Showing papers by "University of Tübingen published in 1980"
TL;DR: The present is indeed a key to the ichnologic past, and vice versa; in practice, however, the present has been studied considerably less than its importance would dictate.
Abstract: Relationships between ichnology and uniformitarianism are perhaps less complicated than those of their sister subdisciplines, paleontology and paleoecology. Trace fossils are manifestations of benthic behavior; and these traits, although evolving in significant ways, have remained stable over longer spans of time than individual species of invertebrates. The fossil record of behavior in fact originated earlier than the fossil record of invertebrate body parts. Although macroinvertebrates and their traces exhibit tremendous diversity of form and function, these fit into a relatively small number of behavioral patterns. The patterns, in turn, may correlate with prevailing environmental conditions, resulting in gradients among trace fossil assemblages, or ichnofacies. Behavioral patterns and characteristic ichnofacies therefore constitute the main basis for uniformity in ichnology. Thus, the most fundamental questions are: What is the specific function represented by the trace? How will it change as the tracemaker is influenced by other genetic, physiologic, or ecologic stimuli? In which facies will it likely occur? and what preservational biases are apt to modify the fossil record of this behavior and its environmental distribution? Approached from this standpoint, the present is indeed a key to the ichnologic past, and vice versa. In practice, however, the present has been studied considerably less than its importance would dictate.
358 citations
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TL;DR: In this paper, a short introduction to algebras in genetics is provided, along with some examples of gametic and copular algebases, which are derived from gametic algebraids.
Abstract: In this section we provide a short introduction to “algebras in genetics”. We explain how algebras arise in population genetics and we construct some examples of gametic algebras. These examples will be reconsidered and discussed in a wider frame-work in section 7. We introduce zygotic and copular algebras and we discuss the construction of these algebras from gametic algebras. The exposition will reveal various elementary though fundamental properties of these algebras.
213 citations
TL;DR: Highly significant differences of SCP between the two required polarities were demonstrated and the most pronounced differences were observed during test trials without feedback of the second session in which a positive shift below baseline level occurred when positivity (or less negativity) was required.
208 citations
TL;DR: In diabetic gs a statistically highly significant positive correlation exists between the grade of fibrosis of the renal cortical interstitium and the serum creatinine concentration at the time of biopsy, which implies Alterations of the postglomerular vessels by interstitial fibrotic changes result in an increased resistance to renal cortical blood flow with a subsequent reduction of glomerular perfusion.
Abstract: Summary Histological and clinical findings in 103 middle-aged patients suffering from diabetic glomerulosclerosis (gs) (biopsy material) are reported. In diabetic gs (as in other inflammatory and non-inflammatory glomerular disease) a statistically highly significant positive correlation exists between the grade of fibrosis of the renal cortical interstitium and the serum creatinine concentration at the time of biopsy. Rank correlations exist between vessel index and relative cortical interstitial volume on the one hand as well as serum creatinine concentration on the other. Significant differences are also shown to exist between the mean values of the cortical interstitium as well as the serum creatinine concentration and the vessel index in the four grades of diabetic gs. Severe glomerular lesions may be accompanied by a normal serum creatinine concentration, only if the interstitium shows no fibrotic changes. Mild glomerular lesions, when accompanied by an interstitial fibrosis, always have elevated serum creatinine concentrations. The incidence of hypertension, proteinuria, the nephrotic syndrome and hematuria in diabetic gs appears to vary greatly. From the highly significant correlation between the cortical interstitium and the serum creatinine concentration we presume the following: Alterations of the postglomerular vessels by interstitial fibrotic changes result in an increased resistance to renal cortical blood flow with a subsequent reduction of glomerular perfusion. This reduction of the glomerular perfusion may result in a rise of the serum creatinine concentration, independently of the severity of the glomerulosclerosis. It is also conceivable that glomerular function is affected by the malfunctioning atrophic tubules in areas of interstitial fibrosis.
197 citations
TL;DR: The results directly support the hypothesis previously put forward, that one of the hexokinases is not only active as a catalytic, but also as a regulatory protein.
Abstract: Mutants with reduced hexokinase activity previously isolated as resistant to carbon catabolite repression of invertase and maltase (Zimmermann and Scheel, 1977) were allele tested with mutant strains of Lobo and Maitra (1977) which had defects in one or several of the genes coding for glucokinase and the two unspecific hexokinases. It could be demonstrated, that the mutation abolishing carbon catabolite repression had occurred in a gene allelic to the structural gene of hexokinase PII. Moreover, the defective mutant allele for hexokinase PII isolated by Lobo and Maitra (1977) was also defective in carbon catabolite repression. Neither glucokinase nor hexokinase PI showed any effect on this regulatory system. Biochemical analysis in crude extracts also showed altered kinetic properties of hexokinases in the hex1 mutants. The results directly support the hypothesis previously put forward, that one of the hexokinases is not only active as a catalytic, but also as a regulatory protein.
174 citations
TL;DR: The glutathione plasma level in man is investigated taking into account the implications of a concentration gradient of >3 orders of magnitude between erythrocyte and plasma and the apparent half-life is determined to be 1 d min.
163 citations
TL;DR: This study provides a procedure for discrimination of inhibitory and peroxidative action which is of particular importance if the increase over control levels is only moderate, and may serve as monitor for the metabolic capacity of a laboratory animal.
135 citations
TL;DR: The enzyme cleaved only N-α-benzoyl-DL-lysine-and-arginine-nitroanilides but not the corresponding leucine or tyrosine derivatives nor a set of diand tripeptides, and was the dominant protein in the growth medium.
Abstract: Excretion of an extracellular protease of Serratia marcescens ATCC 25419 occurred during logarithmic growth and was highest (per cell) when cultures reached the stationary growth phase. Production of the extracellular protease was induced by leucine or casein in minimal medium or by growth in tryptone-yeast medium. In the late stationary phase an intracellular protease activity accumulated which was also observed in mutants with very low extracellular protease activity. The excreted protease was the dominant protein in the growth medium. The protease was purified to homogeneity by column chromatography on Bio-Gel P-100 and on DEAE-cellulose. Quantitative amino acid analysis revealed the absence of sulfur-containing amino acids. The enzyme consists of one polypeptide chain. A molecular weiht of 51,000 and 55,000 was estimated using polyacrylamide gel electrophoresis and chromatography on Bio-Gel P-100 respectively. The enzyme cleaved only N-alpha-benzoyl-DL-lysine-and-arginine-nitroanilides but not the corresponding leucine or tyrosine derivatives nor a set of di- and tripeptides.
108 citations
TL;DR: Enzyme preparations from flowers of defined genotypes of Matthiola incana contain two dif ferent hydroxylases for hydroxolation of naringenin in the 3-and 3′-position, respectively.
Abstract: Abstract Enzyme preparations from flowers of defined genotypes of Matthiola incana contain two dif ferent hydroxylases for hydroxylation of naringenin in the 3-and 3′-position, respectively. The 3-hydroxylase is a soluble enzyme and requires as cofactors 2-oxoglutarate, Fe2+ and ascorbate. Besides naringenin eriodictyol is a substrate for the 3-hydroxylase. The 3′-hydroxylase is localized in the microsomal fraction and requires NADPH as cofactor. Naringenin and dihydro-kaempferol but not 4-coumarate or 4-coumaroyl-CoA are substrates for this enzyme. 3′-Hydroxylase activity is present only in genetic lines of M. incana with the wild-type allele b+.
107 citations
TL;DR: The specificity of the virus determination by RIA from supernatants of HAV-infected cells from passages 1,2, and 3 in Frhk-4 cells was shown with sera that were collected from a chimpanzee infected with MS-1 both before infection as well as during convalescence.
Abstract: A fetal rhesus monkey kidney cell line (Frhk-4) was infected with different hepatitis A-virus (HAV) isolates GBG, GBM, GJA. The time-dependent adsorption of the HAV isolates to Frhk-4 cells was measured. Replication of all three isolates in these cells could be demonstrated intracellularly 8–10 weeks after infection, and release of HAV into the supernatant some 10–15 weeks after infection could be shown. The specificity of the virus determination by RIA from supernatants of HAV-infected cells from passages 1,2, and 3 in Frhk-4 cells was shown with sera that were collected from a chimpanzee infected with MS-1 both before infection as well as during convalescence. These results were subsequently compared with sera collected from human patients before the onset of hepatitis as well as during convalescence. With immunofluorence microscopy a cytoplasmic fluorescence could be shown in HAV-infected Frhk-4 cells and finally the release of 27 nm HAV particles into the supernatant of HAV-infected Frhk-4 cells could be demonstrated by immune electron microscopy.
100 citations
TL;DR: The results of this study demonstrate that pathophysiological changes in the hypertrophied left myocardium of spontaneously hypertensive rats are not the same in all ventricular areas.
Abstract: Hydroxyproline concentration, representing the collagen content, in different areas of hypertrophied hearts from spontaneously hypertensive rats aged 10 and 16 months and in similar areas of hearts from control rats of the same age was investigated. As was expected, the hydroxyproline concentration in the left ventricular free wall from normal rats was lower than in the right ventricle and septum. In different parts of the normal left ventricle (endomyocardial and epimyocardial areas, papillary muscles) the hydroxyproline concentration was approximately the same.
In all myocardial parts from the 16-month-old normal rats, the hydroxyproline concentration was greater than in respective tissue from younger (10-month-old) rats.
The hydroxyproline concentration was increased in all parts of the hypertrophied myocardium in spontaneously hypertensive rats. The increase was greatest in endomyocardial areas of the left ventricular wall. The difference in increase of hydroxyproline concentration between epimyocardial and endomyocardial areas was greater in 10, than in 16-month-old spontaneously hypertensive rats. In the hypertrophied left ventricular papillary muscles the hydroxyproline concentration was lower than the average hydroxyproline concentration in the hypertrophied left ventricle as a whole.
The results of this study demonstrate that pathophysiological changes in the hypertrophied left myocardium of spontaneously hypertensive rats are not the same in all ventricular areas.
TL;DR: Because of the structural similarity between the hopane ring system and cholesterol, a possible similarity in the function within the membrane was investigated, by inserting the glycolipid containing hopane into the cytoplasmic membrane using the monolayer technique.
TL;DR: From the chemogenetic and enzymological evidence, it can be concluded that naringenin-chalcone is the first product of the synthesis of the flavonoid skeleton and that only the conversion of naringanin to naringein furnishes the substrate for the further reactions to flavonol and anthocyanin.
Abstract: In flowers of Dianthus caryophyllus (carnation), the gene I is concerned with a discrete step in flavonoid biosynthesis, Genotypes with recessive (ii) alleles produce yellow flowers, which contain the chalcone isosalipurposide (naringenin-chalcone-2′-glucoside) as the major petal pigment, but in genotypes with wild-type alleles flavonols and anthocyanins can be formed and the flowers are white or red. Enzymatic measurements on petal extracts of four strains with different flower coloration revealed a clear correlation between accumulation of chalcone in recessive genotypes and deficiency of chalcone isomerase (E.C. 5.5.1.6) activity. From the chemogenetic and enzymological evidence it can be concluded that naringenin-chalcone is the first product of the synthesis of the flavonoid skeleton and that only the conversion of naringenin-chalcone to naringenin furnishes the substrate for the further reactions to flavonol and anthocyanin.
TL;DR: Responding of diploid strains to rhodotorulic acid suggested the existence of a third gene, fhuC, required for utilization of this siderophore, but not ferrichrome, which is suggested that fhuB encodes a transport component in the cytoplasmic membrane that is necessary for the uptake of all hydroxamate siders following their receptor-mediated passage across the outer membrane.
Abstract: Cells of Escherichia coli can derive iron from a variety of chelators (siderophores) in addition to enterochelin, the catechol derivative excreted by many enteric bacteria. The genetic control of hydroxamate siderophore utilization was investigated in mutants of E. coli K-12 selected for resistance to lethal agents which adsorb to the tonA protein of the outer membrane (albomycin, colicin M, and phages T5 and φ80). Many of the mutants were unable to utilize hydroxamate siderophores as an iron source. This phenotype was termed Fhu, for ferric hydroxamate uptake. Mutants carrying lesions in the tonA region of the chromosome were studied and fell into several types. Members of one class had lost some or all of the tonA receptor protein9s functions in that they were resistant to the lethal agents and unable to utilize ferrichrome and its analogs, although able to respond to the hydroxamate rhodotorulic acid (FhuA phenotype). Other mutants were unable to utilize any of the hydroxamate siderophores tested and were resistant to albomycin, althogh many were sensitive to the other lethal agents (FhuB phenotype). Members of these classes lacked ferrichrome-mediated iron uptake. Strains carrying transposon Tn 10 insertions in fhuA (previously termed tonA ) lacked the 78,000-molecular-weight outer membrane protein previously described; insertions in fhuB retained this protein and had no detectable change in outer membrane composition. Three-point transduction crosses revealed the gene order to be pan-fhuA-fhuB-metD in the min 3.5 region of the chromosome map. Complementation analyses with F′ merodiploid strains showed that fhuA and fhuB comprise separate transcription units which are both required for utilization of ferrichrome. Response of diploid strains to rhodotorulic acid suggested the existence of a third gene, fhuC , required for utilization of this siderophore, but not ferrichrome. It is suggested that fhuB encodes a transport component in the cytoplasmic membrane that is necessary for the uptake of all hydroxamate siderophores following their receptor-mediated passage across the outer membrane.
TL;DR: The blood-perilymph barrier is morphologically similar to the blood-brain barrier and contains only a few micropinocytotic vesicles in contrast to those of the stria vascularis vessels.
Abstract: Freeze fracture replicas of the guinea pig inner ear were studied under the electron microscope to define the blood-perilymph barrier morphologically This barrier is represented basically by the continuous endothelium of the inner ear capillaries The endothelial cells contain only a few micropinocytotic vesicles in contrast to those of the stria vascularis vessels The cochlear plexus also exhibits some special differences Tight junctions of the continuous mesothelial type connect the endothelial cells of the inner ear capillaries Cell membranes of these cells possess a lower particle density than those of the stria vascularis vessels In general, the blood-perilymph barrier is morphologically similar to the blood-brain barrier
01 Jan 1980
TL;DR: The biotransformation patterns of various phenols aniline derivatives, benzoic and cinnamic acids, coumarins, tropane, furoquinoline, isoquinoline and ergot alkaloids, mono-, di- and triterpenoids, pregnane and androstane derivatives, cholesterol and cardenolides by plant cell cultures are reviewed.
Abstract: The biotransformation patterns of various phenols aniline derivatives, benzoic and cinnamic acids, coumarins, tropane, furoquinoline, isoquinoline and ergot alkaloids, mono-, di- and triterpenoids, pregnane and androstane derivatives, cholesterol and cardenolides by plant cell cultures are reviewed. using biotransformation of cardiac glycosides as an example it is shown that the pattern of biotransformation products obtained depends on the special cell strain used. it is demonstrated that it is possible to isolate cell strains with a high biotransformation capacity of a special desired type, namely hydroxylation of β-methyldigitoxin to β-methyldigoxin. practical application of biotransformation by plant cell cultures is discussed.
TL;DR: In this article, a chiral olefin, 3-methylcyclopentene, has been resolved analytically on optically active dicarbonyl-rhodium(I)-3-trifluoroacetyl-1R-camphorate in squalane.
Abstract: The high selectivity of complexation gas chromatography has been employed for enantiomer resolution and isotope separation. Thus, a chiral olefin, 3-methylcyclopentene, has been resolved analytically on optically active dicarbonyl-rhodium(I)-3-trifluoroacetyl-1R-camphorate in squalane. The deuterated ethylenes C2H4−nDn have been separated on the same rhodium(I)-containing stationary phase. The chiral aliphatic oxiranes epoxypropane andtrans-2,3-epoxybutane have been resolved on optically active nickel(II)-bis-3-trifluoroacetyl-1R-camphorate in squalane.
TL;DR: In this article, an energy-dependent local potential for heavy-ion (HI) scattering is derived from Reid's softcore interaction using the Brueckner theory, and the optical potential for HI scattering is evaluated using the energy-density formalism.
TL;DR: Altering the height of the seesaw showed that a threshold change in the ankle angle was the determining factor in the production of spinal stretch reflex activity for fast regulation of balance.
Abstract: While subjects balanced on a seesaw consisting of a platform with a curved base, the antero-posterior sway of head and body as well as changes in the angle of the ankle joint were recorded and analysed for their frequency power spectrum. The EMG of leg muscles and the position of the resultant force exerted by the seesaw on a force-measuring platform were simultaneously registered and analysed. Balancing oscillations of 4–5 Hz were observed under this condition. They were accompanied by short, reciprocally organized bursts of EMG activity in the leg muscles. When stimulating the tibialis nerves to produce a displacement, the delay until the counterbalancing EMG activity started (about 40 ms) was in the time range of a fast-conducting segmental reflex. After partial ischaemic blocking of group I afferents from the leg muscles or fixation of the ankle joints, the predominant sway frequency was lacking, bursts of EMG activity became longer and stronger, and body balance was more unstable. Altering the height of the seesaw showed that a threshold change in the ankle angle was the determining factor in the production of spinal stretch reflex activity for fast regulation of balance.
TL;DR: The copper complex of indomethacin (1-chlorobenzoyl)-5-methoxy-2-methyl-indole acetate), a common anti-inflammatory drug, was prepared and characterized, and the superoxide dismutating activity was successfully demonstrated in Me2SO/water and acetonitrile/water mixtures using the nitro-blue tetrazolium assay and pulse radiolysis.
TL;DR: In this paper, the effects of L-AOPP and t-cinnamic acid, the product of the deamination of phenylalanine, were investigated in vitro studies with Daucus carota.
Abstract: Cells of Daucus carota grown in a liquid medium produced large amounts of cyanidin as the only flavonoid aglycon. After inoculation in fresh medium a maximum activity of phenylalanine ammonia lyase (PAL; EC 4.3.1.5) was observed within 24 h. L-α-aminooxy-β-phenylpropionic acid (L-AOPP), thought to be a competitive inhibitor of PAL, inhibited cyanidin accumulation up to 80%. In order to study the regulatory role of PAL, the effects of L-AOPP and t-cinnamic acid, the product of the deamination of phenylalanine, were investigated. Cinnamic acid, applied in vivo (10-4 M), was not able to compensate for the inhibition of cyanidin production caused by L-AOPP (10-4 M) in the same sample. Carrot cells treated with L-AOPP exhibited a “super-induction” of PAL already described for gherkin hypocotyls (Amrhein and Gerhardt 1979). This effect was not influenced by t-cinnamic acid. L-AOPP seems to be a very specific inhibitor since it affected neither growth nor soluble protein content, whereas t-cinnamic acid inhibited both. Investigations on the content of soluble amino acids in L-AOPP-treated cells revealed a specific accumulation of soluble phenylalanine, whereas treatment with t-cinnamic acid led to an increase of amino acids in general, thus indicating that the latter compound has a rather unspecific effect on cellular metabolism. In vitro studies with PAL isolated from Daucus carota revealed that L-AOPP inhibited the enzyme at very low doses (KI=2.4·10-9), whereas t-cinnamic acid, by comparison, affected the enzyme at high concentrations (KI=1.8·10-4).
TL;DR: During the transport of iron as ferrichrome complex into cells of Escherichia coli K-12, the ligand was modified and excreted into the medium and could be a mechanism by which cells rid themselves of a potentially deleterious ligand for iron in the cytoplasm.
Abstract: During the transport of iron as ferrichrome complex into cells of Escherichia coli K-12, the ligand was modified and excreted into the medium. The rate of the formation of the modified product corresponded with the rate of iron transport. The modified product showed a decreased affinity for ferric iron and did not serve as an effective iron ionophore. After all of the ferrichrome had been converted, the modified product was taken up into the cell in an iron-free form. The uptake of ferrichrome and of the modified product depended on the transport system specified by the tonA and tonB genes. The modified product could be converted back into ferrichrome by mild acid or alkaline hydrolysis. One mole of acetate was released per mole of ferrichrome. It is proposed that one N-hydroxyl group of ferrichrome is acetylated to explain the low affinity for iron as the N-hydroxyl groups form the ligands for iron (III). A weak ester linkage by which the acetyl group is covalently bonded would account for the easy hydrolysis. The iron-free form of ferrichrome, deferri-ferrichrome, was also rapidly converted when incubated with cells with a functional transport system. It is therefore likely that iron is released from ferrichrome by reduction before modification takes place. The conversion of the ligand could be a mechanism by which cells rid themselves of a potentially deleterious ligand for iron in the cytoplasm. A possible role in ferrichrome transport is discussed.
TL;DR: Lithium carbonate lengthens the circadian period in humans under temporal isolation (arctic summer four groups) and it is found that lithium carbonate acts as a ‘spatially reprograming agent’ to extend the period of daylight saving time.
Abstract: Lithium carbonate lengthens the circadian period of body temperature and sleep-wakefulness in humans under temporal isolation (arctic conditions in Svalbard, 79 degrees N) in two out of four groups.
TL;DR: Serial sections ranging from very young embryos to hatched juveniles and whole embryos of Scyliorhinus show that dentition and dermal skeleton belong to two independent secondary developmental fields that differ both developmentally and structurally.
Abstract: Serial sections ranging from very young embryos to hatched juveniles and whole embryos of Scyliorhinus show that dentition and dermal skeleton belong to two independent secondary developmental fields that differ both developmentally and structurally. The development of the dentition starts very early, with a thickening of the ectoderm in the region of the mouth (stage 04), the invagination of the dental lamina (stage 18), and the formation of the germs of the first generation (stage 20). Tooth replacement movements start only near the end of embryogenesis (stage 35). Scale germs, on the other hand, first begin to form at stage 24. Scales erupt shortly before the animal hatches (stage 43). Only one scale generation is formed during embryogenesis. The forces which erupt the scales may come from fluid pressures in vacuoles of the fibrous layer of the dermis. Those which erupt the teeth probably also result from similar fluid pressures. The crown and upper part of the base of scales and teeth are formed by cells of the inner dental epithelium which are differentiated from the ectoderm. They are also formed by odontoblasts which are derived from the vascular layer of the dermis. However, the basal plates of scales and teeth containing the anchoring fibers are formed by osteoblasts, which are derived from the fibrous layer of the dermis.
TL;DR: The results are compatible with the hypothesis that glucose and exogenous insulin, by modifying the redox state of the NADPH/NADP and GSH/GSSG systems, modulate the sensitivity of the β-cell to the insulin-triggering actions of glucose, p-CMB, and tolbutamide.
Abstract: In isolated rat pancreatic islets, glucose (5.6, 11.1, and 16.7 mM) significantly increased reduced glutathione (GSH) and decreased oxidized glutathione (GSSG) levels in a dose-related manner. This was paralleled by a concomitant increase of NADPH and a decrease of NADP. The change of the GSH level occurred as quickly as one minute after addition of glucose. Exogenous insulin (200, 400, and 800 microU/ml) significantly decreased islet GSH levels in the presence of 5.6 and 16.7 mM glucose and significantly inhibited the insulin-releasing effect of the thiol reagent parachloromercuribenzoate (p-CMB) and tolbutamide. These data, together with earlier observations, suggest that GSH levels in pancreatic islets are increased by glucose and decreased by exogenous insulin via their effects on the pentose phosphate shunt and NADPH. Our results are compatible with the hypothesis that glucose and exogenous insulin, by modifying the redox state of the NADPH/NADP and GSH/GSSG systems, modulate the sensitivity of the beta-cell to the insulin-triggering actions of glucose, p-CMB, and tolbutamide.
TL;DR: Whenever the otologist is dealing with chronic middle ear disease, the following points should always be kept in mind: A dull ache in the ear without obvious inflammatory signs, a whitish-grey appearance of the mucosa and Bulging of granulation tissue from the mastoid cells during surgery.
Abstract: Fourteen cases of tuberculous otitis media are reported. With the declining incidence of pulmonary tuberculosis, the number of reported cases of tuberculous otitis media has become scanty. Nowadays the so-called classical signs of the lesion such as a profuse discharge, profound hearing loss, facial paralysis and multiple perforations, are hardly ever seen. Surgical intervention when done under cover of anti-tubercular drugs has no deleterious effect on the result of surgery. In order not to miss tuberculous otitis media, whenever the otologist is dealing with chronic middle ear disease, the following points should always be kept in mind: (a) A dull ache in the ear without obvious inflammatory signs. (b) A whitish-grey appearance of the mucosa. (c) Bulging of granulation tissue from the mastoid cells during surgery.
01 Jan 1980
TL;DR: There are several reasons for concentrating on the class of vector-borne diseases from a modelling point of view, and the factors which regulate their transmission are usually known qualitatively so that dynamic modelling has a sound basis to start from.
Abstract: There are several reasons for concentrating on the class of vector-borne diseases from a modelling point of view:
1)
They still figure among the health problems of highest priority in most countries outside Europe, North America and Australia;
2)
They require specialized measures for prevention which are mostly directed against the vector populations with an aim to reduce contact between humans or contacts between the reservoir population(s) and humans;
3)
The factors which regulate their transmission are usually known qualitatively so that dynamic modelling has a sound basis to start from;
4)
Many quantitative problems have to be solved before alternative methods for prevention and control (already existing or to be developed) can be evaluated in a rational way.
01 Jan 1980
TL;DR: This article found 24-h rhythms in the mobility or bioluminescence of unicellular algae, in the formation of reproductive structures of fungi, in enzyme activities and cell volume changes of plants, and in the nervous activity and sleep-wakefulness pattern of animals.
Abstract: Complex systems tend to oscillate, whether they be technical systems like bridges or machines, chemical processes like the Zhabotinsky reaction, or biological systems like organisms or ecosystems. In organisms, rhythmic events are widespread and vary common. For example, the spectrum of rhythmic phenomena in mammals ranges from periods of some milliseconds (nerves) to periods of a day (body temperature), a month (estrous cycle in humans), a year (reproductive cycles in larger mammals), or even longer (rhythmic changes in population density). The daily change of environmental factors such as light and temperature in its 24-h structure has apparently favored those organisms that adapted physiologically to this temporal order. This is just a corollary in the time domain to the structural and functional adaptation of organisms to the environment, and not surprising. We find 24-h rhythms in the mobility or’ bioluminescence of unicellular algae, in the formation of reproductive structures of fungi, in enzyme activities and cell volume changes of plants, and in the nervous activity and sleep-wakefulness pattern of animals, to name just a few.
TL;DR: The metabolism — weight relationship 24 different nonpasserine birds follows the equation M=0.138 W0.716, with no pronounced differences found between these birds and representatives of the order Passeriformes.
Abstract: The metabolism — weight relationship 24 different nonpasserine birds follows the equation M=0.138 W0.716. No pronounced differences could be found, relating to the metabolic rate per unit body weight, between these birds and representatives of the order Passeriformes.