ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Keywords: Assessment ; Malaria ; Public Health ; Scale ; Weather ; climate change ; public health policy ; temperature
    Description / Table of Contents: Awareness that many key aspects of public health are strongly influenced by climate is growing dramatically, driven by new research and experience and fears of climate change and the research needed to underpin policy developments in area is growing rapidly . This awareness has yet to translate into a practical use of climate knowledge by health policy-makers. Evidence based policy and practice is the mantra of the health sector. If climate scientists are to contribute effectively to health policy at local and global scales then careful empirical studies must be undertaken – focused on the needs of the public health policy and decision-makers. Results presented at the Wengen conference make clear that the science and art of integrating climate knowledge into the control of climate sensitive diseases on a year to year time frame as well as careful assessments of the potential impacts of climate change on health outcomes over longer time frames is advancing rapidly on many fronts. This includes advances in the empirical understanding of mechanisms, methodologies for modeling future impacts, new partnership developments between the health and climate community along with access to relevant data resources, and education and training. In a rapidly evolving field this book provides a snapshot of these emerging themes.
    Pages: Online-Ressource (X, 232 pages)
    ISBN: 9781402068775
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1420-9136
    Keywords: Pressure ; temperature ; stress ; measurement ; acoustic emissions ; deformation ; techniques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract New and improved techniques and apparatus for testing the mechanical properties of materials at high presures and temperatures are described. These include an improved Griggs-type deformation apparatus designed to operate to 5 GPa and associated servo-controlled hydraulic drive and electronics, the design of hydrostatic (molten alkali halide mixtures) pressure assemblies to measure flow stresses as low as a few MPa, the characterization of temperature gradients and friction in such assemblies, measurement of the melting curve of an alkali halide mixture used as a confining pressure medium, and the measurement of acoustic emissions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 204 (1994), S. 62-69 
    ISSN: 1432-041X
    Keywords: Cell determination ; direct development dorsoventral axis ; echinoids ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the direct-developing sea urchinHeliocidaris erythrogramma the first cleavage division bisects the dorsoventral axis of the developing embryo along a frontal plane. In the two-celled embryo one of the blastomeres, the ventral cell (V), gives rise to all pigmented mesenchyme, as well as to the vestibule of the echinus rudiment. Upon isolation, however, the dorsal blastomere (D) displays some regulation, and is able to form a small number of pigmented mesenchyme cells and even a vestibule. We have examined the spatial and temporal determination of cell fates along the dorsoventral axis during subsequent development. We demonstrate that the dorsoventral axis is resident within both cells of the two-celled embryo, but only the ventral pole of this axis has a rigidly fixed identity this early in development. The polarity of this axis remains the same in half-embryos developing from isolated ventral (V) blastomeres, but it can flip 180° in half-embryos developing from isolated dorsal (D) blastomeres. We find that cell fates are progressively determined along the dorsoventral axis up to the time of gastrulation. The ability of dorsal half-embryos to differentiate ventral cell fates diminishes as they are isolated at progressively later stages of development. These results suggest that the determination of cell fates along the dorsoventral axis inH. erythrogramma is regulated via inductive interactions organized by cells within the ventral half of the embryo.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 191 (1982), S. 1-4 
    ISSN: 1432-041X
    Keywords: Embryo ; RNA ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Frog embryo nuclear and cytoplasmic RNA populations, labeled in vivo and in vitro, were hybridized to, filterbound homologous and heterologous DNA. The transcription of homologous (frog) repetitive DNA into nuclear RNA decreases qualitatively during development while the transcription of heterologous (minnow, human) repetitive DNA into nuclear RNA remains relatively constant qualitatively. The diversity of homologous repetitive mRNA increases during development, but there is only a slight change in the diversity of heterologous repetitive mRNA transcripts. There is a marked restriction of transport of the heterologous RNA sequences to the cytoplasm at a later stage of development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1420-9098
    Keywords: Isoptera ; Termitidae ; Nasutitermitinae ; caste differentiation ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental pattern of the neuter castes was studied in the mandibulate nasute generaCornitermes, Embiratermes andRhynchotermes. InCornitermes walkeri, all the workers and soldiers are male. There are two larval and a single worker instar. Workers can molt into presoldiers. InEmbiratermes chagresi andRhynchotermes perarmatus, both sexes are present among the neuters. A slight sexual dimorphism (males 〉 females) is discernible among both larval instars and among workers ofE. chagresi; female workers can molt into presoldiers. InR. perarmatus, the sexual dimorphism is conspicuous from the first larval instar on. Male larvae go through two instars, then give rise to workers, which do not molt. InR. perarmatus, there is no worker stage in females, but a third larval instar, preceding the presoldier. Hypotheses are proposed as to the evolution of these caste patterns, attempting to conciliate present knowledge of Nasutitermitinae phylogeny and known evolutionary trends affecting termite caste patterns, according to the species' ecology.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1420-9098
    Keywords: Formica exsectoides ; nests ; colony cycle ; temperature ; brood ; reproductives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The nest structure and colony cycle of a population of Allegheny mound ants,Formica exsectoides, were examined in central Michigan. The dispersion pattern of mounds was random. Nest structure and presence of brood were primarily determined by excavation of twenty-three nests over three intervals from June through September. Additional excavations of five nests in 1990 and ten nests in 1991 provided further details on nest structure and colony cycle. Most galleries occurred within the mound and upper 30 cm of soil, but some activity reached depths of 100 to 270 cm. Depth of nests showed little correlation with external measurements of height and diameter. Immature stages were recovered from two strata: the upper 20 cm of nest and mound and the lowest nest depths. Alate sexual forms were found in or near the mound in July, and numerous dealate queens were collected in September from peripheral galleries near the soil surface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 43 (1996), S. 375-389 
    ISSN: 1420-9098
    Keywords: Nasutitermitinae ; Subulitermes ; Coatitermes ; Velocitermes ; evolution ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental pathways of the neuter castes were studied in three species of Nasutitermitinae from central Panama. The humivorousSubulitermes denisae andCoatitermes clevelandi display several primitive traits: absence of sex dimorphism, representation of both sexes among workers and soldiers, and occurrence of successive worker instars. The litter-dwellingVelocitermes barrocoloradensis has a more complex caste system: female larvae are larger than males and give rise to the large workers, which constitute the bulk of the work force; male larvae proceed to soldiers through a small worker or a special larval instar. The resulting soldier caste is polymorphic. These results support previously formulated hypotheses regarding a link between humivorous diet and reduced polymorphism on the one hand, and between forest-floor foraging and large continuous size variation among soldiers on the other. Whereas the caste systems ofSubulitermes andCoatitermes probably represent a primitive condition,Velocitermes shares derived traits withNasutitermes and the other fully nasute genera previously studied. I therefore hypothesize that ancestors with these advanced features may have spread from the neotropics and be at the origin of most nasute genera, including humivorous taxa, present in other regions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 40 (1993), S. 169-180 
    ISSN: 1420-9098
    Keywords: Halictidae ; sociality ; demography ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Several years' observations of population of a primitively social halictine bee,Halictus rubicundus, revealed the following: (1) there is a correlation between ambient temperatures during the spring provisioning phase and the sex ratio of the resulting brood, such that warmer temperatures are associated with an increase in male bias; (2) over the course of the season, the degree of male bias of eggs laid appears to correspond with photoperiod; and (3) increasing male bias in the first brood is associated with decreasing proportions of social colonies formed in the population, and this effect may be accentuated by small population size. These phenomena suggest that abiotic environmental conditions at the time of brood production may profoundly influence the demography of this population, and that the demography in turn determines the degree to which sociality is expressed. These findings are related to hypotheses dealing with caste determination in temperate halictine bees, viewed in the context of the evolution and maintenance of sociality, and it is proposed that these phenomena reveal a mechanism by which social behavior (the occurrence of a “worker” caste, in particular) is facultatively “fine-tuned” to suit the characteristics of the environment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1420-9098
    Keywords: Formicidae ; Leptothoracini ; Tetramoriini ; internal transcribed spacer ; social parasitism ; evolution ; phylogenetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A fragment of the internal transcribed spacer (ITS-1) adjacent to the 5.8S rRNA gene of 20 myrmicine ant species was sequenced. Sequence comparisons were carried out between 11 species of the tribe Leptothoracini, five species of the tribe Tetramoriini, three species of the tribe Solenopsidini and one species of the tribe Myrmicini. Additionally, the formicine antCamponotus ligniperda (tribe Camponotini) was analyzed as an outgroup species. Among all investigated species, the fragment had a variable length of ≈ 230–380 bp with only a few conserved sequence elements. The sequences of this fragment were perfectly identical within four palearctic populations ofLeptothorax acervorum indicating that intraspecific variation is rather low. Within the species of Tetramoriini (includingAnergates atratulus) 94.1% of sequence positions were identical, 95.6% within the species of theLeptothorax s.str.-group and 64.6% within the species of theMyrafant-group. Phylogenetic analysis reveals that the social parasitesHarpagoxenus sublaevis, Doronomyrmex goesswaldi, D. kutteri andD. pacis, Chalepoxenus muellerianus as well asStrongylognathus alpinus andTeleutomyrmex schneideri are most closely related to the groups of their respective host species, which generally confirms the taxonomical classifications of the subfamily Myrmicinae based on morphological criteria. The taxonomical positions of the speciesA. atratulus has as yet been uncertain, however, sequence comparison of the ITS-1 fragment leads to the conclusion thatA. atratulus rather belongs to the tribe Tetramoriini than to the Solenopsidini.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1420-9136
    Keywords: Middle atmosphere ; temperature ; neutral and ion composition ; turbulent transfer ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Using a numerical model for temperature and neutral and ion composition behaviour at middle atmospheric heights, an analysis has been made of the dependence of atmospheric structural parameters on temperature, solar activity, and on turbulent transfer intensity. For mesospheric heights, an inverse dependence of the nitric oxide density on the temperature has been found. It is thus possible to explain experimentally obtained temperature variations over a cyclc of solar activity at mesospheric and lower thermospheric heights. Numerical simulation results indicate that the temperature in the height range ∼75–120 km depends considerably on both the absolute values of turbulent transfer coefficients and their vertical gradients.
    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...