# ALBERT

## All Library Books, journals and Electronic Records Telegrafenberg

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

Proceed reservation?

Export
Filter
• Humans  (26,746)
Collection
Keywords
Years
• 1
Electronic Resource
Springer
Animal cognition 1 (1998), S. 25-35
ISSN: 1435-9456
Keywords: Key words Shape from shading ; Visual search ; Texture segregation ; Chimpanzees ; Humans
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 2
Electronic Resource
Springer
Journal of molecular evolution 27 (1988), S. 311-320
ISSN: 1432-1432
Keywords: Genome composition ; Coding sequences ; Isochores ; Humans ; Murids
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Summary The compositional distributions of coding sequences and DNA molecules (in the 50-100-kb range) are remarkably narrower in murids (rat and mouse) compared to humans (as well as to all other mammals explored so far). In murids, both distributions begin at higher and end at lower GC values. A comparison of homologous coding sequences from murids and humans revealed that their different compositional distributions are due to differences in GC levels in all three codon positions, particularly of genes located at both ends of the distribution. In turn, these differences are responsible for differences in both codon usage and amino acids. When GC levels at first+second codon positions and third codon positions, respectively, of murid genes are plotted against corresponding GC levels of homologous human genes, linear relationships (with very high correlation coefficients and slopes of about 0.78 and 0.60, respectively) are found. This indicates a conservation of the order of GC levels in homologous genes from humans and murids. (The same comparison for mouse and rat genes indicates a conservation of GC levels of homologous genes.) A similar linear relationship was observed when plotting GC levels of corresponding DNA fractions (as obtained by density gradient centrifugation in the presence of a sequence-specific ligand) from mouse and human. These findings indicate that orderly compositional changes affecting not only coding sequences but also noncoding sequences took place since the divergence of murids. Such directional fixations of mutations point to the existence of selective pressures affecting the genome as a whole.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 3
Electronic Resource
Springer
Journal of molecular evolution 35 (1992), S. 7-16
ISSN: 1432-1432
Keywords: Alu source genes ; Humans ; Gorillas ; Retrotransposition
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Summary A member of the young PV Alu sub-family is detected in chimpanzee DNA showing that the PV subfamily is not specific to human DNA. This particular Alu is absent from the orthologous loci in both human and gorilla DNAs, indicating that PV subfamily members transposed within the chimpanzee lineage following the divergence of chimpanzee from both gorilla and human. These findings and previous reports describing the transpositional activity of other Alu sequences within the human, gorilla, and chimpanzee lineages provide phylogenetic evidence for the existence of multiple Alu source genes. Sequences surrounding this particular Alu resemble known transcriptional control elements associated with RNA polymerase III, suggesting a mechanism by which cis-acting elements might be acquired upon retrotransposition.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 4
Electronic Resource
Springer
Journal of molecular evolution 34 (1992), S. 336-344
ISSN: 1432-1432
Keywords: Humans ; Mitochondrial DNA ; Nuclear polymorphisms ; Heteroplasmy ; Genetic differentiation ; Sickle cell ; Rain forest refuges
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Summary The identification of genetically coherent populations is essential for understanding human evolution. Among the culturally uniform ethnic groups of west Africa, there are two geographically distinct populations with high frequencies of sickle-cell hemoglobin (HbS). Although the HbS mutation in each group is found on distinguishable chromosomes 11, these populations have been assumed to be parts of a single population. Analysis of mitochondrial DNA (mtDNA) in these populations demonstrated that the two populations identified by alternative chromosomes 11 bearing HbS have distinct distributions of mitochondrial genotypes, i.e., they are maternally separate. These studies also showed that, contrary to expectation, the mtDNA of some individuals is heteroplasmic. For nuclear loci, a comparison of the frequency of alternative alleles established that these populations are genetically distinct. Both the mitochondrial and nuclear data indicate that these populations have been separate for approximately 50,000 years. Although HbS in the two populations is usually attributed to recent, independent mutations, the duration of the separation and the observed geographic distribution of the population allow for the possibility of an ancient origin of HbS. Assuming an ancient mutation and considering the known biogeography, we suggest that HbS protected selected populations from malaria in rain forest refuges during the most recent ice age.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 5
Electronic Resource
Springer
Journal of molecular evolution 33 (1991), S. 442-449
ISSN: 1432-1432
Keywords: Humans ; Mouse ; Rat ; Codon usage ; Mutation bias ; Selection
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Summary A new statistical test has been developed to detect selection on silent sites. This test compares the codon usage within a gene and thus does not require knowledge of which genes are under the greatest selection, that there exist common trends in codon usage across genes, or that genes have the same mutation pattern. It also controls for mutational biases that might be introduced by the adjacent bases. The test was applied to 62 mammalian sequences, the significant codon usage biases were detected in all three species examined (humans, rats, and mice). However, these biases appear not to be the consequence of selection, but of the first base pair in the codon influencing the mutation pattern at the third position.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 6
Electronic Resource
Amsterdam : Elsevier
Free Radical Biology and Medicine 10 (1991), S. 177-184
ISSN: 0891-5849
Keywords: Free radicals ; Humans ; Noninvasive analytical techniques ; Oxidative stress status
Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
Topics: Biology , Chemistry and Pharmacology , Medicine
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 7
Electronic Resource
Springer
ISSN: 1432-1254
Keywords: Briths ; Humans ; Solar wind ; Geomagnetism ; Melatonin
Source: Springer Online Journal Archives 1860-2000
Topics: Geography , Physics
Notes: Abstract Data obtained from the literature on the annual pattern of human conceptions and plasma melatonin at high latitudes indicated that simple annual rhythms do not exist. Instead, prominent semiannual rhythms are found, with equinoctial troughs and solsticial peaks. A prominent semiannual environmental event is the magnetic disturbance induced by the solar wind. The semiannual magnetic disturbances are worldwide, but most pronounced in the auroral zones where the corpuscular radiation enters the atmosphere. Magnetic indices that predominantly reflect these events were obtained from the literature and correlated with the melatonin and conception data. Significant and inverse correlations were found for Inuit conceptions and the melatonin data. The correlations obtained for 48 contiguous states of the United States indicated that only the extreme northern states exhibited this relationship. These data were compared with a previous correlational study in the United States which established that sunshine was correlated with conceptions in the middle latitude and southern states. An hypothesis of dual control by electromagnetic and magnetic energies is proposed: melatonin is a progonadal hormone in humans controlled by both factors, depending on their relative strength. Other studies are reviewed regarding the possible factors involved in determining the annual pattern of human conceptions. Demographic studies of geographic variation in temporal patterns of conceptions, with particular regard to variations of the magnetic fields on the earth's surface, may provide some insight into the efficacy of these different factors.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 8
Electronic Resource
Springer
Cell & tissue research 242 (1985), S. 229-232
ISSN: 1432-0878
Keywords: Skeletal muscles ; Ultrastructure ; Exercise ; Glycogen ; Humans
Source: Springer Online Journal Archives 1860-2000
Topics: Biology , Medicine
Notes: Summary Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar Iband. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these “depleted” type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 9
Electronic Resource
Springer
Annals of biomedical engineering 21 (1993), S. 489-499
ISSN: 1573-9686
Keywords: Work of breathing ; Inspiratory pressure-time integral ; Respiratory modeling ; Dogs ; Humans
Source: Springer Online Journal Archives 1860-2000
Topics: Medicine , Technology
Notes: Abstract We hypothesized that the viscoelastic properties of the respiratory system should have significant implications for the energetically optimal frequency of breathing, in view of the fact that these properties cause marked dependencies of overall system resistance and elastance on frequency. To test our hypothesis we simulated two models of canine and human respiratory system mechanics during sinusoidal breathing and calculated the inspiratory work ( $$\dot W$$ ) and pressure-time integral (PTI) per minute under both resting and exercise conditions. The two models were a two-compartment viscoelastic model and a single-compartment model. Requiring minute alveolar ventilation to be fixed, we found that both models predicted almost identical optimum breathing frequencies. The calculated PTI was very insensitive to increases in breathing frequency above the optimal frequencies, while $$\dot W$$ was found to increase slowly with frequency above its optimum. In contrast, both $$\dot W$$ and PTI increased sharply as frequency decreased below their respective optima. A sensitivity analysis showed that the model predictions were very insensitive to the elastance and resistance values chosen to characterize tissue viscoelasticity. We conclude that the $$\dot W$$ criterion for choosing the frequency of breathing is compatible with observations in nature, whereas the optimal frequency predictions of the PTI are rather too high. Both criteria allow for a fairly wide margin of choice in frequency above the optimum values without incurring excessive additional energy expenditure. Furthermore, contrary to our expectations, the viscoelastic properties of the respiratory system tissues do not pose a noticeable problem to the respiratory controller in terms of energy expenditure.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
• 10
Electronic Resource
Springer
Mycopathologia 124 (1993), S. 73-77
ISSN: 1573-0832
Keywords: Assessment ; Cancer ; Humans ; Hydrazines ; Mushroom
Source: Springer Online Journal Archives 1860-2000
Topics: Biology , Medicine
Notes: Abstract This assessment focuses on the concentrations of some chemicals present in theAgaricus bisporus mushroom, the cancer-inducing doses of these chemicals or mushroom used in the animal experiments, the total amounts of these chemicals or mushroom needed to induce cancer in these mice, and the estimated total amounts of these chemicals or mushroom needed to induce cancer in humans. By adding the estimated amounts of chemicals needed to induce cancer and by comparing it with the amount of raw mushroom needed to induce the same effect, it becomes obvious that we have accounted for less than 2% of the carcinogenic components of theAgaricus bisporus mushroom. Since some unavailable data handicapped this assessment, it should be regarded as tentative and subject to further adjustment.
Type of Medium: Electronic Resource
Location Call Number Expected Availability
Others were also interested in ...
Close ⊗