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Results for “Data colonialism”

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At least 19 recordsLinked to original sources

PubMed1976

Breeding and reproduction of fifteen wild rodents maintained as laboratory colonies.

Data on reproduction and production were presented for laboratory colonies of Microtus pennsylvanicus tananaensis, M oeconomus macfarlani, M o operarius, M mirurus, M abbreviatus, Lemmus lemmus, L sibiricus trimucronatus, Dicrostonyx stevensoni, Clethrionomys rutilus, Peromyscus maniculatus borealis, P m bairdii, Baiomys taylori, Calomys ducilla, C callosus, Acomys cahirinus. Litter size varied from 2.0 in A cahirinus to 5.5 in C callosus. Infant (neonatal) and juvenile losses through the end of the first month ranged from 9% in C callosus to 45% in M o operarius. Young successfully weaned per female ranged from 3.4 in L sibericus to 15.2 in P m bairdii. The number of young weaned per female per month, which may be the most useful measure of production, ranged from 0.6 in A cahirinus to 2.6 in C ducilla. The most common 21-da interval between litters confirms postpartum estrus and mating, and a 21-da gestation in most cricetids.

Animals↗

PubMed2026

Ethical Governance of Open Data Across Biomedical Research, Healthcare, and Public Health: Privacy, Equity, Trust, and Controlled Access.

Open data has become central to biomedical research and public health, but health information is uniquely sensitive and difficult to share responsibly. In this narrative review, open data is considered as a spectrum of health-data sharing arrangements, ranging from public aggregate datasets to controlled-access repositories, federated analysis, and synthetic data. This narrative review synthesizes the scientific and societal rationale for greater openness with the ethical, legal, and governance constraints that shape what "open" can realistically mean in healthcare. We examine how data sharing supports reproducibility, machine learning, and more efficient research, while also enabling public health surveillance and learning health systems. Against these benefits, we analyze privacy and re-identification risks, consent challenges in large-scale secondary use, inequities including data colonialism, and tensions introduced by commercialization. We integrate lessons from prominent case examples spanning pandemic data sharing, genomic initiatives, population registries, patient-led rare disease infrastructures, and regional data spaces. Across these domains, experience suggests that durable progress depends less on unrestricted openness than on calibrated access, privacy-preserving architectures, clear accountability, and sustained public engagement. We conclude by proposing a pragmatic ethical orientation for healthcare open data: treat openness as a spectrum of controlled sharing arrangements, embed equity and reciprocity into governance, and institutionalize trust-building measures that can persist beyond emergencies and political cycles.

Data colonialism↗

PubMed1976

Lifespan, age changes and tumour incidence in an ageing C57BL mouse colony.

Detailed data from a colony of C57BL mice kept for research into ageing processes are given on weights of 13 organs between the ages of 6 and 30 months; pathological findings and x-ray results from animals aged 6, 24 and 30 months; age-specific tumour incidences in 24 organs in 3-month period up to 36 months of age. Results of previously published age-related studies of reproductive capacity, dental abnormalities and brain changes are summarised.

Aging↗

PubMed1979

Mathematical models and the statistical analyses of cell transformation experiments.

Statistical methods are developed and applied to the fitting of the one-hit curves to chemically induced transformations in Syrian hamster colonies. Data from several experiments in two laboratories are shown to fit the model well at all but the highest doses of benzo(a)pyrene. The ratio of the estimated parameters of the one-hit curves ("transformicities") is proposed as a measure of the enhancement by X-irradiation. Statistical tests for possible nonrandom variation among dishes are developed for the situation where a sample of dishes is used to estimate the total number of surviving cells. The methods of fitting and estimation are also extended to this case. Further analyses exclude selection as an explanation for the observed increase in transformation frequency with increased carcinogen concentration. The reproducibility of the fit of the one-hit model and the radiation enhancement measures is ascribed to the uniqueness of this in vitro system in which the direct target cell-insult interaction is not modulated by host intervention.

Animals↗

PubMed1978

Extrapulmonary colony formation after intravenous injection of tumour cells into heparin-treated animals.

Recent data on extrapulmonary colony formation after heparin administration are inconclusive. A systematic study of this topic was undertaken with 4 experimental tumour systems and 2 distinct periods of reduced clotting capacity in rats and mice. I.v. injection of various numbers of tumour cells into i.p. heparinized animals leads to: (1) Significant reduction in the number of lung colonies. The effect after 9 h anti-coagulation is equal to or probably greater than after 2 h. (2) The reduction in the number of lung colonies caused by heparin is independent of the number of cells injected. (3) The number of extrapulmonary extrathoracic colonies is significantly increased by heparin in 3 of the 4 tumour systems. (4) The number of extrapulmonary intrathoracic colonies is probably unaffected. (5) The increase in extrapulmonary extrathoracic colony formation is not related to the degree of reduction in lung colonies. These data lead to the conclusion that the capacity of the lung capillaries to trap tumour cells can be decreased by heparin-induced alterations in fibrin formation. This results in a lodgement of tumour cells throughout the body which is far more pronounced than in animals with normal clotting capacity.

Animals↗

PubMed1991

Contribution of the VH11 gene family to mitogen-responsive B cell repertoire in C57BL/6 mice.

The contribution of VH11 gene family to the development of the primary B cell repertoire has been studied by analyzing 1.8 x 10(4) mitogen induced B lymphocyte colonies. The data demonstrate that VH11 family is predominantly expressed among neonatal splenic as well as adult peritoneal B cell colonies, both rich in Ly-1+ B cells. VH11 gene family expression among B splenocytes decreases during ontogeny and VH11 family pairs stochastically with different V kappa families among mitogen-activated neonatal B cell colonies, which are representative of an antigen unselected B cell repertoire. Thus, an increased VH11 expression among peritoneal and neonatal B cells points towards its biased expression among Ly-1+ B lymphocytes. The restricted V gene rearrangements and VH11-V kappa 9 pairing observed among anti-bromelain-treated mouse red blood cells autoantibodies are likely to be an outcome of both intrinsic gene recombination processes per se as well as selection by an autoantigen and/or local selective environmental factors.

Age Factors↗

PubMed1992

Mechanisms responsible for size differences between hemopoietic colonies: an analysis using a CSF-dependent hemopoietic cell line.

Cells of the colony stimulating factor (CSF)-dependent continuous hemopoietic cell line 32Dcl-3 generate strikingly different large, medium and small colonies in semisolid cultures. Reculture of cells from such colonies showed that all colony types contained clonogenic cells able again to form colonies of all three size types. Clone mapping showed that late initiation of colony formation did not account for the final size difference between colonies, a conclusion confirmed by mapping studies on normal CSF-stimulated murine granulocyte-macrophage colonies. Clonogenic cells within 32 D Clone 3 (32Dcl-3) colonies varied in quantitative responsiveness to CSF stimulation. This responsiveness was generally lower than that of the initiating clonogenic cell and was higher with cells from small colonies than with cells from corresponding large colonies. The data eliminated differences in intrinsic proliferative potential, cellular hierarchy, cell cycle times or responsiveness to CSF stimulation as an adequate explanation for colony size differences. Colony size differences may possibly arise from random differences in the sequence of self-generative versus differentiative divisions in clonogenic cells in developing clones.

Animals↗

PubMed1979

Megakaryocyte colony formation from human bone marrow precursors.

We report the growth in plasma clot culture of megakaryocyte colonies from adult bone marrow cells with the use of four different sources of erythropoietin (Ep) as the stimulating factor. A major proportion of the megakaryocyte colonies (75%) were pure, while the others were mixed, involving erythroblasts and megakaryocytes. Ultrastructural studies have shown that the maturation of megakaryocytes was essentially normal and that platelet shedding occurred. Megakaryocyte colony formation required a large number of plated cells (greater than 3 X 10(5)/ml). In the absence of erythropoietin, rare spontaneous megakaryocyte colonies could be observed, while no erythroid colonies were present. However, erythropoietin induced a fivefold increase in the total number of colonies. These data suggest that erythropoietin is involved in the differentiation of human megakaryocytes, but that it does not act alone, since another factor related to the number of seeded cells appears essential for the formation of human megakaryocyte colonies.

Animals↗

PubMed1976

[Antigen-binding clone cells in hematopoietic spleen colonies].

The antigen-binding cell clones and the Ig-positive cells were found and quantitatively assessed in the primary hemopoietic splenic colonies. The data ogtained were analyzed assuming that the ratio of clone of specialized B-cells should reflect the quantitative ration in the corresponding V-genes in the given lymphocyte populations at definite stages of its development. The colonies differed from one another markedly by the curves of inhibition by DNP-lysine of rosette-formation with DNP-erythrocytes, i.e. by the avidity of B-cells of the given specificity. The colonies differed significantly by the ratio of the volumes of the two clone groups (cell with anti-DNP and anti-BE Ig-receptors) between themselves and the combination of the Ig-positive cells. These quantitaive regularities were incompatible with the view that each B-cell had any conceivable set of V-genes, i.e. with the germ-line hypothesis of the antibody and receptor diversity.

Animals↗

PubMed1991

Phylogeny of the colonial green flagellates: a study of 18S and 26S rRNA sequence data.

A study of phylogenetic relationships of the colonial green algal flagellates based on nuclear 18S and 26S rRNA sequence data suggests that the colonial habit has had at least two independent origins. All colonial taxa included in the analysis, except Stephanosphaera, are allied in a clade with Chlamydomonas reinhardtii and other Chlamydomonas taxa ascribed to the Euchlamydomonas group by Ettl. In contrast, Stephanosphaera is allied with other unicellular flagellates including Haematococcus. Comparison of the 18S and 26S data shows that the two sets of data yield different results following cladistic analysis. The 18S data provide the principal signal that supports the more basal divergences, but the data do not unambiguously address relationships among taxa in the clade that includes most colonial flagellates and Chlamydomonas taxa representative of the Euchlamydomonas group (sensu Ettl). In contrast, the 26S data have fewer informative sites that support basal divergences than the 18S data, but provide much of the signal that supports resolution of taxa in the colonial flagellate clade in an analysis of the combined 18S and 26S rRNA sequence data. Additional sequence data from the 26S molecule and additional taxa may reduce the topological ambiguity inferred from the sequence data for the colonial flagellates. Alternatively, an ancient and rapid radiation of taxa in the colonial lineage could account for the topological ambiguity. Despite some unresolved questions of relationships, cladistic analysis of the combined data sets provides some robustly supported concepts of evolution in these flagellates.

Animals↗

PubMed1975

Disseminated candidiasis. i. an experimental model in the guinea pig.

A model of experimental disseminated candidiasis was developed in the guinea pig; Candida albicans was injected intraperitoneally or intravenously. The kidney was the most severely affected organ, with maximal colony counts of 26,208 plus or minus 9,152 colony-forming units/g of tissue five days after a sublethal inocluation (one-sixth of the 50% lethal dose) of viable organisms. The heart was the next most severely affected organ, and other organs were affected little. Histologic studies confirmed the data from colony counts and showed a progression of inflammation similar to that seen in human disease. A leukocytosis predominantly of mononuclear cells, and to a lesser degree of granulocytes, occurred and was maximal four days after inoculation. This model will provide the framework for a series of future studies of the various factors important in natural host defense against infection with Candida, as well as the effects of various immunosuppressive agents, particularly corticosteroids, on the development and expression of immunity and protection against infection.

Adrenal Glands↗

PubMed1992

Aerosol generation by two ultrasonic scalers and one sonic scaler. A comparative study.

The purposes of this study were to compare the amount of aerosols generated from ultrasonic and sonic scalers and to measure the potential depth of respiratory tract penetration. Forty subjects were randomly assigned to receive instrumentation with the magnetostrictive, piezoelectric, or air turbine scaler. The Anderson Air Sampler collected total baseline airborne microbes for 20 minutes prior to treatment and for 20 minutes during instrumentation. This cascade impactor system measures the degree of microbial penetration in a simulated respiratory system. Blood agar plates from the sampler were incubated for 24 hours at 37 degrees C. Colony forming units per cubic foot of air (CFUs/cu. ft.) were enumerated by one blind examiner using a Lab Line Colony Counter. Data for total microbial CFUs/cu.ft. and CFUs/cu.ft. by sampler level were analyzed on the log-transformed data using ANCOVA. Baseline values of airborne bacteria served as the covariate. Results showed no significant difference in mean combined total CFUs/cu.ft. for the magnetostrictive, piezoelectric, or air turbine sonic scalers. The magnetostrictive scaler generated the lowest CFUs/cu.ft. at the deepest level of penetration; however, no significant difference in level of penetration was found among the three scalers.

Aerosols↗

PubMed1975

[Method of isolating spontaneous variants of actinomycete cultures, producers of antibiotics].

The necessity of taking into account the specific characteristics of the colony differentiation for isolation of spontaneous variants of the initial culture with the method of monospore plating was shown on the examples of the geliomycin-producing culture Actinomyces chromogenes var. trienicus 141-18. It was found that the population density of the colonies had a significant effect on the differentiation rate during the subsequent stages and completeness of the culture development. The less was the population density, the longer was the period of the colony complete development. Definite levels of the colony organization (fractionation of morphogenesis) corresponded to different dilutions of the monospore suspension providing definite population densities of the colonies on the plates. On the basis of the data on the colony differentiation compared with the data on the population density effect upon differentiation it was possible to determine without mistake stable variants on the plates at any dilution of the monospore culture, i.e. with any population density of the colony.

Actinomyces↗

PubMed1991

Role of the neurotrophic factors BDNF and NGF in the commitment of pluripotent neural crest cells.

Since trophic factors are increasingly recognized as playing a role in some decision-making steps during development, the influence of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) on the commitment of pluripotent neural crest cells was investigated by in vitro clonal analysis. BDNF caused an increase of up to 21-fold in the number of sensory neuron precursors per colony without a corresponding increase in the total number of cells. By contrast, BDNF treatment caused an equivalent decrease in the number of undifferentiated cells per colony. The data suggest that BDNF, but not NGF, directs pluripotent neural crest cells to differentiate along the primary sensory neuron lineage.

Animals↗

PubMed1992

Homicides in Auckland, New Zealand. A 14-year study.

In the 14-year period from 1976 to 1989, there have been 174 homicide victims in the Auckland colonial area. Data accessed from autopsy and police reports show that victims of marital conflict, family dispute, and arguments developing between nonmarried couples made up the largest proportion of homicide cases. Stabbing and assault with a blunt weapon were the most common causes of death. The data also show that homicide is relatively uncommon in Auckland in comparison with other cities of similar size.

Adolescent↗

PubMed1977

Inverse relationship between splenomegaly and stem cell compartment size in mice treated with nitrogen mustard.

Following the administration of similar doses of nitrogen mustard (4 mg/kg) to different strains of mice, wide variations in the subsequent degree of splenomegaly were observed, implying strain differences in the role of the spleen in the compensatory erythropoietic response to haematopoietic stress. This investigation was undertaken to determine whether or not these differences were related to the size of the haematopoietic stem cell compartment size in the various strains of mice. Groups of 4 different strains of mice (Swiss Webster, A/J, C57BL/6J and CS1/ASH) were injected i.v. with nitrogen mustard (4 mg/kg body weight) and autopsied at regular intervals up to 20 d post-injection. At autopsy, the wet weight of the spleen was determined. Subsequently, groups of the same 4 strains of mice were exposed to single doses of wholebody gamma-irradiation in the range of 500-900 rads. 9 d after gamma-irradiation the mice were autopsied, their spleens removed, and the number of endogenous spleen colonies determined. The greatest degree of splenomegaly was observed in the C57BL/6J mice. The Swiss Webster mice showed no splenomegaly during the time period studied. There existed a linear inverse relationship between the maximum degree of splenomegaly observed and the dose of wholebody gamma-irradiation required to completely eliminate endogenous spleen colonies. This data is in accord with the hypothesis that there exists an inverse relationship between the extent of splenomegaly observed following haematopoietic stress and the haematopoietic stem cell compartment size.

Animals↗

PubMed1979

Bacterial flora of the schistosome vector snail Biomphalaria glabrata.

The aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail Biomphalaria glabrata was examined. Internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. The numerically predominant bacterial genera in individual snails included Pseudomonas, Acinetobacter, Aeromonas, Vibrio, and several members of the Enterobacteriaceae. Enterobacteriaceae seldom predominated in laboratory colonies. Our data suggest that Vibrio extorquens and a Pasteurella sp. tend to predominate in high-bacterial-density snails. These snails may be compromised and may harbor opportunistic snail pathogens.

Aerobiosis↗

PubMed1976

Variation among goegraphic strains of Aedes albopictus in susceptibility to infection with chikungunya virus.

Two types of variation were observed when the susceptibility of 16 different geographic strains of Aedes albopictus to oral infection with chikungunya (CHIK) virus was studied. One was differential susceptibility to infection with the virus. The other was variation in the quantity of virus present in infected mosquitoes after a standard incubation period. Mean virus titers of infected mosquitoes of different geographic strains varied almost 1,000-fold. Attempts to develop increasingly resistant or susceptible mosquito lines through genetic selection were unsuccessful. Infection rates did not change significantly despite 3 to 6 generations of selective inbreeding. In contrast, crosses between strains of high and low CHIK susceptibility yielded hybrid mosquitoes with infection rates and mean virus titers intermediate between those of the parent colonies. These data suggest that at least one factor controlling the susceptibility of A. albopictus to CHIK infection is genetic. Two lines of A. albopictus with a marked difference in susceptibility to oral infection with dengue viruses were equally susceptible to oral infection with chikungunya virus.

Aedes↗