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At least 793 records · Page 44Linked to original sources

PubMed2006

Biologic control ability of plant growth-promoting Paenibacillus lentimorbus NRRL B-30488 isolated from milk.

A plant growth-promoting Paenibacillus lentimorbus NRRL B-30488 (B-30488) was isolated from cows' milk. Bacterial colonization and growth responses of different plant species after inoculation with B-30488 were evaluated in a controlled environment and in microplot assays. Survival and colonization of B-30488 in the phytosphere of plants and soil was monitored using a chromosomally located rifampicin-marked mutant B-30488 (B-30488R). The strain showed variable ability to invade plants. The interaction between B-30488R and Fusarium oxysporum f. sp. ciceri was studied by scanning electron microscopy. Chitinase and beta-1,3-glucanase enzymes were produced when B-30488R was grown in the presence of colloidal chitin as sole carbon source. Deliberate dilution of B-30488R with field soil offers a reliable process for decreasing the cost of bacterial inoculants in developing countries. Seed treatment of chickpea demonstrated significantly (P = 0.05) greater seedling mortality in nonbacterized compared with bacterized seedlings. Bacterization significantly (P = 0.05) improved seed germination, plant height, number of pods/plant(-1), and seed dry weight.

Animals↗

PubMed2006

Modelling of predator-prey trophic interactions. Part II: three trophic levels.

A general class of lumped parameter models describing the local dynamics of a tri-trophic chain in a controlled environment is analyzed in detail. The trophic functions characterizing the interactions are defined only by some properties and allow us to treat both prey-dependent and ratio-dependent models in a unified manner. Conditions for existence and stability of extinction and coexistence equilibrium states are determined. Some peculiar aspects of the dynamics of the system depending on the bioecological parameters are presented, with particular attention to bistability situations, limit cycles and chaotic behaviours.

Animals↗

PubMed2006

Tissue culture and transient transformation of Marestail (Conyza canadensis (L.) Cronquist).

Glyphosate resistant crops are useful to agriculture by facilitating the use of nonselective herbicides, such as RoundUp, that have low human and environmental toxicity. The occurrence of glyphosate resistant weeds, however, has raised concern about the future utility of these crops. Conyza canadensis (L.) Cronquist (marestail or horseweed) is one such glyphosate resistant weed that has yet to be fully analyzed or established in tissue culture. Tissue culture enables the examination of physiological characteristics of a plant in an aseptic and controlled environment. For the present study, mairstail was cultured on a Murashige and Skoog based medium supplemented with 6-benzylaminopurine, and alpha-naphthaleneacetic acid. Plant regeneration was achieved on the same basal medium supplemented with only gibberellic acid. Glyphosate resistance could be demonstrated in the cultured tissues. The cultures could also be transformed with Agrobacterium tumefaciens without chemically inducing virulence using phenolics or glucose and resulting in a transformation frequency (transgenic events per total number of explants used) of about 13%. The tissue culture growth, preliminary glyphosate resistance data and genetic transformation data gathered in this project provide the means to further evaluate the mode of glyphosate resistance expressed by marestail.

Agrobacterium tumefaciens↗

PubMed2002

Honey bees store landmarks in an egocentric frame of reference.

Honey bees are well known to rely on stored landmark information to locate a previously visited site. While various mechanisms underlying insect navigation have been thoroughly explored, little is yet known about the degree of integration of spatial parameters to form higher-level spatial representations. In this paper we explore the basic interactions between landmark cues and directional cues, which stand at the basis of our understanding of piloting mechanisms. A novel experimental paradigm allowed us independent manipulation of each parameter in a highly controlled environment. The approach taken was twofold: cue-conflict experiments were first conducted to examine the interactions between positional cues and directional cues. The bees were then successively deprived of sensory cues to question the dependence of landmark navigation on context cues. Our results confirm previous findings that landmark cues are used in concert with external directional cues if present. Conversely, the bees' ability to locate a food site was not disrupted in the absence of an external directional reference. Thus, bees store landmark memories in an egocentric frame of reference and only loose and facultative associations between visual memories and compass cues are formed.

Animals↗

PubMed1999

Mechanisms underlying the age-related decrement in the human sweating response.

To examine the mechanisms underlying the age-related decrement in the ability to sweat, seven older (64-76 years) and seven younger (20-24 years) men participated in a 60-min sweating test. The test consisted of placing the subject's lower legs in a water bath at 42 degrees C while sitting in a controlled environment of 35 degrees C ambient temperature and 45% relative humidity. The rectal (Trc) and skin temperatures, local sweating rates (m(sw): on the forehead, chest, back, forearm and thigh) and the frequency of sweat expulsion (f(sw)) were measured during the test. No group difference was observed in the mean body temperature (Tb) throughout the passive heating, although the older men had a higher Tre and a lower mean skin temperature during the last half of the 60-min test. There were no group differences in the Tb threshold for sweating, although the time to the onset of sweating tended to be longer for the older men regardless of body site. The m(sw) increased gradually for approximately 35 min after the start of heat exposure in the older men and for 30 min in the younger men and then reached a steady state. During the first half of the test, the older men had a significantly lower m(sw) at all sites. During the last half of the test, only m(sw) on the thigh was significantly lower in the older men than in the younger men. There was no group difference in the slope of f(sw) versus Tb (an indicator of the change in the central sudomotor response to thermal input). The slope of m(sw) versus f(sw) (an indicator of the change in peripheral activity in response to central sudomotor changes) was significantly lower on the thigh in the older men, but there were no differences for the other sites. These results suggest that in older men the lower thigh m(sw) observed during the last half of the heat test was possibly due to age-related modifications of peripheral mechanisms involving the sweat glands and surrounding tissues. It was not due to a change in the central drive to sudomotor function. Furthermore, the sluggish m(sw) responses in the older men appear to have been related to age-related modifications of the sensitivity of thermoreceptors in various body regions to thermal stimuli. They may also involve lower sweat glands' sensitivity to cholinergic stimulus or sluggish vasodilatation, and do not reflect age-related changes in the central drive.

Adult↗

PubMed2001

Increased muscle glycogen content is associated with increased capacity to respond to T-system depolarisation in mechanically skinned skeletal muscle fibres from the rat.

The ability of mechanically skinned muscle fibres from the rat to respond to T-system depolarisation was studied in relation to muscle glycogen content. Muscle glycogen was altered by incubating extensor digitorum longus (EDL) muscles in Krebs solution without glucose or in Krebs solution with glucose (10 mM) and insulin (20 U.l-1). The glycogen content of muscles stored without glucose was rather stable between 30 and 480 min (11.27 +/- 0.39 mumol.g-1), while the muscles stored with glucose and insulin maintained an elevated and stable level of glycogen (23.48 +/- 1.67 mumol.g-1) between 100 and 360 min. Single mechanically skinned fibres from paired muscles, incubated in either glucose-free Krebs or in Krebs with glucose and insulin, were subjected to cycles of T-system depolarisation-repolarisation in a controlled environment (8 mM ATP, 10 mM creatine phosphate, 1 mM Mg2+, pH 7.10) and the force response was monitored until the force had declined to 50% of the maximum response (50% rundown). Fibres from muscles with a higher glycogen content reached 50% rundown after a larger number of depolarisations and displayed consistently larger average response capacity values, calculated as the sum of the force responses to 50% rundown divided by the maximum Ca(2+)-activated force response in that fibre. Thus skinned fibres originating from muscles with a higher glycogen content have an increased ability to respond to T-system depolarisation when the effect of metabolite accumulation is minimised and the function of glycogen acting as an energy source is by-passed. This provides direct support to the hypothesis that glycogen has a protective role in maintaining fibre excitability.

Adenosine Triphosphate↗

PubMed2004

The growth of soybean under free air [CO(2)] enrichment (FACE) stimulates photosynthesis while decreasing in vivo Rubisco capacity.

Down-regulation of light-saturated photosynthesis (A(sat)) at elevated atmospheric CO(2) concentration, [CO(2)], has been demonstrated for many C(3) species and is often associated with inability to utilize additional photosynthate and/or nitrogen limitation. In soybean, a nitrogen-fixing species, both limitations are less likely than in crops lacking an N-fixing symbiont. Prior studies have used controlled environment or field enclosures where the artificial environment can modify responses to [CO(2)]. A soybean free air [CO(2)] enrichment (FACE) facility has provided the first opportunity to analyze the effects of elevated [CO(2)] on photosynthesis under fully open-air conditions. Potential ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V(c,max)) and electron transport through photosystem II (J(max)) were determined from the responses of A(sat) to intercellular [CO(2)] (C(i)) throughout two growing seasons. Mesophyll conductance to CO(2) (g(m)) was determined from the responses of A(sat) and whole chain electron transport (J) to light. Elevated [CO(2)] increased A(sat) by 15-20% even though there was a small, statistically significant, decrease in V(c,max). This differs from previous studies in that V(c,max)/J(max) decreased, inferring a shift in resource investment away from Rubisco. This raised the C(i) at which the transition from Rubisco-limited to ribulose-1,5-bisphosphate regeneration-limited photosynthesis occurred. The decrease in V(c,max) was not the result of a change in g(m), which was unchanged by elevated [CO(2)]. This first analysis of limitations to soybean photosynthesis under fully open-air conditions reveals important differences to prior studies that have used enclosures to elevate [CO(2)], most significantly a smaller response of A(sat) and an apparent shift in resources away from Rubisco relative to capacity for electron transport.

Carbon Dioxide↗

PubMed1999

Assimilate export by leaves of ricinus communis L. growing under normal and elevated carbon dioxide concentrations: the same rate during the day, a different rate at night

Castor bean (Ricinus communis L.) plants were grown for 5-7 weeks in a controlled environment at 350 &mgr;l l(-1) or 700 &mgr;l l(-1) CO(2). Carbon assimilation, assimilate deposition, dark respiration and assimilate mobilization were measured in leaves 2, 3 and 4 (counted from the base of the plant), and a balance sheet of carbon input and export was elaborated for both CO(2) concentrations. Carbon dioxide assimilation was nearly constant over the illumination period, with only a slight depression occurring at the end of the day in mature source leaves, not in young source leaves. Assimilation was ca. 40% higher at 700 &mgr;l l(-1) than at 350 &mgr;l l(-1) CO(2). The source leaves increased steadily in weight per unit area during the first 3 weeks, more at 700 &mgr;l l(-1) than at 350 &mgr;l l(-1) CO(2). On top of an irreversible weight increase, there was a large gain in dry weight during the day, which was reversed during the night. This reversible weight gain was constant over the life time of the leaf and ca. 80% higher at 700 &mgr;l l(-1) than at 350 &mgr;l l(-1). Most of it was due to carbohydrates. The carbon content (as a percentage) was not altered by the CO(2) treatment. Respiration was 25% higher in high-CO(2) plants when based on leaf area, but the same when based on dry weight. The rate of carbon export via the phloem was the same during the daytime in plants grown at 350 &mgr;l l(-1) and 700 &mgr;l l(-1) CO(2). During the night the low-CO(2) plants had only 50% of the daytime export rate, in contrast to the high-CO(2) plants which maintained the high export rate. It was concluded that the phloem loading system is saturated during the daytime in both CO(2) regimes, whereas during the night the assimilate supply is reduced in plants in the normal CO(2) concentration. Two-thirds of the carbon exported from the leaves was permanently incorporated as plant dry matter in the residual plant parts. This "assimilation efficiency" was the same for both CO(2) regimes. It is speculated that under 350 &mgr;l l(-1) CO(2) the growing Ricinus plant operates at sink limitation during the day and at source limitation during the night.

Journal Article↗

PubMed1999

Diurnal variations in hydraulic conductivity and root pressure can be correlated with the expression of putative aquaporins in the roots of lotus japonicus

The hydraulic conductivity of excised roots (Lp(r)) of the legume Lotus japonicus (Regel) K. Larsen grown in mist (aeroponic) and sand cultures, was found to vary over a 5-fold range during a day/night cycle. This behaviour was seen when Lp(r) was measured in roots exuding, either under root pressure (osmotic driving force), or under an applied hydrostatic pressure of 0.4 MPa which produced a rate of water flow similar to that in a transpiring plant. A similar daily pattern of variation was seen in plants grown in natural daylight or in controlled-environment rooms, in plants transpiring at ambient rates or at greatly reduced rates, and in plants grown in either aeroponic or sand culture. When detached root systems were connected to a root pressure probe, a marked diurnal variation was seen in the root pressure generated. After excision, this circadian rhythm continued for some days. The hydraulic conductivity of the plasma membrane of individual root cells was measured during the diurnal cycle using a cell pressure probe. Measurements were made on the first four cell layers of the cortex, but no evidence of any diurnal fluctuation could be found. It was concluded that the conductance of membranes of endodermal and stelar cells may be responsible for the observed diurnal rhythm in root Lp(r). When mRNAs from roots were probed with cDNA from the Arabidopsis aquaporin AthPIP1a gene, an abundant transcript was found to vary in abundance diurnally under high-stringency conditions. The pattern of fluctuations resembled closely the diurnal pattern of variation in root Lp(r). The plasma membranes of root cells were found to contain an abundant hydrophobic protein with a molecular weight of about 31 kDa which cross-reacted strongly to an antibody raised against the evolutionarily conserved N-terminal amino acid sequence of AthPIP1a.

Journal Article↗

PubMed1999

Connectivity in the somatosensory cortex of the adolescent rat: an in vitro biocytin study.

A promising way to elucidate neuronal information processing is to establish detailed structure-function relationships of identified single neurons or populations of nerve cells, especially their synaptic connectivity. This has been greatly improved by the development of acute brain slice preparations. The cellular physiology of the rodent primary somatosensory (barrel) cortex has been extensively studied. However, for a meaningful interpretation of physiological experiments the degree and pattern of connectivity has to be known for the particular preparation. Since such studies are not available for rat (P15-25) barrel cortex in vitro, we have traced the cortico-cortical and thalamo-cortical connections in 400-microm-thick slices with biocytin. In coronal slices, a wealth of axonal connections in retrograde and anterograde directions were heavily labeled, resembling the full pattern of cortico-cortical projections described in vivo. The most striking connections were vertical and horizontal connections within the primary somatosensory cortex, as well as a columnar projection to the secondary somatosensory cortex and beyond (mainly the parietal ventral area). Electron microscopic extensions of the study indicated that the full possible set of synaptic contacts with an adult-like appearance was already established in these connections. In thalamo-cortical slices, strong reciprocal connections with the ventrobasal (and to a much lesser extent also the posterior) thalamic nucleus were always observed, together with an intensive ramification of fibers in the reticular nucleus. A striatal terminal field was also consistently found. We conclude that all major intracortical and thalamo-cortical connection are richly preserved in the in vitro slice preparations of rats. Thus, these preparations are suitable for elucidation of the functional interaction of the most crucial brain structures involved in somatosensory information processing combining an in vivo-like anatomical structure with the controlled environment of an in vitro slice.

Animals↗

PubMed2005

Modulation of zinc- and cobalt-binding affinities through changes in the stability of the zinc ribbon protein L36.

Cysteine-rich Zn(II)-binding sites in proteins serve two distinct functions: to template or stabilize specific protein folds, and to facilitate chemical reactions such as alkyl transfers. We are interested how the protein environment controls metal site properties, specifically, how naturally occurring tetrahedral Zn(II) sites are affected by the surrounding protein. We have studied the Co(II)- and Zn(II)-binding of a series of derivatives of L36, a small zinc ribbon protein containing a (Cys)(3)His metal coordination site. UV-vis spectroscopy was used to monitor metal binding by peptides at pH 6.0. For all derivatives, the following trends were observed: (1) Zn(II) binds tighter than Co(II), with an average K (A) (Zn) /K (A) (Co) of 2.8(+/-2.0)x10(3); (2) mutation of the metal-binding ligand His32 to Cys decreases the affinity of L36 derivatives for both metals; (3) a Tyr24 to Trp mutation in the beta-sheet hydrophobic cluster increases K (A) (Zn) and K (A) (Co) ; (4) mutation in the beta-hairpin turn, His20 to Asn generating an Asn-Gly turn, also increases K (A) (Zn) and K (A) (Co) ; (5) the combination of His20 to Asn and Tyr24 to Trp mutations also increases K (A) (Zn) and K (A) (Co) , but the increments versus C(3)H are less than those of the single mutations. Furthermore, circular dichroism, size-exclusion chromatography, and 1D and 2D (1)H NMR experiments show that the mutations do not change the overall fold or association state of the proteins. L36, displaying Co(II)- and Zn(II)-binding sensitivity to various sequence mutations without undergoing a change in protein structure, can therefore serve as a useful model system for future structure/reactivity studies.

Amino Acid Motifs↗

PubMed2026

Integrating genomics, multi-omics, CRISPR and speed breeding for stress-resilient vegetable legume improvement.

Vegetable legumes are nutritionally and ecologically important crops. However, their genetic improvement has not kept pace with the increasing challenges posed by climate change due to the polygenic nature of stress tolerance, narrow genetic diversity, and the persistent gap between molecular discoveries and field-level cultivar development. Although recent reviews have examined individual genomic tools or specific stress responses, a comprehensive synthesis integrating genomics-assisted breeding, multi-omics technologies, genome editing, and speed breeding within a unified crop improvement framework has been lacking. This review addresses that gap by critically evaluating how these complementary approaches can accelerate the development of stress-resilient vegetable legumes, including pea, common bean, cowpea, faba bean, cluster bean, yard-long bean, and hyacinth bean. This review synthesizes advances in QTL mapping, genome-wide association studies, transcriptomics, metabolomics, and CRISPR-based functional genomics that have identified key regulators and pathways underlying resistance to major biotic and abiotic stresses. Rather than considering these technologies independently, the review emphasizes their convergence into a systems-level breeding framework integrating genomic discovery, functional validation, predictive breeding, and accelerated generation advancement to improve breeding efficiency. Speed breeding, enabling up to seven to eight generations annually under optimized controlled-environment experimental conditions in cowpea, is discussed as a complementary strategy with genomic selection and genome editing. The review further identifies major translational bottlenecks, including transformation recalcitrance, limited genomic resources for underutilized vegetable legumes, inadequate multi-environment validation, and fragmented omics integration, and presents an integrated systems-breeding framework to bridge the gap between gene discovery and cultivar development.

Fabaceae↗

PubMed2006

Ozone and/or water stresses could have influenced the Betula ermanii cham. forest decline observed at Oku-Nikko, Japan.

A serious forest decline of Betula ermanii Cham. has been observed at Mt. Mae-Shirane, Oku-Nikko, Japan, where high ozone (O3) concentration and severe water deficiency have been measured. In order to consider the possibility whether O3 and/or water stresses could have been the causes of the forest decline of B. ermanii, plant growth experiments were conducted in environment-controlled growth cabinets. Two-year-old seedlings of B. ermanii were exposed to either charcoal-filtered air (O3 concentration <5 ppb) or 50 ppb O3 (daily average, ranging between 20-100 ppb) for 123 days at 20.0/12.5 +/- 1.0 degrees C (day/night) and 70/80 +/- 7% relative humidity (day/night). Simultaneously, seedlings were treated with three watering regime: 1.0 < pF < 1.8 (no water stress), 1.8 < pF < 2.5 (mild water stress) or 2.5 < pF < 3.0 (severe water stress). O3 exposure significantly reduced the dry weights of leaf, root and the whole plant, while water stress significantly reduced the dry weights of each organ and the whole plant. Significant reductions of net photosynthesis, transpiration and stomatal conductance were also observed under O3 and/or water deficiency treatments, while contents of RuBP carboxylase/oxygenase (Rubisco), chlorophyll( a+b ) and some essential nutrient elements (N, P, K, Mg and Ca) were not markedly changed. It was suggested that the decrease in net photosynthetic rate induced mainly by stomatal closure was the major cause of the growth reduction under O3 and/or water stresses. No significant interactions between O3 and water stresses were observed in terms of the depression of dry matter production, which suggested that simultaneous stress treatments of O3 exposure and water deficiency could affect the tree growth of B. ermanii additively.

Air Pollutants↗

PubMed2005

Are animals just noisy machines?: Louis Boutan and the co-invention of animal and child psychology in the French Third Republic.

Historians of science have only just begun to sample the wealth of different approaches to the study of animal behavior undertaken in the twentieth century. To date, more attention has been given to Lorenzian ethology and American behaviorism than to other work and traditions, but different approaches are equally worthy of the historian's attention, reflecting not only the broader range of questions that could be asked about animal behavior and the "animal mind" but also the different contexts in which these questions were important. One such approach is that represented by the work of the French zoologist Louis Boutan (1859-1934). This paper explores the intellectual and cultural history of Boutan's work on animal language and the animal mind, and contextualizes the place of animal behavior studies within late-nineteenth- and early-twentieth-century French biology. I explore the ways in which Boutan addressed the philosophical issue of whether language was necessary for abstract thought and show how he shifted from the idea that animals were endowed with a purely affective language to the notion that of they were capable of "rudimentary" reasoning. I argue that the scientific and broader socio-cultural contexts in which Boutan operated played a role in this transition. Then I show how Boutan's linguistic and psychological experiments with a gibbon and children provide insights into his conception of "naturalness." Although Boutan reared his gibbon at home and studied it in the controlled environment of his laboratory, he continued to identify its behavior as "natural." I specifically demonstrate the importance of the milieu of the French Third Republic in shaping Boutan's understanding not only of animal intelligence and child education, but also his definition of nature. Finally, I argue that Boutan's studies on the primate mind provide us with a lens through which we can examine the co-invention of animal and child psychology in early-twentieth-century France.

Animal Communication↗

PubMed2006

Assessment of a new prototype hydrogel CO( 2 ) sensor; comparison with air tonometry.

OBJECTIVE: Gastrointestinal ischemia is always accompanied by an increased luminal CO(2). Currently, air tonometry is used to measure luminal CO(2). To improve the response time a new sensor was developed, enabling continuous CO(2) measurement. It consists of a pH-sensitive hydrogel which swells and shrinks in response to luminal CO(2), which is measured by the pressure sensor. We evaluated the potential clinical value of the sensor during an in vitro and in vivo study. METHODS: The response time to immediate, and stepwise change in pCO(2) was determined between 5 and 15 kPa, as well as temperature sensitivity between 25 and 40 degrees C at two pCO(2) levels. Three sensors were compared to air tonometry (Tonocap) in healthy volunteers using a stepwise incremental exercise test, followed by a period of hyperventilation and an artificial CO(2)-peak. RESULTS: The in vitro response time to CO(2) increase and decrease was mean 5.9 and 6.6 min. The bias, precision and reproducibility were +5%, 3% and 2%, resp. Increase of 1 degrees C at constant pCO(2) decreased sensor signal by 8%. In vivo tests: The relation with the Tonocap was poor during the exercise test. The response time of the sensor was 3 min during hyperventilation and the CO(2) peak. CONCLUSION: The hydrogel carbon dioxide sensor enabled fast and accurate pCO(2) measurement in a controlled environment but is very temperature dependent. The current prototype hydrogel sensor is still too unstable for clinical use, and should therefore be improved.

Air↗

PubMed1988

Clinical trials in acute musculoskeletal injury states. An analysis of methodology.

Therapeutic evaluation of nonsteroidal anti-inflammatory drugs in the treatment of acute musculoskeletal diseases and injuries requires the use of adequate models for clinical trials. The objective of a short-term pain study is to determine whether a new treatment is effective and how it compares with a standard or reference drug for the indication being evaluated. Among the requirements for the pain model study are proper protocols and adequate, homogeneous patient populations. Problems in establishing the model include difficulty in finding adequate numbers of patients, inappropriate sites, patient resistance, and varying conditions of natural recovery. Suggestions are presented for conducting these studies: relying on global pain relief scores, keeping a home diary that is simple and objective, and extending the initial observation period in the office to generate single-dose data in a controlled environment. Sports medicine models are useful in allowing investigators the necessary numbers of patients and providing data that meaningfully address pharmacologic treatment for acute musculoskeletal disorders.

Acute Disease↗

PubMed1979

Effects of biorhythms on blood flow distribution in the pregnant uterus (Macaca mulatta).

Ten rhesus monkeys were studied between 143 and 161 days of gestation. The unanesthetized animals were confined to restraining chairs and maintained in a controlled environment with continuous monitoring of spontaneous uterine dynamics. Forty-five determinations of blood flow distribution were made using radionuclide-labeled microspheres. The microsphere injections confirmed a circadian pattern of uterine blood flow. These biorhythms are related to alterations in distribution of blood flow to placental and nonplacental portions of the uterus. Myometrial blood flow is highest during the period of light. It is correlated positively to aortic blood pressure (r = 0.490, p less than 0.05) and inversely to uterine artery blood flow (r = -0.508, p less than 0.05). Placental blood flow is highest during the period of darkness. The flow rates are significantly correlated to intra-amniotic pressure (r = -0.602, p less than 0.05) but not to aortic blood pressure (r = -0.185, p less than 0.05). The data indicate that blood flow distribution in the primate uterus is modulated by factors in addition to physiologic pressure-flow relationships. Extrapolation to the human has potential significance.

Animals↗

PubMed1979

Electron diffraction studies of human erythrocyte membrane and its lipid extracts. Effects of hydration, temperature and hydrolysis.

The organization of lipid molecules in individual human erythrocyte ghost membranes and single bilayers of their total lipid extracts were studied by low-dose electron diffraction in a controlled environment. The highest onset temperature (Ts) at which diffraction rings corresponding to a gel state appeared, were found to be in the range of -2 to -4 degrees C for both the whole ghost membrane and bilayers of its total lipid extracts. The onsets were abolished by dehydration before separated crystallizations of cholesterol and phospholipid occurred. Ts increased as a result of free fatty acids accumulation in membranes after phospholipase A2 treatment or storage.

Erythrocyte Membrane↗