ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1995-1999  (35)
  • 1990-1994  (39)
  • 1980-1984  (26)
Collection
Language
Years
Year
  • 1
    Series available for loan
    Series available for loan
    Washington, DC : United States Gov. Print. Off.
    Associated volumes
    Call number: SR 90.0001(1488)
    In: U.S. Geological Survey bulletin
    Type of Medium: Series available for loan
    Pages: III, 19 S.
    Series Statement: U.S. Geological Survey bulletin 1488
    Language: English
    Location: Lower compact magazine
    Branch Library: GFZ Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Experimental hives obtained from cordovan queens that were instrumentally inseminated with semen from one cordovan and one Italian drone were set up and allowed to swarm. Cordovan provides a resessive genetic marker system (cuticle color) so that the workers from the cordovan and Italian male lines are distinguishable. Our results show that these patrilineal worker groups segregate non-randomly during colony fission and this segregation cannot be explained by observed age structure. Evidence of innate kin recognition in bees has been previously established. We argue that kin recognition could be responsible for the observed non-random grouping of kin during swarming.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-8477
    Keywords: genetic models ; inbreeding depression ; mating cost ; Hymenoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Existing genetic models of the evolution of sibmating behaviour in diploids incorporate inbreeding depression in terms of reduced fecundity of consanguineous mating pairs rather than reduced survival or fecundity of the progeny of such matings. Here we derive a model to correct this deficiency and extend the model to haplodiploids where differential effects of inbreeding in males and females is a crucial consideration. Our analyses indicate that sibmating can readily evolve in both diploids and haplodiploids in which male mating costs and inbreeding depression are reasonably low, provided there is some mechanism to permit sibmating such as siblings being reared in nests or other forms of aggregation. Our analyses also indicate that once sibmating invades, it typically will go to fixation, although sib-/randommating polymorphisms can persist in both diploids and haplodiploids if male mating costs are close to zero and inbreeding depression reduces survival by around one-third. The conditions favouring sibmating are slightly more restrictive in haplodiploids than in diploids. In light of this we may ask why we see intense sibmating in many haplodiploids such as parasitic wasps, fig wasps, ants, bark beetles and mites, and only rarely in diploid animals. The common factor could be certain kinds of aggregation behaviour that are a prerequisite for sibmating in the absence of kin recognition. Another possibility is that inbreeding depression is likely to be more severe in diploids than in haplodiploids because deleterious recessives are purged from haplodiploid populations when expressed by haploid males. Thus, lower levels of inbreeding depression might be one important reason why sibmating appears to arise more frequently in haplodiploids than diploids. Phylogenetic analysis of groups, such as bark beetles and mites, exhibiting both diploid and haplodiploid populations may be useful in elucidating the relative importance of gregarious behaviour and haplodiploidy in facilitating sibmating systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-8477
    Keywords: sibmating ; inbreeding depression ; haplodiploid ; inclusive fitness ; one-locus genetic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We construct an inclusive fitness model of the relative selective advantage of sibmating and outbreeding behaviour, under the assumption that inbred offspring pay a fitness penalty. We are particularly interested in the question of whether such inbreeding depression is enough to generate a stable phenotypic polymorphism, with both kinds of breeding observed. The model predicts that, under diploidy, such a polymorphism is never found, but under haplodiploidy, it exists for a narrow range of parameter values. The inclusive fitness argument is technically interesting because care must be taken with reproductive values. We also present a corrected version of a one-locus genetic model for sibmating and find that the inclusive fitness and genetic models give identical results when selection is weak.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-8477
    Keywords: evolutionary dynamics ; populations ; interactive resources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary I begin by reviewing the derivation of continuous logistic growth and dynamic consumer—resource interaction equations in terms of specific resource extraction and biomass conversion functions that are considered to hold at a population level. Evolutionary stable strategy (ESS) methods are discussed for analysing populations modelled by these equations. The question of selection trade-offs is then considered, particularly in the context of populations being efficient at extracting resources versus converting resources to their own biomass. Questions relating to single populations with high versus low conversion rates and interacting populations with high versus low self-interference rates are also considered. The models discussed here demonstrate conclusively that self-interference is an essential part of any consumption process: without it population growth and interaction processes do not make any sense. The analysis clarifies concepts relating to the somewhat discredited notion ofr—K selection.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-5028
    Keywords: cucumber ; light-regulated gene expression ; NADH-dependent hydroxypyruvate reductase ; organ-specific gene expression ; peroxisome ; photorespiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The 5′- and 3′-flanking regions of HPRA, a cucumber gene that encodes hydroxypyruvate reductase, were evaluated for regulatory activity with respect to light responsiveness and organ specificity. To define the functional regions of the 5′-flanking region of HPRA, a series of deletions was generated and the remaining portions fused to the β-glucuronidase (GUS) reporter gene (uidA) containing a minimal 35S promoter truncated at −90. The region from −66 to +39 was found to be necessary for light-regulated expression of the uidA reporter gene, while the region from −382 to −67 was found to be necessary for its leaf-specific expression. Further deletion of the HPRA 5′ flanking region to −590 resulted in high levels of root expression, suggesting the presence of a negative regulatory element responsible for silencing root expression of the HPRA gene between −590 and −383. The 3′-flanking region of the HPRA gene downstream of the polyadenylation site contains several sequence motifs resembling regulatory elements present in the promoters of several light-responsive genes. An 823 bp portion of the HPRA 3′-flanking region containing these putative regulatory elements enhanced GUS expression in leaves when placed downstream of the uidA reporter gene in the forward orientation, but not in the reverse orientation. When placed 5′ of the −90 35S promoter, the 823 bp fragment enhanced slightly, independently of orientation, the root tip-specific expression pattern intrinsic to the −90 35S promoter, indicating that in some cases this region can act as a transcriptional enhancer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-5028
    Keywords: hydroxypyruvate reductase ; light regulation ; peroxisomal enzymes ; photorespiration ; plant gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several clones corresponding to the gene encoding NADH-dependent hydroxypyruvate reductase have been isolated from a cucumber genomic library. Restriction mapping indicates the presence of two HPR genes, hpr-A and hpr-B, in the cucumber genome. Examination of the DNAs of individual plants suggests that hpr-A and hpr-B are most likely alleles at a single locus. The sequence of a 6.7 kb genomic fragment that includes the entire transcribed region, 2.2 kb of 5′ flanking sequence, and about 0.8 kb of 3′ flanking sequence reveals the presence of 12 introns in hpr-A. These introns are AT-rich relative to the exons. The donor sequence at the 5′ end of the sixth intron contains an unusual dinucleotide, GC, rather than the nearly invariant GT. Primer extension analysis maps the transcription initiation site to 61 nucleotides upstream of the translation initiation codon. An AT-rich stretch is centered at position −31 with respect to the transcription initiation site, and a potential CCAAT box is centered at position −138. Several elements that are homologous to regulatory elements of other plant genes have been identified in the flanking regions of hpr-A.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-5028
    Keywords: cucumber ; cytokinin-responsive ; DNA-binding proteins ; hydroxypyruvate reductase ; transcription
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transcription of the cucumber hpr-A gene is responsive to cytokinin and light. To investigate the molecular basis for transcriptional regulation by cytokinin, we have identified DNA sequences and proteins that may be involved in the regulation of hpr-A gene expression. Transient expression assays in etiolated cucumber cotyledons indicate that the 315 bp fragment (−382 to −67) contains sequences necessary for cytokinin responsiveness of the luciferase reporter gene. Band shift assays detected cytokinin-enhanced and -reduced protein binding sites in a 97 bp fragment (−382 to −285) upstream of the hpr-A gene. DNase I footprinting identified two protein-protected sites, a 15 bp sequence, 5′-AAATGACGAAAATGC-3′, that contains an as-1 TGACG motif found in other plant promoters, and a 13 bp sequence, 5′-AAGATTGATTGAG-3′, of unknown function. Two-dimensional band shift analysis of the cytokinin-responsive DNA protein complex revealed the presence of six DNA protein interactions. Band shift assays showed that cytokinin and light have different effects on the interaction of nuclear proteins to the 97 bp fragment of the hpr-A gene. These data suggest that cytokinin and light do not share identical signal transduction pathways in regulating hpr-A gene expression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-5036
    Keywords: carbon-13 ; cropping systems ; δ13C ; KMnO4 oxidation ; soil organic matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The decline in soil organic matter with cropping is a major factor affecting the sustainability of cropping systems. Changes in total C levels are relativelyinsensitive as a sustainability measure. Oxidation with different strength KMnO4 has been shown to be a more sensitive indicator of change. The relative size of soil C fractions oxidised by 333 mM KMnO4 declined with cropping, whilst the relative size of the unoxidised fraction increased. Changes in δ13C ratio have been used to measure C turnover in systems which include C3 and C4 species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...