Library

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
  • (Schizophrenia)  (1)
  • Boundary layer  (1)
  • Brain lesions  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Schizophrenia Research 3 (1990), S. 117-126 
    ISSN: 0920-9964
    Keywords: (Schizophrenia) ; Aging ; Neuropsychology
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1939
    Keywords: Tropical forest ; Transpiration ; Stomata ; Boundary layer ; Hydraulic conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Environmental and physiological regulation of transpiration were examined in several gap-colonizing shrub and tree species during two consecutive dry seasons in a moist, lowland tropical forest on Barro Colorado Island, Panama. Whole plant transpiration, stomatal and total vapor phase (stomatal + boundary layer) conductance, plant water potential and environmental variables were measured concurrently. This allowed control of transpiration (E) to be partitioned quantitatively between stomatal (g s) and boundary layer (g b) conductance and permitted the impact of invividual environmental and physiological variables on stomatal behavior and E to be assessed. Wind speed in treefall gap sites was often below the 0.25 m s−1 stalling speed of the anemometer used and was rarely above 0.5 m s−1, resulting in uniformly low g b (c. 200–300 mmol m−2 s−1) among all species studied regardless of leaf size. Stomatal conductance was typically equal to or somewhat greater than g b. This strongly decoupled E from control by stomata, so that in Miconia argentea a 10% change in g s when g s was near its mean value was predicted to yield only a 2.5% change in E. Porometric estimates of E, obtained as the product of g s and the leaf-bulk air vapor pressure difference (VPD) without taking g b into account, were up to 300% higher than actual E determined from sap flow measurements. Porometry was thus inadequate as a means of assessing the physiological consequences of stomatal behavior in different gap colonizing species. Stomatal responses to humidity strongly limited the increase in E with increasing evaporative demand. Stomata of all species studied appeared to respond to increasing evaporative demand in the same manner when the leaf surface was selected as the reference point for determination of external vapor pressure and when simultaneous variation of light and leaf-air VPD was taken into account. This result suggests that contrasting stomatal responses to similar leaf-bulk air VPD may be governed as much by the external boundary layer as by intrinsic physiological differences among species. Both E and g s initially increased sharply with increasing leaf area-specific total hydraulic conductance of the soil/root/leaf pathway (G t), becoming asymptotic at higher values of G t. For both E and g s a unique relationship appeared to describe the response of all species to variations in G t. The relatively weak correlation observed between g s and midday leaf water potential suggested that stomatal adjustment to variations in water availability coordinated E with water transport efficiency rather than bulk leaf water status.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 242 (1985), S. 17-23 
    ISSN: 1432-0878
    Keywords: Brain lesions ; 3H Thymidine incorporation ; Astrocytes ; Monocytes/Macrophages ; Capillaries ; Ischemia ; Mongolian gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tritiated thymidine autoradiography was used to measure cellular proliferation after ischemic injury in gerbil brain. Gerbils were subjected to bilateral occlusion of the common carotid arteries which resulted in areas of necrosis, or infarcts, in the posterior thalamus or midbrain. From 12 h to 10 days following the ischemia, gerbils were injected with 3H thymidine, sacrificed 4 h later, and the brains sectioned. In order to identify astrocytes and monocytes/macrophages, immunocytochemistry was performed prior to autoradiography, using antisera against glial fibrillary acidic protein and endothelial-monocyte reticuloendothelial antigen, respectively. Immunocytochemistry was also used to visualize microvessel laminin, myelin, and leakage of serum albumin. Lastly, a histochemical procedure for acid phosphatase activity was employed to verify cellular phagocytic activity in the wound. A reproducible sequence of reactions took place during the first 10 days after ischemia. Early changes included leakage of albumin and myelin breakdown, followed by arrival of monocytes at 2 days and their differentiation into macrophages by 5 days. These cells exhibited intense proliferation from 2 to 6 days post-ischemia. Microvessel endothelial cells were maximally labeled at 4 days post-ischemia. Hypertrophied astrocytes were apparent at 2 days and proliferated from 3 to 7 days post-ischemia, and by 10 days the wound was replaced by a “glial scar”.
    Type of Medium: Electronic Resource
    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...