Synchronous and Non-Synchronous Semelparity in Sibling Species of Pulmonates

Diverse life histories have been documented in terrestrial pulmonates, which inhabit different regions in climate. Life history traits are often phenotypically plastic and vary depending on the environment. Thus, surveys using designs that control for the confounding effects of environment are needed to evaluate the evolutionary differences between populations of closely related species in the wild. We examined the life histories of sibling species of terrestrial pulmonate within two regions of similar climates. Bradybaena pellucida (BP) is endemic to Japanese islands, and has recently been expanding its distribution northeastward, whereas B. similaris (BS) has been introduced by humans into temperate and tropical regions worldwide. We found that these species exhibit discrete differences in population dynamics and life cycle, despite their close relatedness. The annual life cycle of BP is synchronized among individuals in a population. Thus, BP is univoltine with discontinuous generation. In contrast, BS individuals do not synchronize their growth or reproduction, and thus exhibit overlapping generations. Our results indicate that synchronized and non-synchronized population dynamics diverge relatively rapidly in semelparous pulmonates. This type of difference has not been documented in pulmonate life history, and may have been overlooked because only a few studies have explicitly compared life cycles of closely related species within the same climate. Our results provide a basis for further studies of life history evolution in pulmonates.ArticleZOOLOGICAL SCIENCE. 32(4):372-377 (2015)journal articl

Experimental simulation of environmental warming selects against pigmented morphs of land snails

H-R.K. and R.T. were gratefully hosted by INRA-PACA, Avignon, France, during the time of fieldwork in 2017. We gratefully acknowledge assistance in the field and with the open-top chamber experiments by Nik Triebskorn and Tim Triebskorn. The 35 field sites were sampled within the 2018 European Theba survey initiated by H-R.K and Thomas Knigge, Le Havre University, France. We also thank Menno Schilthuizen, Leiden University, the Netherlands, and another anonymous reviewer for constructive remarks on a previous manuscript version. Open access funding enabled and organized by ProjektDEAL.In terrestrial snails, thermal selection acts on shell coloration. However, the biological relevance of small differences in the intensity of shell pigmentation and the associated thermodynamic, physiological, and evolutionary consequences for snail diversity within the course of environmental warming are still insufficiently understood. To relate temperature‐driven internal heating, protein and membrane integrity impairment, escape behavior, place of residence selection, water loss, and mortality, we used experimentally warmed open‐top chambers and field observations with a total of >11,000 naturally or experimentally colored individuals of the highly polymorphic species Theba pisana (O.F. MÜLLER, 1774). We show that solar radiation in their natural Mediterranean habitat in Southern France poses intensifying thermal stress on increasingly pigmented snails that cannot be compensated for by behavioral responses. Individuals of all morphs acted neither jointly nor actively competed in climbing behavior, but acted similarly regardless of neighbor pigmentation intensity. Consequently, dark morphs progressively suffered from high internal temperatures, oxidative stress, and a breakdown of the chaperone system. Concomitant with increasing water loss, mortality increased with more intense pigmentation under simulated global warming conditions. In parallel with an increase in mean ambient temperature of 1.34°C over the past 30 years, the mortality rate of pigmented individuals in the field is, currently, about 50% higher than that of white morphs. A further increase of 1.12°C, as experimentally simulated in our study, would elevate this rate by another 26%. For 34 T. pisana populations from locations that are up to 2.7°C warmer than our experimental site, we show that both the frequency of pigmented morphs and overall pigmentation intensity decrease with an increase in average summer temperatures. We therefore predict a continuing strong decline in the frequency of pigmented morphs and a decrease in overall pigmentation intensity with ongoing global change in areas with strong solar radiation.ProjektDEA

Citizen Science Reveals Unexpected Continental-Scale Evolutionary Change in a Model Organism

Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis). This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow) was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate

Pretreatment with nitrous oxide enhances induction of anesthesia with sevoflurane: A randomized controlled trial

Background and Aims: Inhalation anesthesia with sevoflurane may be enhanced by several drugs or techniques. The aim of the present study was to investigate the effect of nitrous oxide (N 2 O) pretreatment on the speed of anesthesia induction with sevoflurane. Material and Methods: Eighty patients scheduled for hysteroscopy under general anesthesia were randomly assigned to inhale for 10 min before induction 50% N 2 O in oxygen or air via a facemask. Anesthesia was induced with 7-8% sevoflurane in oxygen via a facemask. Bispectral index (BIS), end-tidal carbon dioxide (EtCO 2 ) tidal volume, respiratory rate, oxygen saturation (SpO 2 ), and heart rate were recorded every minute during the 10 min pretreatment periods and every 30 s during the first 300 s of induction with sevoflurane. During induction of anesthesia inspired and end-tidal sevoflurane concentrations were also recorded. Results: During the 10 min of inspired 50% N 2 O or air BIS, EtCO 2 , tidal volume, respiratory rate and heart rate values did not differ between the two groups except for the SpO 2 , which was higher in the N 2 O group (P < 0.001). During induction of anesthesia the N 2 O group exhibited lower BIS values (P = 0.001), being significant at 60-150 s (P < 0.001, P < 0.001, P = 0.002, P = 0.014) as well as at 270 s (P = 0.004). EtCO 2 and tidal volume were consistently lower in the N 2 O group (P = 0.001, P = 0.041 respectively) and respiratory rate was higher (P = 0.007). Conclusion: Our results show that pretreatment of the patients with 50% N 2 O for 10 min enhances the speed of induction with sevoflurane as assessed by the BIS monitoring

Physiological and operative severity score for the enumeration of mortality and morbidity scoring systems for assessment of patient outcome and impact of surgeons' and anesthesiologists' performance in hepatopancreaticobiliary surgery

Context: The physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) is a scoring system used to predict morbidity and mortality. Aims: We compared the physiological and operative risk, the expected morbidity and mortality, and the observed postoperative mortality among patients operated by different surgeons and anesthetized by different anesthesiologists. Settings and Design: This was a retrospective, single center study. Subjects and Methods: The anesthetic records of 159 patients who underwent hepatopancreaticobiliary surgery were analyzed for the physiological and operative severity, POSSUM morbidity, POSSUM and Portsmouth POSSUM (P-POSSUM) mortality scoring systems, observed mortality in 30-days, 3, 6, and 12 months postoperatively, duration of surgery, and units of packed red blood cells (PRBC) transfused. These variables were compared among patients operated by five different surgeons and anesthetized by seven different anesthesiologists. Statistical Analysis: One-way analysis of variance was used for normally and Kruskal-Wallis test for nonnormally distributed responses. Differences in percentages of postoperative mortality were assessed by Chi-squared test. Results: The physiological severity, POSSUM morbidity, POSSUM and P-POSSUM mortality scores, and observed mortality at 1, 3, 6, and 12 months postoperatively did not differ among patients operated by different surgeons and anesthetized by different anesthesiologists. Duration of surgery (P < 0.001), PRBC units transfused (P = 0.002), and operative severity (P = 0.001) differed significantly among patients operated by different surgeons. Conclusions: The physiological severity score, POSSUM and P-POSSUM scores did not differ among patients operated by different surgeons and anesthetized by different anesthesiologists. The different operative severity scores did not influence the observed mortality in the postoperative period. © 2017 Saudi Journal of Anesthesia | Published by Wolters Kluwer - Medknow

Perioperative management of hereditary arrhythmogenic syndromes

Patients with inherited cardiac channel disorders are at high risk of perioperative lethal arrhythmias. Preoperative control of symptoms and a multidisciplinary approach are required for a well-planned management. Good haemodynamic monitoring, adequate anaesthesia and analgesia, perioperative maintenance of normocarbia, normothermia, and normovolaemia are important. In congenital long QT syndrome, torsades de pointes should be prevented with magnesium sulphate infusion and avoidance of drugs such as droperidol, succinylcholine, ketamine, and ondansetron. Propofol and epidural anaesthesia represent safe choices, while caution is needed with volatile agents. In Brugada syndrome, β-blockers, α-agonists, and cholinergic drugs should be avoided, while isoproterenol reverses the ECG changes. Propofol, thiopental, and volatiles have been used uneventfully. In congenital sick sinus syndrome, severe bradycardia resistant to atropine may require isoproterenol or epinephrine. Anaesthetics with vagolytic properties are preferable, while propofol and vecuronium should be given with caution due to risk of inducing bradyarrhythmias. Neuraxial anaesthesia should produce the least autonomic imbalance. Arrhythmogenic right ventricular dysplasia/cardiomyopathy induces ventricular tachyarrhythmias, which should be treated with β-blockers. Generally, β-adrenergic stimulation and catecholamine release should be avoided. Halothane and pancuronium are contraindicated, while large doses of local anaesthetics and epinephrine should be avoided in neuraxial blocks. In catecholaminergic polymorphic ventricular tachycardia, β-blocker treatment should be continued perioperatively. Catecholamine release and β-agonists, such as isoproterenol, should be avoided. Propofol and remifentanil are probably safe, while halothane and pancuronium are contraindicated. Regional anaesthesia, without epinephrine, is relatively safe. In suspicious cardiac deaths, postmortem examination and familial screening are recommended. © The Author [2012]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved

Intravenous morphine and droperidol after caesarean delivery under subarachnoid anaesthesia has no effect on postoperative pain or analgesic requirements

Background and objective Opioids are routinely administered to obtain a better control of postoperative pain. The aim of the present study was to assess the intravenous morphine effect after caesarean delivery on the postoperative morphine requirements and pain. Methods Sixty-two parturients undergoing elective caesarean section under subarachnoid anaesthesia were randomly assigned in a double-blinded manner to the morphine or to the control group, to receive intraoperatively 0.15mg kg-1 morphine in 100 ml of isotonic saline or equal volume of normal saline. Postoperative analgesia was ensured with patient-controlled analgesia morphine. Postoperative pain at rest and after coughwas assessedusing the visual analogue scale (VAS) 2, 4, 8, and 24 h. Morphine consumption was recorded at the same time points. Results Cumulative morphine consumption 2, 4, 8, and 24 h postoperatively was 6±4.8, 14±6.6, 22±9.6, and 42±15.7mg in the morphine and 8±5.1, 18±7.7, 28±9.4, and 43±17.4mg in the control group (F=2.70, DF=1, and P=0.105 for intergroup comparisons). The VAS scores at rest did not differ between the two groups, being 28±22.3, 40±21.4, 28±18.5, and 28±22.2mm in the morphine group and 28±21.5, 43±23.5, 29±24.2, and 19±24.8mm in the controls (F=0.37, DF=1, P=0.848). Similar results apply to the VAS scores recorded after cough. VAS values were 35±20.6, 51±22.5, 42±18.2, and 46±23.6mm in the morphine and 40±22.1, 54±28.9, 47±26.5, and 38±26.9mm in the control group, respectively. Conclusion Morphine given after caesarean delivery under subarachnoid anaesthesia has no effect on analgesic requirements or acute postoperative pain. Eur J Anaesthesiol 26:847-850 © 2009 European Society of Anaesthesiology

Perioperative management of a parturient with hyponatraemia due to carbamazepine therapy

We describe the perioperative management of an epileptic parturient who developed hyponatraemia due to carbamazepine therapy. Caesarean delivery was performed under combined spinal-epidural anaesthesia with a good outcome for both mother and neonate. The diagnostic and therapeutic approach, anaesthetic implications and maternal and neonatal risks for a patient with hyponatraemia complicating carbamazepine therapy are discussed. © 2011 Elsevier Ltd. All rights reserved