Table 5.
Meta-analysis of radius ratio and radius slope across five studies
| Study | Age, Sex, Strain (Whiskers) | Origin of Data | Radius Ratio | Radius Slope |
|---|---|---|---|---|
| Ibrahim and Wright (1975) | 3- to 6-mo-old Male Wistar rat (5 whiskers) | “In rats α, β, γ and δ vibrissae are 3-5 μm at their tips and 160–180 μm at the widest part excluding the club.” (p. 52). Fig. 8A provides data about the arc length of whiskers α, β, γ, and δ. | Smallest possible ratio: 80/2.5 = 32; largest possible ratio: 90/1.5 = 60. | Arc length data (in mm) taken from Fig. 8A, ∼140 days: α = 44; β = 51, γ = 52, δ = 59. Min possible radius slope = (80 − 2.5)/59,000 = 1.31 × 10−3. Max possible radius slope = (90 − 1.5)/44,000 = 2.01 × 10−3. |
| Fig. 6 plots diameter as a function of arc length for the β, A1, A2, A3, and A4 rat vibrissae. The resolution of Fig. 6 is severely limited at the tip. The data were extracted from the figure and are provided in Table 3, Data from Ibrahim and Wright (1975), in the present paper. | Based on data from Table 3 in present work [from Fig. 6 of Ibrahim and Wright (1975)]. Mean ± SD: 27 ± 8. Median: 24. | Based on data from Table 3 in present work [from Fig. 6 of Ibrahim and Wright (1975)]. Mean ± SD: 2.16 × 10−3 ± 0.523 × 10−3. Median: 1.89 × 10−3. | ||
| Neimark et al. (2003) | Unknown age, sex, strain (18 whiskers) | Table 2 provides arc length, base diameter, and tip diameter for 18 whiskers. The whiskers include the Greek column and columns 1, 2, and 3 of rows A–E. | Based on Table 2 in Neimark et al. (2003). Mean ± SD: 29 ± 35. Median: 23. | Based on data from Table 2 in Neimark et al. (2003). Mean ± SD: 1.76 × 10−3 ± 0.457 × 10−3. Median: 1.75 × 10−3. |
| Hartmann et al. (2003) | Adult, female, Sprague-Dawley (24 whiskers) | Fig. 6c shows a log-log plot of diameter vs. arc length for 24 rat whiskers. These original data are provided in Table 3, Data from Hartmann et al. (2003), in the present paper, along with tip diameters. | Based on Table 3 in present work [from Fig. 6c in Hartmann et al. (2003)]. Mean ± SD: 36 ± 20. Median = 33. | Based on Table 4 in present work [from Fig. 6c in Hartmann et al. (2003)]. Mean ± SD: 2.26 × 10−3 ± 0.822 × 10−3. Median = 2.04 × 10−3. |
| Voges et al. (2012) | 14 mo, female, Wistar Hannover (23 whiskers) | Figs. 3 and 4 show data for arc length, base diameter, and tip diameter. The original data were obtained from the authors and provided in Table 3, Data from Voges et al. (2012), in the present paper. | Based on data from Table 4 in present work [from Figs. 3 and 4 of Voges et al. (2012)]. Mean ± SD: 62 ± 31. Median = 51. | Based on data from Table 4 in present work [from Figs. 3 and 4 of Voges et al. (2012)]. Mean ± SD: 2.17 × 10−3 ± 0.553 × 10−3. Median = 2.02 × 10−3. |
| Belli et al. (2016) (present study) | 3–13 mo, male and female, Sprague-Dawley (52 whiskers) | Data collected in present study and tabulated in Table 4. | Mean ± SD: 29 ± 11. Median = 28 | Mean ± SD: 2.48 × 10−3 ± 1.10 × 10−3. Median = 2.18 × 10−3. |
Columns are as follows: study information; age, sex, strain, and number of whiskers; origin of data; means, SD, and median for the five studies for radius ratio; and the means, SD, and median across each of the five studies for radius slope. The Radius Ratio and Radius Slope columns for Ibrahim and Wright (1975) show only extrema for radius ratio because of the large measurement uncertainties in the tip and base diameters. Another version of this table is available as Supplemental Table S2 and at https://github.com/SeNSE-lab/RatWhiskerGeometry.git formatted for readability and scientific clarity.