63 research outputs found

    River ecosystem resilience to extreme flood events

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    Floods have a major influence in structuring river ecosystems. Considering projected increases in highā€magnitude rainfall events with climate change, major flooding events are expected to increase in many regions of the world. However, there is uncertainty about the effect of different flooding regimes and the importance of flood timing in structuring riverine habitats and their associated biotic communities. In addition, our understanding of community response is hindered by a lack of longā€term datasets to evaluate river ecosystem resilience to flooding. Here we show that in a river ecosystem studied for 30 years, a major winter flood reset the invertebrate community to a community similar to one that existed 15 years earlier. The community had not recovered to the preflood state when recurrent summer flooding 9 years later reset the ecosystem back to an even earlier community. Total macroinvertebrate density was reduced in the winter flood by an order of magnitude more than the summer flood. Meiofaunal invertebrates were more resilient to the flooding than macroinvertebrates, possibly due to their smaller body size facilitating greater access to inā€stream refugia. Pacific pink salmon escapement was markedly affected by the winter flood when eggs were developing in redds, compared to summer flooding, which occurred before the majority of eggs were laid. Our findings inform a proposed conceptual model of three possible responses to flooding by the invertebrate community in terms of switching to different states and effects on resilience to future flooding events. In a changing climate, understanding these responses is important for river managers to mitigate the biological impacts of extreme flooding effects

    Analysis of cancer risk and BRCA1 and BRCA2 mutation prevalence in the kConFab familial breast cancer resource

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    INTRODUCTION: The Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab) is a multidisciplinary, collaborative framework for the investigation of familial breast cancer. Based in Australia, the primary aim of kConFab is to facilitate high-quality research by amassing a large and comprehensive resource of epidemiological and clinical data with biospecimens from individuals at high risk of breast and/or ovarian cancer, and from their close relatives. METHODS: Epidemiological, family history and lifestyle data, as well as biospecimens, are collected from multiple-case breast cancer families ascertained through family cancer clinics in Australia and New Zealand. We used the Tyrer-Cuzick algorithms to assess the prospective risk of breast cancer in women in the kConFab cohort who were unaffected with breast cancer at the time of enrolment in the study. RESULTS: Of kConFab's first 822 families, 518 families had multiple cases of female breast cancer alone, 239 had cases of female breast and ovarian cancer, 37 had cases of female and male breast cancer, and 14 had both ovarian cancer as well as male and female breast cancer. Data are currently held for 11,422 people and germline DNAs for 7,389. Among the 812 families with at least one germline sample collected, the mean number of germline DNA samples collected per family is nine. Of the 747 families that have undergone some form of mutation screening, 229 (31%) carry a pathogenic or splice-site mutation in BRCA1 or BRCA2. Germline DNAs and data are stored from 773 proven carriers of BRCA1 or BRCA1 mutations. kConFab's fresh tissue bank includes 253 specimens of breast or ovarian tissue Ć¢ both normal and malignant Ć¢ including 126 from carriers of BRCA1 or BRCA2 mutations. CONCLUSION: These kConFab resources are available to researchers anywhere in the world, who may apply to kConFab for biospecimens and data for use in ethically approved, peer-reviewed projects. A high calculated risk from the Tyrer-Cuzick algorithms correlated closely with the subsequent occurrence of breast cancer in BRCA1 and BRCA2 mutation positive families, but this was less evident in families in which no pathogenic BRCA1 or BRCA2 mutation has been detected.Graham J Mann, Heather Thorne, Rosemary L Balleine, Phyllis N Butow, Christine L Clarke, Edward Edkins, Gerda M Evans, Sian Fereday, Eric Haan, Michael Gattas, Graham G Giles, Jack Goldblatt, John L Hopper, Judy Kirk, Jennifer A Leary, Geoffrey Lindeman, Eveline Niedermayr, Kelly-Anne Phillips, Sandra Picken, Gulietta M Pupo, Christobel Saunders, Clare L Scott, Amanda B Spurdle, Graeme Suthers, Kathy Tucker and Georgia Chenevix-Trenc

    Attachment and coping in psychosis in relation to spiritual figures

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    Background: Studies have found higher levels of insecure attachment in individuals with schizophrenia. Attachment theory provides a framework necessary for conceptualizing the development of interpersonal functioning. Some aspects of the attachment of the believer to his/her spiritual figure are similar to those between the child and his/her parents. The correspondence hypothesis suggests that early child-parent interactions correspond to a person's relation to a spiritual figure. The compensation hypothesis suggests that an insecure attachment history would lead to a strong religiousness/spirituality as a compensation for the lack of felt security. The aim of this study is to explore attachment models in psychosis vs. healthy controls, the relationships between attachment and psychopathology and the attachment processes related to spiritual figures. Methods: Attachment models were measured in 30 patients with psychosis and 18 controls with the AAI (Adult Attachment interview) in relationship with psychopathology. Beliefs and practices related to a spiritual figure were investigated by qualitative and quantitative analyses. Results: Patients with psychosis showed a high prevalence of insecure avoidant attachment. Spiritual entities functioned like attachment figures in two thirds of cases. Interviews revealed the transformation of internal working models within relation to a spiritual figure: a compensation process was found in 7 of the 32 subjects who showed a significant attachment to a spiritual figure. Conclusions: Attachment theory allows us to highlight one of the underlying dimensions of spiritual coping in patients with psychosis

    Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella franklini

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    Currently there is very limited understanding of genetic population structure in the Antarctic benthos. We conducted one of the first studies of microsatellite variation in an Antarctic benthic invertebrate, using the ubiquitous amphipod Orchomenella franklini (Walker, 1903). Seven microsatellite loci were used to assess genetic structure on three spatial scales: sites (100 s of metres), locations (1ā€“10 kilometres) and regions (1000 s of kilometres) sampled in East Antarctica at Casey and Davis stations. Considerable genetic diversity was revealed, which varied between the two regions and also between polluted and unpolluted sites. Genetic differentiation among all populations was highly significant (FSTā€Š=ā€Š0.086, RSTā€Š=ā€Š0.139, p<0.001) consistent with the brooding mode of development in O. franklini. Hierarchical AMOVA revealed that the majority of the genetic subdivision occurred across the largest geographical scale, with Nemā‰ˆ1 suggesting insufficient gene flow to prevent independent evolution of the two regions, i.e., Casey and Davis are effectively isolated. Isolation by distance was detected at smaller scales and indicates that gene flow in O. franklini occurs primarily through stepping-stone dispersal. Three of the microsatellite loci showed signs of selection, providing evidence that localised adaptation may occur within the Antarctic benthos. These results provide insights into processes of speciation in Antarctic brooders, and will help inform the design of spatial management initiatives recently endorsed for the Antarctic benthos

    Physiological normoxia and absence of EGF is required for the long-term propagation of anterior neural precursors from human pluripotent cells

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    Widespread use of human pluripotent stem cells (hPSCs) to study neuronal physiology and function is hindered by the ongoing need for specialist expertise in converting hPSCs to neural precursor cells (NPCs). Here, we describe a new methodology to generate cryo-preservable hPSC-derived NPCs that retain an anterior identity and are propagatable long-term prior to terminal differentiation, thus abrogating regular de novo neuralization. Key to achieving passagable NPCs without loss of identity is the combination of both absence of EGF and propagation in physiological levels (3%) of O2. NPCs generated in this way display a stable long-term anterior forebrain identity and importantly retain developmental competence to patterning signals. Moreover, compared to NPCs maintained at ambient O2 (21%), they exhibit enhanced uniformity and speed of functional maturation, yielding both deep and upper layer cortical excitatory neurons. These neurons display multiple attributes including the capability to form functional synapses and undergo activity-dependent gene regulation. The platform described achieves long-term maintenance of anterior neural precursors that can give rise to forebrain neurones in abundance, enabling standardised functional studies of neural stem cell maintenance, lineage choice and neuronal functional maturation for neurodevelopmental research and disease-modelling

    Patella height measurements in patients with patellofemoral instability: the power to predict patella height indices

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    \ua9 Crown 2024.Introduction: Numerous indices for patella height measurement are described in the literature; however, there is not a universally accepted ā€˜gold standardā€™. Choice of indices varies depending on personal preference and previous experience, making it difficult to compare results between studies. The aims of this study were to assess the correlation between different patella height indices and generate statistically derived formulae that can be used to predict the value of one patella height ratio when another is known. Materials and Methods: Patients with patellofemoral instability were radiologically evaluated using both X-ray and Magnetic Resonance Imaging (MRI) of the knee. Two observers measured six validated patella height indices at two separate time intervals. All measurements were aggregated together and a mean average for each patella height ratio was calculated. These results were then statistically analysed using Pearson product-moment correlation and linear regression tests. Results: Forty-four patients were included in the study. A statistically significant correlation was found between the majority of patella height ratios. On X-ray, the strongest correlation (r = 0.92, p &lt; 0.001) and regression (R2 = 0.85, p &lt; 0.001) coefficients were between the Blackburne-Peel and Caton-Dechamps ratios, with the formula; CD = 0.20 + (0.95xBP). On MRI, the strongest correlation (r = āˆ’ 0.84, p &lt; 0.001) and regression (R2 = 0.71, p &lt; 0.001) coefficients were between the Patellophyseal index and Patellotrochlear index, with the formula; PP = 1.02-(1.10xPT). Conclusion: The formulae produced in this study can predict the value of one patella height ratio when the results of another are known. This could facilitate systematic reviews and meta-analyses by allowing the pooling together of data from many studies
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