Transfer of old ‘reactivated’ memory retrieval cues in rats

The present studies examined whether the retrieval of an old ‘reactivated’ memory could be brought under the control of new contextual cues. In Experiment 1 rats trained in one context were exposed to different contextual cues either immediately, 60 min, or 120 min after a cued reactivation of the training memory. When tested in the shifted context, subjects exposed shortly after reactivation treated the shifted context as the original context. This transfer diminished with longer post-reactivation delays. Experiment 2 replicated the basic finding and demonstrated that the transfer of the old retrieval cues was specific to the contextual cues present during exposure. These findings are consistent with previous research (i.e., Briggs, Fitz, & Riccio, in press) showing the transfer of retrieval cues for a new memory, and demonstrating a similarity (in this case) between newly acquired and old reactivated memories

Fate of the original retrieval cues following the transfer of memory in rats

Exposure to contextual cues immediately after conditioning enables the new stimuli to retrieve the target memory. But what is the fate of the original cues after this type of transfer of properties? Have they been supplanted by the new cues, or are both sets of stimuli now effective? To address this issue, an experiment was conducted investigating the effectiveness of the original training cues following the transfer of retrieval cues to a new context. Rats were exposed to contextual cues different from training immediately after learning a punishment task. Subjects tested in the new context treated the context as if it were the original, i.e., retrieval cues were transferred to the shifted context. In addition, this transfer had no effect on the original memory as rats that were tested in the original context behaved similarly to those tested in the shifted context. It appears that this transfer of retrieval cues is not a case of erase-and-update, but rather the cues remain for the original context and also become associated with the new context where exposure took place

Transfer of extinction retrieval cues attenuates the renewal effect in rats

An experiment using rats investigated whether retrieval cues for an extinction memory could also be brought under the control of cues not physically present during extinction learning. Following the extinction of a fear motivated task in a context different from original learning, rats were exposed to the training context either immediately, 30 min, or 60 min after extinction. When tested back in the original context, rats that were exposed to the training context immediately following extinction treated the context as if it had received extinction in that setting, i.e., no renewal. This attenuation of renewal was reduced or eliminated with longer post-extinction delays, which suggests the importance of an active extinction memory during exposure. These findings are consistent with other research examining the transfer of retrieval cues using original memories and old reactivated memories, and in this case demonstrate a similarity between extinction learning with original acquisition

Behaviour of non-donor specific antibodies during rapid re-synthesis of donor specific HLA antibodies after antibody incompatible renal transplantation

Background: HLA directed antibodies play an important role in acute and chronic allograft rejection. During viral infection of a patient with HLA antibodies, the HLA antibody levels may rise even though there is no new immunization with antigen. However it is not known whether the converse occurs, and whether changes on non-donor specific antibodies are associated with any outcomes following HLA antibody incompatible renal transplantation. Methods: 55 patients, 31 women and 24 men, who underwent HLAi renal transplant in our center from September 2005 to September 2010 were included in the studies. We analysed the data using two different approaches, based on; i) DSA levels and ii) rejection episode post transplant. HLA antibody levels were measured during the early post transplant period and corresponding CMV, VZV and Anti-HBs IgG antibody levels and blood group IgG, IgM and IgA antibodies were quantified. Results: Despite a significant DSA antibody rise no significant non-donor specific HLA antibody, viral or blood group antibody rise was found. In rejection episode analyses, multiple logistic regression modelling showed that change in the DSA was significantly associated with rejection (p = 0.002), even when adjusted for other antibody levels. No other antibody levels were predictive of rejection. Increase in DSA from pre treatment to a post transplant peak of 1000 was equivalent to an increased chance of rejection with an odds ratio of 1.47 (1.08, 2.00). Conclusion: In spite of increases or decreases in the DSA levels, there were no changes in the viral or the blood group antibodies in these patients. Thus the DSA rise is specific in contrast to the viral, blood group or third party antibodies post transplantation. Increases in the DSA post transplant in comparison to pre-treatment are strongly associated with occurrence of rejection

BATSE Observations of Gamma-Ray Burst Spectra. IV. Time-Resolved High-Energy Spectroscopy

We report on the temporal behavior of the high-energy power law continuum component of gamma-ray burst spectra with data obtained by the Burst and Transient Source Experiment. We have selected 126 high fluence and high flux bursts from the beginning of the mission up until the present. Much of the data were obtained with the Large Area Detectors, which have nearly all-sky coverage, excellent sensitivity over two decades of energy and moderate energy resolution, ideal for continuum spectra studies of a large sample of bursts at high time resolution. At least 8 spectra from each burst were fitted with a spectral form that consisted of a low-energy power law, a spectral break at middle energies and a high-energy continuum. In most bursts (122), the high-energy continuum was consistent with a power law. The evolution of the fitted high-energy power-law index over the selected spectra for each burst is inconsistent with a constant for 34% of the total sample. The sample distribution of the average value for the index from each burst is fairly narrow, centered on -2.12. A linear trend in time is ruled out for only 20% of the bursts, with hard-to-soft evolution dominating the sample (100 events). The distribution for the total change in the power-law index over the duration of a burst peaks at the value -0.37, and is characterized by a median absolute deviation of 0.39, arguing that a single physical process is involved. We present analyses of the correlation of the power-law index with time, burst intensity and low-energy time evolution. In general, we confirm the general hard-to-soft spectral evolution observed in the low-energy component of the continuum, while presenting evidence that this evolution is different in nature from that of the rest of the continuum.Comment: 30 pages, with 2 tables and 9 figures To appear in The Astrophysical Journal, April 1, 199

An evidence-based approach to understanding the competency development needs of the health service management workforce in Australia

Background: Competent managers are essential to the productivity of organisations and the sustainability of health systems. Effective workforce development strategies sensitive to the current competency development needs of health service managers (HSMs) are required. Purpose: To conduct a 360° assessment of the competence of Australian HSMs to identify managerial competence levels, and training and development needs. Methods: Assessment of 93 middle-level HSMs from two public hospitals (n = 25) and five community health services (CHS) (n = 68), using the Managerial Competency Assessment Partnership (MCAP) framework and tool, conducted between 2012 and 2014 in Victoria, Australia. Results: Mean competency scores from both self- and combined colleagues' assessments indicated competence (scores greater than five but less than six) without guidance, but many HSMs have not had extensive experience. Around 12% of HSMs were unable to demonstrate the competency of 'evidence-informed decision-making' and 4% of HSMs were unable to demonstrate the competency of 'enabling and managing change'. Conclusion: The assessments confirmed managerial competence for the majority of middle-level HSMs from hospitals and CHS in Victoria, but found competency gaps. In addition, the assessment confirmed managerial strengths and weaknesses varied across management groups from different organisations. These findings suggest that the development of strategies to strengthen the health service management workforce should be multifaceted. Practice implications: A focus on competency in performance evaluation and development using the MCAP framework and tool not only provides insights into performance of HSMs, but also has the potential to provide an organisation strategic advantage through succession planning and advancing managers' competence via learning needs analysis and targeted professional development. Linking competencies of HSMs to organisational objectives and strategies provides optimal use of the human resource capacity, improving the organisation's productivity and sustainability

Towards a fullerene-based quantum computer

Molecular structures appear to be natural candidates for a quantum technology: individual atoms can support quantum superpositions for long periods, and such atoms can in principle be embedded in a permanent molecular scaffolding to form an array. This would be true nanotechnology, with dimensions of order of a nanometre. However, the challenges of realising such a vision are immense. One must identify a suitable elementary unit and demonstrate its merits for qubit storage and manipulation, including input / output. These units must then be formed into large arrays corresponding to an functional quantum architecture, including a mechanism for gate operations. Here we report our efforts, both experimental and theoretical, to create such a technology based on endohedral fullerenes or 'buckyballs'. We describe our successes with respect to these criteria, along with the obstacles we are currently facing and the questions that remain to be addressed.Comment: 20 pages, 13 figs, single column forma

Benefits of robotic cystectomy with intracorporeal diversion for patients with low cardiorespiratory fitness: a prospective cohort study

Background: Patients undergoing radical cystectomy have associated comorbidities resulting in reduced cardiorespiratory fitness. Preoperative cardiopulmonary exercise testing (CPET) measures including anaerobic threshold (AT) can predict major adverse events (MAE) and hospital length of stay (LOS) for patients undergoing open and robotic cystectomy with extracorporeal diversion. Our objective was to determine the relationship between CPET measures and outcome in patients undergoing robotic radical cystectomy and intracorporeal diversion (intracorporeal robotic assisted radical cystectomy [iRARC]). Methods: A single institution prospective cohort study in patients undergoing iRARC for muscle invasive and high-grade bladder cancer. Inclusion: patients undergoing standardised CPET before iRARC. Exclusions: patients not consenting to data collection. Data on CPET measures (AT, ventilatory equivalent for carbon dioxide [VE/VCO2] at AT, peak oxygen uptake [VO2]), and patient demographics prospectively collected. Outcome measurements included hospital LOS; 30-day MAE and 90-day mortality data, which were prospectively recorded. Descriptive and regression analyses were used to assess whether CPET measures were associated with or predicted outcomes. Results: From June 2011 to March 2015, 128 patients underwent radical cystectomy (open cystectomy, n = 17; iRARC, n = 111). A total of 82 patients who underwent iRARC and CPET and consented to participation were included. Median (interquartile range): age = 65 (58–73); body mass index = 27 (23–30); AT = 10.0 (9–11), Peak VO2 = 15.0 (13–18.5), VE/VCO2 (AT) = 33.0 (30–38). 30-day MAE = 14/111 (12.6%): death = 2, multiorgan failure = 2, abscess = 2, gastrointestinal = 2, renal = 6; 90-day mortality = 3/111 (2.7%). AT, peak VO2, and VE/VCO2 (at AT) were not significant predictors of 30-day MAE or LOS. The results are limited by the absence of control group undergoing open surgery. Conclusions: Poor cardiorespiratory fitness does not predict increased hospital LOS or MAEs in patients undergoing iRARC. Overall, MAE and LOS comparable with other series

Late widespread skeletal metastases from myxoid liposarcoma detected by MRI only

Background Myxoid liposarcoma is the second most commonly occurring sub-type of liposarcomas. In contrast to other soft tissue sarcomas, it is known to have a tendency to spread toward extrapulmonary sites, such as soft tissues, retroperitoneum, and the peritoneal surface. Bony spread, however, is not as common. Case presentation We report an unusual case of diffuse skeletal metastases from myxoid liposarcoma occurring 13 years after treatment of the primary tumour in the left lower limb. The skeletal spread of the disease was demonstrated on MRI only after other imaging modalities (plain radiography, CT and TC99 bone scans) had failed to detect these metastases. Conclusion MRI is an extremely sensitive and specific screening tool in the detection of skeletal involvement in these types of sarcomas, and therefore, should be a part of the staging proces