Search PubMed⌕ Search

Biomedical subjects

W D Wilson

Publications and source records attributed to W D Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1999

Inhibition of HIV-1 Tat-TAR interaction by diphenylfuran derivatives: effects of the terminal basic side chains.

A series of four biscationic diphenylfuran derivatives was used to investigate drug binding to the transactivation response element (TAR) RNA. The drugs, which are active against the Pneumocystis carinii pathogen (PCP), differ by the nature of the terminal basic side chains. Furimidazoline (DB60) is more potent at inhibiting binding of the Tat protein to TAR than furamidine (DB75) and the amidine-substituted analogues DB244 and DB226. In vivo studies using the fusion-induced gene stimulation (FIGS) assay entirely agree with the in vitro gel mobility shift data. The capacity of the drugs to antagonize Tat binding correlates with their RNA binding properties determined by melting temperature and RNase protection experiments. Footprinting studies indicate that the bulge region of TAR provides the identity element for the diphenylfurans. Access of the drugs to the major groove cavity at the pyrimidine bulge depends on the bulk of the alkylamine substituents. Experiments using TAR mutants show that the bulge of TAR is critical for drug binding but also reveal that the fit of the drugs into the major groove cavity of TAR does not involve specific contacts with the highly conserved residue U23 or the C x G26-39 base pair. The binding essentially involves shape recognition. The results are also discussed with respect to the known activity of the drug against PCP which is the major cause of mortality in AIDS patients. This study provides guidelines for future development of TAR-targeted anti-HIV-1 drugs.

Amidines↗
PubMed1999

Evaluation of temporal and spatial clustering of horses with Corynebacterium pseudotuberculosis infection.

OBJECTIVE: To determine whether horses with Corynebacterium pseudotuberculosis infections that were examined at a veterinary medical teaching hospital between July 1, 1992, and June 30, 1994 had patterns of temporal or spatial clustering. ANIMALS: 134 case and 800 control horses randomly selected from all non-case horses admitted during the study period. PROCEDURES: Admission date and geographic location were determined. Scan, Cuzick & Edwards', and Knox tests were applied to determine whether case horses had patterns of temporal or spatial clustering. RESULTS: For all windows > or = 3 days (134 case horses) and > or = 7 days (subset of 69 case horses), results of the Scan test were significant. Results of Cuzick & Edwards' test were significant for all data sets. A significant spatial cluster of case horses was observed for October, November, and December 1992. Results of the Knox test were significant for temporal intervals between 7 and 56 days and spatial intervals between 4.3 and 6.5 km. Higher Knox(x) proportions were observed for temporal intervals of 0 to 7, 8 to 14, 22 to 28, and 29 to 35 days. CONCLUSIONS: Significant spatial and temporal clustering of horses with C pseudotuberculosis infection was detected. CLINICAL RELEVANCE: Analysis of the results strongly indicates that this disease is directly or indirectly (ie, short distance and time) transmitted. In addition, data analyses indicated an incubation period of 3 to 4 weeks. The disease could be transmitted through horse-to-horse contact or from infected to susceptible horses via insects, other vectors, or contaminated soil.

Animals↗
PubMed1999

Comparison of microbiologic and high-performance liquid chromatography assays to determine plasma concentrations, pharmacokinetics, and bioavailability of erythromycin base in plasma of foals after intravenous or intragastric administration.

OBJECTIVE: To determine pharmacokinetics and bioavailability of erythromycin base after intragastric administration and erythromycin lactobionate after IV administration to healthy foals and to compare a microbiologic assay with a high-performance liquid chromatography (HPLC) method to determine plasma concentrations of erythromycin A. ANIMALS: 6 healthy foals that were 2 to 4 months old. PROCEDURE: Foals were given single doses of erythromycin (10 mg/kg of body weight, IV, and 25 mg/kg, intragastrically) in a crossover study. Venous blood samples were obtained at specific times after drug administration, and plasma was harvested for determination of erythromycin concentrations by microbiologic assay and a HPLC method Pharmacokinetic analysis of plasma concentration-time data was performed, and results derived from each method were compared. RESULTS: Concentration-time profiles for IV administration were best described by a two-compartment open model. Comparing pharmacokinetic data obtained by the 2 methods revealed substantial differences in results. Values for area under the plasma concentration-time curve and area under the first moment of the curve were substantially higher when determined by the bioassay, indicating overestimation of plasma concentration-time data by this method. The derived rate transfer constants (K21 and K(e)1) and mean residence time were significantly different, when determined by the bioassay. Systemic bioavailability of erythromycin base was low in all foals. CONCLUSIONS AND CLINICAL RELEVANCE: The bioassay method overestimated plasma concentrations of erythromycin, compared with the HPLC method. Despite low systemic bioavailability of erythromycin base administered intragastrically, plasma concentrations of erythromycin exceeded, for at least 4 hours, the minimum inhibitory concentration of most Rhodococcus equi isolates.

Animals↗
PubMed1999

Relationships between topoisomerase II inhibition, sequence-specificity and DNA binding mode of dicationic diphenylfuran derivatives.

Four diphenylfuran derivatives possessing different dicationic terminal side chains were used to investigate sequence-specific binding to DNA and poisoning of human topoisomerase II. Footprinting experiments with a range of DNA substrates attest that all four drugs bind selectively to AT-rich sequences in DNA. However, the quantitative analysis of the footprinting profiles reveals significant differences in terms of AT-selectivity according to the nature of the basic side chains. Furimidazoline (DB60) shows a reduced capacity to interact selectively with A.T tetrads compared with furamidine (DB75) and the 3-pentyl-substituted diamidine analogue DB226. DB244, for which the two amidine ends are substituted with a cyclopentyl group, exhibits the most pronounced AT specificity. It binds tightly to sites composed of at least four adjacent AT base pairs, such as 5'-TAAT, AATT and TTTT. At low concentrations (< 2 microM) DB60 is also capable of forming stable complexes with AT sites but at higher concentrations the binding becomes totally non-specific due to additional intercalation of drug molecules into GC-rich sequences. Nevertheless, DB60 is the only drug is the series which stabilizes DNA-topoisomerase II covalent complexes. This compound effectively promotes DNA cleavage by topoisomerase II whereas DB75, DB226 and DB244 have practically no effect. The topoisomerase II poisoning activity of DB60 correlates with its ability to intercalate into GC sites in DNA whereas the three other diphenylfurans essentially behave as typical AT-selective minor groove binders. The study suggests that the antimicrobial activity of the diphenylfurans, which are active against the Pneumocystis carinii pathogen (PCP), depends essentially on their capacity to recognize AT-rich DNA sequences rather than their ability to interfere with topoisomerase II. In contrast, the cytotoxicity of drugs like DB60 would be connected with the formation of intercalation complexes and the stimulation of DNA cleavage by human topoisomerase II.

Anti-Bacterial Agents↗
PubMed1999

Selective photocleavage of DNA and RNA by anthraquinone derivatives: targeting the single-strand region of hairpin structures.

A tetracationic anthraquinone derivative (27AQS2) binds to hairpin DNA and RNA. Ultraviolet irradiation of the bound quinone causes cleavage in the loop region of both oligonucleotides and at guanines in the stem region of the DNA hairpin. The absence of observable strand cleavage at guanines in the RNA hairpin suggests that either aniline treatment does not cause cleavage at damaged guanines in RNA or that radical cation migration does not occur readily in RNA duplexes. The ability to target the single-stranded regions of DNA and RNA structures is an important property of this photonuclease.

Anthraquinones↗
PubMed1998

Extended aromatic furan amidino derivatives as anti-Pneumocystis carinii agents.

The syntheses of nine new derivatives of 2, 5-bis[4-(N-alkylamidino)phenyl]furans with extended aromatic systems are reported. The interaction of these dicationic furans with poly(dA)poly(dT) and with the duplex oligomers d(CGCGAATTCGCG)2 and d(GCGAATTCGC)2 was determined by Tm measurement, and the effectiveness of these compounds against the immunosuppressed rat model of Pneumocystis carinii was evaluated. At a screening dose of 10 micromol/kg, 4 of the 12 amidino furans described here are more active than the parent compound 1. In general, extension of the aromatic system in the absence of a substitution of the amidino nitrogens resulted in higher affinity for DNA than the parent compound as judged by the larger DeltaTm values and suggests enhanced van der Waals interactions in the amidino furan-DNA complex. Three of the compounds, 3, 5, and 11, yield cysts counts of less than 0.1% of control when administered at a dosage of 10 micromol/kg. Compound 3, which does not have an extended aromatic system, is the most active derivative. Although a direct correlation between anti-P. carinii activity and DNA binding affinity was not observed, all compounds which have significant activity have large DeltaTm values.

Amidines↗
PubMed1998

Passive transfer, rate of decay, and protein specificity of antibodies against equine arteritis virus in horses from a Standardbred herd with high seroprevalence.

OBJECTIVE: To determine rate of decay of passively acquired antibodies in Standardbred foals on a farm with a high seroprevalence to equine arteritis virus (EAV) and to determine whether vertical or horizontal transmission of the virus was responsible for infection on the farm. DESIGN: Repeated-measures study. ANIMALS: 46 Standardbred horses (15 brood mares and their foals, 5 stallions, and 11 young horses). PROCEDURE: Serum samples obtained from horses on the farm were evaluated by serum neutralization and western immunoblot analysis to detect EAV-specific antibodies. The half-life of passively acquired antibodies in foals was estimated by use of regression analysis. RESULTS: Most (14/15) of the mares evaluated were seropositive to EAV. After suckling, their foals were also seropositive. Mean biological half-life for passively acquired antibodies in serum samples obtained from foals was 32 days (r2 = 0.61). The foal born to a seronegative dam and all 11 young horses from the farm were seronegative to EAV. At least 2 of 5 stallions on the farm were persistently infected carriers that were shedding virus in their semen. Immunoblot analysis of seropositive serum samples most consistently recognized the M protein of EAV. CLINICAL IMPLICATIONS: Analysis of these data indicated that a modified-live EAV vaccine can be administered to foals after they are 8 months old without risk of interference from maternal antibodies, regardless of serologic status of the foal's dam. Horizontal transmission of EAV via the respiratory tract apparently was uncommon on the farm, indicating that mares primarily were infected by venereal transmission of virus from carrier stallions.

Animals↗
PubMed1998

NMR solution structure of the N3' --> P5' phosphoramidate duplex d(CGCGAATTCGCG)2 by the iterative relaxation matrix approach.

High-resolution 2D NMR spectra of the duplex CGCGAATTCGCG with deoxyribose sugars but with the normal phosphodiester linker replaced by an N3' --> P5' phosphoramidate (NP) group have been used to establish a solution structure for the duplex. Distance, angle, and base pair hydrogen-bonding constraints were used to refine the structure by use of the iterative relaxation matrix approach (IRMA). The phosphoramidate NH proton signal could be observed in DMSO at low temperature but not in H2O and D2O. For this reason, the structure was refined with the -NH in each of the two possible low-energy configurations. The structure with the nitrogen lone pair located between the nonbridging oxygen atoms of the 5'-phosphate group consistently had the lowest energy and RMSD values, consistent with an X-ray analysis of the same duplex [Tereshko, V., Gryaznov, S. , and Egli, M. (1998) J. Am. Chem. Soc. 120, 269-283]. In the refined structure, the sugars are in the C3'-endo conformation with the change from the normal C2'-endo conformation of deoxyribose apparently being driven by the gauche effect and the change in electronegativity from the 3'O to the 3'NH group. In agreement with preliminary studies [Ding, D., Gryaznov, S. M., Lloyd, D. H., Chandrasekaran, S., Yao, S., Ratmeyer, L., Pan, Y., and Wilson, W. D. (1996) Nucleic Acids Res. 24, 354-360], the backbone conformation in the NP duplex is very close to classical A-form values. Comparison of phosphodiester and phosphoramidate structures suggests that their backbones have global conformations that are primarily a function of the low-energy state of the sugar ring. A somewhat more complex situation arises when base pair conformation is analyzed with many of the base pairs having a conformation between those of classical A- and B-form helices. The effects of the 2' substituent are obviously important in specifying the final conformation of the stacked bases in either an A-form or B-form helix. It is clear, however, that conversion of the normal phosphodiester of DNA into a phosphoramidate linkage yields a nucleic acid that behaves much more like RNA than DNA, and it has been shown that NP sequences can bind to RNA-directed proteins [Rigl, C. T., Lloyd, D. H., Tsou, D. S., Gryaznov, S. M., and Wilson, W. D. (1997) Biochemistry 36, 650-659].

Crystallography, X-Ray↗
PubMed1998

Application and evaluation of a mailed questionnaire for an epidemiologic study of Corynebacterium pseudotuberculosis infection in horses.

The objective of this study is to describe the design, application and validity of a self-administered (mailed) questionnaire to collect data on potential risk factors for Corynebacterium pseudotuberculosis infection in California horses. Horses admitted to the UC Davis Veterinary Medical Teaching Hospital (VMTH) between 1 July 1992 and 30 June 1994 served as the study base for case identification and simple random sampling of 800 control horses. A questionnaire was mailed to owners of the study horses, followed by a reminder postcard and a second copy of a questionnaire. Data were collected on owner and horse identity and demographics, horse management and use, geographic location, and general health-related issues. Return pattern over time as well as differential return proportions were described. The overall return proportion was 66% (587/890), and the completion proportion 55% (491/890). The number of returns over time followed a negative binomial distribution, with over 90% of all returns being in by the end of the fifth week after mailing, and over 99% at the end of the tenth week. Some categories within the variables age (between 2 and 3 years), breed (Thoroughbred and Standardbred horses) and gender (stallions) had significantly lower return proportions than expected (differential return; p < 0.05). The profile of these horses fits a section of the racehorse population that is served by the VMTH. Age, breed and disease status information was available from the VMTH medical records and from the questionnaire, and was used to determine the validity of the survey data. There was good agreement between the data from the two sources, and we therefore concluded that the quality of the survey information was sufficient to perform a risk-factor analysis. The mailed survey provided a rapid and cost-effective method of collecting additional information to supplement existing medical records.

Animals↗
PubMed1998

Risk factors associated with Corynebacterium pseudotuberculosis infection in California horses.

A case-control study was designed using equine medical records from the UC Davis Veterinary Medical Teaching Hospital (VMTH) and data derived through a mailed survey. The objective was to evaluate the associations between horse demographics, horse-management factors, and equine Corynebacterium pseudotuberculosis infection in California. Horses admitted to the VMTH between July 1 1992 and June 30 1994 served as the study base for case identification and simple random sampling of 800 controls. A questionnaire was mailed to the owners of all horses enrolled in the study to collect data on demographics, management and health-related questions. A logistic-regression model containing age, outdoor activity level, other locations in California, insect-control measures, contact with other horses, and summer pasture was developed. The final model was adjusted for the suspected confounding variables admission type, regular teaching hospital patient and breed. Horses of age between 1 and 2 yrs and between 3 and 5 yrs, and horses in contact with other horses or horses on summer pasture had significantly increased odds (p < 0.05) of being diagnosed with C. pseudotuberculosis infection. The results support the hypotheses that the disease predominantly affects young-adult horses of all breeds and both sexes, and that management factors play an important role in occurrence of the disease. Since the existing serological test system is not reliable and destruction of infected animals is not feasible, the most-logical approach for disease prevention is the early identification and isolation of clinical cases and the implementation of management changes like improvement of stable hygiene and insect control and change of pasture practices.

Animals↗
PubMed1998

2,5-bis[4-(N-alkylamidino)phenyl]furans as anti-Pneumocystis carinii agents.

The syntheses of 12 new 2,5-bis[4-(N-alkylamidino)phenyl]furans are reported. The interaction of these dicationic furans with poly(dA-dT) and with the duplex oligomer d(CGCGAATTCGCG)2 was determined by Tm measurements, and the effectiveness of these compounds against the immunosuppressed rat model of Pneumocystis carinii was evaluated. At the screening dose of 10 mumol/kg, 9 of the 14 N-alkylamidino furans described here are more active than the parent compound 1. Substitution of an alkyl group of the amidino nitrogen, except for in 9, 13, and 15, resulted in higher affinity for DNA than the parent compound as judged by the larger delta Tm values and suggests enhanced van der Waals interactions in the bis-amidine-DNA complex. Five of the compounds, 3, 5, 7, 10, and 12, yield cyst counts of less than 0.1% of control when administered at a dosage of 10 mumol/kg. Five compounds, 1, 6, 8, 10, and 12, show significant activity at a dosage of approximately 1 mumol/kg; 12 is the most active derivative, and it is approximately 100 times more effective than pentamidine in this animal model.

Animals↗
PubMed1998

A new Eimeria species (Apicomplexa: Eimeriidae) infecting Onychomys species (Rodentia: Muridae) in New Mexico and Arizona.

Fecal samples from 3 species of Onychomys (Rodentia: Muridae) captured in New Mexico and Arizona were examined for coccidia. Six of the 59 (10%) were infected with a new species of Eimeria. Sporulated oocysts (n = 105) of this new species are subspheroidal, 17.4 x 16.1 (14-21 x 13-19) microm, with ellipsoidal sporocysts 10.4 x 5.7 (9-12 x 5-8) microm. This species occurred in 3 of 24 (13%) Onychomys arenicola, 2 of 31 (6%) Onychomys leucogaster from New Mexico, and 1 of 4 (25%) Onychomys torridus from Arizona. Isolates recovered from O. leucogaster and O. torridus were inoculated into O. leucogaster (n = 5) and produced infections with a prepatent period of 7 days and a patent period of 7-23 days.

Animals↗
PubMed1997

A new type of DNA minor-groove complex: carbazole dication-DNA interactions.

The effect of opportunistic infections (OI) on immune-compromised populations has been known for decades, but the recent AIDS epidemic has sparked renewed interest in the development of new anti-OI agents. The mechanism of action of a series of cationic unfused-aromatic anti-OI drugs is believed to involve binding of the drug to AT sequences in the minor groove of DNA. Some new anti-OI drug candidates have been synthesized with fused aromatic ring systems (e.g. carbazoles) that do not resemble the classical paradigm for minor-groove interactions at AT sequences in DNA. To characterize the DNA interactions of these compounds, we have used UV-vis absorbance, fluorescence, kinetic measurements, and circular dichroism in conjunction with NMR spectroscopy to evaluate the structure of the complexes formed between the carbazoles and DNA. Application of these methods to carbazoles substituted at either the 3,6 or 2,7 positions with cationic imidazoline groups gave conclusive, but very surprising, evidence that both compounds bind strongly in the minor groove at AT DNA sequences. NMR and molecular modeling of the complexes formed between the 3,6- and 2,7-carbazoles and the self-complementary oligomer d(GCGAATTCGC) have been used to establish structural details for the minor-groove complex. These results have been used as constraints for molecular modeling calculations to construct models of the minor-groove-carbazole complexes and to draw conclusions regarding the molecular basis for the effects of substituent position on carbazole-DNA affinities. The surprising result is that the 2,7 carbazole binds in AT sequences with hydrogen bonds involving one imidazoline group and the carbazole NH. The 3,6-carbazole compound binds in a more "classical" model that uses both imidazoline groups for H-bonding while the carbazole NH points out of the minor groove. The carbazoles thus form a new type of DNA minor groove complex and their excellent biological activities indicate that a variety of fused-ring minor-groove binding agents should be investigated.

Binding Sites↗
PubMed1997

Acute hemorrhagic pulmonary infarction and necrotizing pneumonia in horses: 21 cases (1967-1993).

OBJECTIVE: To characterize history, clinical signs, and pathologic findings in horses with histologically confirmed acute hemorrhagic pulmonary infarction and necrotizing pneumonia. DESIGN: Retrospective study. ANIMALS: 21 horses. RESULTS: 19 of the 21 horses were Thoroughbred racehorses in training. Eighteen horses had had strenuous exercise immediately prior to onset of illness. Fifteen horses had a serosanguineous nasal discharge during hospitalization. Seventeen horses had radiographic evidence of pulmonary consolidation and pleural effusion. Nine of 14 horses had ultrasonographic evidence of large pulmonary parenchymal defects consistent with consolidation. Pleurocentesis yielded a suppurative, serosanguineous effusion in the 14 horses in which it was performed. Bacteria were isolated from all transtracheal aspirates (14) and from 6 of 12 pleural fluid samples. Actinobacillus suis-like organisms and Streptococcus equi subsp zooepidemicus were most commonly isolated. Nineteen horses were hospitalized and treated. Mean duration of treatment was 5 days, and most horses were euthanatized because of secondary complications, continued costs of medical treatment, or poor prognosis for future performance. Pathologic lesions included well-demarcated regions of hemorrhagic pulmonary infarction with necrosis and a serosanguineous pleural effusion. Thrombosis of pulmonary vessels was found in 11 horses. CLINICAL IMPLICATIONS: An acute or peracute onset of severe respiratory distress, with serosanguineous nasal discharge, ultrasonographic and radiographic evidence of severe pulmonary consolidation, and serosanguineous suppurative pleural effusion, is strongly suggestive of pulmonary infarction in horses. Horses with pulmonary infarction responded poorly to conventional treatment for pleuropneumonia and had a poor prognosis for recovery.

Actinobacillus↗
PubMed1997

Structural RNA mimetics: N3'-->P5' phosphoramidate DNA analogs of HIV-1 RRE and TAR RNA form A-type helices that bind specifically to Rev and Tat-related peptides.

An attractive strategy for the development of anti-retroviral drugs is the exploration of compounds that mimic RNA control regions of the viral genome and act as "decoys" to sequester viral gene regulatory proteins. Decoys consisting of RNA, however, are chemically unstable and readily degraded by cellular nucleases. DNA decoys, which are slightly more stable, also might not be appropriate because of possible structural differences between RNA and DNA helices and the complexes they form with proteins. It was recently reported, however, that DNA analogs with modified N3'-->P5' phosphoramidate sugar-phosphate backbones are stable and nuclease-resistant and exist predominately as A-form helices in solution [Gryaznov, S., et al. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 5798-5802]. We now report that oligonucleotide N3'-->P5' phosphoramidates DNA analogs of HIV-1 RRE IIB and TAR RNA form stable duplexes that exist in the A form as judged by circular dichroism (CD). Moreover, gel shift assays demonstrate that these phosphoramidates can specifically bind to peptides derived from HIV-1 Rev and Tat proteins. Isosequential phosphodiester DNA duplexes, existing in the B form by CD, do not bind to the respective peptides under the experimental conditions used. These results suggest the possibility that nuclease-resistant oligonucleotide N3'-->P5' phosphoramidates might serve as RNA-like decoys and disrupt specific viral RNA/protein interactions such as RRE/Rev and TAR/Tat in HIV-1.

Binding Sites↗
PubMed1997

Effect of different sampling techniques on odds ratio estimates using hospital-based cases and controls.

Potential biases introduced by the use of hospital admission records have rarely been discussed in the veterinary literature. Veterinary Medical Teaching Hospital (VMTH) patient records kept at the University of California, Davis (UCD) School of Veterinary Medicine provide a unique opportunity to perform in-depth analyses on the effect of different control selection (sampling) techniques on odds ratio (OR) estimates for disease risk factors in a retrospective case-control study. Horses with Corynebacterium pseudotuberculosis abscesses (134) and the (secondary) study base population (source for controls) were identified, and a 'gold standard' OR for each category of the factors admission type, age, breed and sex was derived. Example data were used to calculate sampling ratios (SRs), defined as the ratio between any sample proportion (of an arbitrary risk factor) and the study base proportion for this risk factor. Sampling ratios different from 1.0 introduced biases into the observed OR estimates, when compared with the 'gold standard' OR. Three randomized samples (simple random, stratified random, systematic sampling), one matched (on date of admission) and three different diagnosis samples ('colic', 'cuts and lacerations', 'fractures') were selected from the study base, and the SRs for all categories of the four factors were derived. The matched and two different disease samples ('colic' and 'fractures') had especially wide ranges of observed SRs (and large errors in the OR estimates), whereas simple random and systematic sampling had comparably narrow ranges (less biased OR estimates). For the three randomized sampling techniques under study, repeated sampling was used to derive SR distributions. The SRs were approximately normally distributed. Analysis of variance and covariance showed that simple random and systematic sampling provided SR distributions with means closest to 1.0 (expected value) and small standard deviations. The OR estimates obtained from records selected by these two sampling techniques therefore were least biased. The findings demonstrate the importance of selecting appropriate sampling techniques in addition to properly defining the study (base) population. Sampling design introduces uncertainty into the OR estimates. The direction of the bias, however, depends on the OR between factor and disease in the source population (the 'gold standard'), and on the direction and magnitude of the SR. When combining the results from single and repeated sampling we conclude that sampling design is most influential on the range of the observed SRs (single samples), on the absolute deviation of the SR from 1.0 (expressed as SR delta Mean) and on the SR standard deviation (SD) (repeated sampling).

Animals↗