Wide-band spectral power fluctuations characterize the response of simulated cortical networks to increasing stimulus intensity

The hippocampus is an anatomically distinct region of the medial temporal lobe that plays a critical role in the formation of declarative memories. Here we show that a computer simulation of simple compartmental cells organized with basic hippocampal connectivity is capable of producing stimulus intensity sensitive wide-band fluctuations of spectral power similar to that seen in real EEG. While previous computational models have been designed to assess the viability of the putative mechanisms of memory storage and retrieval, they have generally been too abstract to allow comparison with empirical data. Furthermore, while the anatomical connectivity and organization of the hippocampus is well defined, many questions regarding the mechanisms that mediate large-scale synaptic integration remain unanswered. For this reason we focus less on the specifics of changing synaptic weights and more on the population dynamics. Spectral power in four distinct frequency bands were derived from simulated field potentials of the computational model and found to depend on the intensity of a random input. The majority of power occurred in the lowest frequency band (3-6 Hz) and was greatest to the lowest intensity stimulus condition (1% maximal stimulus). In contrast, higher frequency bands ranging from 7-45 Hz show an increase in power directly related with an increase in stimulus intensity. This trend continues up to a stimulus level of 15% to 20% of the maximal input, above which power falls dramatically. These results suggest that the relative power of intrinsic network oscillations are dependent upon the level of activation and that above threshold levels all frequencies are damped, perhaps due to over activation of inhibitory interneurons.

The professional socialisation of paramedics : the transition from intern to qualified paramedic

The professional socialisation of paramedics encompasses preconceptions developed during childhood and early adulthood, and subsequent changes in perceptions resulting from university studies, clinical placements and encountering the professional workplace as an employee. This study investigates the professional socialisation of university educated paramedics making the transition from paramedic intern to qualified paramedic. Participants were sought from several of Australia’s larger ambulance services and UK NHS Ambulance Trusts to take part in this study. Participants were recruited through Ambulance Service Research Institutes, Clinical Governance Departments and university databases. To be included in this study, participants were required to be university educated, have completed a professional internship year and achieved qualified or registered paramedic status. Data collection was via face to face semi-structured interviews. Transcripts were analysed using socialisation models from the nursing and allied health disciplines and a grounded theory approach. The study found that participants initially enjoyed their new professional status after completing their internship and becoming qualified paramedics. However, for many the excitement of becoming a qualified paramedic was short lived. Newly qualified paramedics experienced increased levels of responsibility and were required to develop mentoring skills while still adjusting to their new roles. Participants had to contend with inner conflicting views about the reality of paramedic work which were developed though preconceptions and experiences as paramedic interns. The transition from paramedic intern to qualified paramedic is reportedly a challenging experience, as newly qualified paramedics are required to deal with added complexities while still adjusting to their new roles.

Kallikrein 4 (hK4) and prostate-specific antigen (PSA) are associated with the loss of E-cadherin and an epithelial-mesenchymal transition (EMT)-like effect in prostate cancer cells

Prostate-specific antigen (PSA) and the related kallikrein family of serine proteases are current or emerging biomarkers for prostate cancer detection and progression. Kallikrein 4 (KLK4/hK4) is of particular interest, as KLK4 mRNA has been shown to be elevated in prostate cancer. In this study, we now show that the comparative expression of hK4 protein in prostate cancer tissues, compared with benign glands, is greater than that of PSA and kallikrein 2 (KLK2/hK2), suggesting that hK4 may play an important functional role in prostate cancer progression in addition to its biomarker potential. To examine the roles that hK4, as well as PSA and hK2, play in processes associated with progression, these kallikreins were separately transfected into the PC-3 prostate cancer cell line, and the consequence of their stable transfection was investigated. PC-3 cells expressing hK4 had a decreased growth rate, but no changes in cell proliferation were observed in the cells expressing PSA or hK2. hK4 and PSA, but not hK2, induced a 2.4-fold and 1.7-fold respective increase, in cellular migration, but not invasion, through Matrigel, a synthetic extracellular matrix. We hypothesised that this increase in motility displayed by the hK4 and PSA-expressing PC-3 cells may be related to the observed change in structure in these cells from a typical rounded epithelial-like cell to a spindle-shaped, more mesenchymal-like cell, with compromised adhesion to the culture surface. Thus, the expression of E-cadherin and vimentin, both associated with an epithelial-mesenchymal transition (EMT), was investigated. E-cadherin protein was lost and mRNA levels were significantly decreased in PC-3 cells expressing hK4 and PSA (10-fold and 7-fold respectively), suggesting transcriptional repression of E-cadherin, while the expression of vimentin was increased in these cells. The loss of E-cadherin and associated increase in vimentin are indicative of EMT and provides compelling evidence that hK4, in particular, and PSA have a functional role in the progression of prostate cancer through their promotion of tumour cell migration.

Porosity: Establishing the relationship between drying parameters and dried food quality [SpringerBriefs in Food, Health, and Nutrition]

The preservation technique of drying offers a significant increase in the shelf life of food materials, along with the modification of quality attributes due to simultaneous heat and mass transfer. Variations in porosity are just one of the microstructural changes that take place during the drying of most food materials. Some studies found that there may be a relationship between porosity and the properties of dried foods. However, no conclusive relationship has yet been established in the literature. This paper presents an overview of the factors that influence porosity, as well as the effects of porosity on dried food quality attributes. The effect of heat and mass transfer on porosity is also discussed along with porosity development in various drying methods. After an extensive review of the literature concerning the study of porosity, it emerges that a relationship between process parameters, food qualities, and sample properties can be established. Therefore, we propose a hypothesis of relationships between process parameters, product quality attributes, and porosity.

Towards inclusion: Provision for diversity in the transition to school

Policies of inclusion challenge the construct of readiness and require schools to prepare for the diversity of children as they transition to school. However, there is limited empirical evidence concerning how this challenge is met. This paper presents two Australian studies that investigate inclusive practices in the transition to school. Study 1 examined the predictors of child outcomes across a sample of 1831 children in 39 schools. The results indicate that both quantity and quality of programme provision influenced outcomes and that programme effects were particularly potent for children with diverse abilities and backgrounds. Study 2 focuses on pedagogy in three of the schools to highlight how this provision can be achieved. Results show that provisions were reactive, that saliency of children’s needs directed school practices and that professional knowledge impacted on measures of quality. Inclusive processes accounting for both child progress and broader family and teaching influences are necessary for improved transition to school.

Intensity and seasonality of physical activity of children during school recess

This study aimed to quantify the intensity of physical activity (PA) of children during school recess (RE), compare the AF gender and seasonal influences. The sample consisted of 30 girls (11.2 ± 1.3 years) and 20 boys (11.3 ± 0.8 years). Heart rate was monitored for three consecutive REs in winter (INV) and spring (PRI) with intensity of the activity being classified as low, moderate and vigorous. Descriptive statistics were used for general data, t test for independent samples for differences between the sexes, paired t test for seasonality. Differences were found between INV and PRI temperatures. Girls had a significant reduction in the AF INV to PRI, which was not observed among boys. The RE represented a small contribution to daily recommendations of AF.

Reduced intensity conditioning for allogeneic hematopoietic stem cell transplant determines the kinetics of acute Graft-Versus-Host Disease

Background Preparative myeloablative conditioning regimens for allogeneic hematopoietic stem-cell transplantation (HSCT) may control malignancy and facilitate engraftment but also contribute to transplant related mortality, cytokine release, and acute graft-versus-host disease (GVHD). Reduced intensity conditioning (RIC) regimens have decreased transplant related mortality but the incidence of acute GVHD, while delayed, remains unchanged. There are currently no in vivo allogeneic models of RIC HSCT, limiting studies into the mechanism behind RIC-associated GVHD. Methods We developed two RIC HSCT models that result in delayed onset GVHD (major histocompatibility complex mismatched (UBI-GFP/BL6 [H-2b]→BALB/c [H-2d]) and major histocompatibility complex matched, minor histocompatibility mismatched (UBI-GFP/BL6 [H-2b]→BALB.B [H-2b])) enabling the effect of RIC on chimerism, dendritic cell (DC) chimerism, and GVHD to be investigated. Results In contrast with myeloablative conditioning, we observed that RIC-associated delayed-onset GVHD is characterized by low production of tumor necrosis factor-α, maintenance of host DC, phenotypic DC activation, increased T-regulatory cell numbers, and a delayed emergence of activated donor DC. Furthermore, changes to the peritransplant milieu in the recipient after RIC lead to the altered activation of DC and the induction of T-regulatory responses. Reduced intensity conditioning recipients suffer less early damage to GVHD target organs. However, as donor cells engraft, activated donor DC and rising levels of tumor necrosis factor-α are associated with a later onset of severe GVHD. Conclusions Delineating the mechanisms underlying delayed onset GVHD in RIC HSCT recipients is vital to improve the prediction of disease onset and allow more targeted interventions for acute GVHD.

Transition metal layered double hydroxides for energy storage

Various types of layered double hydroxides, a type of clay, were synthesised. They were then electrochemically tested to determine whether the samples would be suitable to store energy as supercapacitors. A manganese aluminium layered double hydroxide was electrochemically tested for the first time and found to have a large capacitance.

Making the transition from pharmacy student to pharmacist: Australian interns' perceptions of professional identity formation

Objectives The experience of transitioning from university to practice influences professional identity formation. It is unclear how this transitioning experience influences pharmacy interns' professional identities. This study aims to examine pharmacy interns' perceptions of their transition from university to the workplace and the influence this had on their pharmacist identities. Methods A qualitative approach using in-depth interviews was adopted for this study. Fifteen interns (community and hospital) from one school of pharmacy in Australia were interviewed. Questions were asked about the nature of their current intern role, their university experiences, how they saw themselves as pharmacists and their perceptions of the transition to practice. Key findings The interns interviewed entered the workplace valuing patient-focused aspects of practice and contributing to patient care. The nature of work meant there were limited opportunities to enact these aspects of their professional identities. The interns were challenged by interactions with patients and doctors, and experienced difficulties reconciling this with their university-derived professional identities. Also, the interns lacked the confidence and strategies to overcome these challenges. Some were exploring alternative ways of being pharmacists. Conclusions This paper argues that graduates' experience of the transition to practice was challenging. This was due to nascent professional identities formed in university and a lack of workplace experiences enabling patient-centred practices. The interns' formation of professional identities was highly responsive to the context of work. To facilitate the development of Australian patient-centred pharmacy practice, supporting professional identity formation should be a focus within pharmacy education.

The transition to palliative care: A critical exploration in the context of metastatic melanoma

This research explored the transition to palliative care process through critical analysis of the experiences of patients diagnosed with metastatic melanoma, family carers and health professionals. The outcomes depict a complex intersection between acute care services and palliative care where the discipline of palliative care struggled to position itself within a highly specialised health system. The findings indicate uncertainty around scopes of practice with ambiguity and tension around the transition to palliative care. The research thus argues for stronger and more coherent partnerships and a critical and interdisciplinary conversation about the positioning of palliative care in the acute care sector.

Melanoma cell colony expansion parameters revealed by approximate Bayesian computation

In vitro studies and mathematical models are now being widely used to study the underlying mechanisms driving the expansion of cell colonies. This can improve our understanding of cancer formation and progression. Although much progress has been made in terms of developing and analysing mathematical models, far less progress has been made in terms of understanding how to estimate model parameters using experimental in vitro image-based data. To address this issue, a new approximate Bayesian computation (ABC) algorithm is proposed to estimate key parameters governing the expansion of melanoma cell (MM127) colonies, including cell diffusivity, D, cell proliferation rate, λ, and cell-to-cell adhesion, q, in two experimental scenarios, namely with and without a chemical treatment to suppress cell proliferation. Even when little prior biological knowledge about the parameters is assumed, all parameters are precisely inferred with a small posterior coefficient of variation, approximately 2–12%. The ABC analyses reveal that the posterior distributions of D and q depend on the experimental elapsed time, whereas the posterior distribution of λ does not. The posterior mean values of D and q are in the ranges 226–268 µm2h−1, 311–351 µm2h−1 and 0.23–0.39, 0.32–0.61 for the experimental periods of 0–24 h and 24–48 h, respectively. Furthermore, we found that the posterior distribution of q also depends on the initial cell density, whereas the posterior distributions of D and λ do not. The ABC approach also enables information from the two experiments to be combined, resulting in greater precision for all estimates of D and λ.