Anthocorid predators learn to associate herbivore-induced plant volatiles with presence or absence of prey

We investigated how the plant‐inhabiting, anthocorid predator, Anthocoris nemoralis, copes with variation in prey, host plant and associated herbivore‐induced plant volatiles and in particular whether the preference for these plant odours is innate or acquired. We found a marked difference between the olfactory response of orchard‐caught predators and that of their first generation reared on flour moth eggs in the laboratory, i.e. under conditions free of herbivory‐induced volatiles. Whereas the orchard‐caught predators preferred odour from psyllid‐infested pear leaves, when offered against clean air in a Y‐tube olfactometer, the laboratory‐reared first generation of (naive) predators did not. The same difference was found when a single component (methyl salicylate) of the herbivore‐induced plant volatiles was offered against clean air. After experiencing methyl salicylate with prey, however, the laboratory‐reared predators showed a pronounced preference for this volatile. This acquired preference did not depend on whether the volatile had been experienced in the juvenile period or in the adult phase, but it did depend on whether it had been offered in presence or absence of prey. In the first case, they were attracted to the plant volatile in subsequent olfactometer experiments, but when the volatile had been offered during a period of prey deprivation, the predators were not attracted. We conclude that associative learning is the most likely mechanism underlying acquired odour preference.     

Exploring the role of galectin 3 in kidney function: a genetic approach

Galectin 3 belongs to a family of glycoconjugate-binding proteinsthat participate in cellular homeostasis by modulating cellgrowth, adhesion, and signaling. We studied adult galectin 3null mutant (Gal 3–/–) and wild-type (WT) mice togain insights into the role of galectin 3 in the kidney. Byimmunofluorescence, galectin 3 was found in collecting duct(CD) principal and intercalated cells in some regions of thekidney, as well as in the thick ascending limbs at lower levels.Compared to WT mice, Gal 3–/– mice had ~11% fewerglomeruli (p < 0.04), associated with kidney hypertrophy(p < 0.006). In clearance experiments, urinary chloride excretionwas found to be higher in Gal 3–/– than in WT mice(p < 0.04), but there was no difference in urinary bicarbonateexcretion, in glomerular filtration, or urinary flow rates.Under chronic low sodium diet, Gal 3–/– mice hadlower extracellular fluid (ECF) volume than WT mice (p <0.05). Plasma aldosterone concentration was higher in Gal 3–/–than in WT mice (p < 0.04), which probably caused the observedincrease in -epithelial sodium channel (-ENaC) protein abundancein the mutant mice (p < 0.001). Chronic high sodium dietresulted paradoxically in lower blood pressure (p < 0.01)in Gal 3–/– than in WT. We conclude that Gal 3–/–mice have mild renal chloride loss, which causes chronic ECFvolume contraction and reduced blood pressure levels.     

Effect of porcine respiratory coronavirus infection on lipopolysaccharide recognition proteins and haptoglobin levels in the lungs

Porcine respiratory coronavirus (PRCV) potentiates respiratory disease and proinflammatory cytokine production in the lungs upon intratracheal inoculation with lipopolysaccharide (LPS) at 1 day of infection. This study aimed to quantify LPS-binding protein (LBP), CD14 and haptoglobin in the lungs throughout a PRCV infection. LBP and CD14 recognize LPS and enhance its endotoxic activity, whereas haptoglobin dampens it. Gnotobiotic pigs were inoculated intratracheally with PRCV (n = 34) or saline (n = 5) and euthanized 1-15days post inoculation (DPI). Virus was detected in the lungs from 1 to 9DPI. Cell-associated CD14 in lung tissue increased up to 15 times throughout the infection, due to an increase in highly CD14+ monocyte-macrophages from 1 to 12DPI and CD14+ type 2 pneumocytes from 7 to 9DPI. LBP and soluble CD14 levels in bronchoalveolar lavage fluids were elevated from 1-12DPI, with up to 35- and 4-fold increases, respectively. Haptoglobin levels increased significantly (x4.5) at 7DPI. In addition, we found that PRCV could sensitize the lungs to LPS throughout the infection, but the response to LPS appeared less enhanced at the end of infection (7DPI). The marked increases in LBP, CD14 and haptoglobin were not correlated with the extent of the LPS response.     

Computational study of the electronic structure and magnetic properties of the Ni–C state in [NiFe] hydrogenases including the second coordination sphere

[NiFe] hydrogenases catalyze the reversible formation of H₂. The [NiFe] heterobimetallic active site is rich in redox states. Here, we investigate the key catalytic state Ni?CC of Desulfovibrio vulgaris Miyazaki F hydrogenase using a cluster model that includes the truncated amino acids of the entire second coordination sphere of the enzyme. The optimized geometries, computed g?tensors, hyperfine coupling constants, and IR stretching frequencies all agree well with experimental values. For the hydride in the bridging position, only a single minimum on the potential energy surface is found, indicating that the hydride bridges and binds to both nickel and iron. The influence of the second coordination sphere on the electronic structure is investigated by comparing results from the large cluster models with truncated models. The largest interactions of the second coordination sphere with the active site concern the hydrogen bonds with the cyanide ligands, which modulate the bond between iron and these ligands. Secondly, the electronic structure of the active site is found to be sensitive to the protonation state of His88. This residue forms a hydrogen bond with the spin-carrying sulfur atom of Cys549, which in turn tunes the spin density at the nickel and coordinating sulfur atoms. In addition, the unequal distribution of spin density over the equatorial cysteine residues results from different orientations of the cysteine side chains, which are kept in their particular orientation by the secondary structure of the protein.     

A virtual environment for learning to view during aerial movements

Training the gymnasts to view the landing area when learning aerial skills may lead to more consistent landings but can be problematic and potentially dangerous. A virtual environment allowing gymnasts to get introduced to viewing techniques safely is presented. The system is based on existing simulation models and visualisation software, and is implemented using client-server technology to allow reuse with new simulation models in the future.     

Modeling a viscoelastic gymnastics landing mat during impact

Landing mats that can undergo a large amount of area deformation are now essential for the safe completion of landings in gymnastics. The objective of this study was to develop an analytical model of a landing mat that reproduces the key characteristics of the mat-ground force during impact with minimal simulation run time. A force plate and two high-speed video cameras were used to record the mat deformation during vertical drop testing of a 24-kg impactor. Four increasingly complex point mass spring-damper models, from a single mass spring-damper system, Model 1, to a 3-layer mass spring-damper system, Model 4, were constructed using Matlab to model the mat's behavior during impact. A fifth model composed of a 3-layer mass spring-damper system was developed using visual Nastran 4D. The results showed that Models 4 and 5 were able to match the loading phase of the impact with simulation times of less than 1 second for Model 4 and 28 seconds for Model 5. Both Models 4 and 5 successfully reproduced the key force-time characteristics of the mat-ground interface, such as peak forces, time of peak forces, interpeak minima and initial rates of loading, and could be incorporated into a gymnast-mat model.     

Human proximity and habitat fragmentation are key drivers of the rangewide bonobo distribution

Habitat loss and hunting threaten bonobos (Pan paniscus), Endangered (IUCN) great apes endemic to lowland rainforests of the Democratic Republic of Congo. Conservation planning requires a current, data-driven, rangewide map of probable bonobo distribution and an understanding of key attributes of areas used by bonobos. We present a rangewide suitability model for bonobos based on a maximum entropy algorithm in which data associated with locations of bonobo nests helped predict suitable conditions across the species’ entire range. We systematically evaluated available biotic and abiotic factors, including a bonobo-specific forest fragmentation layer (forest edge density), and produced a final model revealing the importance of simple threat-based factors in a data poor environment. We confronted the issue of survey bias in presence-only models and devised a novel evaluation approach applicable to other taxa by comparing models built with data from geographically distinct sub-regions that had higher survey effort. The model’s classification accuracy was high (AUC = 0.82). Distance from agriculture and forest edge density best predicted bonobo occurrence with bonobo nests more likely to occur farther from agriculture and in areas of lower edge density. These results suggest that bonobos either avoid areas of higher human activity, fragmented forests, or both, and that humans reduce the effective habitat of bonobos. The model results contribute to an increased understanding of threats to bonobo populations, as well as help identify priority areas for future surveys and determine core bonobo protection areas.     

Phosphatidylethanol accumulation promotes intestinal hyperplasia by inducing ZONAB-mediated cell density increase in response to chronic ethanol exposure

Chronic alcohol consumption is associated with increased risk of gastrointestinal cancer. High concentrations of ethanol trigger mucosal hyperregeneration, disrupt cell adhesion, and increase the sensitivity to carcinogens. Most of these effects are thought to be mediated by acetaldehyde, a genotoxic metabolite produced from ethanol by alcohol dehydrogenases. Here, we studied the role of low ethanol concentrations, more likely to mimic those found in the intestine in vivo, and used intestinal cells lacking alcohol dehydrogenase to identify the acetaldehyde-independent biological effects of ethanol. Under these conditions, ethanol did not stimulate the proliferation of nonconfluent cells, but significantly increased maximal cell density. Incorporation of phosphatidylethanol, produced from ethanol by phospholipase D, was instrumental to this effect. Phosphatidylethanol accumulation induced claudin-1 endocytosis and disrupted the claudin-1/ZO-1 association. The resulting nuclear translocation of ZONAB was shown to mediate the cell density increase in ethanol-treated cells. In vivo, incorporation of phosphatidylethanol and nuclear translocation of ZONAB correlated with increased proliferation in the colonic epithelium of ethanol-fed mice and in adenomas of chronic alcoholics. Our results show that phosphatidylethanol accumulation after chronic ethanol exposure disrupts signals that normally restrict proliferation in highly confluent intestinal cells, thus facilitating abnormal intestinal cell proliferation.