Because the developmental performance of a genotype can vary substantially depending on the conditions to which it is exposed, mothers are known to exercise strong choice concerning oviposition ...sites. Females potentially adjust the provisioning or paternity of offspring by responding to multiple environmental factors, but how those factors interact in the context of female assessment has been under investigated and remains poorly understood. In this study, we examine how female perceptions of the larval environment affect the size, fitness and paternity of her brood. We mated female yellow dung flies, Scathophaga stercoraria, with two different males each, manipulated female perception of larval competition levels, and subsequently split clutches across high and low‐competition conditions. We found that females (especially large females) laid more eggs when they perceived low levels of competition for their brood. Females further adjusted brood size depending on the size of their last mate (who typically sires most offspring), increasing brood size for large second mates when perceiving low levels of competition, and for small second mates when they perceived competition to be high. Larval survival was highest for females who perceived the same larval conditions that their larvae experienced, and whose last mate was well suited to such conditions (e.g. small for competitive conditions, or large in the absence of competition). In contrast, the effects of competition on paternity did not depend on maternal perceptions of larval competition, as would be expected if females exercise adaptive cryptic choice to favour alternate male phenotypes depending on the intensity of larval competition. Our experimental approach supports complex and sophisticated changes in female behaviour in response to cues of larval fitness. Our results further emphasize that most plasticity in maternal behaviour serves to improve larval fitness directly, providing valuable empirical support for theoretical assertions of the primacy of material benefits over good‐genes.
1. Polyandry is common in insects. Nevertheless, the evolutionary causes and consequences of this phenomenon remain contentious, in part because of a lack of information about natural mating rates ...and the fact that most post-copulatory processes are hidden from view within female reproductive tracts. 2. We captured wild female yellow dung flies (Scathophaga stercoraria) over the whole spring season and genotyped the sperm from their spermathecae to obtain information on sperm transfer, sperm storage and natural levels of polyandry for this model species of post-copulatory sexual selection research. 3. On average, females stored sperm from a minimum of 2-47 males (based on the most conservative estimate). Incorporating knowledge of population allele frequencies yielded a slightly higher estimate of 3-33 mates per female. 4. Sperm storage and therefore sperm competition intensity showed high temporal variation. The proportion of multiply mated females (i.e. females with sperm from ≥ 2 males within their sperm stores) and the absolute number of ejaculates detected within females increased strongly over the spring season before sharply decreasing as midsummer approached. 5. Interestingly, we detected a positive relationship between the number of stored ejaculates and females' wing injuries, suggesting that mating not only causes measurable cumulative damage to wild females but also provides a potential mechanism by which males may be able to assess the intensity of sperm competition within a female. 6. Our study found no evidence for intraejaculate sperm sorting, but importantly, the number of ejaculates in storage differed amongst the three sperm storage organs (spermathecae) of female yellow dung flies. Different sperm mixtures across the spermathecae could enable females to bias paternity towards certain males if females can selectively use sperm from a certain spermatheca at the time of fertilization.
Organisms are exposed to multiple biotic and abiotic environmental stressors, which can influence the dynamics of individual populations and communities. Populations may also genetically adapt to ...both natural (e.g. disease) and anthropogenic (e.g. chemical pollution) stress. In the present study, we studied fitness consequences of exposure to both a parasite (i.e. biotic) and a pesticide (i.e. abiotic) for the water flea
Daphnia.
In addition, we investigated whether these fitness consequences change through time as a population evolves. Thus, we exposed
Daphnia magna
clones, hatched from dormant eggs isolated from different time layers of a natural dormant egg bank, to the parasite
Pasteuria ramosa
and the insecticide diazinon in a multifactorial experiment. While our experimental treatments for unknown reasons failed to induce disease symptoms in the
Daphnia
, we did observe a reduced survival of
D. magna
when simultaneously exposed to both the parasite and the pesticide. No increased mortality upon exposure to individual stressors was observed. We did not observe an evolutionary change in fitness response of the
Daphnia
clones hatched from different time horizons upon exposure to stressors.
Diagnostic Errors in Medicine Buser, Claudia; Bankova, Andriyana
Praxis (Bern. 1994),
2015-Dec-09, 20151209, Letnik:
104, Številka:
25
Journal Article
Recenzirano
The recognition of diagnostic errors in everyday practice can help improve patient safety. The most common diagnostic errors are the cognitive errors, followed by system-related errors and no fault ...errors. The cognitive errors often result from mental shortcuts, known as heuristics. The rate of cognitive errors can be reduced by a better understanding of heuristics and the use of checklists. The autopsy as a retrospective quality assessment of clinical diagnosis has a crucial role in learning from diagnostic errors. Diagnostic errors occur more often in primary care in comparison to hospital settings. On the other hand, the inpatient errors are more severe than the outpatient errors.
Diagnostische Fehler in der Medizin Buser, Claudia; Bankova, Andriyana
Praxis (Bern. 1994),
12/2015, Letnik:
104, Številka:
25
Journal Article
Recenzirano
Zusammenfassung. Das Erkennen von diagnostischen Fehlern verbessert die Patientensicherheit. Die am häufigsten auftretenden diagnostischen Fehler sind die kognitiven Fehler, gefolgt von den System- ...und den schuldlosen Fehlern. Kognitive Fehler in der klinischen Praxis sind häufig auf angewendete Heuristiken zurückzuführen. Durch ein besseres Verständnis der Heuristiken sowie durch die Einführung von Checklisten kann die Rate der kognitiven Fehler gesenkt werden. Als validierte retrospektive Erfassung von diagnostischen Fehlern gelten die Autopsien. In der ambulanten Medizin im Vergleich zur stationären Medizin treten diagnostische Fehler häufiger auf, anderseits sind die Fehler bei den stationären Patienten schwerwiegender als diese in der Primärversorgung.
The role of the arginine–vasopressin (AVP) system in the response to myocardial ischemia is unclear. Copeptin, the C-terminal part of the AVP prohormone is secreted stoichiometrically with AVP.
A ...total of 253 consecutive patients with suspected myocardial ischemia referred for rest/ergometry myocardial perfusion single-photon emission computed tomography (SPECT) were enrolled. We evaluated the response of copeptin during exercise and determined whether measurement of copeptin may be helpful in the detection of myocardial ischemia.
Myocardial ischemia on perfusion images was detected in 127 patients (50%). Median copeptin levels increased significantly with exercise in patients with ischemia as well as in patients without ischemia (from 3.8 IQR 2.8–6.6 to 12.3 IQR 5.2–39.6 pmol/l,
P
<
0.001; and from 3.6 IQR 2.6–5.7 to 10.8 IQR 5.0–24.5 pmol/l,
P
<
0.001). Median exercise-induced changes in copeptin (Δcopeptin) were similar in both groups (7.7 versus 5.1 pmol/l,
P
=
0.150). The area under the ROC curve for the ability of Δcopeptin to detect myocardial ischemia was 0.552.
Copeptin levels increased threefold with exercise, irrespective of the presence or absence of myocardial ischemia. Therefore, myocardial ischemia does not seem to be a major trigger of the AVP system. Measurement of copeptin does not seem helpful in the detection of exercise-induced myocardial ischemia.
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