Movement kinematic and postural control differences when performing a visuomotor skill in real and virtual environments

Immersive technologies, like virtual and mixed reality, pose a novel challenge for our sensorimotor systems as they deliver simulated sensory inputs that may not match those of the natural environment. These include reduced fields of view, missing or inaccurate haptic information, and distortions of 3D space; differences that may impact the control of motor actions. For instance, reach-to-grasp movements without end-point haptic feedback are characterised by slower and more exaggerated movements. A general uncertainty about sensory input may also induce a more conscious form of movement control. We tested whether a more complex skill like golf putting was also characterized by more consciously controlled movement. In a repeated-measures design, kinematics of the putter swing and postural control were compared between (i) real-world putting, (ii) VR putting, and (iii) VR putting with haptic feedback from a real ball (i.e., mixed reality). Differences in putter swing were observed both between the real world and VR, and between VR conditions with and without haptic information. Further, clear differences in postural control emerged between real and virtual putting, with both VR conditions characterised by larger postural movements, which were more regular and less complex, suggesting a more conscious form of balance control. Conversely, participants actually reported less conscious awareness of their movements in VR. These findings highlight how fundamental movement differences may exist between virtual and natural environments, which may pose challenges for transfer of learning within applications to motor rehabilitation and sport.

A third of the tropical African flora is potentially threatened with extinction

Preserving tropical biodiversity is an urgent challenge when faced with the growing needs of countries. Despite their crucial importance for terrestrial ecosystems, most tropical plant species lack extinction risk assessments, limiting our ability to identify conservation priorities. Using a novel approach aligned with IUCN Red List criteria, we conducted a continental-scale preliminary conservation assessment of 22,036 vascular plant species in tropical Africa. Our results underline the high level of extinction risk of the tropical African flora. Thirty-three percent of the species are potentially threatened with extinction, and another third of species are likely rare, potentially becoming threatened in the near future. Four regions are highlighted with a high proportion (>40%) of potentially threatened species: Ethiopia, West Africa, central Tanzania, and southern Democratic Republic of the Congo. Our approach represents a first step toward data-driven conservation assessments applicable at continental scales providing crucial information for sustainable economic development prioritization.

Action observation for sensorimotor learning in surgery

Background

Acquiring new motor skills to learn complex movements and master the use of a diverse range of instruments is fundamental for developing expertise in surgery. Although aspects of skill development occur through trial and error, watching the performance of another individual (action observation) is an increasingly important adjunct for the acquisition of these complex skills before performing a procedure. The aim of this review was to examine the evidence in support of the use of action observation in surgery.

Methods

A narrative review of observational learning for surgical motor skills was undertaken. Searches of PubMed and PsycINFO databases were performed using the terms ‘observational learning’ OR ‘action observation’ AND ‘motor learning’ OR ‘skill learning’.

Results

Factors such as the structure of physical practice, the skill level of the demonstrator and the use of feedback were all found to be important moderators of the effectiveness of observational learning. In particular, observation of both expert and novice performance, cueing attention to key features of the task, and watching the eye movements of expert surgeons were all found to enhance the effectiveness of observation. It was unclear, however, whether repeated observations were beneficial for skill learning. The evidence suggests that these methods can be employed to enhance surgical training curricula.

Conclusion

Observational learning is an effective method for learning surgical skills. An improved understanding of observational learning may further inform the refinement and use of these methods in contemporary surgical training curricula.

Phase II study of gemcitabine, oxaliplatin in combination with panitumumab in KRAS wild-type unresectable or metastatic biliary tract and gallbladder cancer

BACKGROUND

Current data suggest that platinum-based combination therapy is the standard first-line treatment for biliary tract cancer. EGFR inhibition has proven beneficial across a number of gastrointestinal malignancies; and has shown specific advantages among KRAS wild-type genetic subtypes of colon cancer. We report the combination of panitumumab with gemcitabine (GEM) and oxaliplatin (OX) as first-line therapy for KRAS wild-type biliary tract cancer.

METHODS

Patients with histologically confirmed, previously untreated, unresectable or metastatic KRAS wild-type biliary tract or gallbladder adenocarcinoma with ECOG performance status 0-2 were treated with panitumumab 6 mg kg(-1), GEM 1000 mg m(-2) (10 mg m(-2) min(-1)) and OX 85 mg m(-2) on days 1 and 15 of each 28-day cycle. The primary objective was to determine the objective response rate by RECIST criteria v.1.1. Secondary objectives were to evaluate toxicity, progression-free survival (PFS), and overall survival.

RESULTS

Thirty-one patients received at least one cycle of treatment across three institutions, 28 had measurable disease. Response rate was 45% and disease control rate was 90%. Median PFS was 10.6 months (95% CI 5-24 months) and median overall survival 20.3 months (95% CI 9-25 months). The most common grade 3/4 adverse events were anaemia 26%, leukopenia 23%, fatigue 23%, neuropathy 16% and rash 10%.

CONCLUSIONS

The combination of gemcitabine, oxaliplatin and panitumumab in KRAS wild type metastatic biliary tract cancer showed encouraging efficacy, additional efforts of genetic stratification and targeted therapy is warranted in biliary tract cancer.

Permanent genetic resources added to molecular ecology resources database 1 December 2012-31 January 2013

This article documents the addition of 268 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alburnoides bipunctatus, Chamaerops humilis, Chlidonias hybrida, Cyperus papyrus, Fusarium graminearum, Loxigilla barbadensis, Macrobrachium rosenbergii, Odontesthes bonariensis, Pelteobagrus vachelli, Posidonia oceanica, Potamotrygon motoro, Rhamdia quelen, Sarotherodon melanotheron heudelotii, Sibiraea angustata, Takifugu rubripes, Tarentola mauritanica, Trimmatostroma sp. and Wallago attu. These loci were cross-tested on the following species: Alburnoides fasciatus, Alburnoides kubanicus, Alburnoides maculatus, Alburnoides ohridanus, Alburnoides prespensis, Alburnoides rossicus, Alburnoides strymonicus, Alburnoides thessalicus, Alburnoides tzanevi, Carassius carassius, Fusarium asiaticum, Leucaspius delineatus, Loxigilla noctis dominica, Pelecus cultratus, Phoenix canariensis, Potamotrygon falkneri, Trachycarpus fortune and Vimba vimba.

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2011-31 January 2012

This article documents the addition of 473 microsatellite marker loci and 71 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Barteria fistulosa, Bombus morio, Galaxias platei, Hematodinium perezi, Macrocentrus cingulum Brischke (a.k.a. M. abdominalis Fab., M. grandii Goidanich or M. gifuensis Ashmead), Micropogonias furnieri, Nerita melanotragus, Nilaparvata lugens Stål, Sciaenops ocellatus, Scomber scombrus, Spodoptera frugiperda and Turdus lherminieri. These loci were cross-tested on the following species: Barteria dewevrei, Barteria nigritana, Barteria solida, Cynoscion acoupa, Cynoscion jamaicensis, Cynoscion leiarchus, Cynoscion nebulosus, Cynoscion striatus, Cynoscion virescens, Macrodon ancylodon, Menticirrhus americanus, Nilaparvata muiri and Umbrina canosai. This article also documents the addition of 116 sequencing primer pairs for Dicentrarchus labrax.

Microdeletion/duplication at 15q13.2q13.3 among individuals with features of autism and other neuropsychiatric disorders

BACKGROUND

Segmental duplications at breakpoints (BP4-BP5) of chromosome 15q13.2q13.3 mediate a recurrent genomic imbalance syndrome associated with mental retardation, epilepsy, and/or electroencephalogram (EEG) abnormalities.

PATIENTS

DNA samples from 1445 unrelated patients submitted consecutively for clinical array comparative genomic hybridisation (CGH) testing at Children's Hospital Boston and DNA samples from 1441 individuals with autism from 751 families in the Autism Genetic Resource Exchange (AGRE) repository.

RESULTS

We report the clinical features of five patients with a BP4-BP5 deletion, three with a BP4-BP5 duplication, and two with an overlapping but smaller duplication identified by whole genome high resolution oligonucleotide array CGH. These BP4-BP5 deletion cases exhibit minor dysmorphic features, significant expressive language deficits, and a spectrum of neuropsychiatric impairments that include autism spectrum disorder, attention deficit hyperactivity disorder, anxiety disorder, and mood disorder. Cognitive impairment varied from moderate mental retardation to normal IQ with learning disability. BP4-BP5 covers approximately 1.5 Mb (chr15:28.719-30.298 Mb) and includes six reference genes and 1 miRNA gene, while the smaller duplications cover approximately 500 kb (chr15:28.902-29.404 Mb) and contain three reference genes and one miRNA gene. The BP4-BP5 deletion and duplication events span CHRNA7, a candidate gene for seizures. However, none of these individuals reported here have epilepsy, although two have an abnormal EEG.

CONCLUSIONS

The phenotype of chromosome 15q13.2q13.3 BP4-BP5 microdeletion/duplication syndrome may include features of autism spectrum disorder, a variety of neuropsychiatric disorders, and cognitive impairment. Recognition of this broader phenotype has implications for clinical diagnostic testing and efforts to understand the underlying aetiology of this syndrome.

Modelling the partially unknown distribution of wall lizards (Podarcis) in North Africa: ecological affinities, potential areas of occurrence, and methodological constraints

Species distribution modelling (SDM) is a powerful tool to investigate various biological questions with a spatial component, but is also sensitive to presence-data characteristics, particularly data precision and clustering. Here, we investigate the effect of these two factors on SDM using Maxent as the modelling technique and wall lizards (genus Podarcis Wagler, 1830) from North Africa as a model system. Podarcis are not ubiquitous in Africa as they are in Europe, but their ecological and distributional characteristics in this area are poorly known. Our results show that the most important environmental factors related to the distribution of this genus in North Africa are humidity, habitat type, and temperature. The areas of potential distribution predicted by models based on data sets with different precision and clustering characteristics show high relatedness to coastal areas and mountain ranges and extend to areas were presence records for these lizards are lacking. Our comparison of models based on different data sets indicates that finer scale models, even if based on fewer presence locations, outperform coarser scale ones. Data clustering does not have a negative effect on model performance, but is rather overcome by sample-size effects. Similar approaches may be of general application to other stenoic species for which available locations are scarce in comparison with the extension of the study area.

Contrasting patterns of population subdivision and historical demography in three western Mediterranean lizard species inferred from mitochondrial DNA variation

Pleistocene climatic oscillations were a major force shaping genetic variability in many taxa. We analyse the relative effects of the ice ages across a latitudinal gradient in the Western Mediterranean region, testing two main predictions: (i) species with historical distributions in northern latitudes should have experienced greater loss of suitable habitat, resulting in higher extinction of historical lineages than species distributed in southern latitudes, where the effects of the ice ages were not as drastic. This would be reflected in the observation of lower diversity and number of differentiated lineages in northern areas. (ii) a signature of demographic expansion following the climate amelioration should be obvious in northern species, whereas in the south evidence of long-term effective population size stability should be observed. We used as models three species of wall lizards (Podarcis bocagei, Podarcis carbonelli and Podarcis vaucheri) that replace each other along the study area. We investigated the patterns of mitochondrial DNA diversity and subdivision and obtained demographic parameter estimates for each species. Our results suggest that P. bocagei, the northernmost species, bears low genetic diversity, a shallow coalescent history and marks of a demographic expansion. In contrast, P. vaucheri, the species with a southernmost distribution, shows deeper coalescence events, complex geographical substructure and no evidence for population growth. The species with an intermediate distribution, P. carbonelli, shows average levels of diversity, substructure and population growth. Taken together, these results conform to our main predictions and are explained by a differential influence of the ice ages on distinct latitudes.

Ancient introgression of Lepus timidus mtDNA into L. granatensis and L. europaeus in the Iberian Peninsula

A 587 bp fragment of cytochrome b sequences from 90 individuals of 15 hare (Lepus) species and two outgroups were phylogenetically analysed and compared to an analysis derived from 474 bp sequences of the nuclear transferrin gene. Mountain hare (Lepus timidus) type mtDNA was observed in L. granatensis and L. europaeus from the Iberian Peninsula, far away from the extant distributional range of L. timidus. In addition to these two hare species, other hare species may also contain mtDNA from L. timidus. This species may have introgressed with other species of Lepus that occur within its present range, or where fossils indicate its historical presence during glacial periods. L. timidus mtDNA is common in the northern part of the L. granatensis range. Finally, we reassessed the phylogenetic relationships of the five European hare species based on both mitochondrial and nuclear DNA sequences.

Phylogeography of the Madeiran endemic lizard Lacerta dugesii inferred from mtDNA sequences

Partial sequences from two mitochondrial DNA genes, cytochrome b and 12S rRNA, were used to assess the phylogenetic relationships of populations of Lacerta dugesii from the volcanic Atlantic islands of Madeira, the Desertas, Porto Santo, and the Selvagens. All four-island groups are genetically distinguishable and populations within each contain similar degrees of genetic diversity. Molecular clock estimates suggest that the islands were colonized much later after their emergence compared to other Atlantic islands, possibly due to their greater geographical isolation. Mismatch analysis of all populations is consistent with exponential growth, as expected after colonization of empty niches. The Selvagens contain genetic substructuring between the islets.

Extracorporeal membrane oxygenation for Legionnaires disease: a case report

A case of Legionella pneumonia, severe adult respiratory distress syndrome (ARDS) and multiple organ failure is described in a patient who required extracorporeal membrane oxygenation (ECMO) prior to transfer to a hospital with ECMO facilities. She eventually made a good recovery, highlighting the potential benefits of ECMO in patients with severe and refractory ARDS.

Structure and evolution of the mitochondrial DNA complete control region in the Drosophila subobscura subgroup

The complete A + T-rich region of mitochondrial DNA (mtDNA) has been cloned and sequenced in the species of the Drosophila subobscura subgroup D. subobscura, D. madeirensis and D. guanche. Comparative analysis of these sequences with others already published has identified new sequence motifs that are conserved in Drosophila and other insects. A putative bi-directional promoter and a stop signal are proposed to be involved in the primary mtDNA strand replication of Drosophila. This region strongly resolves relationships of the species included in a phylogenetic analysis, both for closely related species and also at deeper phylogenetic levels when only the left and central domains are taken into account.

Partial correction of defective Cl(-) secretion in cystic fibrosis epithelial cells by an analog of squalamine

Defective cystic fibrosis (CF) transmembrane conductance regulator (CFTR)-mediated Cl(-) transport across the apical membrane of airway epithelial cells is implicated in the pathophysiology of CF lungs. A strategy to compensate for this loss is to augment Cl(-) transport through alternative pathways. We report here that partial correction of this defect could be attained through the incorporation of artificial anion channels into the CF cells. Introduction of GL-172, a synthetic analog of squalamine, into CFT1 cells increased cell membrane halide permeability. Furthermore, when a Cl(-) gradient was generated across polarized monolayers of primary human airway or Fischer rat thyroid cells in an Ussing chamber, addition of GL-172 caused an increase in the equivalent short-circuit current. The magnitude of this change in short-circuit current was ~30% of that attained when CFTR was maximally stimulated with cAMP agonists. Patch-clamp studies showed that addition of GL-172 to CFT1 cells also increased whole cell Cl(-) currents. These currents displayed a linear current-voltage relationship and no time dependence. Additionally, administration of GL-172 to the nasal epithelium of transgenic CF mice induced a hyperpolarization response to perfusion with a low-Cl(-) solution, indicating restoration of Cl(-) secretion. Together, these results demonstrate that in CF airway epithelial cells, administration of GL-172 is capable of partially correcting the defective Cl(-) secretion.

Identification of a dominant negative homeodomain mutation in Rieger syndrome

Mutations in the PITX2 bicoid-like homeobox gene cause Rieger syndrome. Rieger syndrome is an autosomal-dominant human disorder characterized by glaucoma as well as dental hypoplasia, mild craniofacial dysmorphism, and umbilical stump abnormalities. PITX2 has also been implicated in the development of multiple organs and left-right asymmetry in the body plan. The PITX2 homeodomain has a lysine at position 50, which has been shown to impart the bicoid-type (TAATCC) DNA binding specificity to other homeodomain proteins. A mutation (K88E), found in a Rieger syndrome patient, changes this lysine to glutamic acid. We were intrigued by the relatively pronounced phenotypic consequences of this K88E mutation. In the initial analyses, the mutant protein appeared to simply be inactive, with essentially no DNA binding and transactivation activities and, unlike the wild type protein, with an inability to synergize with another transcription factor, Pit-1. However, when the K88E DNA was cotransfected with wild type PITX2, analogous to the patient genotype, the K88E mutant suppressed the synergism of wild type PITX2 with Pit-1. In contrast, a different PITX2 homeodomain mutant, T68P, which is also defective in DNA binding, transactivation, and Pit-1 synergism activities, did not suppress the wild type synergism with Pit-1. These results describe the first dominant negative missense mutation in a homeodomain and support a model that may partially explain the phenotypic variation within Rieger syndrome.

Relationships of scincid lizards (Mabuya spp; Reptilia: Scincidae) from the Cape Verde islands based on mitochondrial and nuclear DNA sequences

Partial DNA sequences from two mitochondrial (mt) and one nuclear gene (cytochrome b, 12S rRNA, and C-mos) were used to estimate the phylogenetic relationships among the six extant species of skinks endemic to the Cape Verde Archipelago. The species form a monophyletic unit, indicating a single colonization of the islands, probably from West Africa. Mabuya vaillanti and M. delalandii are sister taxa, as indicated by morphological characters. Mabuya fogoensis and M. stangeri are closely related, but the former is probably paraphyletic. Mabuya spinalis and M. salensis are also probably paraphyletic. Within species, samples from separate islands always form monophyletic groups. Some colonization events can be hypothesized, which are in line with the age of the islands. C-mos variation is concordant with the topology derived from mtDNA.

Eating disturbances in women of color: an exploratory study of contextual factors in the development of disordered eating in Mexican American women

The relationship between ethnocultural identity, eating practices, and cultural expectations is complex. When there are conflicting cultural demands, eating disturbances can occur. These disturbances affect many aspects of a woman's life, including her quality of life, health, relationships, and academic/career success. Contextual variables that may influence eating disorders in women of color include (a) level of acculturation, (b) socioeconomic status (SES), (c) peer socialization, (d) family structure, and (e) immigration status. This study examined these variables in a college sample of 115 Mexican American women. Each completed a demographic questionnaire and standardized instruments to measure acculturation, eating disorder symptoms, and family issues. Multiple regression analysis indicated that family rigidity contributes to an increased susceptibility for bulimic symptoms (p < .0001). Poor peer socialization and family rigidity were related to the preoccupation with body size and slimness, thus placing young Mexican American women at greater risk for developing self-destructive eating patterns such as severe weight control and dieting behaviors (p < .0001). Implications for health, quality of life, and appropriate therapeutic care are discussed.

Autosomal dominant inheritance of a negative electroretinogram phenotype in three generations

PURPOSE

We report an abnormal electroretinogram with a negative configuration in a child who presented with moderate myopia, nystagmus, and visual developmental delay. We investigated the electroretinogram and explored the possibility of a metabotropic glutamate receptor subtype 6 mutation in six family members spanning four generations.

METHODS

Case report and family study: Complete eye examinations and Ganzfeld electroretinograms were recorded from the maternal great-grandmother, maternal grandmother, mother, uncle, and sibling of the 7-month-old female proband. The electroretinogram was repeated in the proband at 17 months of age. Dark adaptometry was performed in all adult subjects. Fundus photographs and visual field examinations were administered to the grandmother and mother. The metabotropic glutamate receptor subtype 6 gene was amplified and sequenced in all affected subjects.

RESULTS

The proband had a negative electroretinogram and a normal fundus. The maternal grandmother, uncle, and mother had an abnormal electroretinogram identical to the proband yet had no visual complaints. The ophthalmology examinations in the adult subjects were normal, and subsequent examination of the proband at 17 months, 5 years, and 6.5 years of age showed no changes in the fundus or refractive error. Her nystagmus resolved by 5 years of age. Rod threshold and visual fields were normal in the affected adult subjects. No mutation in the metabotropic glutamate receptor subtype 6 gene was found.

CONCLUSIONS

In this family, a negative electroretinogram was not associated with decreased rod threshold, visual acuity loss, visual field loss, muscle disease, or metabotropic glutamate receptor subtype 6 mutation. Additional study will be required to understand the nature of the negative electroretinogram phenotype in this family.

The monophyletic origin of freshwater crayfish estimated from nuclear and mitochondrial DNA sequences

Despite their widespread use as model organisms, the phylogenetic status of the around 520 species of freshwater crayfish is still in doubt. One hypothesis suggests two distinct origins of freshwater crayfish as indicated by their geographical distribution, with two centres of origin near the two present centres of diversity; one in south-eastern United States and the other in Victoria, Australia. An alternative theory proposes a single (monophyletic) origin of freshwater crayfish. Here we use over 3000 nucleotides from three different gene regions in estimating phylogenetic relationships among freshwater crayfish and related Crustacea. We show clear evidence for monophyly of freshwater crayfish and for the sister-group relationship between crayfish and clawed lobsters. Monophyly of the superfamilies Astacoidea and Parastacoidea is also supported. However, the monophyly of the family Cambaridae is questioned with the genus Cambaroides being associated with the Astacidae.

Enrollment of women in cardiovascular clinical trials funded by the National Heart, Lung, and Blood Institute

BACKGROUND

With the recognition that certain aspects of cardiovascular disease are specific to sex, the government has sought to ensure that federally funded clinical research yields adequate high-quality information about heart disease in women.

METHODS

We tabulated the numbers of men and women in cardiovascular clinical trials funded by the National Heart, Lung, and Blood Institute (NHLBI) between 1965 and 1998, recording both total numbers and the numbers for each type of cardiovascular disease. We analyzed the data according to the sex-specific prevalence of disease and assessed changes in enrollment over time. We performed a similar analysis after excluding all single-sex trials.

RESULTS

A total of 398,801 subjects (215,796 women and 183,005 men) were enrolled in NHLBI-funded studies of cardiovascular disease. The overall enrollment rate for women (54 percent) exceeded the prevalence of cardiovascular disease in women in the general population (49 percent) and increased over time (P=0.002). With single-sex trials excluded, the enrollment rate for women was 38 percent, which did not change significantly over time. In studies of coronary artery disease and hypertension the rates of enrollment of women were similar to or exceeded the prevalence of these disorders in women. The enrollment rate increased significantly over time in studies of coronary artery disease (P<0.001) but not in studies of hypertension or arrhythmia. Women were under-enrolled in studies of heart failure, and the rate of enrollment did not change significantly over time. When single-sex trials were excluded from the analysis of enrollment rates according to the prevalence of disease, the results were similar. There was no change in enrollment rates overtime for any category of disease.

CONCLUSIONS

Federal efforts to increase the representation of women in clinical trials have been moderately successful primarily because of the institution of a small number of large, single-sex trials involving coronary artery disease. There has been no change in the sex composition of cohorts in the majority of studies of cardiovascular disease.

Cationic lipid structure and formulation considerations for optimal gene transfection of the lung

Enhanced gene transduction to the lung using cationic lipids could be attained through optimization of the structure of the lipids and the formulation of the cationic lipid:plasmid DNA (pDNA) complexes. We have expanded on our earlier observation of the importance of the structural orientation of the cationic lipid headgroup. Through the synthesis of a number of matched pairs of cationic lipids differing only in the configuration of their headgroup, we confirmed that those harboring a T-shape headgroup are more active than their linear counterparts, at least when tested in the lungs of BALB/c mice. Additionally, we demonstrated that not only are the structural considerations of these cationic lipids important, but also their protonation state, the free base being invariably more active than its salt counterpart. The salt forms of cationic lipids bound pDNA with greater avidity, which may have affected their subsequent intracellular dissolution and transit of the pDNA to the nucleus. Inclusion of a number of frequently used solutes in the vehicle severely inhibited the gene transfection activity of the cationic lipids. The selection of neutral co-lipids was also an important factor for overall transfection activity of the formulation, with significant gains in transfection activity realized when diphytanoylphosphatidylethanolamine or dilinoleoylphosphatidylethanolamine were used in lieu of dioleoylphosphatidylethanolamine. Finally, we showed that a transacylation reaction could occur between the cationic lipid and neutral co-lipid which reduced the transfection activity of the complexes. It is the hope that as our understanding of the many factors that influence the activity of these cationic lipid:pDNA complexes improves, formulations with much greater potency can be realized for use in the treatment of pulmonary diseases.

Intragenomic variation within ITS1 and ITS2 of freshwater crayfishes (Decapoda: Cambaridae): implications for phylogenetic and microsatellite studies

Intragenomic variation in ITS1 and ITS2 is known to exit but is widely ignored in phylogenetic studies using these gene regions. The amount of variation in seven crayfish species, including three populations of Orconectes luteus and two of Procambarus clarkii, was assessed by sequencing 3, 5, or 10 clones from the same individuals, for a total of 77 sequences. The ITS1 and ITS2 sequences reported here are some of the longest known, with aligned lengths of 760 and 1,300 bp, respectively. They contain multiple microsatellite insertions, all of which show considerable intragenomic variation in the number of repeat elements. This variation is enough to obscure phylogenetic relationships at the population level, although relationships between species can be estimated. Given the hybridization techniques used to locate microsatellites, multiple-copy regions like ITS1 and ITS2 will be preferentially found if they contain microsatellites, and in these cases the microsatellites will not behave as typical Mendelian markers and could give spurious results.

Evaluation of Western Australian canola meal for growing pigs

Twenty samples of canola seed collected throughout south-western Australia after the 1995 harvest were analysed for oil and total glucosinolate levels. Average oil and total glucosinolate levels were 378 g/kg and 14.0 mmol/kg (oil-free dry matter, DM), respectively. The subsequent single-press canola meal [containing an average of 96 g/kg oil and 10.5 mmol/kg total glucosinolates (oil-free DM)] extracted from 8 batches of the original canola seed was then used in 2 growth experiments. In Expt 1, canola meal was included in diets for growing–finishing pigs at levels of 0, 50, 100, 150, and 200 g/kg in the diet, and replaced Australian sweet lupins. In this study, feed was offered on an ad libitum basis between 23 and 110 kg liveweight (LW). In Expt 2, the same inclusion levels of canola meal were used; however, feed intake was standardised across treatments (approximately 3 times maintenance) to assess the impact of glucosinolate intake on performance and thyroid weight in pigs between 19 and 94 kg LW. In Expt 1, performance was similar (P > 0.05) in pigs offered up to 200 g/kg of canola meal. In Expt 2, average daily gain was similar between treatments (P > 0.05), although a linear decline in both daily gain (P = 0.244) and feed : gain (P < 0.05) with increasing canola meal levels was detected. Increasing amounts of canola meal in the diet were associated with heavier (P < 0.001) thyroid weights, suggesting a negative influence of the products of glucosinolate hydrolysis on thyroid function. Single-press canola meal is a suitable alternative to other protein sources; however, at levels >150 g/kg for growing–finishing pigs, higher intakes of glucosinolates were associated with a tendency for decreased pig performance and thyroid hypertrophy despite the canola varieties used being ‘low glucosinolate’.