Ontogeny vs. phylogeny in Primate/Canid comparisons: a meta-analysis of the object choice task

The Object Choice Task (OCT) is a widely used paradigm with which researchers measure the ability of a subject to comprehend deictic (directional) cues, such as pointing gestures and eye gaze. There is a widespread belief that nonhuman primates evince only a weak capacity to use deictic cues; in contrast, domestic dogs (Canis familiaris) tend to demonstrate high success rates. This pattern of canid superiority has been taken to support the Domestication Hypothesis, which posits enhancing effects of artificial selection on the sociocognitive abilities of dogs and humans. Here we review nearly two decades of published findings, using variants of the OCT. We find systematic confounds with species classification in task-relevant preparation of the subjects, in the imposition of a barrier between reward and subject, and in the specific deictic cues used to indicate the location of hidden objects. Thus, the widespread belief that dogs outperform primates on OCTs is undermined by the systematic procedural differences in the assessments of these skills, differences that are confounded with taxonomic classification

The Future of Iron Fertilisation Experiments

The Iron Hypothesis put forward by J. H. Martin (1990) is behind the development of artificial iron fertilisation as a geoengineering method which could be used to draw down anthropogenic carbon dioxide (CO2) levels. The Southern Ocean, which is rich in macronutrients but iron limited, is a focus for experiments on iron fertilisation. The past experiments (1999 to 2009) have shown that iron increases phytoplankton bloom productivity, and utilised surface water CO2, which would promote draw down of atmospheric CO2. What has not been proven to a climatically relevant extent is the export of carbon to the deep ocean, and over what time scale it could be stored for. These are key components of a CO2 removal method. Also poorly monitored as a result of increased productivity, were side effects such as ecosystem community structures, local food web impacts or the production of other greenhouse gases such as nitrous oxide (N2O). Future experiments should be conducted to understand these side effects and increase monitoring and validation of carbon export, if iron fertilisation is to be considered a legitimate method for CO2 removal

Antarctic Futures: Governance, Scientific Expeditions, Commercial Tourism, Resource Exploitation and Climate Change

Assessing and managing future effects is an inherent problem in environmental management and law applications. Antarctica is no exception. To assist with this problem, trend analyses are applied to understand the potential future impacts of scientific expeditions, commercial tourism, mineral resource exploitation and climate change on the Antarctic environment in 5-10 years and 30-50 years. Together with an understanding of the Antarctic Treaty System (“ATS”), this information is used to determine that the existing governance regime is expected to withstand the next 50 years; albeit considerable modification of legal instruments under the Antarctic Treaty (1959) (“Treaty”) being recommended in light of instability. Such modifications are principally required to address the impacts of scientific expeditions and commercial tourism. Refinement of existing policy is necessary to reduce the risk of a move towards mineral exploitation, which is not expected to occur within the next 50 years owing to stringent policy and decision-making processes already in place. Improved coordination of multilateral international agreements is also required to address the impacts of climate change. Sovereignty issues remain frozen, but unresolved under the ATS. They are likely to come to the forefront of decision-making processes at some stage over the next 50 years

Multifunctional cellulase catalysis targeted by fusion to different carbohydrate-binding modules

Background:Carbohydrate binding modules (CBMs) bind polysaccharides and help target glycoside hydrolases catalytic domains to their appropriate carbohydrate substrates. To better understand how CBMs can improve cellulolytic enzyme reactivity, representatives from each of the 18 families of CBM found in Ruminoclostridium thermocellum were fused to the multifunctional GH5 catalytic domain of CelE (Cthe_0797, CelEcc), which can hydrolyze numerous types of polysaccharides including cellulose, mannan, and xylan. Since CelE is a cellulosomal enzyme, none of these fusions to a CBM previously existed. Results:CelEcc_CBM fusions were assayed for their ability to hydrolyze cellulose, lichenan, xylan, and mannan. Several CelEcc_CBM fusions showed enhanced hydrolytic activity with different substrates relative to the fusion to CBM3a from the cellulosome scaffoldin, which has high affinity for binding to crystalline cellulose. Additional binding studies and quantitative catalysis studies using nanostructure-initiator mass spectrometry (NIMS) were carried out with the CBM3a, CBM6, CBM30, and CBM44 fusion enzymes. In general, and consistent with observations of others, enhanced enzyme reactivity was correlated with moderate binding affinity of the CBM. Numerical analysis of reaction time courses showed that CelEcc_CBM44, a combination of a multifunctional enzyme domain with a CBM having broad binding specificity, gave the fastest rates for hydrolysis of both the hexose and pentose fractions of ionic-liquid pretreated switchgrass. Conclusion:We have shown that fusions of different CBMs to a single multifunctional GH5 catalytic domain can increase its rate of reaction with different pure polysaccharides and with pretreated biomass. This fusion approach, incorporating domains with broad specificity for binding and catalysis, provides a new avenue to improve reactivity of simple combinations of enzymes within the complexity of plant biomass

MOESM3 of Multifunctional cellulase catalysis targeted by fusion to different carbohydrate-binding modules

Additional file 3: Differential equations. Differential equations corresponding to the kinetic schemes of Figure 7 are presented in Mathematica format

MOESM1 of Multifunctional cellulase catalysis targeted by fusion to different carbohydrate-binding modules

Additional file 1.  Differential equations corresponding to the kinetic schemes shown in Fig. 7a (hexose products derived from cellulose) and in Fig. 7b (pentose products derived from hemicellulose)

Characterization of an Acinetobacter baumannii Monofunctional Phosphomethylpyrimidine Kinase That Is Inhibited by Pyridoxal Phosphate

Thiamin and its phosphate derivatives are ubiquitous molecules involved as essential cofactors in many cellular processes. The de novo biosynthesis of thiamin employs the parallel synthesis of 4-methyl-5-(2-hydroxyethyl)thiazole (THZ-P) and 4-amino-2-methyl-5(diphosphooxymethyl) pyrimidine (HMP) pyrophosphate (HMP-PP), which are coupled to generate thiamin phosphate. Most organisms that can biosynthesize thiamin employ a kinase (HMPK or ThiD) to generate HMP-PP. In nearly all cases, this enzyme is bifunctional and can also salvage free HMP, producing HMP-P, the monophosphate precursor of HMP-PP. Here we present high-resolution crystal structures of an HMPK from Acinetobacter baumannii (AbHMPK), both unliganded and with pyridoxal 5-phosphate (PLP) noncovalently bound. Despite the similarity between HMPK and pyridoxal kinase enzymes, our kinetics analysis indicates that AbHMPK accepts HMP exclusively as a substrate and cannot turn over pyridoxal, pyridoxamine, or pyridoxine nor does it display phosphatase activity. PLP does, however, act as a weak inhibitor of AbHMPK with an IC50 of 768 μM. Surprisingly, unlike other HMPKs, AbHMPK catalyzes only the phosphorylation of HMP and does not generate the diphosphate HMP-PP. This suggests that an additional kinase is present in A. baumannii, or an alternative mechanism is in operation to complete the biosynthesis of thiamin