Diverging life cycle patterns of two Diamesa species (Diptera, Chironomidae) in High Arctic streams, Svalbard

The fauna of streams in the High Arctic, dominated by chironomids, is shaped by extreme environmental conditions that represent the physiological limits for benthic invertebrates. Despite their ecological importance, little is known of chironomid life histories, development strategies and the key abiotic drivers limiting larval growth in High Arctic streams. We investigated the larval development and growth in three High Arctic rivers with contrasting water sources, thermal regimes and nutrient characteristics. Populations of the larvae of Diamesa bohemani (Goetghebuer 1932) and Diamesa aberrata (Lundbeck 1898) from two sampling occasions in July and August 2016 were morphometrically analysed to determine life history patterns and instream productivity. Water temperature differences lead to diverging development patterns on local spatial scales. The lowest larval growth was in a groundwater/snowmelt fed stream with low food concentration and quality, suggesting that stream productivity is not primarily water source dependant, but is dependent on the nutrient supply. Glacially influenced streams are clearly more productive than previously assumed, resulting in comparable secondary production to groundwater/snowmelt-fed streams.

Mating marks on museum specimens reveal breeding patterns in species of Pterostichus Bonelli (Carabidae, Pterostichini)

We found distinct and consistently placed, species- and sex-specific abrasions of the cuticle on museum specimens of 14 species of the Pterostichus Bonelli, 1810 (Carabidae, Pterostichini) subgenus Hypherpes Chaudoir, 1838. We deduced that these marks are generated during mating and, therefore, can be used to distinguish between preserved specimens of beetles that had previously mated at the time of capture and those that had not mated. In addition to describing and detailing the occurrence of the marks and providing evidence that they are the result of mating, we demonstrate their utility for inferring life history using a museum voucher collection. By scoring these indications of mating from pinned specimens, we describe life cycle patterns in two similar, relatively closely related and sympatric species of the subgenus Hypherpes, P. vicinus Mannerheim, 1843 and P. californicus (Dejean, 1828). Both were sampled during a pitfall trap study in Contra Costa, California, USA from 2014–2019 and deposited in the Essig Museum of Entomology, UC Berkeley. Both species had very low adult activity through the drought and end of drought period prior to the spring of 2017 and are significantly more abundant in the post-drought period. Based on mating marks, both species responded to accumulated precipitation ending the drought by the emergence of an active, mostly unmated cohort of adults. The spring activity peak, following the end of the drought, was dominated by unmarked and presumably unmated beetles, but samples from subsequent springs included a nearly equal mix of beetles showing mating marks and apparently unmated beetles. The beetle activity appears to correspond more with the accumulated rainfall of the preceding rainy season than with the rains of the sample year. Beetles sampled in autumn and winter (rainy season) predominantly show mating marks. The occurrence throughout the year of beetles that are marked as having mated is consistent with iteroparous beetles with a lifespan of more than one year and also consistent with dynamic phenotypic polyvariance in which the adult activity period is synchronised by adjusting development time. The dominant pattern fits with a life cycle that is typically annual univoltine, or possibly biennial semivoltine in dry years, rainy season breeding (autumn-winter) iteroparous, with adult summer aestivation and possibly facultative larval hibernation. However, unmarked and so apparently unmated individuals and teneral adults were captured during peak activity periods regardless of the season, suggesting that either the beetles diapause as teneral adults that then complete development and become active at various points during the year and/or there are multiple periods of breeding and oviposition each year in at least some portion of the population.

Research on Pharmaceutical Product Life Cycle Patterns for Sustainable Growth

An important agenda of pharmaceutical companies is the establishment of therapeutic area strategies, drug modality, and geographic strategies for research and development. It is worthwhile to understand the changes in therapeutic area, modality and internationalization of the top-selling pharmaceutical drugs over the past. Hence, the purposes of this study are to investigate changes in therapeutic area, modality and internationalization of the top-selling drugs and to identify their life cycle patterns. We compared the top-selling drugs between 2011 and 2017, and found that the percentages of nichebuster cancer drugs and home region-oriented drugs have increased whereas the proportions of traditional blockbuster cardiovascular drugs and global drugs have decreased. We compared product life cycle patterns via a Kruskal–Wallis test, and identified the features of product life cycle patterns per therapeutic area and modality. We performed a case study on drugs in the same class with the same pharmacological mechanism but found no differences across cases. Our results provide insights into therapeutic area strategies that consider life cycle patterns and geographic strategies that consider the competitive advantages of home region-oriented drugs. Finally, we presented new and simple models of life cycle patterns. This approach may help such enterprises establish and maintain sustainable growth.

Life cycle patterns of cognitive performance over the long run

Little is known about how the age pattern in individual performance in cognitively demanding tasks changed over the past century. The main difficulty for measuring such life cycle performance patterns and their dynamics over time is related to the construction of a reliable measure that is comparable across individuals and over time and not affected by changes in technology or other environmental factors. This study presents evidence for the dynamics of life cycle patterns of cognitive performance over the past 125 y based on an analysis of data from professional chess tournaments. Individual move-by-move performance in more than 24,000 games is evaluated relative to an objective benchmark that is based on the respective optimal move suggested by a chess engine. This provides a precise and comparable measurement of individual performance for the same individual at different ages over long periods of time, exploiting the advantage of a strictly comparable task and a comparison with an identical performance benchmark. Repeated observations for the same individuals allow disentangling age patterns from idiosyncratic variation and analyzing how age patterns change over time and across birth cohorts. The findings document a hump-shaped performance profile over the life cycle and a long-run shift in the profile toward younger ages that is associated with cohort effects rather than period effects. This shift can be rationalized by greater experience, which is potentially a consequence of changes in education and training facilities related to digitization.

Diversity of Karyolysus and Schellackia from the Iberian lizard Lacerta schreiberi with sequence data from engorged ticks

Apicomplexan haemoparasites of the genera Schellackia Reichenow, 1919, and Karyolysus Labbé, 1894, seem to be common in lizards and widespread across the world. For decades, their identification has been based on morphological descriptions and life cycle patterns, with molecular characterizations, applied only recently. We used molecular characterization to confirm the identification of haemoparasites detected by microscopy in blood smears of Lacerta schreiberi Bedriaga, 1878, a lizard of the Iberian Peninsula. Since blood samples other than blood smears were not available from the studied lizards, 264 engorged ticks Ixodes ricinus (Linneaus, 1758) collected from them were used as an alternative non-invasive source of haemoparasite DNA for molecular genetic analyses. Of the 48 blood smears microscopically examined, 31 were positive for blood parasites (64.6% prevalence). We identified trophozoites and gamonts similar to Karyolysus lacazei (Labbé, 1894) (24/48; 50%) and Schellackia-like sporozoites (20/48; 41.7%). Mixed infections with both species occurred in 13 blood smears (27.1%). Sequence data were obtained for both parasites from engorged ticks. Phylogenetic analyses placed our unique haemogregarine sequence within the Karyolysus clade, nevertheless, within substantial polytomy. Thus, according to its morphology and effect on the host cell, we refer to this haemogregarine as Karyolysus cf. lacazei. Besides the Schellackia sequences being identical to a previously identified haplotype, we also obtained sequences of three new closely related haplotypes.