IPBES-6: the best plenary yet?

The Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) held its 6th plenary session in Medellin (Colombia) during March 2018. Several assessments were due for acceptance by the plenary. We here give news from the plenary and the platform, sketch out important key messages from the regional assessments as well as of the global thematic assessment on land degradation and restoration. We further give an outlook on the work ahead and potential for contributions from the scientific community to the important work of IPBES.     

The best of all worlds or the best possible world? Developmental constraint in the evolution of β-tubulin and the sperm tail axoneme

Through evolutionary history, some features of the phenotype show little variation. Stabilizing selection could produce this result, but the possibility also exists that a feature is conserved because it is developmentally constrained--only one or a few developmental mechanisms can produce that feature. We present experimental data documenting developmental constraint in the assembly of the motile sperm tail axoneme. The 9+2 microtubule architecture of the eukaryotic axoneme has been deeply conserved. We argue that the quality of motility supported by axonemes with this morphology explains their long conservation, rather than a developmental necessity for the 9+2 architecture. However, our functional tests in Drosophila spermatogenesis reveal considerable constraint in the coevolution of testis-specific beta-tubulin and the sperm tail axoneme. The evolution of testis beta-tubulins used in insect sperm tail axonemes is highly punctuated, indicating some pressure acting on their evolution. We provide a mechanistic explanation for their punctuated evolution by testing structure-function relationships between testis beta-tubulin and the motile axoneme in D. melanogaster. We discovered that a highly conserved sequence feature of beta-tubulins used in motile axonemes is needed to specify central pair formation. Second, our data suggest that cooperativity in the function of internal beta-tubulin amino acids is needed to support the long axonemes characteristic of Drosophila sperm tails. Thus, central pair formation constrains the evolution of the axoneme motif, and intramolecular cooperativity makes the evolution of the internal residues path dependent, which slows their evolution. Our results explain why a highly specialized beta-tubulin is needed to construct the Drosophila sperm tail axoneme. We conclude that these constraints have fixed testis-specific beta-tubulin identity in Drosophila.     

Taking the brakes off-are IC foundries in the industry's best interest?

Following up last issue's editorial topic, GaAs evangelism, another prime driving factor for the IC industry is the need for more design freedom. Before any new technology can be taken up, there must be enough engineers out there versed in the methodology. This obvious statement begs the question: where does this knowledge come from? Most noticeably from the IC foundries who are, for the most part, keen to restrict the spread of this knowledge outside their “club” of users. Is this in the best interest of progress in the GaAs industry as a whole?     

How can the functional reponse best be determined?

Summary We evaluated three methods for the analysis of functional response data by asking whether a given method could discriminate among functional responses and whether it could accurately identify regions of positive density-dependent predation. We evaluated comparative curve fitting with foraging models, linear least-squares analysis using the angular transformation, and logit analysis. Using data from nature and simulations, we found that the analyses of predation rates with the angular transformation and logit analysis were best at consistently determining the true functional response, i.e. the model used to generate simulated data. These methods also produced the most accurate estimates of the true regions of density dependence. Of these two methods, functional response data best fulfill the assumptions of logit analysis. Angularly transformed predation rates only approximate the assumptions of linear leastsquares analysis for predation rates between 0.1 and 0.9. Lack-of-fit statistics can reveal inadequate fit of a model to a data set where simple regression statistics might erroneously suggest a good match.     

Is vegetation composition or soil chemistry the best predictor of the soil microbial community?

With the species composition and/or functioning of many ecosystems currently changing due to anthropogenic drivers it is important to understand and, ideally, predict how changes in one part of the ecosystem will affect another. Here we assess if vegetation composition or soil chemistry best predicts the soil microbial community. The above and below-ground communities and soil chemical properties along a successional gradient from dwarf shrubland (moorland) to deciduous woodland (Betula dominated) were studied. The vegetation and soil chemistry were recorded and the soil microbial community (SMC) assessed using Phospholipid Fatty Acid Extraction (PLFA) and Multiplex Terminal Restriction Fragment Length Polymorphism (M-TRFLP). Vegetation composition and soil chemistry were used to predict the SMC using Co-Correspondence analysis and Canonical Correspondence Analysis and the predictive power of the two analyses compared. The vegetation composition predicted the soil microbial community at least as well as the soil chemical data. Removing rare plant species from the data set did not improve the predictive power of the vegetation data. The predictive power of the soil chemistry improved when only selected soil variables were used, but which soil variables gave the best prediction varied between the different soil microbial communities being studied (PLFA or bacterial/fungal/archaeal TRFLP). Vegetation composition may represent a more stable ‘summary’ of the effects of multiple drivers over time and may thus be a better predictor of the soil microbial community than one-off measurements of soil properties.     

Human adult olfactory bulb neurogenesis? Novelty is the best policy

There is ongoing controversy as to whether the understanding of adult mammalian neurogenesis gained from rodent studies is applicable to humans. In this issue of Neuron, Bergmann et al. (2012) propose that adult human olfactory bulb neurogenesis with long-term neuronal survival is extremely limited.     

What is the best control strategy for multiple infectious disease outbreaks?

Effective control of infectious disease outbreaks is an important public health goal. In a number of recent studies, it has been shown how different intervention measures like travel restrictions, school closures, treatment and prophylaxis might allow us to control outbreaks of diseases, such as SARS, pandemic influenza and others. In these studies, control of a single outbreak is considered. It is, however, not clear how one should handle a situation where multiple outbreaks are likely to occur. Here, we identify the best control strategy for such a situation. We further discuss ways in which such a strategy can be implemented to achieve additional public health objectives.     

Optimal radio-tracking strategy — The best results with the least effort?

We tested the need to radio-track nocturnal mammals, such as raccoon dogsNyctereutes procyonoides (Gray, 1834) and badgersMeles meles (Linnaeus, 1758), throughout the night for reliable estimates of home range size and habitat selection. We also tested the possibility to reduce the tracking effort by decreasing the number of tracking-nights. The results indicated that the locations collected before midnight gave good estimates of home range sizes but those collected after midnight or by reducing the number of tracking-nights resulted in smaller home ranges than those estimated using the total data. Thus, if one aims to estimate only the home range size, locations before midnight would be adequate. Locations of raccoon dogs taken only before or after midnight did not reveal all habitats, which were favoured on the basis of the total data. Although locations of badgers before midnight seemed to give correct results of habitat selection, we recommend radio-tracking also badgers at least few times through the night, because their core areas shifted during the night. In the case of badgers, but not of raccoon dogs, we obtained correct results of habitat selection by reducing the tracking effort by decreasing the number of tracking-nights.     

Is divalent magnesium cation the best cofactor for bacterial β-galactosidase?

β-Galactosidase is a metal-activated enzyme, which breaks down the glucosidic bond of lactose and produces glucose and galactose. Among several commercial applications, preparation of lactose-free milk has gained special attention. The present objective is to demonstrate the activity kinetics of β-galactosidase purified from a non-pathogenic bacterium Arthrobacter oxydans SB. The enzyme was purified by DEAE-cellulose and Sephadex G-100 column chromatography. The purity of the protein was checked by high-performance liquid chromatography (HPLC). The purified enzyme of molecular weight ~ 95 kDa exhibited specific activity of 137.7 U mg^?1 protein with a purification of 11.22-fold and yield 12.42 %. The exact molecular weight (95.7 kDa) of the purified protein was determined by MALDI-TOF. Previously, most of the studies have used Mg⁺² as a cofactor of β- galactosidase. In this present investigation, we have checked the kinetic behavior of the purified β-galactosidase in presence of several bivalent metals. Lowest K_m with highest substrate (ortho-nitrophenyl-β-galactoside or ONPG) affinity was measured in presence of Ca²⁺ (42.45 µM ONPG). However, our results demonstrated that V_max was maximum in presence of Mn⁺² (55.98 µM ONP produced mg^?1 protein min^?1), followed by Fe⁺², Zn⁺², Mg⁺², Cu⁺² and Ca⁺². A large number of investigations reported Mg⁺² as potential co factor for β-galacosidase. However, β-galactosidase obtained from Arthrobacter oxydans SB has better activity in the presence of Mn⁺² or Fe²⁺.     

What is the best approach to treating schizophrenia in developing countries?

BACKGROUND TO THE DEBATE: Schizophrenia affects an estimated 25 million people in low- and middle-income countries, with an average lifetime risk of about 1%. The illness is associated with excess mortality from a variety of causes. A 2001 Institute of Medicine report on mental illness in developing countries found that in 1990, over two-thirds of people with schizophrenia in these countries were not receiving any treatment (http://www.nap.edu/catalog/10111.html). The report found no evidence that the proportion of treated people in the developing world had increased since 1990. There is now a debate among mental health professionals in low-income countries over how best to improve patient care. In this article, three psychiatrists give their different viewpoints on the current status of treatment efforts for schizophrenia in the developing world and the measures that can be taken to increase the proportion of patients receiving treatment.