placeholder
and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Proceed order?

Export
Filter
Document type
Language
Year
  • 1
    Language: German
    Subject(s): Rüstungspolitik ; Militärische Bedrohung ; Militärpolitik ; Deutschland
    Source: Münchener DigitalisierungsZentrum (Bayerische Staatsbibliothek)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    In: Journal of Biogeography, January 2014, Vol.41(1), pp.81-94
    Description: Aim In contrast to the attention given to southern Europe both as a centre of speciation and differentiation and as a Pleistocene refugium of Western Palaearctic taxa, North Africa has been relatively neglected. In this paper, we set out to address this shortfall. Location North-West Africa and the Mediterranean. Methods We reviewed the existing literature on the biogeography of North Africa, and carried out analyses of species distribution data using parsimony, nestedness and co-occurrence methods. Results In many cases, distribution patterns of non-flying mammals, bats, amphibians, reptiles, butterflies, zygaenid moths and odonates demonstrated important biogeographical affinities between Europe and North Africa at the species level. On the other hand, species co-occurrence, nestedness and parsimony analysis also revealed some deep splits between the Maghreb and Europe; yet even in these cases the closest affinities were found between the Iberian Peninsula and the Maghreb. Furthermore, North Africa harbours the highest proportion of endemic taxa (13.7%) across all groups analysed. Many molecular studies demonstrated a strong genetic cohesiveness between North Africa and Europe despite the potential barrier effect of the Mediterranean Sea. In other taxa, however, remarkable splits were detected. In addition, southern European genetic lineages were often nested within North African clades, and many taxa showed exceptionally high genetic variability and differentiation in this region. Main conclusions The Maghreb was an important differentiation and speciation centre for thermophilic organisms during the Pliocene and Pleistocene with high relevance as a colonization source for Europe. The regions around the sea straits of Gibraltar and Sicily have acted as important biogeographical links between North Africa and Europe at different times. [PUBLICATION ]
    Subject(s): Biodiversity Hotspot ; Climatic Oscillations ; Differentiation Centre ; Genetic Structure ; North Africa ; Phylogeography ; Quaternary ; Refugia ; Sea Straits ; Species Assemblages
    ISSN: 0305-0270
    E-ISSN: 1365-2699
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: BMC evolutionary biology, 02 June 2014, Vol.14, pp.115
    Description: Closely related species often occur in geographic isolation, yet sometimes form contact zones with the potential to hybridize. Pre-zygotic barriers may prevent cross breeding in such contact zones. In East Africa, White-eye birds have evolved into various species, inhabiting different habitat types. Zosterops poliogaster is found in cool and moist cloud forests at higher elevations, whereas Z. abyssinicus is distributed across the dry and hot lowland savannahs. In most areas, these two species occur allopatrically, but in the contact zone where the mountain meets the savannah, the distributions of these species sometimes overlap (parapatry), and in a few areas the two taxa occur sympatrically. Acoustic communication is thought to be an important species recognition mechanism in birds and an effective prezygotic barrier for hybridisation. We recorded contact calls of both the lowland and highland species in (i) distinct populations (allopatry), (ii) along contact zones (parapatry), and (iii)... We found significant differences in call characteristics between the highland and lowland species, in addition to call differentiation within species. The highland Z. poliogaster shows a strong call differentiation among local populations, accompanied by comparatively low variability in their contact calls within populations (i.e. a small acoustic space). In contrast, calls of the lowland Z. abyssinicus are not differentiated among local sites but show relatively high variability in calls within single populations. Call patterns in both species show geographic clines in relation to latitude and longitude. Calls from parapatric populations from both species showed greater similarity to the other taxon in comparison to heterospecific populations found in allopatry. However, where the two species occur sympatrically, contact calls of both species are more distinct from each other than in either allopatric or parapatric populations. The contrasting patterns reflect divergent spatial distributions: the highland Z. poliogaster populations are highly disjunct, while Z. abyssinicus lowland populations are interconnected. Higher similarity in contact calls of heterospecific populations might be due to intermixing. In contrast, sympatric populations show reproductive character displacement which leads to strongly divergent call patterns.
    Subject(s): Biological Evolution ; Sympatry ; Vocalization, Animal ; Passeriformes -- Classification
    ISSN: 1471-2148
    E-ISSN: 1471-2148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    In: Journal of Biogeography, August 2013, Vol.40(8), pp.1475-1489
    Description: Abstract Aim Thermophilic species persisted in southern refugia during the cold phases of the Pleistocene, and expanded northwards during warming. These processes caused genetic imprints, such as a differentiation of genetic lineages and a loss of genetic diversity in the wake of (re)colonization. We used molecular markers and species distribution models (SDMs) to study the impact of range dynamics on the common wall lizard, Podarcis muralis, from southern refugia to the northern range margin. Location Parts of the Western Palaearctic. Methods We genotyped 10 polymorphic microsatellites in 282 individuals of P. muralis and sequenced the mitochondrial DNA (mtDNA) cytochrome b gene to study the genetic structure, divergence times and ancestral distributions. Furthermore, we generated SDMs for climate scenarios for 6 and 21 ka derived from two different global circulation models. Results We detected two major mtDNA lineages – a western France clade (Pyrenees to Brittany), and an eastern France clade (southern France to Germany, Belgium and Luxembourg). This split was dated to c. 1.23 Ma. The latter clade was divided into two subclades, which diverged c. 0.38 Ma. Genetic diversity of microsatellites within each clade was nested and showed a significant loss of genetic diversity from south to north, a strong pattern of allele surfing across nearly all loci, and an increase in genetic differentiation towards the northern range margin. Results from SDMs suggest that southward range retraction during the late glacial period split the distribution into geographically distinct refugia. Main conclusions The strong genetic differentiation mirrors the effects of long‐term isolation of P. muralis in multiple refugia. Post‐glacial recolonization of Northern Europe has taken place from two distinct refugia, most probably along river systems (Rhône, Rhine, Moselle) and along the Atlantic coastline, with subsequent nested elimination of genetic diversity and increasing genetic differentiation at the northern range margin.
    Subject(s): Climatic Oscillations ; Europe ; Genetic Structure ; Leading Edge ; Lizard Phylogeography ; Microsatellites ; Post‐Glacial Pathways ; Rear Edge ; Refugia ; Species Distribution Models
    ISSN: 0305-0270
    E-ISSN: 1365-2699
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    In: Ecology and Evolution, December 2015, Vol.5(24), pp.5974-5982
    Description: Species distribution patterns range from highly disjunct to continuous, depending on their ecological demands and the availability of respective habitats. East African savannahs are mostly interconnected and ecologically comparatively homogenous and thus provide a prerequisite for a rather panmictic distribution pattern for species occurring in this habitat. The Abyssinian white‐eye is a savannah inhabiting bird species, representing such a continuous distribution. This species occurs in high abundances and is very mobile, and past population genetic studies have suggested that gene flow is high and genetic differentiation is low even across relatively large geographic distances. Further, only little morphological differences were found. In order to test for potential divergence in acoustic traits despite its interconnected geographic distribution, we analyzed 2795 contact calls of which were recorded at 19 sites across Kenya. Our data indicate weak, but significant differentiation in call characteristics across latitudinal gradients. We found strong changes in call characteristics in populations where occurs in sympatry with its highland congener, . However, the changes in call characteristics in sympatry were in different directions and lead to strong differentiation of the sympatric populations to other conspecific populations potentially representing a case of cascade reinforcement. The detected spatial gradients likely result from ecological differences and balancing effects of natural and sexual selection. Abyssinian White‐eyes, , here at Mt. Kulal, are common in the lowlands of East Africa, but can also be found at higher elevations. The species has an interconnected distribution across major parts of East Africa; despite its panmictic distribution the birds show significant divergence in contact calls with latitudinal and longitudinal gradients.
    Subject(s): Acoustic Communication ; Allopatry ; Character Displacement ; Contact Calls ; Geographic Gradients ; Sonogram ; Sympatry
    ISSN: 2045-7758
    E-ISSN: 2045-7758
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: BMC evolutionary biology, 01 July 2018, Vol.18(1), pp.1-9
    Description: Abstract Background Spatial isolation, diverging environmental conditions and social structures may lead to the differentiation of various traits, e.g. molecules, morphology and behaviour. Bird calls may provide important information on effects of geographic isolation and may reflect diverging ecological conditions related to altitude. Furthermore, bird calls are strongly shaped by the social behaviour of species. The Kenyan endemic bird Hinde’s Babbler, Turdoides hindei, is a cooperative breeder existing in distinct family groups. The species occurs in five isolated population groups at different altitudes across its distribution range in south-eastern Kenya. With this model species we test for potential effects of geographic isolation, diverging altitudes, and social structures. We recorded and analysed contact and alarm calls of T. hindei, including its entire distribution range and all existing population groups. Results Our data show significant differentiation of call characteristics...
    Subject(s): Altitude ; Geographic Isolation ; Environmental Conditions ; Social Structures ; Birds ; Cooperative Breeder ; Biology
    E-ISSN: 1471-2148
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: CONSERVATION GENETICS, 2014
    Description: East-African mountain forest species often occur in small and isolated populations, whereas species inhabiting the dry lowland savannahs exist in large and interconnected population networks. Taxa with closely related highland and lowland species, such as the East-African White-eye birds, allow testing for the potential effects of the two contrasting distribution patterns, mountain disjunction versus lowland panmixia. In this study, we compare the population genetic and bioacoustic differentiation of two representatives of the genus Zosterops: Zosterops poliogaster is exclusively found in forests at higher elevations; in comparison, Zosterops abyssinicus, only occurs in the dry and warm lowland savannahs. Both species were analysed across a similar geographical scale. Population genetic differentiation was inferred using the same set of 15 polymorphic microsatellite loci for both species. In addition, we quantitatively analyzed bioacoustic traits. Both data sets indicate a strong population differentiation among populations of the highland species, but an absence of differentiation in the lowland species. In addition, the lowland Z. abyssinicus was characterised by a twofold higher genetic diversity than detected for the highland Z. poliogaster. These two contrasting intraspecific population structures may reflect the opposite ecology and distribution of these species: the strong population isolation of Z. poliogaster resulting from long-term restriction to the cool and moist mountain forests at higher elevations has led to strong differentiation among local populations and resulted in a comparatively low level of intraspecific variability. In contrast, population panmixia in the lowland Z. abyssinicus provides a high level of gene flow allowing the maintenance of high genetic diversity and avoiding strong population structuring. These findings need to be considered when planning conservation actions.
    Subject(s): Biology And Life Sciences ; Cloud Forest ; Bioacoustics ; Differentiation ; Disjunction ; Diversity ; Panmixia ; Population Genetics ; Savannah ; Population-Structure ; Diversification ; Software ; Forests ; Conservation ; Mountains ; Radiation ; Inference ; Richness ; Patterns
    ISSN: 1566-0621
    Source: Ghent University
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Conservation Genetics, 2014, Vol.15(3), pp.655-664
    Description: East-African mountain forest species often occur in small and isolated populations, whereas species inhabiting the dry lowland savannahs exist in large and interconnected population networks. Taxa with closely related highland and lowland species, such as the East-African White-eye birds, allow testing for the potential effects of the two contrasting distribution patterns, mountain disjunction versus lowland panmixia. In this study, we compare the population genetic and bioacoustic differentiation of two representatives of the genus Zosterops : Zosterops poliogaster is exclusively found in forests at higher elevations; in comparison, Zosterops abyssinicus , only occurs in the dry and warm lowland savannahs. Both species were analysed across a similar geographical scale. Population genetic differentiation was inferred using the same set of 15 polymorphic microsatellite loci for both species. In addition, we quantitatively analyzed bioacoustic traits. Both data sets indicate a strong population differentiation among populations of the highland species, but an absence of differentiation in the lowland species. In addition, the lowland Z. abyssinicus was characterised by a twofold higher genetic diversity than detected for the highland Z. poliogaster . These two contrasting intraspecific population structures may reflect the opposite ecology and distribution of these species: the strong population isolation of Z. poliogaster resulting from long-term restriction to the cool and moist mountain forests at higher elevations has led to strong differentiation among local populations and resulted in a comparatively low level of intraspecific variability. In contrast, population panmixia in the lowland Z. abyssinicus provides a high level of gene flow allowing the maintenance of high genetic diversity and avoiding strong population structuring. These findings need to be considered when planning conservation actions.
    Subject(s): Bioacoustics ; Cloud forest ; Differentiation ; Disjunction ; Diversity ; Panmixia ; Population genetics ; Savannah
    ISSN: 1566-0621
    E-ISSN: 1572-9737
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: ECOLOGY AND EVOLUTION, 2015
    Description: The moist and cool cloud forests of East Africa represent a network of isolated habitats that are separated by dry and warm lowland savannah, offering an opportunity to investigate how strikingly different selective regimes affect species diversification. Here, we used the passerine genus Zosterops (white-eyes) from this region as our model system. Species of the genus occur in contrasting distribution settings, with geographical mountain isolation driving diversification, and savannah interconnectivity preventing differentiation. We analyze (1) patterns of phenotypic and genetic differentiation in high- and lowland species (different distribution settings), (2) investigate the potential effects of natural selection and temporal and spatial isolation (evolutionary drivers), and (3) critically review the taxonomy of this species complex. We found strong phenotypic and genetic differentiation among and within the three focal species, both in the highland species complex and in the lowland taxa. Altitude was a stronger predictor of phenotypic patterns than the current taxonomic classification. We found longitudinal and latitudinal phenotypic gradients for all three species. Furthermore, wing length and body weight were significantly correlated with altitude and habitat type in the highland species Z.poliogaster. Genetic and phenotypic divergence showed contrasting inter- and intraspecific structures. We suggest that the evolution of phenotypic characters is mainly driven by natural selection due to differences in the two macro-habitats, cloud forest and savannah. In contrast, patterns of neutral genetic variation appear to be rather driven by geographical isolation of the respective mountain massifs. Populations of the Z.poliogaster complex, as well as Z.senegalensis and Z.abyssinicus, are not monophyletic based on microsatellite data and have higher levels of intraspecific differentiation compared to the currently accepted species.
    Subject(s): Biology And Life Sciences ; Cloud Forest ; Disjunction ; Gradient ; Microsatellites ; Morphometrics ; Natural Selection ; Panmixis ; Polyphyletic ; Savannah ; Phylogenetic-Relationships ; Morphological Divergence ; Q(St)-F-St Comparisons ; Contrasting Patterns ; Species Delimitation ; Population-Structure ; Quantitative Traits ; Canary-Islands ; Arc Mountains ; Forest Bird
    ISSN: 2045-7758
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Obesity Surgery, 2006, Vol.16(3), pp.288-296
    Description: Background: While numerous promising short-term results of open gastric bypass for morbid obesity were published, the long-term outcome of earlier versions was somewhat disappointing. Thus, it was not until 1993 that this procedure was reintroduced with current modifications and now performed laparoscopically. Published long-term results of gastric bypass are still lacking. Methods: Out of an original population of 195 patients, we retrospectively analyzed the outcome of 98 patients (82 women, 16 men, mean age 32 years [range 17-54], mean weight 132 kg [range 65-200], mean BMI 46.6 kg/m 2 ) operated on in Erlangen with mean follow-up 22.9 years (range 16.5-25.4). 3 different bariatric operations were performed: horizontal gastroplasty (HGP, n=18), stapled Roux-en-Y gastric bypass (S-RYGBP, n=14) and transected Roux-en-Y gastric bypass (T-RYGBP, n=66). BMI and percentage of excess weight loss (%EWL) were calculated at time 0, and after 1, 2, 3, 10, 15, 20 and 25 years. Results: Statistically significant weight loss was found for the whole patient population at every postoperative time-point compared to preoperative values. Maximal weight loss was achieved mainly during the first 3 years. However, initial and long-term outcome after HGP was significantly worse than after S-RYGBP or T-RYGBP. Gender did not significantly influence the results. Conclusion: Traditional open gastric bypass resulted in acceptable and safe long-term weight reduction. It may be assumed that laparoscopic gastric bypass with modern tiny pouch volumes based on the lesser curvature achieves even better and life-long weight reduction.
    Subject(s): MORBID OBESITY ; BARIATRIC SURGERY ; GASTRIC BYPASS ; HORIZONTAL GASTROPLASTY ; OUTCOME ; LONG-TERM RESULTS ; WEIGHT REDUCTION
    ISSN: 0960-8923
    E-ISSN: 1708-0428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...