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Stem cells give rise to the entirety of cells within an organ. Maintaining stem cell identity and coordinately regulating stem cell divisions is crucial for proper development. In plants, mobile proteins, such as WUSCHEL-RELATED HOMEOBOX 5 (WOX5) and SHORTROOT (SHR), regulate divisions in the root stem cell niche. However, how these proteins coordinately function to establish systemic behaviour is not well understood. We propose a non-cell autonomous role for WOX5 in the cortex endodermis initial (CEI) and identify a regulator, ANGUSTIFOLIA (AN3)/GRF-INTERACTING FACTOR 1, that coordinates CEI divisions. Here, we show with a multi-scale hybrid model integrating ordinary differential equations (ODEs) and agent-based modeling that quiescent center (QC) and CEI divisions have different dynamics. Specifically, by combining continuous models to describe regulatory networks and agent-based rules, we model systemic behaviour, which led us to predict cell-type-specific expression dynamics of SHR, SCARECROW, WOX5, AN3 and CYCLIND6;1, and experimentally validate CEI cell divisions. Conclusively, our results show an interdependency between CEI and QC divisions.
Food security status is a continuum ranging from high to very low food security. While marginal food security falls next to high food security on the spectrum, new quantitative research indicates marginal food security status is associated with negative health outcomes and poor academic performance among college students. Qualitative research focusing on college students experiencing marginal food security has not been conducted. This study aims to qualitatively explore experiences of college students with marginal food security and to identify themes to better understand and provide context regarding how marginal food security impacts students.
Students were recruited for semi-structured interviews with questions designed to study the challenges associated with students’ food situations. All interviews were recorded and transcribed with themes identified via an inductive approach.
A large public university on the US west coast.
Thirty college students.
Key themes that emerged: purchasing cheap unhealthy foods; insufficient time to prepare and eat meals on a regular basis; stress and anxiety around the inability to eat healthy food and future health issues; self-perception of health when eating poorly along with physical symptoms; and low academic motivation by not fully participating in their courses due to few healthy food options or missing meals.
Marginal food security can potentially diminish students’ health and their capacity to learn and succeed in their coursework. The results emphasize that students experiencing marginal food security should not be grouped with students experiencing high food security.
Fundamental knowledge about the processes that control the functioning of the biophysical workings of ecosystems has expanded exponentially since the late 1960s. Scientists, then, had only primitive knowledge about C, N, P, S, and H2O cycles; plant, animal, and soil microbial interactions and dynamics; and land, atmosphere, and water interactions. With the advent of systems ecology paradigm (SEP) and the explosion of technologies supporting field and laboratory research, scientists throughout the world were able to assemble the knowledge base known today as ecosystem science. This chapter describes, through the eyes of scientists associated with the Natural Resource Ecology Laboratory (NREL) at Colorado State University (CSU), the evolution of the SEP in discovering how biophysical systems at small scales (ecological sites, landscapes) function as systems. The NREL and CSU are epicenters of the development of ecosystem science. Later, that knowledge, including humans as components of ecosystems, has been applied to small regions, regions, and the globe. Many research results that have formed the foundation for ecosystem science and management of natural resources, terrestrial environments, and its waters are described in this chapter. Throughout are direct and implicit references to the vital collaborations with the global network of ecosystem scientists.
Colleges and universities around the world engaged diverse strategies during the COVID-19 pandemic. Baylor University, a community of ˜22,700 individuals, was one of the institutions which resumed and sustained operations. The key strategy was establishment of multidisciplinary teams to develop mitigation strategies and priority areas for action. This population-based team approach along with implementation of a “Swiss Cheese” risk mitigation model allowed small clusters to be rapidly addressed through testing, surveillance, tracing, isolation, and quarantine. These efforts were supported by health protocols including face coverings, social distancing, and compliance monitoring. As a result, activities were sustained from 1 August to 8 December 2020. There were 62,970 COVID-19 tests conducted with 1,435 people testing positive for a positivity rate of 2.28%. A total of 1,670 COVID-19 cases were identified with 235 self-reports. The mean number of tests per week was 3,500 with approximately 80 of these positive (11 per day). More than 60 student tracers were trained with over 120 personnel available to contact trace, at a ratio of one per 400 university members. The successes and lessons learned provide a framework and pathway for similar institutions to mitigate the ongoing impacts of COVID-19 and sustain operations during a global pandemic.
Does exposure to cyber terrorism prompt calls for retaliatory military strikes? By what psychological mechanism does it do so? Through a series of controlled, randomized experiments, this study exposed respondents (n = 2,028) to television news reports depicting cyber and conventional terror attacks against critical infrastructures in the United States, United Kingdom and Israel. The findings indicate that only lethal cyber terrorism triggers strong support for retaliation. Findings also confirm that anger bridges exposure to cyber terrorism and retaliation, rather than psychological mechanisms such as threat perception or anxiety as other studies propose. These findings extend to the cyber realm a recent trend that views anger as a primary mechanism linking exposure to terrorism with militant preferences. With cyber terrorism a mounting international concern, this study demonstrates how exposure to this threat can generate strong public support for retaliatory policies, depending on the lethality of the attack.
Haematopoietic stem cell transplantation is an important and effective treatment strategy for many malignancies, marrow failure syndromes, and immunodeficiencies in children, adolescents, and young adults. Despite advances in supportive care, patients undergoing transplant are at increased risk to develop cardiovascular co-morbidities.
This study was performed as a feasibility study of a rapid cardiac MRI protocol to substitute for echocardiography in the assessment of left ventricular size and function, pericardial effusion, and right ventricular hypertension.
A total of 13 patients were enrolled for the study (age 17.5 ± 7.7 years, 77% male, 77% white). Mean study time was 13.2 ± 5.6 minutes for MRI and 18.8 ± 5.7 minutes for echocardiogram (p = 0.064). Correlation between left ventricular ejection fraction by MRI and echocardiogram was good (ICC 0.76; 95% CI 0.47, 0.92). None of the patients had documented right ventricular hypertension. Patients were given a survey regarding their experiences, with the majority both perceiving that the echocardiogram took longer (7/13) and indicating they would prefer the MRI if given a choice (10/13).
A rapid cardiac MRI protocol was shown feasible to substitute for echocardiogram in the assessment of key factors prior to or in follow-up after haematopoietic stem cell transplantation.
Since the beginning of 2020, the COVID-19 pandemic has dramatically influenced almost every aspect of human life. Activities requiring human gatherings have either been postponed, cancelled, or held completely virtually. To supplement lack of in-person contact, people have increasingly turned to virtual settings on-line, advantages of which include increased inclusivity and accessibility and reduction of carbon footprint. However, emerging online technologies cannot fully replace, in-person scientific events. In-person meetings are not susceptible to poor internet connectivity problems, and they provide novel opportunities for socialization, creating new collaborations, and sharing ideas. To continue such activities, a hybrid model for scientific events could be a solution offering both in-person and virtual components. While participants can freely choose the mode of their participation, virtual meetings would most benefit those who cannot attend in-person due to the limitations. In-person portions of meetings should be organized with full consideration of prevention and safety strategies including risk assessment and mitigation, venue and environmental sanitation, participant protection and disease prevention, and promoting the hybrid model. This new way of interaction between scholars can be considered as a part of a resilience system which was neglected previously and should become a part of routine practice in scientific community.
Tracing the flow of solid matter during an explosion requires a rugged tag that can be measured by a unique identifiable signature. Silica-covered semiconductor quantum dots (QDs) provide a unique and tunable photoluminescent signature that emits from within a sacrificial outer layer. Five types of silica-covered zinc sulfide QDs were synthesized and covalently bound to commercial luminescent powders. The combination of five dots and five powders enables a matrix of 25 unique tags. The tracers are shown to be tolerant of environments associated with chemical explosives and provides a unique tag to evaluate debris fields.
The coronavirus disease 2019 (COVID-19) has greatly impacted health-care systems worldwide, leading to an unprecedented rise in demand for health-care resources. In anticipation of an acute strain on established medical facilities in Dallas, Texas, federal officials worked in conjunction with local medical personnel to convert a convention center into a Federal Medical Station capable of caring for patients affected by COVID-19. A 200,000 square foot event space was designated as a direct patient care area, with surrounding spaces repurposed to house ancillary services. Given the highly transmissible nature of the novel coronavirus, the donning and doffing of personal protective equipment (PPE) was of particular importance for personnel staffing the facility. Furthermore, nationwide shortages in the availability of PPE necessitated the reuse of certain protective materials. This article seeks to delineate the procedures implemented regarding PPE in the setting of a COVID-19 disaster response shelter, including workspace flow, donning and doffing procedures, PPE conservation, and exposure event protocols.
The Minimal Data Set are demographic and tobacco use questions asked during enrollment at many quitlines. We tested whether these questions can be used to predict program engagement and success, and to evaluate whether findings can inform the tailoring of protocols to disparate populations. We analyzed 7,920 Arizona Smokers' Helpline treatment records to test a Structural Equation Model of the mediating effects of quitline services and short-term cessation outcomes on the relationship between intake questions and 7-month quit rate. Education (b = 0.05), gender (b = 0.03), Medicaid (b = −0.09), longest length of previous quit attempt (b = 0.05), confidence in quitting for 24 h (b = 0.04), environmental risk (b = −0.05), and life stress (b = 0.04) all significantly (P < 0.05) predicted engagement in quitline services. Program engagement had a direct effect on an in-program cessation outcomes construct (b = 0.47) and 7-month quit rate (b = 0.44). This in-program cessation outcomes construct had a significant direct effect on 7-month quit rate (b = −0.12). This model showing the relationship between program engagement and outcomes suggests that tailoring protocols can focus on engaging clients who have historically not taken full advantage of quitline services.
Direct simulations of two-dimensional plane channel flow of a viscoelastic fluid at Reynolds number
reveal the existence of a family of attractors whose structure closely resembles the linear Tollmien–Schlichting (TS) mode, and in particular exhibits strongly localized stress fluctuations at the critical layer position of the TS mode. At the parameter values chosen, this solution branch is not connected to the nonlinear TS solution branch found for Newtonian flow, and thus represents a solution family that is nonlinearly self-sustained by viscoelasticity. The ratio between stress and velocity fluctuations is in quantitative agreement for the attractor and the linear TS mode, and increases strongly with Weissenberg number,
. For the latter, there is a transition in the scaling of this ratio as
increases, and the
at which the nonlinear solution family comes into existence is just above this transition. Finally, evidence indicates that this branch is connected through an unstable solution branch to two-dimensional elastoinertial turbulence (EIT). These results suggest that, in the parameter range considered here, the bypass transition leading to EIT is mediated by nonlinear amplification and self-sustenance of perturbations that excite the TS mode.
We describe 14 yr of public data from the Parkes Pulsar Timing Array (PPTA), an ongoing project that is producing precise measurements of pulse times of arrival from 26 millisecond pulsars using the 64-m Parkes radio telescope with a cadence of approximately 3 weeks in three observing bands. A comprehensive description of the pulsar observing systems employed at the telescope since 2004 is provided, including the calibration methodology and an analysis of the stability of system components. We attempt to provide full accounting of the reduction from the raw measured Stokes parameters to pulse times of arrival to aid third parties in reproducing our results. This conversion is encapsulated in a processing pipeline designed to track provenance. Our data products include pulse times of arrival for each of the pulsars along with an initial set of pulsar parameters and noise models. The calibrated pulse profiles and timing template profiles are also available. These data represent almost 21 000 h of recorded data spanning over 14 yr. After accounting for processes that induce time-correlated noise, 22 of the pulsars have weighted root-mean-square timing residuals of
in at least one radio band. The data should allow end users to quickly undertake their own gravitational wave analyses, for example, without having to understand the intricacies of pulsar polarisation calibration or attain a mastery of radio frequency interference mitigation as is required when analysing raw data files.
The professional experience of school counsellors in training in Australia is subject to different supervisor-supervisee relationships and school settings. The current study explored the first-year New South Wales school counsellor in training professional experience via an adapted qualitative content and framework analysis approach. Participants were students undertaking their first professional experience as part of the Master of Teaching (School Counselling) at the University of Sydney. The most common descriptive reflections explored professional psychological learning, followed by system- and process-related knowledge of the school setting. Emergent themes highlighted that professional experience prepared students for the role, which varied based on supervisor and school setting, and helped the students form professional identities via observing rich ethical and professional practice. Future professional experiences may be enriched with explicit reflections, peer-to-peer learning and support to foster working supervisor-supervisee relationships.
OBJECTIVES/GOALS: People living with HIV, despite antiretroviral therapy (ART), have increased burden of inflammatory and aging-related comorbidities such as periodontitis. Oral microbiota have been linked to periodontitis, but not in the context of HIV. We aim to compare relationships between the oral microbiome and periodontal disease in HIV+ vs healthy controls. METHODS/STUDY POPULATION: In an ongoing cohort study we have been recruiting pre- and post-menopausal women with HIV+ on ART for ≥6 months and HIV- controls matched by menopausal status (target n = 30 per arm; currently HIV+: n = 30 post- and 9 pre-M; HIV-: n = 15 post- and 6 pre-M). Patients age <18 or on antibiotics within 3 mos., except prophylaxis, are excluded. Patients provide saliva, then subgingival plaque collection during a dental examination through scaling from six index teeth. Standard CDC/AAP classifications of periodontitis are used. We will perform 16S rRNA and ITS sequencing to profile bacterial and fungal communities in saliva and plaque. Linear mixed effect regression and differential abundance analyses will be used to identify microbial and mycobial oral signatures of periodontal disease severity in HIV+ and HIV- populations. RESULTS/ANTICIPATED RESULTS: We found a markedly high prevalence of severe periodontal disease in HIV+ women despite ART (59%, compared to 11% in HIV- controls). In post-menopausal women with HIV, saliva bacterial α- and β-diversity in the saliva differed significantly with periodontal disease severity. Fungal α-diversity was also significantly lower in plaque from teeth with severe loss of tissue attachment (CAL ≥4 mm). We identified bacterial and fungal taxa significantly enriched in post-menopausal HIV+ women with severe compared to no or mild periodontitis. We hypothesize, similarly, associations between the oral microbiome and periodontitis in HIV- controls. However, we expect overall diversity metrics to be significantly altered in HIV+ compared to HIV- patients, indicating long-term dysbiosis despite treatment with ART. DISCUSSION/SIGNIFICANCE OF IMPACT: Contrasting associations between the oral microbiome and periodontal disease with respect to HIV will provide evidence for the role of microbiota in accelerated aging phenotype caused by HIV. Our results would also provide rationale for interventions targeting co-morbidities in people living with HIV to account for both inflammation and dysbiosis.
The region of Khevsureti in Georgia is the historic home of a group of Kartvelian highlanders known as Khevsurs. As Khevsureti’s popularity as a mountain tourist destination has grown, so too has the popularity of an old story that asserts the Khevsurs are the descendants of a lost band of Crusaders. For 200 years, this meme has manifested itself in books about the region, newspaper articles, the work of a few scholars, and now much Internet discussion. The growing collection of cases has created the illusion of an unconsolidated quantity of evidence and many commentators have since taken the story to be a credible theory or actual legend. A systematic deconstruction and analysis of this story shows how this set of details initially formed, grew, and spread based on a few unreliable accounts in circulation beginning in the early 19th century. This article offers a case study of how such memes form and propagate; it provides an additional example of a Western tendency to romanticize and project elements of their own ethnicities into the Caucasus; and it examines this false history in terms of cultural appropriation and the relationship between ethnicity and narrative, adding to the literature on invented histories and pseudoarchaeology. Finally, this careful deconstruction and repudiation will help remove this story from serious discussions of cultural heritage in Khevsureti and show how historical memes and popular examples of pseudoarcheology spread and capture imaginations.
Antibiotics are widely used in food animal production to treat disease outbreaks, to prevent disease and, in some countries, to improve feed efficiency and enhance animal growth. Due to this complexity, the availability of reliable data on antibiotic use in livestock production is limited, but improving, especially for OECD countries. The highlight intensive animal production systems tend to use more antibiotics than the extensive systems. Over recent decades the adoption of improved biosecurity measures, animal husbandry practices and better farm management have contributed to a reduction in the use of antibiotics in many countries. All pathways of transmission of resistant pathogens between animals, humans and the environment (and vice versa) are not well understood, and this remains a major challenge for researchers and policymakers. With the growing public awareness of the risks associated with AMR, there is increased interest in developing alternative interventions to antibiotics in animal production. While estimating the economic costs and benefits of antibiotic use in production can be reduced without any adverse impact of farmers’ income, animal health and welfare.
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.