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Saxifraga tricuspidata Rottbøll Figure 17G Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°26′39″N, 61°57′18″W; 159 m a.s.l.; 26 Jul. 2019; habitat: mesic, with till and rocks as substrates, dominated by Juncus biglumis, moss, and lichen; QFA0635004. Identification. Plants 3.5–7.5 cm high; herbaceous; caespitose (cushion shape). Taproots and rhizomes present. Stems 2.5–7.0 cm long; erect; hairy, with glandular hairs. Leaves basal and cauline; heterophyllous; alternate; subsessile (basal leaves) or sessile (cauline leaves). Basal leaf blades 3–10 mm long, 1.5–4.0 mm wide; linear or oblanceolate; bases cuneate; lobed, with 1–3 triangular, cuspidate lobes; green or red; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs. Cauline leaf blades 2.5–6.5 mm long, 0.5–1.5 mm wide; elliptic or oblanceolate; unlobed or sometimes lobed, with narrow triangular lobes; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs; apices cuspidate. Inflorescence a cyme, with 2–7 flowers. Pedicels hairy. Sepals 5; 1.5–2.0 mm long, 0.8– 1.5 mm wide; ovate; green or purple; surface glabrous; margins glabrous; apices obtuse. Petals 5; 2.5–5.0 mm long, 1–3 mm wide; obovate or oblanceolate; unlobed; ivory or yellow, with apically yellow, orange, or red dots. Androecium with 10 stamens and 0.3–0.7 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish S. tricuspidata from the other Saxifraga species present on Ellesmere Island can be found under S. cernua., Published as part of Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew & Berteaux, Dominique, 2021, Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas, pp. 181-225 in Check List 17 (1) on page 219, DOI: 10.15560/17.1.181

Sabulina rubella (Wahlenberg) Dillenberger & Kadereit Figure 6D Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°26′22″N, 062°50′39″W; 201 m a.s.l.; 7 Aug. 2019; habitat: barren ground in a slope, with till and rocks as substrates; QFA0635573. Identification. Plants 1.5–3.5 cm high; herbaceous; caespitose. Taproots present. Stems 0.8–2.5 cm long; prostrate, decumbent, or ascending; hairy, with glandular hairs. Leaves cauline; opposite; sessile. Leaf blades 3.0– 5.7 mm long, 0.5–1.0 mm wide; lanceolate or linear; straight or acending; veins 3; green; abaxial and adaxial surfaces both glabrous; margins ciliate, with glandular hairs; apices acute or apiculate. Inflorescence a solitary flower. Pedicels hairy. Sepals 5; 2–3 mm long, 0.5–1.4 mm wide; lanceolate; purple or green, with hyaline margins; surface glabrous or hairy, with glandular hairs; margins glabrous; apices acute. Petals 5; 2–3 mm long, 1.0– 1.5 mm wide; oblanceolate or obovate; unlobed; white. Androecium with 10 stamens and 0.2–0.3 mm long, yellow anthers. Gynoecium with 3 styles and 1 stigma per style. Fruit a capsule; 2.8–3.0 mm long, 1.4– 1.6 mm wide; ovoid or conical; straw-colored; glabrous. Characteristics allowing to distinguish S. rubella from the other Sabulina species present on Ellesmere Island can be found under S. rossii., Published as part of Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew & Berteaux, Dominique, 2021, Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas, pp. 181-225 in Check List 17 (1) on page 196, DOI: 10.15560/17.1.181

Dryas integrifolia Vahl subsp. integrifolia Figure 15A–C Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°28′34″N, 062°26′49″W; 128 m a.s.l.; 2 Jul. 2019; habitat: barren ground, with till and rocks as substrates, and sparse dominance of Saxifraga oppositifolia; QFA0635001. Identification. Plants 3–8 cm high; dwarf shrubs. Taproots and rhizomes present. Branches prostrate, sometimes rooting at nodes. Leaves evergreen; basal and cauline; isomorphic; alternate; petiolate. Stipules green or brown; hairy. Petioles 2–5 mm long; hairy, with white hairs. Leaf blades 4–9 mm long, 1–3 mm wide; lanceolate; bases cordate or truncate; unlobed; abaxial surface tomentose, with white hairs; adaxial surface shiny dark green, glabrous or sparsely hairy on the midvein; margins entire or slightly crenate, revolute, and glabrous; apices acute. Inflorescence a solitary flower. Pedicels 15– 25 mm long; erect; hairy with woolly hyaline hairs and dark purple glandular hairs. Epicalyx absent. Sepals 7 or 8; 3–7 mm long, 1–2 mm wide; linear or lanceolate; dark green; surface hairy, with woolly hyaline hairs and dark purple glandular hairs; margins ciliate; apices acute. Petals 8; 7–11 mm long, 3–5 mm wide; obtrullate or obovate; unlobed; white or ivory. Androecium with 40–70 stamens and 0.5–0.9 mm long anthers. Gynoecium consisting of numerous separate carpels, with 5–6 mm long conical styles. Fruit an achene, with elongate plumose styles., Published as part of Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew & Berteaux, Dominique, 2021, Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas, pp. 181-225 in Check List 17 (1) on page 214, DOI: 10.15560/17.1.181

At high air temperatures (Ta) atmospheric water vapor can markedly influence an animal’s heat dissipation by reducing evaporative cooling capacities. At low Tahowever, the impact of increased water vapor on heat exchange has sparsely been investigated, despite human populations at northern latitudes insisting on feeling colder on days with higher humidity (i.e., humid-cold). Here, we aimed to investigate the humid-cold perception by determining whether Black-capped Chickadees (Poecile atricapillus) exhibited greater energy expenditure through increased heat loss under humid-cold conditions relative to dry-cold. We measured resting metabolic rates (RMR) of captive chickadees (n=10) during exposure to two Tatreatments, below freezing (Ta≈ −7°C) and above freezing (Ta≈ 10°C), with either dry or saturated air. We found that Tasubstantially impacted RMR, with RMR ≈1.5-fold greater at −7°C compared with 10°C. Conversely, humidity did not have a statistically significant impact on RMR at either Ta. Our data thus suggest that humidity does not significantly influence an individual’s heat exchange with the environment at cold Ta. This presumably reflects the fact that cold air can hold minimal amounts of water vapor and any possible influence on heat loss is negligible. Instead, we suggest that a greater contributor to the humid-cold myth is the frequency of overcast days during which direct solar radiation is blocked.Summary statementBlack-capped chickadees significantly increased their resting metabolic rates at air temperatures below freezing relative to air temperatures above freezing, whereas humidity level did not significantly affect resting metabolic rates.

To analyze the indications for and clinical procedures resulting from knee magnetic resonance imaging (MRI) in older patients.We retrospectively analyzed 215 medical records of patients 50 years of age and older who had undergone a unilateral knee MRI in 2009.Centre hospitalier universitaire de Sherbrooke in Quebec.Patients 50 years of age and older who underwent a knee MRI in 2009.The main outcome measure was an invasive procedure in the same knee that underwent an MRI. Medical charts were reviewed up to 2014 for patient characteristics, MRI indication, ordering physician specialty, radiography before MRI, MRI findings, and clinical procedures resulting from the MRI.The patients' mean (SD) age was 60.6 (7.5) years. The main MRI indications were meniscopathy (148 [68.8%]) and chronic pain (92 [42.8%]). The main MRI findings were osteoarthritis (OA) (185 [86.0%]) and meniscal lesions (170 [79.1%]). Only 82 (38.1%) patients had a plain radiograph in the 24 months preceding the MRI, usually without a standing anteroposterior view. Findings on pre-MRI radiography (n = 201) demonstrated OA in 144 (71.6%) patients. Overall, 87 (40.5%) patients were seen by an orthopedic surgeon and 27 (31.0%) of these patients underwent an invasive intervention. Among the 81 patients with moderate to severe OA on MRI, 36 (44.4%) had radiographic evidence of moderate to severe OA and only 3 (3.7%) underwent arthroscopic meniscectomy.Our study reproduces the known association between OA and degenerative meniscal changes in older patients. We have found a surprising underuse of the standing anteroposterior view on radiography. Most patients in our cohort could have been appropriately diagnosed and treated based on such radiographic information, as demonstrated by pre-MRI findings, thus avoiding the MRI and subsequent evaluation by an orthopedic surgeon. Meniscectomy was rarely performed, particularly in patients with advanced OA. Educational and pragmatic measures must be emphasized to encourage the use of radiography and to limit the inappropriate use of MRI, a costly technique.

Background Difficulty descending stairs is a common functional complaint reported by patients with meniscal tears. Abnormal knee movement patterns, such as dynamic valgus of the knee or decreased knee flexion during step down, have been reported by clinicians, but 3D knee kinematics descending stairs has never been described in this population. Objective The objective of this study is to compare 3D knee kinematics of individuals with a meniscal tear to that of control individuals during a step-down task. Methods Ten participants (6 men and 4 women) diagnosed with a meniscal tear and eleven healthy participants (3 men and 8 women) were recruited. Three-dimensional knee kinematic data were recorded during five step-down task trials with a VICON™ motion analysis system. The following parameters were extracted from the stance phase period only: maximum angle, minimum knee angle, and range of motion (maximum minus minimum) values for sagittal, frontal, and transverse planes. A group comparison was performed by ANOVA using the velocity of the step-down task as the control variable. Findings Significant reductions in the mean maximum knee flexion angle, knee flexion/extension range of motion, and knee abduction/adduction were observed among the participants with a meniscal tear compared to the control group (mean differences and P values were 4.7°, P = 0.02; 5.4°, P = 0.02 and 1.6°, P = 0.03 respectively). Differences in rotation movement were not significant. Interpretation This study is the first to describe and compare 3D knee kinematics of persons with a meniscal tear during a step-down task. These findings support that significant kinematic changes occur in the sagittal and frontal plane in individuals with a meniscal tear compared to normal controls.