A predictive model for ethylene-mediated auxin and cytokinin patterning in the Arabidopsis root

The interaction between auxin and cytokinin is important in many aspects of plant development. Experimental measurements of both auxin and cytokinin concentration and reporter gene expression clearly show the coexistence of auxin and cytokinin concentration patterning in Arabidopsis root development. However, in the context of crosstalk between auxin, cytokinin and ethylene, little is known about how auxin and cytokinin concentration patterns simultaneously emerge and how they regulate each other in the Arabidopsis root. This work utilizes a wide range of experimental observations to propose a mechanism for simultaneous patterning of auxin and cytokinin concentration. In addition to the regulatory relationships between auxin and cytokinin, the mechanism reveals that ethylene signalling is an important factor in achieving simultaneous auxin and cytokinin patterning, while also predicting other experimental observations. Combining the mechanism with a realistic in silico root model reproduces experimental observations of both auxin and cytokinin patterning. Predictions made by the mechanism can be compared with a variety of experimental observations, including those conducted by our group and other independent experiments reported by other groups. Examples of these predictions include patterning of auxin biosynthesis rate, PIN1 and PIN2 pattern changes in pin3, 4, 7 mutants, cytokinin patterning change in the pls mutant, PLS patterning, as well as various trends in different mutants. This research unravels a plausible mechanism for simultaneous patterning of auxin and cytokinin concentrations in Arabidopsis root development and suggests a key role for ethylene pattern integration. [Abstract copyright: Copyright © 2024. Published by Elsevier Inc.

Use of the out-of-hours emergency dental service at two south-east London hospitals

<p>Abstract</p> <p>Background</p> <p>Prior to the introduction of the 2006 NHS dental contract in England and Wales, general dental practitioners (GDPs) were responsible for the provision of out-of-hours (OOH) emergency dental services (EDS); however there was great national variation in service provision. Under the contractual arrangements introduced 1^stApril 2006, local commissioning agencies became formally responsible for the provision of out-of-hours emergency dental services. This study aimed to examine patients' use of an out-of-hours emergency dental service and to determine whether the introduction of the 2006 national NHS dental contract had resulted in a change in service use, with a view to informing future planning and commissioning of care.</p> <p>Methods</p> <p>A questionnaire was administered to people attending the out-of-hours emergency dental service at two inner city London hospitals over two time periods; four weeks before and six months after the introduction of the dental contract in April 2006. The questionnaire explored: reasons for attending; dental registration status and attendance; method of access; knowledge and use of NHS Direct; satisfaction with the service; future preferences for access and use of out-of-hours dental services. Data were compared to determine any impact of the new contract on how and why people accessed the emergency dental service.</p> <p>Results</p> <p>The response rate was 73% of attendees with 981 respondents for the first time period and 546 for the second. There were no significant differences between the two time periods in the gender, age, ethnic distribution or main language of service users accessing the service. Overall, the main dental problem was toothache (72%) and the main reason for choosing this service was due to the inability to access another emergency dental service (42%). Significantly fewer service users attended the out-of-hours emergency dental service during the second period because they could not get an appointment with their own dentist (p = 0.002 from 28% to 20%) and significantly more service users in the second period felt the emergency dental service was easier to get to than their own dentist (P = 0.003 from 8% to 14%). Service users found out about the service from multiple sources, of which family and friends were the most common source (30%). In the second period fewer service users were obtaining information about the service from dental receptionists (P = 0.002 from 14% to 9%) and increased use of NHS Direct for a dental problem was reported (P = 0.002 from 16% to 22%) along with more service users being referred to the service by NHS Direct (P = 0.02 from 19% to 24%). The most common preference for future emergency dental care was face-to-face with a dentist (79%).</p> <p>Conclusion</p> <p>This study has provided an insight into how and why people use an out-of-hours emergency dental service and has helped to guide future commissioning of these services. Overall, the service was being used in much the same way both before and after the 2006 dental contract. Significantly more use was being made of NHS Direct after April 2006; however, informal information networks such as friends and family remain an important source of information about accessing emergency dental services.</p

Utilizing Spatial Demographic and Life History Variation to Optimize Sustainable Yield of a Temperate Sex-Changing Fish

Fish populations vary geographically in demography and life history due to environmental and ecological processes and in response to exploitation. However, population dynamic models and stock assessments, used to manage fisheries, rarely explicitly incorporate spatial variation to inform management decisions. Here, we describe extensive geographic variation in several demographic and life history characteristics (e.g., size structure, growth, survivorship, maturation, and sex change) of California sheephead (Semicossyphus pulcher), a temperate rocky reef fish targeted by recreational and commercial fisheries. Fish were sampled from nine locations throughout southern California in 2007–2008. We developed a dynamic size and age-structured model, parameterized separately for each location, to assess the potential cost or benefit in terms of fisheries yield and conservation objectives of changing minimum size limits and/or fishing mortality rates (compared to the status quo). Results indicate that managing populations individually, with location-specific regulations, could increase yield by over 26% while maintaining conservative levels of spawning biomass. While this local management approach would be challenging to implement in practice, we found statistically similar increases in yield could be achieved by dividing southern California into two separate management regions, reflecting geographic similarities in demography. To maximize yield, size limits should be increased by 90 mm in the northern region and held at current levels in the south. We also found that managing the fishery as one single stock (the status quo), but with a size limit 50 mm greater than the current regulations, could increase overall fishery yield by 15%. Increases in size limits are predicted to enhance fishery yield and may also have important ecological consequences for the predatory role of sheephead in kelp forests. This framework for incorporating demographic variation into fisheries models can be exported generally to other species and may aid in identifying the appropriate spatial scales for fisheries management

Mortality Among Adults With Cancer Undergoing Chemotherapy or Immunotherapy and Infected With COVID-19

Importance: Large cohorts of patients with active cancers and COVID-19 infection are needed to provide evidence of the association of recent cancer treatment and cancer type with COVID-19 mortality. // Objective: To evaluate whether systemic anticancer treatments (SACTs), tumor subtypes, patient demographic characteristics (age and sex), and comorbidities are associated with COVID-19 mortality. // Design, Setting, and Participants: The UK Coronavirus Cancer Monitoring Project (UKCCMP) is a prospective cohort study conducted at 69 UK cancer hospitals among adult patients (≥18 years) with an active cancer and a clinical diagnosis of COVID-19. Patients registered from March 18 to August 1, 2020, were included in this analysis. // Exposures: SACT, tumor subtype, patient demographic characteristics (eg, age, sex, body mass index, race and ethnicity, smoking history), and comorbidities were investigated. // Main Outcomes and Measures: The primary end point was all-cause mortality within the primary hospitalization. // Results: Overall, 2515 of 2786 patients registered during the study period were included; 1464 (58%) were men; and the median (IQR) age was 72 (62-80) years. The mortality rate was 38% (966 patients). The data suggest an association between higher mortality in patients with hematological malignant neoplasms irrespective of recent SACT, particularly in those with acute leukemias or myelodysplastic syndrome (OR, 2.16; 95% CI, 1.30-3.60) and myeloma or plasmacytoma (OR, 1.53; 95% CI, 1.04-2.26). Lung cancer was also significantly associated with higher COVID-19–related mortality (OR, 1.58; 95% CI, 1.11-2.25). No association between higher mortality and receiving chemotherapy in the 4 weeks before COVID-19 diagnosis was observed after correcting for the crucial confounders of age, sex, and comorbidities. An association between lower mortality and receiving immunotherapy in the 4 weeks before COVID-19 diagnosis was observed (immunotherapy vs no cancer therapy: OR, 0.52; 95% CI, 0.31-0.86). // Conclusions and Relevance: The findings of this study of patients with active cancer suggest that recent SACT is not associated with inferior outcomes from COVID-19 infection. This has relevance for the care of patients with cancer requiring treatment, particularly in countries experiencing an increase in COVID-19 case numbers. Important differences in outcomes among patients with hematological and lung cancers were observed

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Shared Scientific Thinking in Everyday Parent-Child Activity

Current accounts of the development of scientific reasoning focus on individual children\u27s ability to coordinate the collection and evaluation of evidence with the creation of theories to explain the evidence. This observational study of parent–child interactions in a children\u27s museum demonstrated that parents shape and support children\u27s scientific thinking in everyday, nonobligatory activity. When children engaged an exhibit with parents, their exploration of evidence was observed to be longer, broader, and more focused on relevant comparisons than children who engaged the exhibit without their parents. Parents were observed to talk to children about how to select and encode appropriate evidence and how to make direct comparisons between the most informative kinds of evidence. Parents also sometimes assumed the role of explained by casting children\u27s experience in causal terms, connecting the experience to prior knowledge, or introducing abstract principles. We discuss these findings with respect to two dimensions of children\u27s scientific thinking: developments in evidence collection and developments in theory construction