Fly

Reported cases of extensive oral myiasis in the literature are still scarce, particularly from Yemen. This report aims to present the first case, as up to my knowledge, of extensive oral myiasis in a girl who was clearly predisposed to infestation. It concluded that several entities of myiasis, which can be referred to as a disease of the poor, are endemic in Yemen. Climate change, illiteracy, the practice of keeping domestic animals indoors, constant increases in flies populations, deteriorating social and economic conditions and improper housing, hygiene and sanitation explain the high incidence of fly-borne diseases in Yemen. Further molecular studies are needed to identify all responsible strains.

A key goal of developmental biology is to understand the mechanisms that coordinate organ growth. It has long been recognized that the genes that control apico-basal cell polarity also regulate tissue growth. How loss of cell polarity contributes to tissue overgrowth has been the subject of much speculation. Do loss-of-function mutations in cell polarity regulators result in secondary effects that globally deregulate cell proliferation, or do these genes specifically control growth pathways? Three recent papers have shown that the apico-basal polarity determinants Lgl/aPKC and Crb regulate tissue growth independently of their roles in cell polarity and coordinately regulate cell proliferation and cell death via the Salvador/Warts/Hippo (SWH) pathway. Lgl/aPKC are required for the correct localization of Hippo (Hpo)/Ras associated factor (RASSF), while Crb regulates the levels and localization of Expanded (Ex), indicating that cell polarity determinants modify SWH pathway activity by distinct mechanisms. Here, we review the key data that support these conclusions, highlight remaining questions and speculate on the underlying mechanisms by which the cell polarity complexes interact with the SWH pathway. Understanding the interactions between cell polarity regulators and the SWH pathway will improve our knowledge of how epithelial organization and tissue growth are coordinated during development and perturbed in disease states such as cancer.

Terminal velocity is the highest velocity attainable by an object as it falls through a fluid (e.g. water or air) and there is no acceleration. Free-fall Free-fall is the downward movement of an object towards the ground under the force of gravity only. The equation for the drag on a skydiver at terminal velocity: Drag = 0.5 (Velocity 2 × Air Density × Surface Area × Drag Coefficient) Equation B Weight = Mass × Gravity Force = Mass × Acceleration Equation C Fluid Pressure = (Volume of Air × Air Density × Acceleration) / Area Equation D Upward Buoyancy Force = Net Air Pressure × Surface Area = (Volume of Air × Air Density × Acceleration) / Area) × Surface Area = Volume of Air × Air Density × Acceleration = Mass of Air × Gravity where the buoyancy force is measured every second. Abstract Estimates show that skydivers in free-fall displace a mass of air downwards equal to their own mass every second, in order to maintain a constant terminal velocity. This is also demonstrated at indoor skydiving centers where air blown upwards can suspend skydivers in mid-air. Like a boat floating in water, the skydiver is floating on air. Consequently, Archimedes principle of buoyancy can be used to explain the physics of terminal velocity in skydiving. Conventional physics explains that drag, the force needed to push air out of a skydiver's path, sets a limit to a skydiver's velocity. Which is correct but incomplete. It is more accurate to add that according to buoyancy, the skydiver's velocity will increase until a mass of air equal to his own mass is displaced each second. Drag on a skydiver is defined by the equation: Drag = 0.5 (Velocity 2 × Air Density × Surface Area × Drag Coefficient) This equation has severe limitations as It relies on a drag coefficient which must be already known in order to calculate terminal velocity. Worse, this drag coefficient cannot be directly measured and changes constantly. Why is this important? This demonstrates that buoyancy applies to objects that move and is measured over a one second time period. At present, buoyancy is only applied to stationary objects, such as boats or balloons. Also, buoyancy provides a simpler and more accurate method to estimate terminal velocity, without having to know the drag coefficient. This paper predicts that all objects falling at terminal velocity will displace a mass of fluid equal to their own mass each second to maintain buoyancy and a constant terminal velocity. An explanatory video: " Buoyancy explains terminal velocity in skydiving, " is available on youtube, on channel of 'N Landell'

In recent years, in many regions of the country where cereals are grown, in the crops there has been a spread of species of wheat flies and an increase in their harmfulness. Therefore, there is a need for research.
The article presents information data for 2015-1019 on the types of Diptera that damage crops, their distribution, the damage they cause and the measures taken against them.
According to studies and observations in various grain-growing regions of the republic, 14 species from 5 families belonging to the species of Diptera were identified. It was found that during the growing season grain crops are seriously damaged by species such as the Swedish barley fly, Green-eye, and Yellow cereal gall midge. The observance of agrotechnical conditions was indicated as preventive measures to control grain flies, as a measure of chemical control in areas where the processing of seed material is widespread, and the use of effective insecticides during the growing season. Currently, the use of insecticides with the composition of neonicotinoids - thiamethoxam and imidacloprid - for seed treatment plays a key role in controlling flies. Due to the effectiveness of their systemic effects, these drugs can reliably protect plants from larvae of flies.

Drosophila have a variety of innate immune strategies for defending itself from infection, including humoral and cell mediated responses to invading microorganisms. At the front lines of these responses, are a diverse group of pattern recognition receptors that recognize pathogen associated molecular patterns. These patterns include bacterial lipopolysaccharides, peptidoglycans, and fungal beta-1,3 glucans. Some of the receptors catalytically modify the pathogenic determinant, but all are responsible for directly facilitating a signaling event that results in an immune response. Some of these events require multiple pattern recognition receptors acting sequentially to activate a pathway. In some cases, a signaling pathway may be activated by a variety of different pathogens, through parallel receptors detecting different pathogenic determinants. In this chapter, we review what is known about pattern recognition receptors in Drosophila, and how those lessons may be applied towards a ...

Given the limited information regarding the anatomy of the thoracic limb in European avian
species, we decided to investigate the related muscles in the grey heron (Ardea cinerea), in
the eurasian buzzard (Buteo buteo), and in the common kestrel (Falco tinnunculus). Therefore
we performed a stratigraphic dissection of the wing in 3 subjects. The pars major and minor
of the musculus deltoideus, despite being roughly in line with those reported by other
authors in other species, displayed unique features. Concerning the pars propatagialis of the
musculus deltoideus, from what was observed in the grey heron, we believe this structure can
contribute to maintain the propatagial tension. In this way vibrations of this structure, which
could cause diminished lift, are avoided. Moreover the peculiarity evidenced in the distal
insertion of the common kestrel could influence the control of the pronation‑supination of
the wing during hovering. With respect to the musculus flexor carpi ulnaris, we believe the
presence of a sesamoid‑like structure at the base tendon, found in the grey heron and in the
eurasian buzzard, may help complete the articular surfaces of the elbow. This study shows
interesting data on species not previously examined and provides a possible functional
correlation between the peculiarity observed and the kind of flight of each species.

Heterochromatin is the enigmatic eukaryotic genome compartment found mostly at telomeres and centromeres. Conventional approaches to sequence assembly and genetic manipulation fail in this highly repetitive, gene-sparse, and recombinationally silent DNA. In contrast, genetic and molecular analyses of euchromatin-encoded proteins that bind, remodel, and propagate heterochromatin have revealed its vital role in numerous cellular and evolutionary processes. Utilizing the 12 sequenced Drosophila genomes, Levine et al1 took a phylogenomic approach to discover new such protein “surrogates” of heterochromatin function and evolution. This paper reported over 20 new members of what was traditionally believed to be a small and static Heterochromatin Protein 1 (HP1) gene family. The newly identified HP1 proteins are structurally diverse, lineage-restricted, and expressed primarily in the male germline. The birth and death of HP1 genes follows a “revolving door” pattern, where new HP1s appear to replace old HP1s. Here, we address alternative evolutionary models that drive this constant innovation.

The willistoni species subgroup has been the subject of several studies since the latter half of the past century and is considered a Neotropical model for evolutionary studies, given the many levels of reproductive isolation and different evolutionary stages occurring within them. Here we present for the first time a phylogenetic reconstruction combining morphological characters and molecular data obtained from 8 gene fragments (COI, COII, Cytb, Adh, Ddc, Hb, kl-3 and per). Some relationships were incongruent when comparing morphological and molecular data. Also, morphological data presented some unresolved polytomies, which could reflect the very recent divergence of the subgroup. The total evidence phylogenetic reconstruction presented well-supported relationships and summarized the results of all analyses. The diversification of the willistoni subgroup began about 7.3 Ma with the split of D. insularis while D.paulistorum complex has a much more recent diversification history, wh...

The willistoni species subgroup has been the subject of several studies since the latter half of the past century and is considered a Neotropical model for evolutionary studies, given the many levels of reproductive isolation and different evolutionary stages occurring within them. Here we present for the first time a phylogenetic reconstruction combining morphological characters and molecular data obtained from 8 gene fragments (COI, COII, Cytb, Adh, Ddc, Hb, kl-3 and per). Some relationships were incongruent when comparing morphological and molecular data. Also, morphological data presented some unresolved polytomies, which could reflect the very recent divergence of the subgroup. The total evidence phylogenetic reconstruction presented well-supported relationships and summarized the results of all analyses. The diversification of the willistoni subgroup began about 7.3 Ma with the split of D. insularis while D.paulistorum complex has a much more recent diversification history, wh...

One basic condition of postmating sexual selection is that females mate more than once before fertilizing their ova. Knowledge of the frequency and extent of multiple mating in a given population or species is therefore important in order to fully understand the potential for sexual selection, in the form of sperm competition, sexual conflict and cryptic female choice. Surprisingly, there are only a handful of studies that have attempted to estimate the frequency of multiple mating in insects (including Drosophila) and none have made direct observations over extended periods of time. Here we use time-lapse photography to directly score matings in isolated pairs of D. melanogaster and show that multiple mating in the laboratory occurs at a high frequency but at comparable rates with wild caught females. We also find that the interval to remating rises approximately additively with each mating, indicating either an increase in female resistance or male reluctance to remate. These resu...

The yeast transcription factor GAL4 is widely used in Drosophila genetics to misexpress genes that are under control of the yeast upstream activator sequence (UAS). Here we show that high levels of GAL4 change the expression of many Drosophila genes in a UAS-independent manner, including genes that encode components of important signaling pathways. We find that at least part of the genomic response to GAL4 appears to be caused by effects of GAL4 on stress and immune response pathways. Finally, using the transcription factor Senseless as an example, we demonstrate how an interaction between GAL4 and a GAL4-driven protein can impede the use of the GAL4/UAS system in experiments aimed at determining the transcriptional response to a misexpressed gene.