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
  • ASTRONOMY
  • Biochemistry and Biotechnology
  • Life and Medical Sciences
  • 1990-1994
  • 1985-1989
  • 1970-1974  (34)
  • 1915-1919
  • 1972  (34)
Collection
Publisher
Years
  • 1990-1994
  • 1985-1989
  • 1970-1974  (34)
  • 1915-1919
Year
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 14 (1972), S. 391-410 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Studies were performed using pure cultures of A. acrogenes and E. coli and a heterogeneous microbial population growing in carbon-limited chemostats with glucose as the sole carbon and energy source. A two-level factorial experimental design was employed to test the hypothesis that the concentration of growth-limiting substrate in a chemostat is controlled by the growth rate alone and is independent of the concentration of substrate entering the reactor. The pure culture experiments showed that the conclusions depend upon the measurement employed for growth-limiting substrate. When the concentration of glucose was measured directly, the hypothesis was found to be true within the limits of the study (500-1500 mg/liter). However, if the chemical oxygen demand (COD) test was used as the measure of growth-limiting substrate the hypothesis was found to be false. When heterogeneous cultures were employed the hypothesis was false regardless of the technique used to measure the concentration of growth-limiting substrate. Nevertheless, it was possible to generate regression equations which described the interactions among influent COD, growth rate, and effluent COD with a high level of correlation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetic behavior of heterogeneous microbial populations of sewage origin was studied in a single-stage isothermal continuous flow completely mixed aeration tank. A series of experiments were carried out at various dilution rates using glucose as the growth limiting substrate. The steady-state behavior of the system was observed at each dilution rate and the results were found to fit fairly well with the steady-state equation bayed on the Monod model with an endogenous respiration term included, i.e., μ = μmS/(Ks + S) - Kd. The growth kinetics of cells harvested at steady state for each dilution rate were studied using batch experiments. The multiple response data of the system as functions of time were used to estimate the parameter values in the above kinetic model. It was found that values of the growth parameters changed significantly and systematically with cell population. For example, values of μm were high at high dilution rates and low at low dilution rates. It was also found that only those batch growth parameters from cells obtained at fairly high dilution rates are comparable with those estimated by the results of steady-state operations. The results of this investigation suggest that (1) different cell populations pre dominated at different steady-state dilution rates, with high dilution rates resulting in predominantly fast-growing organisms and low dilution rates resulting in predominantly slow-growing cells, and (2) risk exists in any randomly picked batch experiment to predict the steady-state behavior of the system when heterogeneous microbial populations must be used.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 14 (1972), S. 207-231 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetic behavior of heterogeneous microbial populations of sewage origin was studied in a single-stage, isothermal, continuous flow, completely mixed aeration tank. A series of experiments were carried out at various dilutions rates using glucose as the limiting substrate. The cell dry weight and substrate concentration in terms of chemical oxygen demand (COD) were continuously monitored. The results indicate that reproducible steady-state conditions can generally be obtained; however, multiple steady states were observed at dilution rates near washout. At low dilution rates (below about 0.1 hr-1) the contribution of microorganism decay became appreciable. Using the multiresponse data of cell dry weight and COD, the parameter values in various existing growth models were estimated. The analyses of variance and residuals revealed that models proposed by Moser, Monod, and Contois, each with a decay term added, were significantly better than the other models which were tested.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 14 (1972), S. 533-570 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Parameter estimation studies have been conducted employing mathematical models developed previously by the investigators and experimental data collected by the last author. A batch fermentation process in which Candida lipolytica were cultured on n-hexadecane dissolved in dewaxed gas oil was employed to obtain the experimental data. The kinetic data from a number of batch experiments conducted at different initial substrate concentrations and different dispersed phase volume fractions were analyzed assuming that, the basic model parameters (maximum specific growth rate, saturation constant, substrate phase equilibrium constant, adsorption constant, desorption constant, etc.) did not change from experiment to experiment. The Gauss-Newton method with modification by Greenstadt, Eisenpress, Bard, and Carroll was used to minimize the conventional sum of squares criterion on the IBM 300/50 computer. The individual confidence intervals were obtained for each individual parameter. Tin- models were compared employing the F-test for equality of variances and an analysis of residuals. For the two best models, the estimated parameter values were compared with available experimental information. The results showed good agreement between the experimental data and the values predicted by the mathematical models. The results presented in this work did suggest that growth on small segregated drops may be more important than continuous phase growth on dissolved substrate.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The response of unfertilized sea urchin eggs stimulated with continuous D.C. was studied using cinematographic techniques. As reported by previous workers, the initiation of the response was anodal in polarity and followed a typical strength-duration curve. However, the anodal response may be swelling and/or contraction, depending on the amplitude of the applied stimulus, i.e., the magnitude of the contraction is directly related to the applied stimulus and is a graded response. It is suggested that the phenomena of anodal swelling and anodal contraction represent a continuum of responses based on ion exchange.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The calcium uptake and ATPase activities of isolated sarcoplasmic reticulum were studied during the first six days of chick skeletal muscle maturation in tissue culture. Statistically significant increases in these activities were observed between the second and the sixth day of maturation. Increases in oxalate-dependent calcium uptake were demonstrated at concentrations of 2.5 × 10-5 M calcium and 10-4 M calcium. Calcium-binding determinations conducted in the absence of oxalate displayed changes manifested by an increase at day 5 followed by a significant decrease at day 6. Increases in total ATPase activity during maturation paralleled the sequential increases in calcium uptake. Calcium-stimulated ATPase activity, however, did not change significantly during periods of marked increase in calcium uptake, suggesting that these activities are dissociated during development of the sarcoplasmic reticulum. These data demonstrate that calcium uptake and total ATPase activity increase during muscle maturation in tissue culture and that these activities are present prior to spontaneous contractions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 138 (1972), S. 375-385 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of the electric organs of Gymnarchus niloticus has been studied and the origin and histogenesis of an electroplate worked out. A segmental origin of the electroplate is reported for the first time for this fish. Light has been thrown on many hitherto obscure phenomena, viz., growth of core girth, loss of transverse striations on the myofibrillar elements, differentiation of electroplate polarities, shortening in length of the electroplate etc. The transverse striations of the myofibrillar bundle of the electroplate primordium progressively disappear with development owing to splitting apart of the constituent myofilaments and consequent loss of their parallel order, and not to degeneration of the myofibrillar bundle. The excessive growth of the core girth of the electroplates is caused by the deposition of some kind of interfibrillar substance probably secreted by the peripheral cytoplasm.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 138 (1972), S. 407-431 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A cephalic organ of presumed sensory function is described in nauplii and copepodids of the ascidicolous copepod Doropygus seclusus Illg. The receptor, located bilaterally in the anterodorsal head region, is composed of dendrites of extra optic protocerebral origin which have ciliary protrusions with basal bodies, no rootlets, and a basal infrastructure of the 9 + 0 type. The cilia do not branch and their distal terminations contain only one to four microtubules. In nauplii and free-living copepodids, a large epidermal supporting cell encapsulates the end of one dendrite and its cilia in a sac. Other dendrites and their cilia pass through the supporting cell and, terminally, the cilia escape to form a whorled fascicle which contacts the anterolateral cephalic cuticle. The latter end organ reaches its greatest development in the second copepodid stage  -  the stage which infects the ascidian. All of the symbiotic stages of the copepod have only a proportionately smaller end organ of the saccular type and apparently lack the end organ consisting of whorls of ciliary ends. The function of the receptor is unknown, but it is suggested that the end organ which disappears in the symbiotic stages functions in second copepodids in host recognition.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of the integument of the aquatic mite Arrenurus major Marshall is presented. When the cuticle is examined with the unaided eye and the light microscope, it appears to possess numerous tiny pits. However, scanning electron micrographs of the cuticle reveal that it is a solid surface with topographical sculpturing of the epicuticle, indicating that the “pits” are an internal phenomenon. In cuticle which has been sectioned, areas devoid of cuticular material beneath the thin exocuticle are revealed. These areas are the pits which are goblet-shaped.The integument consists of five major strata. These are from the outside to the inside: (1) a superficial layer with a maximum observed thickness of 725 Å, (2) an epicuticle with a thickness of about 900 Å and composed of at least four sublayers, (3) an exocuticle with a thickness of about 1.5 Å. Fibers of the exocuticle are arranged in a Bouligand pattern and exhibit a regularly occurring discontinuity with a spacing of 200 Å. (4) An endocuticle ranging from 15 to 20 μ in thickness. The endocuticle is characterized by bandings which superficially resemble the lamellae of insects but are not homologous, microfibers which exhibit a preferred orientation, and the presence of the pits; and (5) an epidermis lying beneath the endocuticle and extending into the pits.Pore canals are present only in the exocuticle and have their origin at the apices of the pits. The pore canals contain a central filament, and a plug is present just beneath the epicuticle.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report presents light microscopic descriptions of lymphoid organs and aggregates in the snapping turtle Chelydra serpentina. The thymus and spleen were found to be similar to those of other ectothermic vertebrates. Certain gut associated lymphoid aggregates suggest the presence of reptilian equivalents of tonsils, Peyer's patches and the avian bursa of Fabricius. Lymphoid aggregates located in the axillary and inguinal regions were apparent for the first time in an ectothermic vertebrate. These are of particular interest since they may represent ancestors of true lymph nodes in analogous locations in mammals. It is concluded that the snapping turtle is not deficient in lymphoid tissue, although there is a conspicuous absence of typical germinal centers, characteristic of mammalian organs.
    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...