389 research outputs found

    Searching by Rules: Pigeons’ (\u3ci\u3eColumba livia\u3c/i\u3e) Landmark-Based Search According to Constant Bearing or Constant Distance

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    Pigeons (Columba livia) searched for a goal location defined by a constant relative spatial relationship to 2 landmarks. For one group, landmark-to-goal bearings remained constant while distance varied. For another group, landmark-to-goal distances remained constant while direction varied. Birds were trained with 4 interlandmark distances and then tested with 5 novel interlandmark distances. Overall error magnitude was similar across groups and was larger than previously reported for Clark’s nutcrackers (Nucifraga columbiana). During training, error magnitude increased with interlandmark distance for constant-bearing but not constant-distance birds. Both groups searched less accurately along the axis parallel to landmarks than along the perpendicular axis. Error magnitude increased with novel extrapolated interlandmark distances but not with novel interpolated distances. Results suggest modest geometric rule learning by pigeons

    Ribosomal stress activates eEF2K-eEF2 pathway causing translation elongation inhibition and recruitment of Terminal Oligopyrimidine (TOP) mRNAs on polysomes

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    The synthesis of adequate amounts of ribosomes is an essential task for the cell. It is therefore not surprising that regulatory circuits exist to organize the synthesis of ribosomal components. It has been shown that defect in ribosome biogenesis (ribosomal stress) induces apoptosis or cell cycle arrest through activation of the tumor suppressor p53. This mechanism is thought to be implicated in the pathophysiology of a group of genetic diseases such as Diamond Blackfan Anemia which are called ribosomopathies. We have identified an additional response to ribosomal stress that includes the activation of eukaryotic translation elongation factor 2 kinase with a consequent inhibition of translation elongation. This leads to a translational reprogramming in the cell that involves the structurally defined group of messengers called terminal oligopyrimidine (TOP) mRNAs which encode ribosomal proteins and translation factors. In fact, while general protein synthesis is decreased by the impairment of elongation, TOP mRNAs are recruited on polysomes causing a relative increase in the synthesis of TOP mRNA-encoded proteins compared to other proteins. Therefore, in response to ribosomal stress, there is a change in the translation pattern of the cell which may help restore a sufficient level of ribosomes

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    Reactive astrocytes potentiate tumor aggressiveness in a murine glioma resection and recurrence model

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    Surgical resection is a universal component of glioma therapy. Little is known about the postoperative microenvironment due to limited preclinical models. Thus, we sought to develop a glioma resection and recurrence model in syngeneic immune-competent mice to understand how surgical resection influences tumor biology and the local microenvironment

    Introductory biology undergraduate students\u27 mixed ideas about genetic information flow

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    The core concept of genetic information flow was identified in recent calls to improve undergraduate biology education. Previous work shows that students have difficulty differentiating between the three processes of the Central Dogma (CD; replication, transcription, and translation). We built upon this work by developing and applying an analytic coding rubric to 1050 student written responses to a three‐question item about the CD. Each response was previously coded only for correctness using a holistic rubric. Our rubric captures subtleties of student conceptual understanding of each process that previous work has not yet captured at a large scale. Regardless of holistic correctness scores, student responses included five or six distinct ideas. By analyzing common co‐occurring rubric categories in student responses, we found a common pair representing two normative ideas about the molecules produced by each CD process. By applying analytic coding to student responses preinstruction and postinstruction, we found student thinking about the processes involved was most prone to change. The combined strengths of analytic and holistic rubrics allow us to reveal mixed ideas about the CD processes and provide a detailed picture of which conceptual ideas students draw upon when explaining each CD process

    “You felt like a prisoner in your own self, trapped”: The experiences of Aboriginal people with acquired communication disorders

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    Purpose: Aboriginal Australians are under-represented in brain injury rehabilitation services despite a high incidence of both stroke and traumatic brain injury in this population. This study aimed to explore the experiences of Aboriginal Australian adults with acquired communication disorders (ACDs) after brain injury for the first time to inform the development of accessible and culturally secure service delivery models. Methods and materials: Semi-structured interviews were undertaken with 32 Aboriginal people who had experienced a brain injury resulting in ACDs (aged 35–79 years) and 18 family members/carers across Western Australia. Thematic analysis identified common themes across participants. Results: Overall themes related to communication (both related to the communication disorder and general healthcare interactions), health and social contexts, recovery, and support, being away from family and country, knowledge and beliefs about brain injury, and follow-up. Conclusions: An increase in healthcare staff’s appreciation of the health and social contexts of Aboriginal people after brain injury is needed in order to improve communication with Aboriginal patients and the ability to offer accessible rehabilitation services. Ongoing support is required, with cultural identity noted as key to ensuring cultural security and ultimately recovery. Involvement of family and other Aboriginal people in recovery processes, as well as access to relevant Aboriginal languages and proximity to ancestral lands is central. Implications for rehabilitation Acknowledgment of cultural identity and strengths through involvement of extended family and Aboriginal Hospital Liaison Officers, access to language and proximity to country all central to rehabilitation planning for Aboriginal people after brain injury. Cultural security training for rehabilitation staff is recommended focusing on clear two-way communication skills to make medical information accessible for Aboriginal patients and to listen to patients’ concerns in a way that respects cultural context. Information regarding practical support and implications for ongoing management of life after brain injury (for the person and their family) is essential, and should supplement the medical-related information provided. Follow-up post discharge from hospital best facilitated through establishing contact with local Aboriginal community through Aboriginal community controlled health services, community elders, and Aboriginal health workers across organisations

    Acceptability of OP/Na swabbing for SARS-CoV-2: a prospective observational cohort surveillance study in Western Australian schools

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    Objectives: When the COVID-19 pandemic was declared, Governments responded with lockdown and isolation measures to combat viral spread, including the closure of many schools. More than a year later, widespread screening for SARS-CoV-2 is critical to allow schools and other institutions to remain open. Here, we describe the acceptability of a minimally invasive COVID-19 screening protocol trialled by the Western Australian Government to mitigate the risks of and boost public confidence in schools remaining open. To minimise discomfort, and optimise recruitment and tolerability in unaccompanied children, a combined throat and nasal (OP/Na) swab was chosen over the nasopharyngeal swab commonly used, despite slightly reduced test performance. Design, setting and participants: Trialling of OP/Na swabbing took place as part of a prospective observational cohort surveillance study in 79 schools across Western Australia. Swabs were collected from 5903 asymptomatic students and 1036 asymptomatic staff in 40 schools monthly between June and September 2020. Outcome measures: PCR testing was performed with a two-step diagnostic and independent confirmatory PCR for any diagnostic PCR positives. Concurrent surveys, collected online through the REDCap platform, evaluated participant experiences of in-school swabbing. Results: 13 988 swabs were collected from students and staff. There were zero positive test results for SARS-CoV-2, including no false positives. Participants reported high acceptability: 71% of students reported no or minimal discomfort and most were willing to be reswabbed (4% refusal rate). Conclusions: OP/Na swabbing is acceptable and repeatable in schoolchildren as young as 4 years old and may combat noncompliance rates by significantly increasing the acceptability of testing. This kind of minimally-invasive testing will be key to the success of ongoing, voluntary mass screening as society adjusts to a new ‘normal’ in the face of COVID-19. Trial registration number: Australian New Zealand Clinical Trials Registry—ACTRN12620000922976
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