Fertilization Mode Covaries with Body Size.

AbstractThe evolution of internal fertilization has occurred repeatedly and independently across the tree of life. As it has evolved, internal fertilization has reshaped sexual selection and the covariances among sexual traits, such as testes size, and gamete traits. But it is unclear whether fertilization mode also shows evolutionary associations with traits other than primary sex traits. Theory predicts that fertilization mode and body size should covary, but formal tests with phylogenetic control are lacking. We used a phylogenetically controlled approach to test the covariance between fertilization mode and adult body size (while accounting for latitude, offspring size, and offspring developmental mode) among 1,232 species of marine invertebrates from three phyla. Within all phyla, external fertilizers are consistently larger than internal fertilizers: the consequences of fertilization mode extend to traits that are only indirectly related to reproduction. We suspect that other traits may also coevolve with fertilization mode in ways that remain unexplored.

Macroevolutionary patterns in marine hermaphroditism.

Most plants and many animals are hermaphroditic; whether the same forces are responsible for hermaphroditism in both groups is unclear. The well-established drivers of hermaphroditism in plants (e.g., seed dispersal potential, pollination mode) have analogues in animals (e.g., larval dispersal potential, fertilization mode), allowing us to test the generality of the proposed drivers of hermaphroditism across both groups. Here, we test these theories for 1153 species of marine invertebrates, from three phyla. Species with either internal fertilization, restricted offspring dispersal, or small body sizes are more likely to be hermaphroditic than species that are external fertilizers, planktonic developers, or larger. Plants and animals show different biogeographical patterns, however: animals are less likely to be hermaphroditic at higher latitudes-the opposite to the trend in plants. Overall, our results suggest that similar forces, namely, competition among offspring or gametes, shape the evolution of hermaphroditism across plants and three invertebrate phyla.

CF Fungal Disease in the Age of CFTR Modulators.

Fungi are increasingly recognised to have a significant role in the progression of lung disease in Cystic fibrosis with Aspergillus fumigatus the most common fungus isolated during respiratory sampling. The emergence of novel CFTR modulators has, however, significantly changed the outlook of disease progression in CF. In this review we discuss what impact novel CFTR modulators will have on fungal lung disease and its management in CF. We discuss how CFTR modulators affect antifungal innate immunity and consider the impact of Ivacaftor on fungal disease in individuals with gating mutations. We further review the increasing complication of drug-drug interactions with concurrent use of azole antifungal medication and highlight key unknowns that require addressing to fully understand the impact of CFTR modulators on fungal disease.

Maternal age alters offspring lifespan, fitness, and lifespan extension under caloric restriction.

Maternal age has a negative effect on offspring lifespan in a range of taxa and is hypothesized to influence the evolution of aging. However, the mechanisms of maternal age effects are unknown, and it remains unclear if maternal age alters offspring response to therapeutic interventions to aging. Here, we evaluate maternal age effects on offspring lifespan, reproduction, and the response to caloric restriction, and investigate maternal investment as a source of maternal age effects using the rotifer, Brachionus manjavacas, an aquatic invertebrate. We found that offspring lifespan and fecundity decline with increasing maternal age. Caloric restriction increases lifespan in all offspring, but the magnitude of lifespan extension is greater in the offspring from older mothers. The trade-off between reproduction and lifespan extension under low food conditions expected by life history theory is observed in young-mother offspring, but not in old-mother offspring. Age-related changes in maternal resource allocation to reproduction do not drive changes in offspring fitness or plasticity under caloric restriction in B. manjavacas. Our results suggest that the declines in reproduction in old-mother offspring negate the evolutionary fitness benefits of lifespan extension under caloric restriction.

Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring.

While many studies have focused on the detrimental effects of advanced maternal age and harmful prenatal environments on progeny, little is known about the role of beneficial non-Mendelian maternal inheritance on aging. Here, we report the effects of maternal age and maternal caloric restriction (CR) on the life span and health span of offspring for a clonal culture of the monogonont rotifer Brachionus manjavacas. Mothers on regimens of chronic CR (CCR) or intermittent fasting (IF) had increased life span compared with mothers fed ad libitum (AL). With increasing maternal age, life span and fecundity of female offspring of AL-fed mothers decreased significantly and life span of male offspring was unchanged, whereas body size of both male and female offspring increased. Maternal CR partially rescued these effects, increasing the mean life span of AL-fed female offspring but not male offspring and increasing the fecundity of AL-fed female offspring compared with offspring of mothers of the same age. Both maternal CR regimens decreased male offspring body size, but only maternal IF decreased body size of female offspring, whereas maternal CCR caused a slight increase. Understanding the genetic and biochemical basis of these different maternal effects on aging may guide effective interventions to improve health span and life span.

Patterns of intraspecific variability in the response to caloric restriction.

Caloric restriction (CR) is cited as the most robust means of increasing lifespan across a range of taxa, yet there is a high degree of variability in the response to CR, both within and between species. To examine the intraspecific evolutionary conservation of lifespan extension by CR, we tested the effects of chronic caloric restriction (CCR) at multiple food levels and of intermittent fasting (IF) in twelve isolates from the Brachionus plicatilis species complex of monogonont rotifers. While CCR generally increased or did not change lifespan and total fecundity, IF caused increased, unchanged, or decreased lifespan, depending upon the isolate, and decreased total fecundity in all but one isolate. Lifespan under ad libitum (AL) feeding varied among isolates and predicted the lifespan response to CR: longer-lived isolates under AL were less likely to have a significant increase in lifespan under CCR and were more likely to have a significantly shortened lifespan under IF. Lifespan under AL conditions and the response to CR were not correlated with hydroperiodicity of native habitat or with time in culture. Lack of trade-off between lifespan and fecundity under CCR, and differences in lifespan and fecundity under CCR and IF, even when average food intake was similar, suggest that longevity changes are not always directly determined by energy intake and that CCR and IF regimens extend lifespan through diverse genetic mechanisms.

The role of Afro-Canadian status in police or ambulance referral to emergency psychiatric services.

OBJECTIVE: This study tested the hypothesis that among patients admitted to a hospital with psychosis, Afro-Canadian patients would be more likely than Euro-Canadian or Asian-Canadian patients to be brought to emergency services by police or ambulance. METHODS: Data on psychotic patients admitted to the psychiatry ward in 1999 were extracted from records of a general hospital in Montreal. Logistic regression models examined the relationship between being Afro-Canadian and being brought to the emergency service by police or ambulance, while controlling for age, gender, marital status, and number of psychotic symptoms. RESULTS: Of the 351 patients with psychosis, 59 percent were Euro-Canadian, 11 percent were Afro-Canadian, and 18 percent were Asian Canadian. Most Afro-Canadian patients in the study were immigrants from the Caribbean and Africa. Being Afro-Canadian was independently and positively associated with police or ambulance referral to emergency services. CONCLUSIONS: Afro-Canadians admitted to the hospital with psychosis are overrepresented in police and ambulance referrals to emergency psychiatric services.

Comparison of Three-Class Attributes Sampling Plans and Variables Sampling Plans for Lot Acceptance Sampling in Food Microbiology.

Lot acceptance sampling is an established method of assessing the microbiological quality and safety of batches or consignments of food, but the choice between three-class attributes plans and variables plans is not always clear. Application of variables plans requires that the microorganism of concern be distributed normally, or log-normally. When such is not true, variables plans may place either the consumer or the producer at increased risk. Validation of normality is therefore essential when using variables plans. However, with small numbers of sample units as are typically analyzed in microbiological testing of food, statistical tests are unlikely to detect non-normality. Three-class attributes plans do not require strong distributional assumptions for correct application, and as well they have several practical and operational advantages over variables plans. Moreover, three-class attributes plans assess lot quality in a fashion fundamentally different from variables plans, and this difference precludes the usual statistical comparisons based on relative discriminatory ability. We conclude that when selecting acceptance sampling plans for microbiological testing of food, whether the plans be for regulatory, port-of-entry or in-plant purposes, three-class plans are generally preferable to variables plans.