switzerland. In this study, we use mitochondrial DNA and nuclear DNA markers to investigate the recolonization and assess contemporary genetic structure in relation to broad topographic features, in order to understand underlying ecological processes, inform future roe deer management strategies, and explore the opportunity for development of forensic traceability tools. The results concerning the recolonization origin support natural, multidirectional immigration from neighboring countries. We further demonstrate that there is evidence of weak genetic differentiation within Switzerland among topographic regions. Finally, we conclude that the genetic data support the recognition of a single roe deer management unit within Switzerland, within which there is a potential for broad‐scale geographic origin assignment using nuclear markers to support law enforcement. 相似文献
132.
Celia F. Goodhew Graham W. Pettigrew Bart Devreese jozef van Beeumen Rob J.M. van Spanning Simon C. Baker Neil Saunders stuart J. Ferguson Ian P. Thompson 《FEMS microbiology letters》1996,137(1):95-101
Abstract The c -type cytochrome and protein profiles were compared for a number of cultures of Paracoccus denitrificans obtained from a range of culture collections. The cultures fell into two groups corresponding to the two original isolates of this bacterial species. One group, which included NCIMB 8944, ATCC 13543, ATCC 17741, ATCC 19367, Pd 1222 and DSM 413, were similar or identical to LMD 22.21. The second group, including DSM 65 and LMG 4218, were similar or identical to LMD 52.44. These groupings were not compatible with the recorded history of culture deposition. Mass spectrometry and amino acid sequence comparisons showed that the cytochrome c -550 of the LMD 52.44 culture group differed by 16% from that of the LMD 22.21 group, and yet was only 1% different from the cytochrome c -550 of Thiosphaera pantotropha . These results suggest that consideration should be given to creation of a new species of Paracoccus pantotropha , which would include Thiosphaera pantotropha and Paracoccus denitrificans LMD 52.44. 相似文献
133.
Episodic switching between Tropodiaptomus spectabilis and Metadiaptomus meridianus in L. Midmar (29° 30 S, 30° 12 E), and transitory seasonal alternation of these taxa in L. Albert Falls (29° 26 S, 30° 26 E) recorded in comparative studies of these inter-leading reservoirs between 1989 and 1999, along with historical records for Midmar extending back to 1978, are updated and re-evaluated in light of subsequent and additional findings. In the longer term, an `exclusive' occupancy by one or another species has been maintained in these and other inter-leading impoundments on the quasi-subtropical Mgeni River. Sympatry was invariably transitional. It lasted several months in the upper Midmar system, and where protracted over several years as in the downstream Albert Falls system, was effectively negated by seasonal separation of the taxa. Possible influences of parasitism, changes in water turbidity or pH, dependent or independent of inter-basin water transfers, and such water transfers themselves, are explored and rejected as proximate causes of species replacement. Because evidence for the existence of resting eggs was contradictory (respectively present and absent in preserved and live samples), emergence from diapause is considered an unlikely source of re-colonisation. The guild complement of invertebrate planktivores is comparable in both lakes, seemingly removing predation as a determinant factor. The comparability of food thresholds for various measures of demographic performance suggests remarkable similarity in the competitive potential of these species, which additionally show considerable niche overlap in terms of adult diet, and comparable vulnerability to ellobiopsid parasitism. Ecological separation is thus limited to differentiation of thermal optima, functional feeding biology of juvenile stages – especially nauplii, and sediment tolerance. Evidence now available supports previous arguments that species separations remain attributable largely to marginal species differences in thermal optima, mirrored in the pattern of seasonal separation during an episode of sympatry (1990 to early 1994) in the down-stream Albert Falls system. While no causal explanation can be substantiated from evidence gleaned during this decade of study, the species replacements observed in Midmar appear to reflect alternative stable states, induced by presently unknown factor(s), plausibly temperature, or improbably, human translocation. By contrast, alternative stable states are not manifest in Albert Falls, wherein the longer term, T. spectabilis seemingly represents the only stable state, a feature apparently shared by other warmer reservoirs down the Mgeni cascade. The unpredictability of chaotic dynamics precludes its analysis in this situation, while conversely, the system provides a unique model for meta-population analysis, related to uni-directionality of natural dispersal. However, the cost-effectiveness of continued monitoring for unforeseeable events poses a serious practical dilemma. 相似文献
134.
135.
Excitatory synaptic transmission in the mammalian brain is mediated primarily by alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors that are thought to be co-localized at individual synapses. However, recent electrophysiological and anatomical data suggest that the synaptic localization of AMPA and NMDA receptors may be independently regulated by neural activity. These data are reviewed here and the implications of these findings for the mechanisms underlying synaptic plasticity are discussed. 相似文献
136.
137.
Temporal instability in tree-growth/climate response in the Lower Bavarian Forest region: implications for dendroclimatic reconstruction 总被引:11,自引:3,他引:8
This paper explores the temporal stability of growth/climate relationships in ring-width chronologies of Norway spruce [ Picea abies (L.) Karst] and silver fir ( Abies alba Mill) in the Lower Bavarian Forest region in southern Germany. These chronologies were compiled, using both historic and living tree-ring data, with the main aim of developing a dendroclimatic reconstruction for the region covering the last 500 years. Moving window correlation analysis shows that prior to the twentieth century, both species co-vary in a similar way (1480–1899 mean r =0.66). There is no significant correlation between the species chronologies since ca. 1930, which partly reflects anomalous growth trends in the fir chronology since ca. 1960. Multiple regression analysis was utilised to assess the ability of both species chronologies to model March–August precipitation. The precipitation signal of the spruce data was found to be both stronger than the fir data (1872–1930 calibration: r 2=0.45 vs 0.25) and more time stable. After ca. 1930, the fir chronology loses it ability to model March–August precipitation until there is no climate signal at all in the fir data in recent decades. The spruce data also express a later weakening in their climate signal in the mid 1970s. We present compelling evidence indicating that the anomalous trends observed in the fir data, since the mid 1960s, appear to be predominantly related to local SO2 emissions from power plants and refineries. It is also likely that this local anthropogenic forcing is the cause of the weakening of the climate signal in the spruce data since the mid 1970s. The conclusions from this study are: (1) The fir tree-ring data cannot be used for traditional dendroclimatic calibration, although prior to the twentieth century the decadal variability in the fir data is very similar to spruce and so these data could be used to extend potential reconstructions in the future; (2) The recent decline and recovery event in the fir data appears to be unique to the twentieth century and is not part of a natural episodic phenomenon; (3) Traditional dendroclimatic calibration of March–August precipitation will be made using solely the spruce ring-width data. However, due to SO2 forcing in recent decades, the calibration period will be shortened to the 1871–1978 period. 相似文献
138.
Markha KR Bloor SJ Nicholson R Rivera R Shemluck M Kevan PG Michener C 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(9-10):625-630
The major pigments responsible for the flower color within the black flowered Gentianaceae, Lisianthius nigrescens, were characterized by HPLC and chemical analyses HPLC analysis showed one major and one minor anthocyanin and 3 major and 3 minor flavone glycosides. The anthocyanins [delphinidin-3-O-rhamnol(1-6)galactoside and its 5-O-glucoside] comprised an extraordinary 24% of the dry weight of wild collected L. nigrescens corallas, and were accompanied in a 1:1 ratio by a range of apigenin and luteolin 8-C-glucosides and their 7-O-methyl ethers. The high levels of anthocyanins and flavones (and their co-pigmentation) is thought to account for the almost complete absorption of both UV and visible wavebands observed by reflectance photography. 相似文献
139.
Analytical product study of germanium-containing medicine by different ICP-MS applications. 总被引:1,自引:0,他引:1
For several years organo-germanium containing medicine has been used for special treatments of e.g. cancer and AIDS. The active substances contain germanium as beta-carboxyethylgermanium sesquioxide ((GeCH2CH2COOH)203/"Ge-132"), spirogermanium, germanium-lactate-citrate or unspecified forms. For humans, germanium is not essential and in general the toxicity of the mentioned organo-germanium compounds is low. Acute and chronic toxic effects of inorganic germanium dioxide have been demonstrated. It is obvious that especially inorganic germanium has a higher potential of negative effects. Therefore, a widespread analytical product control is indispensable. Inductively coupled plasma mass spectrometry (ICP-MS) is the preferred technique and different applications were developed for controlling various parameters: (i) A speciation method using high performance liquid chromatography (HPLC) coupled with quadrupole (Q-) ICP-MS was developed for the identification of organo-germanium species in medicine. (ii) The nuclear magnetic resonance (NMR) technique was applied to confirm the molecular structure and to determine the molecule concentration. (iii) The total concentration of germanium in the medicine was determined in the diluted sample by high resolution (HR-) ICP-MS. (iv) For a general overview, a multi-element screening method of 56 elements with HR-ICP-MS was developed. The semi-quantitative mode was used for quantification and elements of higher abundance are reported. (v) Investigations about matrix-based interferences on masses of isotopes, which are generally determinable without remarkable problems. Isotopes like e.g. 85Rb, 88Sr, 89y, 90Zr, 93Nb and the isotopes of Ba are strongly interfered by different Ge-based molecules and need to be analysed in a higher resolution mode than used for other common matrices. 相似文献
140.