Insect-inspired AI for autonomous robots.

Autonomous robots are expected to perform a wide range of sophisticated tasks in complex, unknown environments. However, available onboard computing capabilities and algorithms represent a considerable obstacle to reaching higher levels of autonomy, especially as robots get smaller and the end of Moore's law approaches. Here, we argue that inspiration from insect intelligence is a promising alternative to classic methods in robotics for the artificial intelligence (AI) needed for the autonomy of small, mobile robots. The advantage of insect intelligence stems from its resource efficiency (or parsimony) especially in terms of power and mass. First, we discuss the main aspects of insect intelligence underlying this parsimony: embodiment, sensory-motor coordination, and swarming. Then, we take stock of where insect-inspired AI stands as an alternative to other approaches to important robotic tasks such as navigation and identify open challenges on the road to its more widespread adoption. Last, we reflect on the types of processors that are suitable for implementing insect-inspired AI, from more traditional ones such as microcontrollers and field-programmable gate arrays to unconventional neuromorphic processors. We argue that even for neuromorphic processors, one should not simply apply existing AI algorithms but exploit insights from natural insect intelligence to get maximally efficient AI for robot autonomy.

Genotype analysis of noroviruses associated with gastroenteritis outbreaks in childcare centres, Victoria, Australia, 2012-2015.

The characteristics of norovirus outbreaks in children (0-5 years) in childcare centres in Victoria, Australia (2012-2015) were examined. The three most common open reading frame (ORF) 2 genotypes in childcare centre outbreaks were GII.4 (42%), GII.6 (21%) and GII.3 (14%); the remaining genotypes (GI.2, GI.3, GI.4, GI.8, GI.13, GII.1, GII.2, GII.7 and GII.13) each made up <10%. The GII.4 genotype was the only norovirus genotype seen in all 4 years of the study and was the most common genotype in 2012-2014 but in 2015 the most common genotype was GII.2. The GII.4 genotype was more common in children 0-2 years, whereas GII.2 and GII.7 were more common in children 4-5 years. ORF 1/ORF 2 recombinant forms identified were GII.P4_NewOrleans_2009/GII.4_Sydney_2012, GII.P12/GII.3, GII.Pb (GII.21)/GII.3, GII.Pe/GII.2, GII.Pe/GII.4_Sydney_2012 and GII.Pg/GII.1. The findings indicate that norovirus genotype prevalence patterns in children were influenced by the age of the children and the year in which the analysis was carried out. The majority of norovirus infections (84%) occurred after the first year of life so that vaccination before the age of one would appear to be the most efficacious.

Norovirus genotype diversity associated with gastroenteritis outbreaks in aged-care facilities.

Noroviruses are a major cause of gastroenteritis. Vaccine strategies against norovirus are currently under consideration but depend on a detailed knowledge of the capsid genotypes. This study examined the incidence of norovirus outbreaks in residential aged-care facilities in Victoria, Australia over one year (2013) and documented the (capsid) norovirus genotypes associated with these outbreaks. It was found that 65·0% of 206 outbreaks tested were associated with norovirus infection, thereby showing norovirus to be the major cause of viral gastroenteritis in residential aged-care facilities. Fifteen capsid (open reading frame 2) genotypes were identified as follows: GI.2 (0·9%), GI.3 (1·8%), GI.4 (3·7%), GI.6 (0·9%), GI.7 (0·9%), GI.8 (0·9%), GII.1 (0·9%), GII.2 (0·9%), GII.3 (1·8%), GII.4 (2009-like) (0·9%), GII.4 (2012) (48·6%), GII.4 (2012-like) (16·5%), GII.4 (unknown) (9·2%), GII.5 (2·8%), GII.6 (0·9%), GII.7 (0·9%), GII.13 (6·4%) and an as yet unclassified GII genotype (0·9%). Although GII.4 was the most common norovirus capsid genotype detected, the great diversity of norovirus genotypes in the elderly indicates vaccination strategies for this demographic are not straightforward.

Evaluation of the RIDAGENE real-time PCR assay for the detection of GI and GII norovirus.

The current study examined the efficacy of the RIDAGENE norovirus (NoV) real-time polymerase chain reaction assay (R-Biopharm, Darmstadt, Germany) for use in a routine diagnostic laboratory. The RIDAGENE assay had an overall sensitivity of 98% but was more sensitive for GII than GI NoV. The assay had a specificity of 98%. The RIDAGENE assay could detect a variety of GI and GII open reading frame 2 genotypes including GI.1, GI.3, GI.8, GI.13, GII.2, GII.3, GII.4 (including the following variants: 2006b, 2009, 2012, and 3 others that have not been assigned), GII.6, GII.12, and GII.13. The assay did not cross react with a number of gastroenteritis viruses including adenovirus, astrovirus, rotavirus, and sapovirus. The assay was straightforward to perform, and for a run of 50 specimens, a result was obtainable in roughly 4 hours. The RIDAGENE assay can be recommended as a valuable detection method for NoV.

Emergence of GII.e as a major ORF 1 norovirus genotype and its associated ORF 2 GII.4 variant forms.

The noroviruses are a major cause of outbreaks of gastroenteritis. The norovirus genotype "GII.e", identified by ORF (Open Reading Frame) 1 nucleotide sequencing, appears to be an obligatory recombinant, in that no unique GII.e ORF 2 genotype has been identified. In 2012 GII.e norovirus became the predominant ORF 1 genotype in norovirus outbreaks in Victoria, Australia, and the current study documents changes in the ORF 1 region of GII.e norovirus since it first emerged in 2008, as well as in the ORF 2 genotypes associated with GII.e norovirus. GII.e norovirus underwent significant genetic change in ORF 1 between 2010 and 2012 and this genetic change corresponded to a significant increase in the prevalence of the virus. Nucleotide sequencing of the ORF 2 region of GII.e specimens showed that in 2008-2009, all the ORF 2 sequences corresponded to the GII.4 (2007) variant, in 2010 all the ORF 2 sequences corresponded to the GII.4 (2012-like) variant and in 2012 all the ORF 2 sequences corresponded to the GII.4 (2012) variant, the GII.4 (2012-like) variant, or the GII.4 (2009-like) variant. The evidence indicated that the development of the 2012 GII.e epidemic strains was due to evolutionary change rather than a novel recombination event. The results also support the notion that ORF 1 is critical in determining the virulence of a norovirus strain.

Altered patterns of norovirus GII.b recombinant forms in gastroenteritis outbreaks in Victoria, Australia, 2002-2005 compared to 2006-2011.

GII.b norovirus is an obligatory recombinant with an open reading frame (ORF) 1 comprising the GII.b genotype and the ORF 2 region corresponding to one of a number of other norovirus genotypes. GII.b is the second most common genotype after GII.4 associated with gastroenteritis outbreaks in Victoria, Australia. The study involved norovirus testing of 14,186 specimens from 2,743 Victorian gastroenteritis outbreaks in the period 2002-2011. The noroviruses identified were further characterized by nucleotide sequencing and phylogenetic analysis. In the period 2002-2005, 21 GII.b norovirus outbreaks were identified, with the GII.b ORF 2 recombinant genotypes comprising GII.1 (47.6%), GII.3 (47.6%), and GII.13 (4.8%). For the period 2006-2011, 56 GII.b norovirus outbreaks were identified. In 51 of these, the ORF 2 genotype was identified, and comprised GII.1 (2.0%), GII.3 (94.1%), GII.13 (2.0%), and GII.21 (2.0%). GII.b norovirus outbreaks could occur in a range of settings involving individuals with a broad range of ages. However, GII.b/GII.3 norovirus tended to occur in a younger demographic and all outbreaks involving specifically children's settings had the GII.b/GII.3 genotype. Nucleotide sequencing studies demonstrated major changes in both the ORF 1 and ORF 2 regions of the GII.b/GII.3 noroviruses but not in the GII.b/GII.1 and GII.b/GII.13 noroviruses when the noroviruses for the two time periods 2002-2005 and 2006-2011 were compared. The findings suggest nucleotide changes in the pre-existing GII.b/GII.3 noroviruses resulted in a more virulent form.

Dose-response effects of diclazuril against pathogenic species of ovine coccidia and the development of protective immunity.

Twin lambs at pasture with their ewes, were divided into seven groups of 10 lambs. One group of 10 lambs served as a non-infected, untreated control. Five groups of 10 lambs were infected with 10,000 oocysts of Eimeria crandallis and 10,000 oocysts of Eimeria ovinoidalis when they were 3 weeks old (day 21 of the study). This produced a good level of infection with high oocysts production and diarrhoea in the lambs. Fourteen days after the primary, artificial challenge (day 35) four of these groups were treated with oral diclazuril at 0.25, 1.0, 2.0 or 4.0mg/kg. Diclazuril treatment was highly effective, dramatically reducing symptoms of diarrhoea and reducing faecal oocyst output by 79.7%, 97.3%, 99.4% and 99.5% respectively in the treated groups within four days. Two weeks post-treatment, and 28 days after the primary coccidial challenge (day 49 of the study), five groups of lambs were re-challenged with 100,000 oocysts of E. crandallis and 100,000 oocysts of E. ovinoidalis (secondary challenge). A group of lambs which had received neither the primary coccidia infection, nor drug treatment (susceptible controls) were also given the secondary challenge. All lambs given the secondary challenge produced high numbers of coccidia and exhibited varying degrees of diarrhoeic faeces. The lambs, which had previously received the higher doses of diclazuril at 2.0 and 4.0mg/kg, developed clinical signs of coccidiosis. These lambs were completely susceptible despite having received the early primary immunising infection of coccidia on day 21. The effects of the secondary challenge were more severe in the groups dosed with the two highest levels of diclazuril than in the susceptible control lambs, which had presumably been exposed to continued low levels of pasture contamination and had acquired a limited degree of immunity from this exposure. It would appear that treatment at the higher dose levels not only eliminated most of the oocysts from the primary challenge but also adventitious infection derived from the grazing paddocks. In contrast, lambs which had received the two lower drug levels of diclazuril (0.25 and 1.0mg/kg) whilst producing large numbers of oocysts, had only transient diarrhoea following secondary challenge. It was concluded that when used as a metaphylactic treatment, diclazuril works rapidly and is effective within four days of administration. Overall, a single dose of diclazuril at either 0.25-1.0mg/kg appears to be highly effective in the control of coccidiosis in young lambs at pasture whilst allowing the development of protective immunity against subsequent heavy coccidia challenge.

Coccidian oöcysts as type-specimens: long-term storage in aqueous potassium dichromate solution preserves DNA.

Preservation of the exogenous oöcyst stage of coccidian parasites (phylum Apicomplexa N.D. Levine, 1970) as type-specimens of newly described species has long been problematical. Conventional fixatives have proved unsatisfactory, and compromises such as embedding oöcysts in resin or photographing them are not entirely appropriate for various reasons. As an alternative, chilled potassium dichromate solution (normally used in the laboratory to prevent putrefaction of temporary preparations of live oöcysts) has been tested as a long-term preservative of sporulated oöcysts of Eimeria brunetti P.P. Levine, 1942, E. maxima Tyzzer, 1929, E. mitis Tyzzer, 1929, E. necatrix Johnson, 1930, E. praecox Johnson, 1930 and E. tenella (Railliet & Lucet, 1891) (suborder Eimeriorina Léger, 1911; family Eimeriidae Minchin, 1903). Oöcysts from faeces of chickens Gallus gallus (Linnaeus) were placed in 2.5% w/v aqueous potassium dichromate solution (PDS) and stored in the dark at 4 +/- 2 degrees C. After 23 years in storage, oöcysts of each species were administered orally to chickens and failed to initiate infections, indicating that the oöcysts were dead. Nevertheless, after about 24 years, DNA was still recoverable from the oöcysts, and the original species identifications made by classic parasitological methods were confirmed by polymerase chain reaction assays. Furthermore, after almost 25 years, microscopical examination revealed that the walls and internal structures remained well preserved in 83-98% of the oöcysts of the six species investigated. Hence, PDS is potentially suitable for the long-term preservation of sporulated coccidian oöcysts as type-specimens for taxonomic purposes. The samples used in this study are now in the care of the Natural History Museum, London, UK. It is recommended that they be monitored in like manner, by suitably qualified scientists, at intervals of about 5 years to assess their state of preservation and the recoverability of DNA. Enough material is available to monitor it until it is at least 100 years old.

Molecular and epidemiological features of GIIb norovirus outbreaks in Victoria, Australia, 2002-2005.

The epidemiology of GIIb norovirus outbreaks and the characteristics of GIIb open reading frame (ORF) 2 recombinant forms are poorly understood and this study examined these questions using norovirus-associated gastroenteritis outbreaks in Victoria, Australia, during 2002-2005. Twenty-one GIIb outbreaks were detected and were the second most common ORF 1 norovirus outbreak genotype (5%) after GII.4 (90%). Both GIIb and GII.4 outbreaks peaked in warmer months of the year but their periodicity was different. ORF 2 sequencing analysis was carried out in the two regions previously designated C and D. RT-PCR region D primers were less sensitive than region C primers. No evidence of recombination between regions C and D was found. ORF 2 genotypes for the 21 GIIb outbreaks were: GII.1 (10 outbreaks), GII.3 (10 outbreaks) and, apparently for the first time, GII.13 (1 outbreak). GIIb outbreaks could occur in a broad range of settings and there was no correlation between ORF 2 genotype and setting except that all 5 outbreaks involving mainly young children were associated with GIIb/GII.3.

Identification of a novel codon in the norovirus GII.4 polymerase region which acts as a marker of major GII.4 norovirus epidemics.

Noroviruses are considered the most common cause of outbreaks of non-bacterial gastroenteritis in humans and the GII.4 genotype the most common norovirus genotype. Previous studies have shown that two adjacent codons acted as markers of the severity of GII.4 norovirus outbreak epidemics. In this study, a further such codon was identified at nucleotide position 4670-4672 relative to the norovirus strain Lordsdale virus (GenBank accession no. X86557). Taken together, the data indicate these epidemic marker sites occur, on average, about once in 30 amino acids (aa) in the polymerase region. None of the variant forms associated with the three codons resulted in an aa change. The three codons were not associated with the active sites of the polymerase gene. It is possible changes in these marker sites may influence norovirus virulence by altering the timing of co-translational folding in the norovirus genome.

A comparative evaluation of the sensitivity of two automated and two manual nucleic acid extraction methods for the detection of norovirus by RT-PCR.

The aim of the study was to compare the sensitivity of a norovirus RT-PCR method using two manual RNA extraction methods (Qiagen and Roche) and two automated RNA extraction methods (Qiagen and Corbett). All four RNA extraction methods gave similar sensitivities although the automated methods, especially the Corbett, required significantly less labour than the manual methods. The automated methods also enabled RNA extraction of approximately two to three times the number of specimens in a given time period compared to manual methods.

Why do house-hunting ants recruit in both directions?

To perform tasks, organisms often use multiple procedures. Explaining the breadth of such behavioural repertoires is not always straightforward. During house hunting, colonies of Temnothorax albipennis ants use a range of behaviours to organise their emigrations. In particular, the ants use tandem running to recruit naïve ants to potential nest sites. Initially, they use forward tandem runs (FTRs) in which one leader takes a single follower along the route from the old nest to the new one. Later, they use reverse tandem runs (RTRs) in the opposite direction. Tandem runs are used to teach active ants the route between the nests, so that they can be involved quickly in nest evaluation and subsequent recruitment. When a quorum of decision-makers at the new nest is reached, they switch to carrying nestmates. This is three times faster than tandem running. As a rule, having more FTRs early should thus mean faster emigrations, thereby reducing the colony's vulnerability. So why do ants use RTRs, which are both slow and late? It would seem quicker and simpler for the ants to use more FTRs (and higher quorums) to have enough knowledgeable ants to do all the carrying. In this study, we present the first testable theoretical explanation for the role of RTRs. We set out to find the theoretically fastest emigration strategy for a set of emigration conditions. We conclude that RTRs can have a positive effect on emigration speed if FTRs are limited. In these cases, low quorums together with lots of reverse tandem running give the fastest emigration.

Cryptosporidium parvum infection in orphan lambs on a farm open to the public.

A longitudinal survey was undertaken on an open farm to investigate the occurrence of Cryptosporidium species infection in orphan lambs obtained from three local flocks. During an initial pilot study, Cryptosporidium oocysts were detected by a fluorescent antibody test (fat) in the faeces of two of 21 lambs aged between one and three weeks derived from one flock (flock A). Pooled pen samples of faeces were collected weekly from lambs derived from each flock; oocysts were detected by fat in 24 (49.0 per cent) of 49 samples from lambs from flock A, 18 (30.5 per cent) of 59 samples from lambs from flock B and 14 (29.8 per cent) of 47 samples from lambs from flock C. Oocyst counts of 1 x 10(3) to more than 2 x 10(6) per gram of faeces were detected in lambs up to 12 weeks old, with the peak counts occurring at six weeks of age in the lambs from flocks A and B and at four weeks of age in those from flock C. The oocysts were confirmed by molecular analysis as Cryptosporidium parvum. Virtually all the infections were subclinical.

Norovirus mixed infection in an oyster-associated outbreak: an opportunity for recombination.

We describe an outbreak of gastroenteritis in which the nucleic acid of three distinct noroviruses was amplified from the same fecal sample. To enable the separate amplification of each virus, an inclusion/exclusion RT-PCR primer design strategy was developed. This paired a virus-specific exclusion primer (designed with the exact sequence of one virus in a region displaying low conservation among the three viruses) with a virus-nonspecific inclusion primer (designed in a conserved region). Thus, in each reaction the exclusion primer provided specificity for a single virus, and the inclusion primer increased the sensitivity and allowed hybridization in a region of unknown sequence. Analysis of the partial genomic sequences of the three viruses (3.6-3.8 kb) indicated that each virus belonged to a separate genogroup II cluster, and each displayed evidence of a potential recombination event when the sequences were compared with other published norovirus sequences. Our results, which show a mixed norovirus infection in a single individual, confirm the need to be aware of the possibility of mixed norovirus infections, and of the possibility of genomic recombination causing anomalies in phylogenetic analyses in such instances.

Molecular features of astrovirus associated with a gastroenteritis outbreak in an aged-care centre.

The study presented here was conducted in order to gain a better understanding of the role of astroviruses (AsVs) in outbreaks of gastroenteritis among the elderly. This report is the first to provide detailed information on the molecular characteristics of an AsV causing an outbreak in an aged-care centre and is the first to clearly establish that individuals infected in such an outbreak were, in fact, elderly. The outbreak under investigation took place in Victoria, Australia, in October 2005. Twelve individuals (mean age +/- standard deviation [SD] 85.5 +/- 12.3 years) became ill during the outbreak from a total population of 86 susceptible residents. The mean duration (+/-SD) of illness was 2.3 +/- 1.6 days; symptoms included diarrhoea, abdominal pain, nausea and headache. No bacterial pathogens were detected. AsV was identified in five faecal specimens using electron microscopy and reverse transcription-polymerase chain reaction methodologies; no other gastroenteritis virus was detected. Nucleotide sequence analysis indicated the AsV identified could be assigned to the 1d lineage of AsV serotype 1 and that the AsV was not a recombinant form. The findings, taken together with previous work, indicate the AsV serotype most commonly associated with gastroenteritis outbreaks among the elderly is serotype 1 AsV.

Evaluation of a commercial enzyme immunoassay for detection of norovirus in outbreak specimens.

The aim of the study presented here was to use faeces from 41 gastroenteritis outbreaks (130 specimens) in Victoria, Australia, to evaluate the sensitivity and specificity of the RIDASCREEN norovirus enzyme immunoassay (EIA) kit relative to reverse transcription-polymerase chain reaction and/or electron microscopy. Seven specimens known to contain sapovirus, adenovirus, astrovirus and rotavirus were also tested. For single-specimen diagnosis the kit gave a specificity and sensitivity of 47% and 71%, respectively; altering the positivity cut-off to give a specificity of 73% reduced the sensitivity to 44%. Thus, the kit cannot be recommended for single-specimen diagnosis. One specimen containing adenovirus but not norovirus was identified as non-specifically positive by the EIA kit. If the criterion used for outbreak positivity was at least one EIA-positive specimen per outbreak, the kit's outbreak sensitivity was 94% but the outbreak specificity was only 60%.

The SPINK1 N34S mutation is not associated with Type 2 diabetes mellitus in a population of the USA.

AIMS: Mutations in the serine protease inhibitor (SPINK1) gene have been associated with all forms of chronic pancreatitis. Recently, an association of SPINK1 mutations with early-onset Type 2 diabetes mellitus has been reported in patients from Bangladesh. Therefore, we determined the frequency of SPINK1 N34S mutations in patients with Type 2 diabetes mellitus from the USA. METHODS: The study population of Hispanic and non-Hispanic white people consisted of 387 patients with Type 2 diabetes and familial clustering of the disease, 232 family members without diabetes, 259 patients with Type 2 diabetes without a family history, and 302 ethnically matched healthy controls as part of the San Luis Valley Diabetes Study. We performed linkage- and association-analysis in 82 multiplex families with Type 2 diabetes mellitus. RESULTS: No significant linkage or allele sharing was detected between Type 2 diabetes mellitus and the SPINK1 locus. The frequency of the N34S mutation was determined by fluorescence polarization and was similar between patients (n = 14/387 patients with familial clustering; n = 2/259 patients without family history) and controls (n = 5/232 family members without diabetes; n = 10/302 individuals). Variables such as ethnicity, age of diabetes onset and percentage of individuals with impaired glucose tolerance did not differ significantly between carriers and homozygous normal individuals. CONCLUSION: The SPINK1 N34S mutation appears not to predispose Hispanic or non-Hispanic white people from the USA to the development of Type 2 diabetes mellitus.