A morphological trait involved in reproductive isolation between Drosophila sister species is sensitive to temperature.

Male genitalia are usually extremely divergent between closely related species, but relatively constant within one species. Here we examine the effect of temperature on the shape of the ventral branches, a male genital structure involved in reproductive isolation, in the sister species Drosophila santomea and Drosophila yakuba. We designed a semi-automatic measurement machine learning pipeline that can reliably identify curvatures and landmarks based on manually digitized contours of the ventral branches. With this method, we observed that temperature does not affect ventral branches in D. yakuba but that in D. santomea ventral branches tend to morph into a D. yakuba-like shape at lower temperature. We found that male genitalia structures involved in reproductive isolation can be relatively variable within one species and can resemble the shape of closely related species' genitalia through plasticity to temperature. Our results suggest that reproductive isolation mechanisms can be dependent on the environmental context.

Ultrasound-guided continuous femoral nerve block: a randomized trial on the influence of femoral nerve catheter orifice configuration (six-hole versus end-hole) on post-operative analgesia after total knee arthroplasty.

BACKGROUND: Multiorifice catheters have been shown to provide superior analgesia and significantly reduce local anesthetic consumption compared with end-hole catheters in epidural studies. This prospective, blinded, randomized study tested the hypothesis that, in continuous femoral nerve block (CFNB) under ultrasound guidance, multiorifice catheter would reduce local anesthetic consumption at 24 h compared with end-hole catheter. METHODS: Eighty adult patients (aged ≥18 years) scheduled to undergo primary total knee arthroplasty under a combination of CFNB, sciatic nerve block and general anesthesia were randomized to CFNB using either a 3-pair micro-hole (Contiplex, BRAUN®, 20G - 400 mm) or an end-hole (Silverstim VYGON®, 20G - 500 mm) catheter. Once the femoral catheter was sited, a bolus of 20 mL lidocaine 1% was injected. An electronic pump then delivered an automated 5 mL bolus of ropivacaine 0.2% hourly, with 10 mL self-administered patient controlled analgesia boluses. RESULTS: There was no inter-group difference in either median number of ropivacaine boluses on demand during the first 24 h (4(2-7) vs. 4(2-8) in six-hole and end-hole groups, respectively; P = 0.832) or median ropivacaine consumption at 48 h (365(295-418) vs. 387(323-466); P = 0.452). No significant differences were recorded between the groups at 24 h regarding median average verbal rate pain scale (2(0-3) vs. 2(0-4); P = 0.486) or morphine consumption (0(0-20) vs. 0(0-20); P = 0.749). Quadriceps muscle strength declined to 7% (0-20) and 10% (0-28) in the six-hole and end-hole groups, respectively, at 24 h after surgery (P = 0.733). CONCLUSIONS: In this superiority trial, catheter orifice configuration did not influence the effectiveness of CFNB in this setting: quality of analgesia was similar, with no reduction in either local anesthetic or morphine consumption, and equivalent postoperative quadriceps weakness. TRIAL REGISTRATION: Retrospectively registered at ( NCT03376178 ). Date: 21 November 2017.

Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial.

BACKGROUND: Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. METHODS: One hundred one patients undergoing major shoulder surgery under general anesthesia with ultrasound-guided continuous interscalene block were randomly assigned to receive 0.2% ropivacaine via interscalene end-hole catheter either by continuous infusion 4 mL/h (n = 50) or as automated bolus 4 mL/h (n = 51). Both delivery methods were combined with 5 mL PRN boluses of 0.2% ropivacaine with a lockout time of 30 minutes. Postoperative number of PRN boluses, 24- and 48-hour local anesthetic consumption, pain scores, rescue analgesia (morphine), and adverse events were recorded. RESULTS: There were no significant differences in either the number of PRN ropivacaine boluses or total 48 hour local anesthetic consumption between the groups (18.5 [11-25.2] PRN boluses in the continuous infusion group vs 17 [8.5-29] PRN boluses in the automated bolus group). Postoperative pain was similar in both groups; on day 2, the median average pain score was 4 (2-6) in the continuous infusion group versus 3 (2-5) in the automated bolus group (P = 0.54). Nor were any statistically significant intergroup differences observed with respect to morphine rescue, incidence of adverse events, or patient satisfaction. CONCLUSIONS: In continuous interscalene blockade under ultrasound guidance after shoulder surgery, automated boluses of local anesthetic combined with PRN boluses did not provide any reduction in local anesthetic consumption or rescue analgesia, compared with continuous infusion combined with PRN boluses.