An accelerometer-derived ballistocardiogram method for detecting heart rate in free-ranging marine mammals.

Physio-logging methods, which use animal-borne devices to record physiological variables, are entering a new era driven by advances in sensor development. However, existing datasets collected with traditional bio-loggers, such as accelerometers, still contain untapped eco-physiological information. Here, we present a computational method for extracting heart rate from high-resolution accelerometer data using a ballistocardiogram. We validated our method with simultaneous accelerometer-electrocardiogram tag deployments in a controlled setting on a killer whale (Orcinus orca) and demonstrate the predictions correspond with previously observed cardiovascular patterns in a blue whale (Balaenoptera musculus), including the magnitude of apneic bradycardia and increase in heart rate prior to and during ascent. Our ballistocardiogram method may be applied to mine heart rates from previously collected accelerometery data and expand our understanding of comparative cardiovascular physiology.

Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more frequently in common bottlenose dolphins () under human care than in free-ranging common bottlenose dolphins.

Ammonium urate nephrolithiasis frequently develops in common bottlenose dolphins () managed under human care but is rare in free-ranging common bottlenose dolphins. In other species, the dietary cation-anion difference (DCAD) can affect ammonium urate urolith formation by increasing proton excretion as ammonium ions. Therefore, differences in diet between the 2 dolphin populations could affect urolith formation, but the DCAD of most species consumed by free-ranging and managed dolphins is unknown. To compare the nutrient composition of diets consumed by free-ranging and managed bottlenose dolphins, samples ( = 5) of the 8 species of fish commonly consumed by free-ranging bottlenose dolphins in Sarasota Bay, FL, and the 7 species of fish and squid commonly fed to managed bottlenose dolphins were analyzed for nutrient content. Metabolizable energy was calculated using Atwater factors; the DCAD was calculated using 4 equations commonly used in people and animals that use different absorption coefficients. The nutrient composition of individual species was used to predict the DCAD of 2 model diets typically fed to managed common bottlenose dolphins and a model diet typically consumed by common bottlenose dolphins in Sarasota Bay. To mimic differences in postmortem handling of fish for the 2 populations of bottlenose dolphins, "free-ranging" samples were immediately frozen at -80°C and minimally thawed before analysis, whereas "managed" samples were frozen for 6 to 9 mo at -18°C and completely thawed. "Free-ranging" species contained more Ca and P and less Na and Cl than "managed" fish and squid species. As a consequence, the DCAD of both model managed dolphin diets obtained using 3 of the 4 equations was much more negative than the DCAD of the model free-ranging bottlenose dolphin diet ( < 0.05). The results imply that managed bottlenose dolphins must excrete more protons in urine than free-ranging bottlenose dolphins, which will promote nephrolith formation. The nutrient composition of the free-ranging bottlenose dolphin diet, determined for the first time here, can be used as a guide for feeding managed bottlenose dolphins, but research in vivo is warranted to determine whether adding more cations to the diet will prevent urolith formation in managed dolphins.

Reproductive physiology of the female Magellanic penguin (Spheniscus magellanicus): Insights from the study of a zoological colony.

Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10week period, commencing at 5weeks prior to egg lay (EL), to increase our understanding of the species' reproductive biology. Females in cordoned nest sites underwent cloacal artificial insemination (AI) every 4-7days with different semen donors for each insemination. The EL interval was 97.9±3.6h (range: 84-108h) and paternity analyses revealed that conceptive inseminations occurred from 11.5 to 4.5days before oviposition. A biphasic pattern of estradiol, testosterone, progesterone and the biochemical analytes triglyceride, iron, calcium and phosphorus occurred in relation to EL, with values increasing (P<0.05) to maximal concentrations during the three weeks preceding oviposition, then decreasing (P<0.05) rapidly after oviposition completion. In comparison with post-lay (baseline) values, concentrations of estradiol and testosterone relative to the first oviposition were elevated at Week-5, and those of triglyceride, a yolk formation index, as well as iron, calcium and phosphorus, became elevated at Week-4 (P<0.05). Collective data indicate an estimated total egg formation interval of 29days, with oviducal transit of the ovulated ovum occurring over the majority of the ∼4day EL interval. These findings indicate that egg formation is prolonged with folliculogenesis initiated at 5weeks or more prior to oviposition. Consequently, the period of folliculogenesis and egg formation is estimated to overlap with the final ∼3weeks that wild females spend at sea prior to returning to land for breeding.

The promoter of the human sodium/iodide-symporter gene responds to retinoic acid.

It was shown previously that hNIS mRNA expression is stimulated by retinoic acid (RA) in human follicular thyroid carcinoma cell lines FTC-133 and FTC-238, and patients with thyroid carcinomas lacking iodide uptake respond to RA treatment with increased radioiodide transport. Here, in transient transfection experiments using FTC-238 cells, hNIS promoter/luciferase reporter constructs showed an up to 2.5-fold increase in transcriptional activity after incubation with 1 microM RA. Stimulation by 10 nM T3 was up to 2.4-fold. Deletion or block mutation of a putative nuclear receptor recognition site, 'DR10', abolished RA and T3 responses. Four copies of the DR10 cloned 5' to the thymidine kinase promoter gave a 2.6-fold and a 1.4-fold increase in transcriptional activity after RA and T3 stimulation, respectively. In electrophoretic mobility shifts, a wildtype DR10 oligonucleotide, but not block mutants of either DR10 halfsite, interacted with nuclear receptors. Thus, RA redifferentiation of advanced thyroid carcinomas may reinduce iodide uptake by stimulating hNIS expression and thereby make tumours accessible for radioiodide therapy again.

Transcriptional regulation of the human sodium/iodide symporter gene by Pax8 and TTF-1.

The regulation of the human Na(+)/I(-) symporter (NIS) gene is of considerable interest for both the diagnosis and therapy of thyroid pathologies. We investigated the influence of the thyroid-specific transcription factors TTF-1 and Pax8 on the NIS promoter and its 5'-flanking sequence. Reporter genes containing the corresponding genomic fragments coupled to a luciferase reporter gene were cotransfected with expression vectors carrying the the cDNA's for TTF-1 and Pax8. Transient transfection assays were performed in HeLa and COS-7 cells, which do not express endogenously these transcription factors. The experiments showed, that TTF-1 had no influence on the NIS promoter. Pax8, on the other hand, had a moderate stimulating effect (threefold) on the proximal NIS promoter. ABCD assays indicated an interaction of in vitro-translated Pax8 with the NIS promoter. However, DNase I footprinting experiments with bacterially expressed Pax8 were negative, suggesting an indirect mode of action with the participation of other proteins. A putative NIS upstream enhancer (NUE) 9000 bp upstream of the NIS gene, which was cloned based on its sequence homology to the rat NUE, was not transactivated by either Pax8 or TTF-1. The present data demonstrate, that the combination of Pax8 and TTF-1 is less important for NIS gene transcription than for other thyroid-specific genes. This is presumably related to the fact, that NIS is expressed also in other tissues such as mammary and salivary gland.

Thyroid transcription factor 1 and Pax8 synergistically activate the promoter of the human thyroglobulin gene.

Thyroglobulin (Tg) is an essential thyroid-specific protein, which serves as the matrix for thyroid hormone biosynthesis. To obtain new insights in the regulation of Tg gene expression, we investigated the interaction of the human Tg promoter with the thyroid-specific transcription factors TTF-1 and Pax8. A reporter gene, containing a 202 bp fragment from the human Tg 5'-flanking region including the promoter sequence and the transcriptional start site, and expression vectors containing the cDNAs for human TTF-1 and Pax8 were used in cotransfection experiments, in the non-thyroidal cell lines COS-7 and HeLa. Pax8 increased the specific transcriptional activity of the Tg promoter about threefold, whereas cotransfection with the homeodomain-containing protein TTF-1 stimulated promoter activity from six- to tenfold. The simultaneous expression of both factors stimulated the Tg promoter activity in a multiplicative manner up to 25-fold. TTF-1 binding sites could be localized precisely by lectron mobility shift assay. The two binding elements corresponded to sites A and C in the rat Tg promoter. Site-directed mutagenesis of three nucleotides in each binding element inhibited binding of TTF-1 to the two oligonucleotides. In cotransfection experiments, the mutant site C decreased TTF-1 transactivation to 26% of the wild-type, whereas an additional mutation in the site A reduced this value to almost zero, thus proving the physiological relevance of these sites. The present results demonstrate that the activity of the human Tg promoter is closely dependent on the function of TTF-1 and Pax8, opening the field for further investigations of pathological alterations of Tg gene expression.

Cloning and characterization of repressory and stimulatory DNA sequences upstream the Na/I-symporter gene promoter.

To investigate the existence of potential enhancer or silencer elements in the 5'-flanking region of the human Na+/I-symporter (NIS) gene, we cloned 2,512 bp of genomic DNA further upstream of the previously defined proximal promoter. When tested in reporter gene assays, this sequence had no transcriptional activity per se, but was able to repress the activity of the heterologous SV40 promoter. Conversely, when fused to the homologous NIS gene promoter and thus comprising 3,800 bp 5'-flanking region, the transcription of the proximal NIS promoter was stimulated in the human cell lines FTC-133 (from thyroid) and HeLa, but inhibited in the rat thyroid cell line FRTL-5. This might be due to differences between the upstream regions of the rat and human NIS gene. Comparative analysis with standard promoters (SV40) led to the conclusion that the 5'-flanking region of the human NIS gene also exhibited transcriptional activity in non-thyroid cells. Thyroid-stimulating hormone (TSH) had a moderately stimulating effect on the full length NIS reporter gene construct in FRTL-5 cells. This stimulation is presumably mediated by a putative cAMP responsive element found in the first half of the cloned sequence.

Whole virus influenza vaccine activates dendritic cells (DC) and stimulates cytokine production by peripheral blood mononuclear cells (PBMC) while subunit vaccines support T cell proliferation.

Three types of trivalent influenza vaccines were analysed for their in vitro stimulatory properties on immune cells from young healthy volunteers. A whole inactivated virus (WV) vaccine, a conventional subunit (c-SU) preparation and a new virosomal subunit (v-SU) vaccine were used. Blood-derived DC up-regulated MHC class II, CD54, CD80 and CD86 after exposure to WV vaccine, indicating their functional maturation, but were only moderately affected by subunit (SU) vaccines. In addition, IL-12 and tumour necrosis factor-alpha (TNF-alpha) secretion by DC were markedly enhanced by WV, but not by SU vaccines. The production of IL-2 and interferon-gamma (IFN-gamma) by PBMC was also strongly stimulated by WV, but much less by SU vaccines, among which the v-SU vaccine was a better stimulator of IL-2 secretion. In contrast to WV vaccine both SU vaccines were powerful stimulators of PBMC proliferation. Our results suggest that the presence of influenza core components leads to the activation of DC and triggers the production of cytokines by PBMC. SU vaccines are in contrast excellent stimulators of T cell growth. A combination of WV and SU vaccines in immunization regimes might allow optimal T cell priming as well as the efficient generation and maintenance of memory cells.

Cloning of a functional promoter of the human sodium/iodide-symporter gene.

We have cloned and sequenced genomic DNA from a human library extending 1300 bp upstream the 5'-untranslated sequence of the cDNA coding for the sodium/iodide symporter. In transient transfection assays this sequence exhibited promoter activity, which could be confined to nucleotides -443 to -395 relative to the ATG start codon. This minimal promoter, including a putative GC- and TATA- box, was preferentially activated in the rat thyroid cell line FRTL-5, but was also active in non-thyroidal cells, such as COS-7 and Chinese-hamster ovary, albeit to a markedly lower extent.

The production of the Alzheimer amyloid precursor protein (APP) in extraneuronal tissue does not increase in old age.

Alzheimer's disease (AD) is characterized by the cerebral deposition of beta-amyloid (A beta). A beta plaques also occur in the brains of healthy aged individuals, and A beta concentrations are increased in the cerebrospinal fluid (CSF) in old age. Based on results from an in vitro senescence model on human fibroblasts, it was proposed that the production of the beta-amyloid precursor protein (APP) was increased during aging. No information was available as to whether APP production was also augmented in aged humans. It was therefore the aim of the present study to analyze APP in connective tissue, skeletal muscle, peripheral blood mononuclear cells, and serum samples from young and aged healthy individuals. APP production was assessed by Northern and Western blotting. The expression of the different APP isoforms was studied by reverse transcription-polymerase chain reaction (RT-PCR) technique. The results demonstrate that APP messenger ribonucleic acid (mRNA) and protein concentrations were identical in blood and tissue samples from young and aged individuals and that there were no age-dependent changes in the APP isoform production pattern. Thus, our data strongly argue against the possibility of an altered production of APP during healthy aging and underline the point that in vitro aging models may not accurately reflect the in vivo situation.

Stretch activation and isoforms of myosin heavy chain and troponin-T of rat skeletal muscle fibres.

Recent studies on single mammalian skeletal muscle fibres revealed a correlation between the kinetics of stretch-induced delayed force increase (stretch activation) and the isoforms of the myosin heavy chain. This observation suggests a causal relation between stretch activation and myosin heavy chain. However, the assumption is weakened by the fact that isoforms of other myofibrillar proteins tend to be coexpressed with myosin heavy chain isoforms. The relation between the isoforms of the tropomyosin-binding troponin subunit and myosin heavy chain is unknown. For a variety of reasons, tropomyosin-binding troponin subunit is a possible candidate for being involved in stretch activation. Therefore, we measured stretch activation of single, maximally Ca(2+)-activated skinned rat skeletal muscle fibres and characterized them by their myosin heavy chain composition, as well as by the isoform species of tropomyosin-binding troponin subunit. Four myosin heavy chain isoforms (I, IIa, IId or IIx and IIb) and six tropomyosin-binding troponin subunit isoforms (TnT1s, TnT2s, TnT1f, TnT2f, TnT3f, TnT4f) were distinguished. The following preferential coexpression patterns of the myosin heavy chain and tropomyosin-binding troponin subunit isoforms were observed: MHCI-TnT1s, MHCIIa-TnT3f, MHCIId-TnT1f, and MHCIIb-TnT4f. Stretch activation kinetics was found to be correlated with the myosin heavy chain isoform complement also in fibres not displaying one of the preferential MHC-TnTf isoform coexpression patterns. This corroborates the assumption of a causal relation between myosin heavy chain and stretch activation.

Amyloid beta-protein(25-35) increases cellular APP and inhibits the secretion of APPs in human extraneuronal cells.

Amyloid beta-protein (A beta) is the core component of the senile plaques occurring during Alzheimer's disease and in its aggregated form is cytotoxic for neuronal and extraneuronal cells. In this study, the influence of the spontaneously aggregating fragment A beta(25-35) on the expression and metabolism of beta-amyloid precursor protein (APP) was investigated in human extraneuronal cells. Cellular extracts and conditioned supernatants were analyzed by immunoblotting. A beta(25-35) strongly increased the cellular content of APP in cultured epithelial cells from thyroid glands and kidneys as well as in the promyelogranulocytotic cell line HL-60. At the same time A beta reduced the secretion of soluble APPs to less than one-third of its control value, but did not alter the secretion of fibronectin, which was used as a control protein. Despite these changes, APP transcription was not changed following A beta(25-35) treatment. These results demonstrate that A beta(25-35) strongly increases the APP content of extraneuronal cells by inhibiting its secretory processing. This may result in a deviation of APP metabolism towards an internal, potentially amyloidogenic pathway.

Interactions of the Alzheimer beta amyloid fragment (25-35) with peripheral blood dendritic cells.

We have previously demonstrated that soluble amyloid beta protein (A beta) induces IL-2 receptor expression and proliferation in peripheral T cells from young and old healthy individuals, but not from patients with Alzheimer's disease (AD). It seemed of interest to examine how the immune system would react upon stimulation with A beta in its aggregated form. It was the aim of this study to define interactions between the spontaneously aggregating A beta (25-35) and antigen-presenting cells. Human dendritic cells (DC), propagated from the peripheral blood of young healthy individuals, were incubated with A beta (25-35) and its effects on DC survival, cytokine release, and surface marker expression were monitored. The question whether DC could present amyloid to T cells was also addressed. We demonstrated that A beta (25-35) does not induce DC apoptosis or necrosis. This was shown by electron microscopy as well as by nuclear staining with propidium iodide. Some peptide aggregates were found in intracellular vacuoles of DC. This process did not increase production of TNF alpha and did not change the surface expression of CD18, CD11a or CD11b. A decreased surface expression of MHC class II molecules was, however, noted. DC pulsed with A beta aggregates were unable to stimulate T cells in an autologous coculture system. The results demonstrate that amyloid may escape immune recognition by its failure to activate antigen-presenting cells and by inhibiting MHC class II surface expression.

Tumor necrosis factor alpha augments amyloid beta protein (25-35) induced apoptosis in human cells.

No information is yet available on the effect of tumor necrosis factor alpha (TNFalpha) on amyloid beta protein (Abeta)-induced cytotoxicity in human cells. For this reason the induction of apoptosis by TNFalpha and Abeta (25-35) was studied in primary cultures of human thyroid and kidney cells as well as in the neuroblastoma line SK-N-SH and in DU-145 cells. Apoptosis occurred in all cell types after Abeta (25-35) treatment, but was markedly enhanced when TNFalpha was additionally present. This effect was less pronounced in transformed cell lines than in primary cultures, in which TNFalpha on its own was not cytotoxic. Apoptosis was still more prevalent under serum free culture conditions. The results demonstrate that TNFalpha may support the occurrence of Abeta-mediated cell death and thus contribute to the development of pathological changes in Alzheimer's disease (AD).

The production of an amyloidogenic metabolite of the Alzheimer amyloid beta precursor protein (APP) in thyroid cells is stimulated by interleukin 1 beta, but inhibited by interferon gamma.

Thyroid epithelial cells have been shown to have a high APP expression and to produce large amounts of its metabolic derivatives, namely secreted APPs and a potentially amyloidogenic 41-kDa C-terminal fragment. It was the aim of the present study to analyze how APP production and metabolism were regulated in human thyroid cells. The effects of three cytokines, interferon gamma (IFN gamma), interleukin 1beta (IL-1 beta) and transforming growth factor (TGF) beta, were investigated. Cell extracts and supernatants were studied by immunoblotting using specific N- and C-terminal APP antibodies. Quantification was performed by densitometric scanning. We demonstrate that IFN gamma has a strong suppressive effect on the production and metabolism of APP. From a concentration of 30 U/ml upwards it reduces the cellular APP content, decreases the amounts of secreted APPs and inhibits the generation of the 41-kDa amyloidogenic APP fragment. In contrast, IL-1 beta has a stimulatory influence on the generation of the amyloidogenic 41-kDa APP metabolite, but does not affect the cellular holoprotein or APPs. TGFbeta has no significant effect on APP. Our results demonstrate that cytokines can regulate APP production and metabolism in thyroid cells. IFN gamma is the first naturally occurring agent described to inhibit the generation of amyloidogenic APP fragments. It may be of relevance in preventing amyloid deposition during inflammatory processes in the thyroid gland, but may exert a similar protective effect in other non-neuronal and neuronal tissues.

Thyroid epithelial cells produce large amounts of the Alzheimer beta-amyloid precursor protein (APP) and generate potentially amyloidogenic APP fragments.

The Alzheimer beta-amyloid precursor protein (APP) is a transmembrane glycoprotein from which the amyloid beta-protein is proteolytically derived. The latter is a hydrophobic peptide that can aggregate and forms the core of the senile plaques found in the brains of patients suffering from Alzheimer's disease (AD). In view of the known association between familial AD and thyroid autoimmune disease, the expression pattern and cellular processing of APP in human thyroid cells were investigated. Cultured thyroid epithelial cells and homogenized thyroid tissue from normal and pathological thyroid samples were analyzed by immunoblotting using specific N- and C-terminal APP antibodies as well as by reverse transcription-polymerase chain reaction in which two sets of oligonucleotide primers were used. The results of these studies demonstrated that APP isoforms 770 and 751 were expressed in fresh thyroid extracts as well as in cultured thyroid epithelial cells, with APP 770 being the predominant form. Compared to other types of cells, such as lymphocytes and fibroblasts, thyroid epithelial cells produced larger amounts of APP. Most of the mature protein was cleaved within the amyloid beta region, as a result of which a large N-terminal APP fragment was released into the culture medium, whereas a C-terminal nonamyloidogenic fragment of 14 kilodaltons (kDa) was retained within the cell. Interestingly, thyroid epithelial cells also contained larger C-terminal APP fragments of 21, 35, and 41 kDa. From the sizes of these fragments it could be deduced that they contained the entire amyloid beta sequence and were thus potentially amyloidogenic. The 41-kDa fragment was unique to thyroid cells. These fragments may be released into the circulation after thyroid cell damage. Increased/altered thyroid APP expression in familiar AD may induce alterations in thyroid epithelial cells and cell damage, and thus explain the frequent occurrence of thyroid autoimmunity in this disease.

Stretch activation, unloaded shortening velocity, and myosin heavy chain isoforms of rat skeletal muscle fibres.

1. Contractile properties were investigated on single skinned-fibre preparations from rat leg muscles. Following the mechanical measurements, the myosin heavy chain (HC) composition of the same fibre was analysed by gradient gel electrophoresis. 2. Fibres were typed according to their myosin HC isoform composition (HCI, type I; HCIIA, type IIA; HCIID, type IID; HCIIB, type IIB). Many fibres showed the co-existence of two myosin HC isoforms (hybrid fibres). 3. A strong correlation was found between fibre type and time characteristics of stretch-induced delayed force increase (stretch activation) of fully Ca(2+)-activated fibres. 4. The maximal unloaded shortening velocity (Vmax), as measured with the slack test, was lowest in type I fibres. Within the type II group, a continuum of Vmax values was found, with large overlaps of the different fibre types. 5. The results suggest that the kinetics of stretch activation is determined by the myosin HCs whereas unloaded fibre shortening seems to be determined by other myofibrillar proteins in addition to the myosin HCs. Assuming that stretch activation represents certain steps of the cross-bridge turnover under isometric conditions and Vmax reflects cross-bridge detachment under unloaded conditions it can be deduced that different myofibrillar proteins are responsible for different steps within the cross-bridge turnover.

Fiber type-specific distribution of parvalbumin in rabbit skeletal muscle. A quantitative microbiochemical and immunohistochemical study.

A highly sensitive sandwich ELISA for parvalbumin (PA), based on a fluorometric detection system, was developed. This assay detected PA concentrations as low as 20 pg/ml (2 pg per assay) and was used for measuring PA contents in fragments of single muscle fibers isolated from freeze-dried 100-150 microns thick cross sections. The fibers were typed according to their histochemically assessed mATPase in parallel cross sections. Type I fibers from rabbit tibialis anterior (TA) and vastus lateralis (VL) muscles contained extremely low PA concentrations (2-5 micrograms/g w.wt.). Type IIA fibers displayed slightly higher values with mean values of 17 and 29 micrograms/g w.wt. (range 5-65) in TA and VL, respectively. Much higher PA concentrations were found in type IIB fibers with wide ranges from 75-1150 micrograms/g w.wt. in TA and 440-1370 micrograms/g w.wt. in VL. Whereas the IIB fibers of the TA displayed a continuum, two subgroups were distinguishable according to their PA contents (means of 590 and 1230 micrograms/g w.wt.) in VL. Possibly, the population with the lower PA content which was histochemically defined as type IIB in the present study, corresponds to fiber type IID. The finding that PA is predominantly present in type IIB fibers was also confirmed by the parallel decay of PA and type IIB fibers during chronic low-frequency stimulation. The use of freeze substitution, or alternatively, of freeze-drying, made it possible to demonstrate PA immunohistochemically without artifacts and to evaluate the staining intensity by microphotometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Intermodal organization: a methodological localization study.

The nature of organization among vision, right hand, and left hand was studied. A target was presented to one of the three modalities, and a response was required by one of the other two modalities. Constant errors from the resulting six conditions were examined to determine whether the three modalities function as an organized system, such that the relation between two modalities may be predicted from the relations of each of the two with the third. Predictions were correct in direction but incorrect in magnitude. The data also were analyzed to bear on the usually implicit assumption in research on localization that a response modality has consistent error characteristics regardless of the nature of the target being localized. It was concluded that such assumptions may not be valid.

On the plasticity of visual-proprioceptive bias effects.

Recent research has suggested that attentional factors play a role in determining the direction of intermodality adaptation. The present work explored the role of such factors in the visual/proprioceptive dominance, or bias, paradigm. In a preliminary experiment, an instructional approach was used and proved totally ineffective in shifting dominance. In Experiments 1 and 2, an active pointing approach was used, in which the subject was caused to concentrate on one modality or the other by having him localize a large number of unconflicted targets in that modality. This approach was successful in changing the normal dominance relation. Such an altered dominance relation may indeed be a necessary part of the shifting of normal adaptation patterns.