Ecology and evolution of Cardiaspina psyllids, their bacterial endosymbionts and parasitoid wasps

Identifying, classifying and ranking the major factors and processes influencing population dynamics and community structure of animals are the greatest challenges of ecological research. Examples of these factors and processes are climate, competition, resource limitation, natural enemies and symbionts. Cardiaspina (Hemiptera: Aphalaridae) are psyllids that specifically feed on Eucalyptus and are well known for experiencing major population outbreaks that can result in area-wide defoliation. An outbreak of a Cardiaspina sp. of uncertain species assignment on Eucalyptus moluccana (Grey Box) in the critically endangered Cumberland Plain Woodland of Western Sydney that had started just prior to the start of this PhD project provided an ideal case study to investigate the factors and processes driving this major herbivore outbreak during its peak and decline (Chapter 2). Minimum winter temperature differences in different study sites of the fragmented woodland across the large outbreak region had a significant direct impact on psyllid population development and distribution. Furthermore, winter temperature may have indirectly impacted outbreak dynamics via constrained parasitoid aggregation between study sites due to host developmental differences. Resource depletion due to area-wide defoliation and summer heat waves were responsible for the dramatic decline in psyllid populations that occurred during this study, while the principal natural enemies (parasitoid wasps) did not appear to play a significant role. Parasitoid wasps were inhibited in their regulation of the psyllid outbreak by a greater mortality rate in larval stages than their psyllid host. Parasitised hosts were more susceptible than unparasitised hosts to mortality brought about by host overabundance (resulting into intraspecific psyllid competition), and summer heat waves. Larval parasitoid mortality, loss of life cycle synchrony between woodland fragments and hyperparasitisation of parasitoids by hyperparasitoids all appeared to contribute to parasitisation being inversely density dependent to host density. It was concluded that this may provide a general explanation for the low incidence of reported density dependence of parasitisation in natural ecosystems, in particular during outbreaks, and therefore when host density is high. At a different trophic level, psyllids harbour bacterial endosymbionts. Carsonella (Gammaproteobacteria) is their primary bacterial endosymbiont and expected to provide its hosts with essential amino acids that are deficient in their plant sap diet. Using cophylogenetic analyses, Carsonella appeared to show strict and long-term cospeciation with its psyllid hosts, indicative of a long history of coevolution (Chapter 4). This association also allowed testing of phylogenetic relationships, based on psyllid and Carsonella DNA, of psyllid species with uncertain species assignment and highlighted the need for future taxonomic revision and potential collapse of several Cardiaspina species into fewer taxa. Furthermore, recent genome analyses of Carsonella and psyllid secondary bacterial endosymbionts has suggested that secondary endosymbionts may be required to complement Carsonella which is not able to provide the full suite of essential amino acids to its hosts. In this study, it was found that a secondary endosymbiont (Arsenophonus or Sodalis, both Gammaproteobacteria) was present at 100 % prevalence in 12 populations of Cardiaspina psyllids and one of the closely related Glycaspis. While cophylogenetic analyses indicated their coevolution with psyllids includes host switches and endosymbiont replacement, there were molecular patterns in two endosymbiont lineages that were characteristic of long-term host associations. Secondary endosymbionts of Cardiaspina appeared to have obligate relationships with psyllid hosts just as it was confirmed for their primary endosymbiont. This is possibly applicable to the entire superfamily Psylloidea. The principal natural enemies of psyllids, parasitoids belonging to the Psyllaephagus genus (Hymenoptera: Encyrtidae), were prominent in up to seven species of Cardiaspina psyllids and in one species of related Spondyliaspis (Chapter 5). Psyllaephagus appeared to be characterised by the presence of cryptic species. Diversification of Psyllaephagus was largely comprised of patterns of host specialisation and host switches between co-occurring hosts, while the generalist hyperparasitoid Coccidoctonus psyllae (Hymenoptera: Encyrtidae) codiverged with its primary parasitoid host complex suggesting potential ongoing speciation in this hyperparasitoid species. The high degree of specialisation suggested that the generalist strategy of parasitoids is likely to be rare even amongst closely related hosts, such as the Cardiaspina species of this study, and that parasitoid species richness is probably much higher than currently estimated. This PhD thesis has unravelled major factors and processes influencing population dynamics, community structure and biodiversity of Australian native psyllids that are of ecological significance due to their outbreak potential on Eucalyptus. Population dynamic studies of outbreaking species are important for predictions of future insect outbreaks, in particular as the frequency and intensity of insect outbreaks are expected to increase with climate change

Renal calcified mass misdiagnosed as a renal calculus in an adult with tuberculosis “autonephrectomy”: a case report

INTRODUCTION: Tuberculosis was once a disease much more prominent in the minds of UK urologists. The dramatic reduction in incidence following the success of antituberculous therapy has meant that new generation surgeons have little or no experience of the effects and management of tuberculosis of the kidney. With concern over multidrug resistant tuberculosis, human immunodeficiency virus associated tuberculosis and immigration of persons from areas endemic with this disorder, clinicians may see an increase in cases of renal tuberculosis. Renal tuberculosis "autonephrectomy" is the end stage of chronic renal tuberculosis infection and results from the caseous necrosis and progressive cavitation of the kidney. Resultant calcification may mimic the appearances of a renal calculus on plane film X-ray. Back, flank and abdominal pain are non-specific symptoms often investigated by General Practitioners using plane film X-ray. Clinicians not considering a diagnosis of renal tuberculosis may confuse the radiographic appearances with that of a renal calculus as occurred in our case. Once a diagnosis of tuberculosis autonephrectomy is made the next decision is whether any further investigations and treatment is necessary as the condition has been reported to be a cause of hypertension and reactivation of tuberculosis is also possible. CASE PRESENTATION: We describe the case of a 66 year old Caucasian female who presented to her General Practitioner with left sided lumber and loin pain. A lumbar spine X-ray showed a calcified mass reported as a renal calculus. Urological opinion was sort and a computerised tomogram confirmed a renal tuberculosis "auto nephrectomy". The patient had been diagnosed with tuberculosis aged 16. The patient had no lower urinary tract symptoms and normal urinalysis. Although there is some evidence to suggest nephrectomy is beneficial in treating hypertension in these patients (the patient in our case was on two anti hypertensive preparations), the patient did not want to consider surgery as her symptoms had settled spontaneously. CONCLUSION: Although very rare in non endemic countries clinicians still need to consider a diagnosis of renal tuberculosis in patients with previous tuberculosis exposure and calcification of the urinary tract. In cases of uncontrolled hypertension consideration should be given to nephrectomy in cases of end stage renal tuberculosis. This decision should be made in consultation with a nephrologist

Poor cardiorespiratory fitness is a risk factor for sepsis in patients awaiting liver transplantation

Background Patients with advanced liver disease are at increased risk of infection and other complications. A significant proportion of patients also have poor fitness and low muscle mass. The primary aim of this study was to investigate if cardiorespiratory fitness and body composition are risk factors for sepsis and other complications of advanced liver disease. Methods Patients being listed for liver transplantation underwent cardiopulmonary exercise testing to determine ventilatory threshold (VT). Computed tomography was used to measure skeletal muscle and subcutaneous and visceral adipose tissue indexes. All unplanned hospital admissions, deaths or delistings prior to transplantation were recorded. Results Eighty-two patients [aged 55.1 (50.6–59.4) years, median (interquartile range); male 87%] achieved a median VT of 11.7 (9.7–13.4) mL[BULLET OPERATOR]kg-1[BULLET OPERATOR]min-1. Their median MELD-Na score was 18 (14–22); and 37 had hepatocellular carcinoma. There were 50 admissions in 31 patients; with 16 admissions for sepsis in 13 patients. Patients with sepsis had a significantly lower VT [sepsis 9.5 (7.8–11.9), no sepsis 11.8 (10.5–13.8) mL[BULLET OPERATOR]kg-1[BULLET OPERATOR]min-1; P=0.003]. No body composition variables correlated with sepsis, nor were there any significant associations between VT and unplanned admissions for other indications. Multivariate logistic regression demonstrated that VT was independently associated with a diagnosis of sepsis (P=0.03). Poisson regression revealed that VT was a significant predictor for the number of septic episodes (P=0.02); independent of age, MELD-Na score, hepatocellular carcinoma diagnosis, presence of ascites, and beta-blocker use. Conclusion Poor cardiorespiratory fitness is an independent risk factor for the development of sepsis in advanced liver disease

Strong glacial-interglacial variability in upper ocean hydrodynamics, biogeochemistry, and productivity in the southern Indian Ocean

In the southern Indian Ocean, the position of the subtropical front - the boundary between colder, fresher waters to the south and warmer, saltier waters to the north - has a strong influence on the upper ocean hydrodynamics and biogeochemistry. Here we analyse a sedimentary record from the Agulhas Plateau, located close to the modern position of the subtropical front and use alkenones and coccolith assemblages to reconstruct oceanographic conditions over the past 300,000 years. We identify a strong glacial-interglacial variability in sea surface temperature and productivity associated with subtropical front migration over the Agulhas Plateau, as well as shorter-term high frequency variability aligned with variations in high latitude insolation. Alkenone and coccolith abundances, in combination with diatom and organic carbon records indicate high glacial export productivity. We conclude that the biological pump was more efficient and strengthened during glacial periods, which could partly account for the reported reduction in atmospheric carbon dioxide concentrations. Migration of the Subtropical Front during glacial and interglacial periods resulted in variability in the strength of the biological pump in the Southern Ocean sector of the Indian Ocean, according to sedimentary records from the Agulhas Plateau.This work used samples and data provided by the IODP. We are thankful for the support from the crew of the R/V JOIDES Resolution and IODP staff. This work is funded through the Universidad de Salamanca Postdoctoral Contract supported by the Ministerio de Ciencia, Innovación y Universidades Grant RTI2018-099489-B-I00 and the German Science Foundation (DFG) Research Center/Cluster of Excellence ‘The Ocean in the Earth System' (MARUM; Grant No. 49926684). We acknowledge financial support from the National Science Foundation of the US under Award No. 1737218 (M.A.B), the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska Curie Grant Agreement No. 799531 (M.S.P.), and the Spanish Ministry of Science and Innovation Grant CTM2017-89711-C2-1-P, co-funded by the European Union through FEDER funds (F.J.J.E.

Osseous metaplasia in an ulcerating tubular adenoma of the colon: a case report

<p>Abstract</p> <p>Introduction</p> <p>Heterotopic bone is rarely found in the gastrointestinal tract. Here we report a rare case of metaplastic ossification within a benign ulcerating adenoma and review the literature concerning the aetiology.</p> <p>Case presentation</p> <p>A 63-year-old woman, who presented with a history of melaena, was found at colonoscopy to have a pedunculated ulcerating polyp. Histological examination demonstrated multiple areas of osseous metaplasia within the polyp stroma.</p> <p>Conclusion</p> <p>Heterotopic ossification in colonic adenomas is a particularly rare phenomenon, with the majority of cases occurring within malignant lesions. The suggested mechanisms for its aetiology still remain unclear.</p

Novel patient-derived xenograft mouse model for pancreatic acinar cell carcinoma demonstrates single agent activity of oxaliplatin

Additional file 4: Figure S3. Integrated genomic viewer (IGV) of BRCA2 gene. IGV displays genomic data of the PA-018 PAAC PDTX model. Chromosome 13 (Chr 13) is shown and 5bp deletions are found after position 32907365 (c.1755_1759del5), this region resides on exon 10 of BRCA2. The bottom of the image shows the nucleotides and amino acids that correspond to the reference sequence of the BRCA2 gene and protein

Glacial southern ocean expansion recorded in foraminifera-bound nitrogen isotopes from the Agulhas plateau during the mid-Pleistocene transition

The emergence of 100-Kyr glacial cycles (The Mid-Pleistocene Transition [MPT]) is attributed in part to slower global overturning circulation and iron stimulation of biological carbon drawdown in the Southern Ocean. We present foraminifera-bound nitrogen isotope values and polar planktic foraminifera abundances from the Agulhas Plateau that show that increases in biogenic sediment accumulation coincide with northward migrations of the Subtropical Frontal Zone (STFZ) and elevated foraminifera-bound nitrogen isotope values during MPT glacial episodes. The nitrogen isotope values of two planktic foraminifera species, Globigerina bulloides and Globorotalia inflata show remarkable coherence amongst the sea surface temperature gradient between the STFZ and SAZ, and polar foraminifera abundances, indicating a strong relationship between nitrogen isotope dynamics above the Agulhas Plateau and migrations of the STFZ. Northward migration of the STFZ may have been essential to prolonging glacial intervals by increasing deep ocean carbon storage via a northward shift of the South Westerly Winds and a reduction in upwelling, delivery of fresher surface waters into the upper limb of global overturning circulation, or inhibiting heat and salt delivery to the Atlantic as Agulhas Leakage

Metal-organic framework templated electrodeposition of functional gold nanostructures

Utilizing a pair of quick, scalable electrochemical processes, the permanently porous MOF HKUST-1 was electrochemically grown on a copper electrode and this HKUST-1-coated electrode was used to template electrodeposition of a gold nanostructure within the pore network of the MOF. Transmission electron microscopy demonstrates that a proportion of the gold nanostructures exhibit structural features replicating the pore space of this ∼1.4 nm maximum pore diameter MOF, as well as regions that are larger in size. Scanning electron microscopy shows that the electrodeposited gold nanostructure, produced under certain conditions of synthesis and template removal, is sufficiently inter-grown and mechanically robust to retain the octahedral morphology of the HKUST-1 template crystals. The functionality of the gold nanostructure within the crystalline HKUST-1 was demonstrated through the surface enhanced Raman spectroscopic (SERS) detection of 4-fluorothiophenol at concentrations as low as 1 μM. The reported process is confirmed as a viable electrodeposition method for obtaining functional, accessible metal nanostructures encapsulated within MOF crystals

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy