Intangible shells

The following essay mimics the constant disruption of a fragmented memory. It reflects on intergenerational gendered family dynamics since the civil war and dictatorship-era Spain and how memory articulates narratives of belonging within the matrilineal lineage. A process of excavation departs from personal memories, familial archives, contemporary interviews, theoretical readings, photographic reenactments, and observations of traces in the landscape of Almayate’s town. The author attempts to retrace her roots, as well as her family history, acknowledging the impossibility of making personal histories tangible

ANALYSIS OF JOHN RAWLS PERSPECTIVE OF JUSTICE VALUE ON BARTER MARKET IN LAMALERA VILLAGE

This journal examines how justice takes place in the barter market in Lamalera village from the perspective of justice John Rawls. There are values of justice that occur in the barter market in Lamalera village which has become a sacred value that has been believed for generations. According to John Rawls, the principle of equality states that everyone has the same right to the most basic basic freedoms, as wide as the same freedoms for all people. Or in other words everyone has the same rights to the whole system of equal human rights and is accessed by everyone. This principle regulates the application of rights and obligations and regulates the distribution of social and economic benefits. The principle of equality of fairness makes all social arrangements lead peaceful lives. The barter market in Lamalera village shows how justice and family values are created. The market system which has been a legacy of ancestors and is still preserved or still preserved up to now with values that are already considered sacred because it is a noble heritage of ancestors. Limited economic conditions require the people of Lamalera to operate a barter market by instilling the values of justice, family and socialist values which are indicated by mutual agreement in the exchange of goods for goods

A shared mechanism of defense against predators and parasites: chitin regulation and its implications for life-history theory

Defenses against predators and parasites offer excellent illustrations of adaptive phenotypic plasticity. Despite vast knowledge about such induced defenses, they have been studied largely in isolation, which is surprising, given that predation and parasitism are ubiquitous and act simultaneously in the wild. This raises the possibility that victims must trade-off responses to predation versus parasitism. Here, we propose that arthropod responses to predators and parasites will commonly be based on the endocrine regulation of chitin synthesis and degradation. The proposal is compelling because many inducible defenses are centered on temporal or spatial modifications of chitin-rich structures. Moreover, we show how the chitin synthesis pathway ends in a split to carapace or gut chitin, and how this form of molecular regulation can be incorporated into theory on life-history trade-offs, specifically the Y-model. Our hypothesis thus spans several biological scales to address advice from Stearns that “Endocrine mechanisms may prove to be only the tip of an iceberg of physiological mechanisms that modulate the expression of genetic covariance”

Application of a robust MALDI mass spectrometry approach for bee pollen investigation

Pollen collected by pollinators can be used as a marker of the foraging behavior as well as indicate the botanical species present in each environment. Pollen intake is essential for pollinators’ health and survival. During the foraging activity, some pollinators, such as honeybees, manipulate the collected pollen mixing it with salivary secretions and nectar (corbicular pollen) changing the pollen chemical profile. Different tools have been developed for the identification of the botanical origin of pollen, based on microscopy, spectrometry, or molecular markers. However, up to date, corbicular pollen has never been investigated. In our work, corbicular pollen from 5 regions with different climate conditions was collected during spring. Pollens were identified with microscopy-based techniques, and then analyzed in MALDI-MS. Four different chemical extraction solutions and two physical disruption methods were tested to achieve a MALDI-MS effective protocol. The best performance was obtained using a sonication disruption method after extraction with acetic acid or trifluoroacetic acid. Therefore, we propose a new rapid and reliable methodology for the identification of the botanical origin of the corbicular pollens using MALDI-MS. This new approach opens to a wide range of environmental studies spanning from plant biodiversity to ecosystem trophic interactions

Big Defensins, a Diverse Family of Antimicrobial Peptides That Follows Different Patterns of Expression in Hemocytes of the Oyster Crassostrea gigas

Background: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are encoded by distinct genomic sequences. All Cg-BigDefs contain a hydrophobic N-terminal domain and a cationic C-terminal domain that resembles vertebrate beta-defensins. Both domains are encoded by separate exons. We found that big defensins form a group predominantly present in mollusks and closer to vertebrate defensins than to invertebrate and fungi CS alpha beta-containing defensins. Moreover, we showed that Cg-BigDefs are expressed in oyster hemocytes only and follow different patterns of gene expression. While Cg-BigDef3 is non-regulated, both Cg-BigDef1 and Cg-BigDef2 transcripts are strongly induced in response to bacterial challenge. Induction was dependent on pathogen associated molecular patterns but not damage-dependent. The inducibility of Cg-BigDef1 was confirmed by HPLC and mass spectrometry, since ions with a molecular mass compatible with mature Cg-BigDef1 (10.7 kDa) were present in immune-challenged oysters only. From our biochemical data, native Cg-BigDef1 would result from the elimination of a prepropeptide sequence and the cyclization of the resulting N-terminal glutamine residue into a pyroglutamic acid. Conclusions: We provide here the first report showing that big defensins form a family of antimicrobial peptides diverse not only in terms of sequences but also in terms of genomic organization and regulation of gene expression

The antimicrobial peptide Defensin cooperates with tumour necrosis factor to drive tumour cell death in Drosophila

Antimicrobial peptides (AMPs) are small cationic molecules best known as mediators of the innate defence against microbial infection. While in vitro and ex vivo evidence suggest AMPs’ capacity to kill cancer cells, in vivo demonstration of an anti-tumour role of endogenous AMPs is lacking. Using a Drosophila model of tumourigenesis, we demonstrate a role for the AMP Defensin in the control of tumour progression. Our results reveal that Tumour Necrosis Factor mediates exposure of phosphatidylserine (PS), which makes tumour cells selectively sensitive to the action of Defensin remotely secreted from tracheal and fat tissues. Defensin binds tumour cells in PS-enriched areas, provoking cell death and tumour regression. Altogether, our results provide the first in vivo demonstration for a role of an endogenous AMP as an anti-cancer agent, as well as a mechanism that explains tumour cell sensitivity to the action of AMPs

The Response of the Honey Bee Gut Microbiota to Nosema ceranae Is Modulated by the Probiotic Pediococcus acidilactici and the Neonicotinoid Thiamethoxam.

The honey bee Apis mellifera is exposed to a variety of biotic and abiotic stressors, such as the highly prevalent microsporidian parasite Nosema (Vairimorpha) ceranae and neonicotinoid insecticides. Both can affect honey bee physiology and microbial gut communities, eventually reducing its lifespan. They can also have a combined effect on the insect's survival. The use of bacterial probiotics has been proposed to improve honey bee health, but their beneficial effect remains an open question. In the present study, western honey bees were experimentally infected with N. ceranae spores, chronically exposed to the neonicotinoid thiamethoxam, and/or supplied daily with the homofermentative bacterium Pediococcus acidilactici MA18/5M thought to improve the honey bees' tolerance to the parasite. Deep shotgun metagenomic sequencing allowed the response of the gut microbiota to be investigated with a taxonomic resolution at the species level. All treatments induced significant changes in honey bee gut bacterial communities. Nosema ceranae infection increased the abundance of Proteus mirabilis, Frischella perrara, and Gilliamella apicola and reduced the abundance of Bifidobacterium asteroides, Fructobacillus fructosus, and Lactobacillus spp. Supplementation with P. acidilactici overturned some of these alterations, bringing back the abundance of some altered species close to the relative abundance found in the controls. Surprisingly, the exposure to thiamethoxam also restored the relative abundance of some species modulated by N. ceranae. This study shows that stressors and probiotics may have an antagonistic impact on honey bee gut bacterial communities and that P. acidilactici may have a protective effect against the dysbiosis induced by an infection with N. ceranae

Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic E. coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analyzed. Among hundreds of compounds, only a few homologous compounds were identified that contained isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole containing analogs, sulfonamides, furanones, flavanones, and known to possess broad-spectrum antimicrobial properties, and possess anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs

Differential expression of hemolymph proteins in wild bumblebees provides insights into species-specific impacts of heat stress

peer reviewedWildlife faces an increasing threat from extreme climatic events, such as heatwaves, which can have a severe impact on various species, including crucial pollinators like bumblebees. Bumblebees are cold-adapted and heterothermic, possessing the ability to regulate their internal temperature. The impact of heat stress seems species specific in bumblebees. While most species are impacted, some bumblebee species manage to survive, potentially by employing physiological mechanisms, including the modulation of their protein profile (e.g. Heat Shock Proteins). However, there is limited understanding of how their protein profiles are associated with heat exposure. In this study, we examined the global variation in the protein profile of males from two bumblebee species sampled in the wild: the heat-tolerant Bombus terrestris and the heat-sensitive Bombus magnus. After subjecting them to heat stupor at 40°C in controlled condition, it was observed that nearly all B. terrestris survived the stress, while over 50% of B. magnus individuals succumbed to the heat exposure. Through off-gel bottom-up proteomics and LC–MS/MS analysis of the hemolymph proteome, we identified 164 proteins in both species with a large part of differentially expressed proteins after heat exposure. Additionally, quantitative analysis of fat bodies revealed that the relative mass was stable in B. terrestris, while it was significantly lower in B. magnus exposed to heat stress. Our data suggest that compared with B. magnus, B. terrestris displays a higher adaptability of its hemolymph proteome in response to heat stress. This adaptability could be a key factor contributing to the high physiological resistance of B. terrestris and its ability to adapt to new, stressful environments expected due to climate change. Understanding these mechanisms of protein regulation in bumblebees could provide valuable insights into their resilience and vulnerability facing environmental stresses.15. Life on lan