Comportamento de ovoposição de fêmeas selvagens de Zabrotes subfasciatus (Coleoptera, Chrysomelidae) privadas do hospedeiro Phaseolus vulgaris (Fabaceae)

The insects oviposition behavior is fundamental to study population dynamics, life history evolution, insect-plant and parasitoid-host interactions. Zabrotes subfasciatus (Boheman, 1833) females oviposition behavior in the presence and absence of a host is unknown. The main objective of this study was to describe in detail the oviposition behavior of host deprived or non-deprived females, and observe how the several situations of deprivation (days without host) influence oviposition. Six groups were assembled, three deprived of the host (for 2, 5 and 8 days) and three control groups (with host), each containing one newly-emerged couple (0-24h) of wild Z. subfasciatus, The non-deprived (control) groups received the hosts every day (5 bean seeds Phaseolus vulgaris (Fabaceae)) and the others were deprived for 2, 5 and 8 days, respectively. For each group 12 repetitions were made. Consequently, 12 couples were host deprived during two days, 12 couples were host deprived during five days and 12 couples were host deprived during eight days. When the seeds of the deprived groups were added the experiments started. There was a control group for each deprived group. The experiments and the insects were maintained at constant temperature 29 ± 2ºC and 70-80% relative humidity. At 15 minutes interval, the number of times the females manifested the different categories of behavior was observed (frequency). The behavior categories were: rest inside the box, locomotion, resource exploration (seeds), copulation and oviposition. The deprived females stayed most of the time in contact with the host to carry out oviposition, while the non-deprived (control) females spent most of the time at rest. This was observed in all the deprivation times. The results show that host deprivation influences the oviposition behavior of the studied species and also shows the flexibility in the oviposition strategies that these females present when the environment changes (absence and presence of resources)O comportamento de oviposição de insetos é fundamental em pesquisas de dinâmica populacional, evolução da história de vida, interações inseto-planta e parasitóide-hospedeiro. O comportamento de oviposição de fêmeas de Zabrotes subfasciatus (Boheman, 1833) na presença e ausência de hospedeiro é desconhecido. O principal objetivo deste trabalho foi verificar de que modo as várias situações de privação temporária de hospedeiro influenciam a oviposição. Foram montados 6 grupos, sendo 3 privados de hospedeiro (por 2, 5 e 8 dias) e 3 controles (com hospedeiro), cada um contendo um casal recém-emergido (0-24 h) de Z. subfasciatus selvagem. Apenas os grupos controles receberam os hospedeiros todos os dias (5 sementes de feijão, Phaseolus vulgaris (Fabaceae)); os demais ficaram sem o hospedeiro por 2, 5 e 8 dias, respectivamente. Para cada grupo, 12 repetições foram realizadas. Desta forma, 12 casais foram privados do hospedeiro por 2 dias, 12 casais foram privados do hospedeiro por 5 dias e 12 casais foram privados do hospedeiro por 8 dias. Quando as sementes dos feijões foram adicionadas nos grupos privados, as observações iniciavam. Havia um grupo controle para cada grupo privado. Os experimentos e os insetos foram mantidos a uma temperatura constante de 29 ± 2ºC e 70-80:% umidade relativa. A cada 15 minutos, foi observado o número de vezes que as fêmeas manifestavam as diferentes categorias de comportamento (frequência). As categorias de comportamento foram: repouso dentro da caixa, locomoção, exploração dos recursos (sementes), cópula e oviposição. As fêmeas privadas ficaram a maior parte do tempo em contato com o hospedeiro para realizar a oviposição, enquanto as controles ficaram a maior parte do tempo em repouso. Isto foi observado em todos os tempos de privação. Os resultados mostram que a privação de hospedeiro influencia o comportamento de oviposição da espécie estudada e também mostra a flexibilidade nas estratégias de oviposição que estas fêmeas apresentam quando o ambiente se altera (ausência e presença de recursos

Intracapillary leucocyte accumulation as a novel antihaemorrhagic mechanism in acute pancreatitis in mice

Background: Pancreatic infiltration by leucocytes represents a hallmark in acute pancreatitis. Although leucocytes play an active role in the pathophysiology of this disease, the relation between leucocyte activation, microvascular injury and haemorrhage has not been adequately addressed.Methods: We investigated intrapancreatic leucocyte migration, leucocyte extravasation and pancreatic microperfusion in different models of oedematous and necrotising acute pancreatitis in lys-EGFP-ki mice using fluorescent imaging and time-lapse intravital microscopy.Results: In contrast to the current paradigm of leucocyte recruitment, the initial event of leucocyte activation in acute pancreatitis was represented through a dose- and time-dependent occlusion of pancreatic capillaries by intraluminally migrating leucocytes. Intracapillary leucocyte accumulation (ILA) resulted in dense filling of almost all capillaries close to the area of inflammation and preceded transvenular leucocyte extravasation. ILA was also initiated by isolated exposure of the pancreas to interleukin 8 or fMLP, demonstrating the causal role of chemotactic stimuli in the induction of ILA. The onset of intracapillary leucocyte accumulation was strongly inhibited in LFA-1-/- and ICAM-1-/- mice, but not in Mac-1-/- mice. Moreover, prevention of intracapillary leucocyte accumulation led to the development of massive capillary haemorrhages and transformed mild pancreatitis into lethal haemorrhagic disease.Conclusions: ILA represents a novel protective and potentially lifesaving mechanism of haemostasis in acute pancreatitis. This process depends on expression of LFA-1 and ICAM-1 and precedes the classical steps of the leucocyte recruitment cascade

The Shepard Illusion Is Reduced in Children With an Autism Spectrum Disorder Because of Perceptual Rather Than Attentional Mechanisms

Earlier studies demonstrate reduced illusion strength in the Shepard illusion in adults and adolescents with an autism spectrum disorder (ASD) and in typically developing (TD) adults with high levels of autistic traits. We measured the strength of the Shepard illusion in ASD and TD children and tested if ten different eye-tracking measurements could predict group differences in illusion strength. The ASD children demonstrated reduced illusion strength relative to the TD group. Despite this, there were no mean differences on any of the eye-tracking measurements between groups. Even though none of the eye-tracking measurements revealed mean differences between the two groups, the degree to which spatial attention was directed toward the standard stimulus, as indexed by the number of saccades within and toward this stimulus, predicted the strength of the illusion in the overall sample. Furthermore, this active scanning of the standard stimulus was found to enhance illusion strength more strongly in the ASD than the TD group. Together, we conclude that scan patterns and the degree to which participants are able to shift between different locations in a visual scene did not account for group differences in illusion strength. Thus, the reduced strength of the Shepard illusion in ASD does not appear to be driven by how attention shifts or is spatially allocated. Rather, differences may relate instead to perceptual mechanisms that integrate visual information. Strategies that may aid ASD individuals to see this illusion more strongly could have them make even more eye movements within and between the stimuli presented in the illusion display

Evaluating bodily self-consciousness and the brain using multisensory perturbation and fMRI

In this article, we consider the usefulness of functional magnetic resonance imaging (fMRI) and perturbation in evaluating causal relationships between bodily self-consciousness and the brain. We argue that fMRI research is not always restricted to correlational statements when it is combined with perturbation techniques and can sometimes permit some degree of causal inferencing, such as when bodily illusions are examined with fMRI. In these instances, one is changing a participant’s conscious bodily self by experimentally perturbing mechanisms that are involved in multisensory integration

The contribution of linear perspective cues and texture gradients in the perceptual rescaling of stimuli inside a Ponzo illusion corridor

We examined the influence of linear perspective cues and texture gradients in the perceptual rescaling of stimuli over a highly-salient Ponzo illusion of a corridor. We performed two experiments using the Method of Constant Stimuli where participants judged the size of one of two rings. In experiment 1, one ring was presented in the upper visual-field at the end of the corridor and the other in the lower visual-field at the front of the corridor. The perceived size of the top and bottom rings changed as a function of the availability of linear perspective and textures. In experiment 2, only one ring was presented either at the top or the bottom of the image. The perceived size of the top but not the bottom ring changed as a function of the availability of linear perspective and textures. In both experiments, the effects of the cues were additive. Perceptual rescaling was also stronger for the top compared to the bottom ring. Additional eye-tracking revealed that participants tended to gaze more in the upper than the lower visual-field. These findings indicate that top-down mechanisms provide an important contribution to the Ponzo illusion. Nonetheless, additional maximum likelihood estimation analyses revealed that linear perspective fulfilled a greater contribution in experiment 2, which is suggestive of a bottom-up mechanism. We conclude that both top-down and bottom-up mechanisms play important roles. However, the former seems to fulfil a more prominent role when both stimuli are presented in the image

Perceptual Discrimination of Basic Object Features Is Not Facilitated When Priming Stimuli Are Prevented From Reaching Awareness by Means of Visual Masking

Our understanding of how form, orientation and size are processed within and outside of awareness is limited and requires further investigation. Therefore, we investigated whether or not the visual discrimination of basic object features can be influenced by subliminal processing of stimuli presented beforehand. Visual masking was used to render stimuli perceptually invisible. Three experiments examined if visible and invisible primes could facilitate the subsequent feature discrimination of visible targets. The experiments differed in the kind of perceptual discrimination that participants had to make. Namely, participants were asked to discriminate visual stimuli on the basis of their form, orientation, or size. In all three experiments, we demonstrated reliable priming effects when the primes were visible but not when the primes were made invisible. Our findings underscore the importance of conscious awareness in facilitating the perceptual discrimination of basic object features

Sampling of conformational ensemble for virtual screening using molecular dynamics simulations and normal mode analysis

Aim: Molecular dynamics simulations and normal mode analysis are well-established approaches to generate receptor conformational ensembles (RCEs) for ligand docking and virtual screening. Here, we report new fast molecular dynamics-based and normal mode analysis-based protocols combined with conformational pocket classifications to efficiently generate RCEs. Materials \& methods: We assessed our protocols on two well-characterized protein targets showing local active site flexibility, dihydrofolate reductase and large collective movements, CDK2. The performance of the RCEs was validated by distinguishing known ligands of dihydrofolate reductase and CDK2 among a dataset of diverse chemical decoys. Results \& discussion: Our results show that different simulation protocols can be efficient for generation of RCEs depending on different kind of protein flexibility

Selectins mediate macrophage infiltration in obstructive nephropathy in newborn mice11See Editorial by Kipari and Hughes, p. 760.

Selectins mediate macrophage infiltration in obstructive nephropathy in newborn mice.BackgroundUrinary tract obstruction during development leads to tubular atrophy and causes interstitial fibrosis. Macrophage infiltration into the interstitium plays a central role in this process. Selectins, a family of three adhesion molecules, are involved in leukocyte recruitment to sites of inflammation and immune activity. We investigated the role of selectins in obstructive nephropathy in newborn mice.MethodsTriple selectin-deficient mice (EPL-/-), L-selectin deficient mice (L-/-) and wild type mice (WT) were subjected to complete unilateral ureteral obstruction (UUO) or sham operation within the first 48 hours of life, and were sacrificed 5 and 12 days later. Kidneys were removed, and sections were stained for macrophage infiltration (mAb F4/80), apoptosis (TUNEL), tubular atrophy (periodic acid-Schiff) and interstitial fibrosis (Masson trichrome).ResultsSelectin deficient mice showed a marked reduction in macrophage infiltration into the obstructed kidney compared to WT at day 5 and day 12 after UUO. Tubular apoptosis was strongly reduced in EPL-/- at day 5 after UUO, and in EPL-/- and L-/- at day 12 after UUO when compared to WT. The number of apoptotic tubular cells was correlated with macrophage infiltration, suggesting that macrophages stimulate tubular apoptosis in obstructive nephropathy. In addition, tubular atrophy and interstitial fibrosis were significantly diminished in EPL-/- and L-/- compared to WT at day 12 after UUO.ConclusionFollowing UUO, selectins mediate macrophage infiltration into the obstructed kidney, which in turn may induce tubular apoptosis, tubular atrophy and interstitial fibrosis

Targeting Neutrophil Adhesive Events to Address Vaso-Occlusive Crisis in Sickle Cell Patients

Neutrophils are essential to protect the host against invading pathogens but can promote disease progression in sickle cell disease (SCD) by becoming adherent to inflamed microvascular networks in peripheral tissue throughout the body. During the inflammatory response, leukocytes extravasate from the bloodstream using selectin adhesion molecules and migrate to sites of tissue insult through activation of integrins that are essential for combating pathogens. However, during vaso-occlusion associated with SCD, neutrophils are activated during tethering and rolling on selectins upregulated on activated endothelium that line blood vessels. Recently, we reported that recognition of sLex on L-selectin by E-selectin during neutrophil rolling initiates shear force resistant catch-bonds that facilitate tethering to endothelium and activation of integrin bond clusters that anchor cells to the vessel wall. Evidence indicates that blocking this important signaling cascade prevents the congestion and ischemia in microvasculature that occurs from neutrophil capture of sickled red blood cells, which are normally deformable ellipses that flow easily through small blood vessels. Two recently completed clinical trials of therapies targeting selectins and their effect on neutrophil activation in small blood vessels reveal the importance of mechanoregulation that in health is an immune adaption facilitating rapid and proportional leukocyte adhesion, while sustaining tissue perfusion. We provide a timely perspective on the mechanism underlying vaso-occlusive crisis (VOC) with a focus on new drugs that target selectin mediated integrin adhesive bond formation