Columbus Surpassed: Biophysical Aspects of How Stingless Bees Place an Egg Upright on Their Liquid Food

The highly eusocial stingless bees (reviewed in [1, 2]) constitute a phylogenetically old group [3] within the Apidae. Probably related to this ancient origin is their mass provisioning of brood cells: they deposit all the food on which the larva will develop into the brood cell, prior to oviposition and subsequent closure of the cell. The other social members of the Apidae, the honeybees and the bumblebees, regularly visit the larvae in their cells to administer small amounts of liquid food at a time. This system is called progressive provisioning. Mass provisioning is practiced by almost all the other bees. However, while most of them have a solid type of larval food, the stingless bees produce a liquid food. In relation to this, their cylindrical brood cells are constructed vertically and are often arranged in horizontal combs. The food, regurgitated from the stomach, consists of a mixture of pollen, nectar, and glandular secretions [1, 2, 4]. After the workers have put this liquid food into the cell, the queen oviposits. Her egg, with its elongated shape, stands upright on the fluid

High Humidity in the Honey Bee (Apis mellifera L.) Brood Nest Limits Reproduction of the Parasitic Mite Varroa jacobsoni Oud.

Factors influencing reproduction of the parasitic mite Varroa jacobsoni have become a central theme of honey bee pathology. In large parts of the world the mite has made it impossible for colonies of the honey bee Apis mellifera to survive if no measures of treatment are applied [1]. Originally a parasite of the Eastern honey bee A. cerana, the mite was detected in colonies of A. mellifera only less than 4 decades ago [2]. A. cerana colonies are not damaged by V. jacobsoni because several factors prevent the build-up of a large mite population [3]. The most important factor is that in colonies of A. cerana the parasite, which can reproduce only in capped brood cells, reproduces exclusively in drone brood cells while in colonies of A. mellifera it reproduces in worker brood cells as well [4]. In cold, temperate, and Mediterranean climates the mite population grows exponentially until the colony collapses, due mainly to a high percentage of bees damaged by V. jacobsoni during their pupal development [5]

Jataí (Tetragonisca angustula)

De angelloze bij Jataí (Tetragonisca angustula) kiest haar nestplaats op de meest willekeurige plaatsen. Bijvoorbeeld, holtes in de grond, tuinmuren of verlaten mierennesten

Uruçu amerela (Melipona rufiventris)

Beschrijving en leefwijze van de Uruçu amerela (Melipona rufiventris), van het geslacht Melipona. De Melipona's zijn de grootste onder de angelloze bijen, maar verschillen onderling erg. De grotere worden in Brazilië Uruçu genoemd, de kleinere Jandaira

Boca de Sapo (partamona helleri)

De volksnaam van deze Braziliaanse bij, Boca de Sapo, is zeer toepasselijk: kikkermond. Dit verwijst naar de grote nestopening bovenaan

Delta Doping of Ferromagnetism in Antiferromagnetic Manganite Superlattices

We demonstrate that delta-doping can be used to create a dimensionally confined region of metallic ferromagnetism in an antiferromagnetic (AF) manganite host, without introducing any explicit disorder due to dopants or frustration of spins. Delta-doped carriers are inserted into a manganite superlattice (SL) by a digital-synthesis technique. Theoretical consideration of these additional carriers show that they cause a local enhancement of ferromagnetic (F) double-exchange with respect to AF superexchange, resulting in local canting of the AF spins. This leads to a highly modulated magnetization, as measured by polarized neutron reflectometry. The spatial modulation of the canting is related to the spreading of charge from the doped layer, and establishes a fundamental length scale for charge transfer, transformation of orbital occupancy and magnetic order in these manganites. Furthermore, we confirm the existence of the canted, AF state as was predicted by de Gennes [P.-G. de Gennes, Phys. Rev. 118, 141 (1960)], but had remained elusive

Psychopathology symptoms in a sample of female cosmetic surgery patients

Objective: During the past decades, cosmetic surgery has become increasingly popular. People with certain psychopathology disorders, for example, body dysmorphic disorder (BDD), are dissatisfied with their physical appearance, and a significant number try to receive cosmetic medical treatment for their complaints. It seems relatively easy for them to receive this type of surgery, despite the fact that it has no or even adverse effects on the symptoms. The present study aimed to investigate the psychological condition and especially the presence of psychopathological symptoms such as BDD in cosmetic surgery patients. Methods: Questionnaires about body image dissatisfaction, symptoms of BDD and psychopathology in general and satisfaction about surgery were sent to patients who had been treated in a large cosmetic surgery clinic. Results: Of the patients who replied, 86% were pleased with the outcome of the cosmetic procedure. Further, 21-59% of these former patients scored higher on questionnaires of body image dissatisfaction and psychopathological symptoms than a norm group from the general population. When differentiating the group on the basis of BDD symptomatology, it appeared that the high BDD symptomatic group displayed significantly worse outcome on all measurements. That is, high BDD symptomatic patients were more dissatisfied about the result of surgery, exhibited higher levels of psychopathology, and had lower self-esteem than the low symptomatic BDD patients. Conclusion: These findings clearly suggest that the evaluation of the psychological condition and motivation of the candidate patient might be a valuable addition to the standard procedure in cosmetic medical treatment settings

Magnetically asymmetric interfaces in a (LaMnO3_3)/(SrMnO3_3) superlattice due to structural asymmetries

Polarized neutron reflectivity measurements of a ferromagnetic [(LaMnO$_3$)$_{11.8}$/(SrMnO$_3$)$_{4.4}$]$_6$ superlattice reveal a modulated magnetic structure with an enhanced magnetization at the interfaces where LaMnO$_3$ was deposited on SrMnO$_3$ (LMO/SMO). However, the opposite interfaces (SMO/LMO) are found to have a reduced ferromagnetic moment. The magnetic asymmetry arises from the difference in lateral structural roughness of the two interfaces observed via electron microscopy, with strong ferromagnetism present at the interfaces that are atomically smooth over tens of nanometers. This result demonstrates that atomic-scale roughness can destabilize interfacial phases in complex oxide heterostructures.Comment: 5 pages, 4 figure

Goede hygiene belangrijk voor boerenkaas

Minder goede stalhygiëne kan doorwerken in melkkwaliteit en als van rauwe melk boerenkaas gemaakt wordt, in kaaskwaliteit

Single-Cell Virus Sequencing of Influenza Infections That Trigger Innate Immunity.

Influenza virus-infected cells vary widely in their expression of viral genes and only occasionally activate innate immunity. Here, we develop a new method to assess how the genetic variation in viral populations contributes to this heterogeneity. We do this by determining the transcriptome and full-length sequences of all viral genes in single cells infected with a nominally "pure" stock of influenza virus. Most cells are infected by virions with defects, some of which increase the frequency of innate-immune activation. These immunostimulatory defects are diverse and include mutations that perturb the function of the viral polymerase protein PB1, large internal deletions in viral genes, and failure to express the virus's interferon antagonist NS1. However, immune activation remains stochastic in cells infected by virions with these defects and occasionally is triggered even by virions that express unmutated copies of all genes. Our work shows that the diverse spectrum of defects in influenza virus populations contributes to-but does not completely explain-the heterogeneity in viral gene expression and immune activation in single infected cells.IMPORTANCE Because influenza virus has a high mutation rate, many cells are infected by mutated virions. But so far, it has been impossible to fully characterize the sequence of the virion infecting any given cell, since conventional techniques such as flow cytometry and single-cell transcriptome sequencing (scRNA-seq) only detect if a protein or transcript is present, not its sequence. Here we develop a new approach that uses long-read PacBio sequencing to determine the sequences of virions infecting single cells. We show that viral genetic variation explains some but not all of the cell-to-cell variability in viral gene expression and innate immune induction. Overall, our study provides the first complete picture of how viral mutations affect the course of infection in single cells