Contributions to the cytology of endosperm in some angiosperms-VIII.Chrysanthemum carinatum L.

Cytological studies ofChrysanthemum carinatum have shown that the endosperm was free nuclear in the beginning, but, as the wall formation commenced very early, it was cellular for most of its life. The endosperm, in general, was triploid with 3n=27 chromosomes, but polyploidy (6n) and aneuploidy also occurred in a small number of cells.Although most of the nuclei in the main part of the endosperm were uniform in size and shape, they showed some variation in the haustorial region. The possible cause of this variation has been suggested to be endoduplication.Mitotic aberrations such as bridges, laggards and multipolar divisional stages appear to be the probable causes for the failure of endosperm in some of the immature seeds, resulting in a low seed set.     

The “mosco” (Hemiptera: Corixidae and Notonectidae) of Lake Cuitzeo,Mexico: an unusual inland water fishery

Limnology - Lake Cuitzeo is Mexico’s second-largest lake (~ 425 km2). The West Basin is shallow, seasonally astatic and alkaline, and it contains saltwater; it is in this...     

Emergence of artemisinin-resistant Plasmodium falciparum with kelch13 C580Y mutations on the island of New Guinea

The rapid and aggressive spread of artemisinin-resistant Plasmodium falciparum carrying the C580Y mutation in the kelch13 gene is a growing threat to malaria elimination in Southeast Asia, but there is no evidence of their spread to other regions. We conducted cross-sectional surveys in 2016 and 2017 at two clinics in Wewak, Papua New Guinea (PNG) where we identified three infections caused by C580Y mutants among 239 genotyped clinical samples. One of these mutants exhibited the highest survival rate (6.8%) among all parasites surveyed in ring-stage survival assays (RSA) for artemisinin. Analyses of kelch13 flanking regions, and comparisons of deep sequencing data from 389 clinical samples from PNG, Indonesian Papua and Western Cambodia, suggested an independent origin of the Wewak C580Y mutation, showing that the mutants possess several distinctive genetic features. Identity by descent (IBD) showed that multiple portions of the mutants’ genomes share a common origin with parasites found in Indonesian Papua, comprising several mutations within genes previously associated with drug resistance, such as mdr1, ferredoxin, atg18 and pnp. These findings suggest that a P. falciparum lineage circulating on the island of New Guinea has gradually acquired a complex ensemble of variants, including kelch13 C580Y, which have affected the parasites’ drug sensitivity. This worrying development reinforces the need for increased surveillance of the evolving parasite populations on the island, to contain the spread of resistance.     

An African bat in Europe,Plecotus gaisleri: Biogeographic and ecological insights from molecular taxonomy and Species Distribution Models

Because of the high risk of going unnoticed, cryptic species represent a major challenge to biodiversity assessments, and this is particularly true for taxa that include many such species, for example, bats. Long‐eared bats from the genus Plecotus comprise numerous cryptic species occurring in the Mediterranean Region and present complex phylogenetic relationships and often unclear distributions, particularly at the edge of their known ranges and on islands. Here, we combine Species Distribution Models (SDMs), field surveys and molecular analyses to shed light on the presence of a cryptic long‐eared bat species from North Africa, Plecotus gaisleri, on the islands of the Sicily Channel, providing strong evidence that this species also occurs in Europe, at least on the islands of the Western Mediterranean Sea that act as a crossroad between the Old Continent and Africa. Species Distribution Models built using African records of P. gaisleri and projected to the Sicily Channel Islands showed that all these islands are potentially suitable for the species. Molecular identification of Plecotus captured on Pantelleria, and recent data from Malta and Gozo, confirmed the species' presence on two of the islands in question. Besides confirming that P. gaisleri occurs on Pantelleria, haplotype network reconstructions highlighted moderate structuring between insular and continental populations of this species. Our results remark the role of Italy as a bat diversity hotspot in the Mediterranean and also highlight the need to include P. gaisleri in European faunal checklists and conservation directives, confirming the usefulness of combining different approaches to explore the presence of cryptic species outside their known ranges—a fundamental step to informing conservation.     

Effects of an anthropogenic diet on indicators of physiological challenge and immunity of white ibis nestlings raised in captivity

When wildlife forage and/or live in urban habitats, they often experience a shift in resource availability and dietary quality. Some species even use human handouts, such as bread, as well as human refuse, as a large part of their new diets; yet the influences of this nutritional shift on health and survival remain unclear. American white ibises are increasingly being seen in urban areas in Florida; they collect handouts, such as bread and other food items, from humans in parks, and are also found foraging on anthropogenic sources in trash heaps. We hypothesized that the consumption of these new anthropogenic food sources may trigger increases in indicators of physiological challenge and dampen immune responses. We tested this experimentally by raising 20 white ibis nestlings in captivity, and exposing 10 to a simulated anthropogenic diet (including the addition of white bread and a reduction in seafood content) while maintaining 10 on a diet similar to what ibises consume in more natural environments. We then tested two indicators of physiological challenge (corticosterone and heat shock protein 70), assessed innate immunity in these birds via bactericidal assays and an in vitro carbon clearance assay, and adaptive immunity using a phytohemagglutinin skin test. The anthropogenic diet depressed the development of the ability to kill Salmonella paratyphi in culture. Our results suggest that consuming an anthropogenic diet may be detrimental in terms of the ability to battle a pathogenic bacterial species, but there was little effect on indicators of physiological challenge and other immunological measures.     

Generation of APOE knock-down SK-N-SH human neuroblastoma cells using CRISPR/Cas9: a novel cellular model relevant to Alzheimer’s disease research

APOE ε4 is the major genetic risk factor for Alzheimer’s disease (AD). A precise role for apolipoprotein E (apoE) in the pathogenesis of the disease remains unclear in part due to its expression in multiple cell types of the brain. APOE is highly expressed in astrocytes and microglia, however its expression can also be induced in neurons under various conditions. The neuron-like cell line SK-N-SH is a useful model in the study of the cellular and molecular effects of apoE as it can be differentiated with retinoic acid to express and secrete high levels of apoE and it also shows the same apoE fragmentation patterns observed in the human brain. We previously found that apoE is cleaved into a 25-kDa fragment by high temperature-requirement serine protease A1 (HtrA1) in SK-N-SH cells. To further understand the endogenous functions of apoE, we used CRISPR/Cas9 to generate SK-N-SH cell lines with APOE expression knocked-down (KD). APOE KD cells showed lower APOE and HTRA1 expression than parental SK-N-SH cells but no overt differences in neuritogenesis or cell proliferation compared with the CRISPR/Cas9 control cells. This research shows that the loss of apoE and HtrA1 has a negligible effect on neuritogenesis and cell survival in SK-N-SH neuron-like cells.     

Using life cycle assessment to achieve a circular economy

The International Journal of Life Cycle Assessment - The current global interest in circular economy (CE) opens an opportunity to make society’s consumption and production patterns more...