466 research outputs found
Etiology and factors associated with urogenital fistula among women who have undergone cesarean section: a cross-sectional study
Background: The prevalence and impact of fistulas are more common in developing countries with limited access to emergency obstetric care. As a result, women in these settings often experience adverse psychosocial factors. The purpose of this study was to describe the characteristics of Congolese women who developed urogenital fistula following Cesarean sections (CS) to determine the characteristics associated with two etiologies: (1) prolonged obstructed labor; and (2) a complication of CS following obstructed labor.
Methods: We performed a cross-sectional study on abstracted data from all patients with urogenital fistula following CS who received care during a surgical campaign in a remote area of the Democratic Republic of the Congo (DRC). Descriptive analyses characterized patients with fistula related to obstructed labor versus CS. Univariate and multivariate logistic regression models identified factors associated with obstetric fistula after cesarean delivery following obstructed labor. Variables were included in the logistic regression models based upon biological plausibility.
Results: Among 125 patients, urogenital fistula etiology was attributed to obstructed labor in 77 (62%) and complications following CS in 48 (38%). Women with a fistula, attributed to obstructed labor, developed the fistula at a younger age (p =.04) and had a lower parity (p =.02). Attempted delivery before arriving at the hospital was associated with an increased risk of obstetric fistula after cesarean delivery following obstructed labor (p <.01).
Conclusion: CS are commonly performed on women who arrive at the hospital following prolonged obstructed labor and fetal demise, and account for almost 40% of urogenital fistula. Obstetric providers should assess maternal status upon arrival to prevent unnecessary CS and identify women at risk of developing a fistula
Using phenocams to monitor our changing earth: Toward a global phenocam network
Rapid changes to the biosphere are altering ecological processes worldwide. Developing informed policies for mitigating the impacts of environmental change requires an exponential increase in the quantity, diversity, and resolution of field-collected data, which, in turn, necessitates greater reliance on innovative technologies to monitor ecological processes across local to global scales. Automated digital time-lapse cameras â âphenocamsâ â can monitor vegetation status and environmental changes over long periods of time. Phenocams are ideal for documenting changes in phenology, snow cover, fire frequency, and other disturbance events. However, effective monitoring of global environmental change with phenocams requires adoption of data standards. New continental-scale ecological research networks, such as the US National Ecological Observatory Network (NEON) and the European Union's Integrated Carbon Observation System (ICOS), can serve as templates for developing rigorous data standards and extending the utility of phenocam data through standardized ground-truthing. Open-source tools for analysis, visualization, and collaboration will make phenocam data more widely usable
In Situ Kinase Profiling Reveals Functionally Relevant Properties of Native Kinases
SummaryProtein kinases are intensely studied mediators of cellular signaling, yet important questions remain regarding their regulation and in vivo properties. Here, we use a probe-based chemoprotemics platform to profile several well studied kinase inhibitors against >200 kinases in native cell proteomes and reveal biological targets for some of these inhibitors. Several striking differences were identified between native and recombinant kinase inhibitory profiles, in particular, for the Raf kinases. The native kinase binding profiles presented here closely mirror the cellular activity of these inhibitors, even when the inhibition profiles differ dramatically from recombinant assay results. Additionally, Raf activation events could be detected on live cell treatment with inhibitors. These studies highlight the complexities of protein kinase behavior in the cellular context and demonstrate that profiling with only recombinant/purified enzymes can be misleading
Modelling food security: Bridging the gap between the micro and the macro scale
Achieving food and nutrition security for all in a changing and globalized world remains a critical challenge of utmost importance. The development of solutions benefits from insights derived from modelling and simulating the complex interactions of the agri-food system, which range from global to household scales and transcend disciplinary boundaries. A wide range of models based on various methodologies (from food trade equilibrium to agent-based) seek to integrate direct and indirect drivers of change in land use, environment and socio-economic conditions at different scales. However, modelling such interaction poses fundamental challenges, especially for representing non-linear dynamics and adaptive behaviours. We identify key pieces of the fragmented landscape of food security modelling, and organize achievements and gaps into different contextual domains of food security (production, trade, and consumption) at different spatial scales. Building on in-depth reflection on three core issues of food security â volatility, technology, and transformation â we identify methodological challenges and promising strategies for advancement. We emphasize particular requirements related to the multifaceted and multiscale nature of food security. They include the explicit representation of transient dynamics to allow for path dependency and irreversible consequences, and of household heterogeneity to incorporate inequality issues. To illustrate ways forward we provide good practice examples using meta-modelling techniques, non-equilibrium approaches and behavioural-based modelling endeavours. We argue that further integration of different model types is required to better account for both multi-level agency and cross-scale feedbacks within the food system.</p
Summary results of the 2014-2015 DARPA Chikungunya challenge
BACKGROUND: Emerging pathogens such as Zika, chikungunya, Ebola, and dengue viruses are serious threats to national and global health security. Accurate forecasts of emerging epidemics and their severity are critical to minimizing subsequent mortality, morbidity, and economic loss. The recent introduction of chikungunya and Zika virus to the Americas underscores the need for better methods for disease surveillance and forecasting.
METHODS: To explore the suitability of current approaches to forecasting emerging diseases, the Defense Advanced Research Projects Agency (DARPA) launched the 2014â2015 DARPA Chikungunya Challenge to forecast the number of cases and spread of chikungunya disease in the Americas. Challenge participants (n=38 during final evaluation) provided predictions of chikungunya epidemics across the Americas for a six-month period, from September 1, 2014 to February 16, 2015, to be evaluated by comparison with incidence data reported to the Pan American Health Organization (PAHO). This manuscript presents an overview of the challenge and a summary of the approaches used by the winners.
RESULTS: Participant submissions were evaluated by a team of non-competing government subject matter experts based on numerical accuracy and methodology. Although this manuscript does not include in-depth analyses of the results, cursory analyses suggest that simpler models appear to outperform more complex approaches that included, for example, demographic information and transportation dynamics, due to the reporting biases, which can be implicitly captured in statistical models. Mosquito-dynamics, population specific information, and dengue-specific information correlated best with prediction accuracy.
CONCLUSION: We conclude that with careful consideration and understanding of the relative advantages and disadvantages of particular methods, implementation of an effective prediction system is feasible. However, there is a need to improve the quality of the data in order to more accurately predict the course of epidemics
Assessing the structure of the posterior visual pathway in bilateral macular degeneration
Abstract Macular degeneration (MD) embodies a collection of disorders causing a progressive loss of central vision. Cross-sectional MRI studies have revealed structural changes in the grey and white matter in the posterior visual pathway in MD but there remains a need to understand how such changes progress over time. To that end we assessed the posterior pathway, characterising the visual cortex and optic radiations over a ~â2-year period in MD patients and controls. We performed cross-sectional and longitudinal analysis of the former. Reduced cortical thickness and white matter integrity were observed in patients compared to controls, replicating previous findings. While faster, neither the rate of thinning in visual cortex nor the reduction in white matter integrity during the ~â2-year period reached significance. We also measured cortical myelin density; cross-sectional data showed this was higher in patients than controls, likely as a result of greater thinning of non-myelinated tissue in patients. However, we also found evidence of a greater rate of loss of myelin density in the occipital pole in the patient group indicating that the posterior visual pathway is at risk in established MD. Taken together, our results revealed a broad decline in grey and white matter in the posterior visual pathway in bilateral MD; cortical thickness and fractional anisotropy show hints of an accelerated rate of loss also, with larger effects emerging in the occipital pole
Utilizing Technology for Diet and Exercise Change in Complex Chronic Conditions Across Diverse Environments (U-DECIDE): Protocol for a Randomized Controlled Trial
BACKGROUND: The metabolic syndrome is common across many complex chronic disease groups. Advances in health technology have provided opportunities to support lifestyle interventions. OBJECTIVE: The purpose of this study is to test the feasibility of a health technology-assisted lifestyle intervention in a patient-led model of care. METHODS: The study is a single-center, 26-week, randomized controlled trial. The setting is specialist kidney and liver disease clinics at a large Australian tertiary hospital. The participants will be adults with a complex chronic condition who are referred for dietetic assessment and display at least one feature of the metabolic syndrome. All participants will receive an individualized assessment and advice on diet quality from a dietitian, a wearable activity monitor, and standard care. Participants randomized to the intervention group will receive access to a suite of health technologies from which to choose, including common base components (text messages) and optional components (online and mobile appâbased nutrition information, an online home exercise program, and group-based videoconferencing). Exposure to the optional aspects of the intervention will be patient-led, with participants choosing their preferred level of engagement. The primary outcome will be the feasibility of delivering the program, determined by safety, recruitment rate, retention, exposure uptake, and telehealth adherence. Secondary outcomes will be clinical effectiveness, patient-led goal attainment, treatment fidelity, exposure demand, and participant perceptions. Primary outcome data will be assessed descriptively and secondary outcomes will be assessed using an analysis of covariance. This study will provide evidence on the feasibility of the intervention in a tertiary setting for patients with complex chronic disease exhibiting features of the metabolic syndrome. RESULTS: The study was funded in 2019. Enrollment has commenced and is expected to be completed by June 2022. Data collection and follow up are expected to be completed by December 2022. Results from the analyses based on primary outcomes are expected to be submitted for publication by June 2023. CONCLUSIONS: The study will test the implementation of a health technologyâassisted lifestyle intervention in a tertiary outpatient setting for a diverse group of patients with complex chronic conditions. It is novel in that it embeds patient choice into intervention exposure and will inform health service decision-makers in regards to the feasibility of scale and spread of technology-assisted access to care for a broader reach of specialist services. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry ACTRN12620001282976; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378337 INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/3755
Assessing functional reorganization in visual cortex with simulated retinal lesions
Macular degeneration (MD) causes central vision loss, removing input to corresponding representations in the primary visual cortex. There is disagreement concerning whether the cortical regions deprived of input can remain responsive, and the source of reported cortical responses is still debated. To simulate MD in controls, normally sighted participants viewed a bright central disk to adapt the retina, creating a transient 'retinal lesion' during a functional MRI experiment. Participants viewed blocks of faces, scrambled faces and uniform grey stimuli, either passively or whilst performing a one-back task. To assess the impact of the simulated lesion, participants repeated the paradigm using a more conventional mean luminance simulated scotoma without adaptation. Our results suggest our attempt to create a more realistic simulation of a lesion did not impact on responses in the representation of the simulated lesion. While most participants showed no evidence of stimulus-driven activation within the lesion representation, a few individuals (22%) exhibited responses similar to a participant with juvenile MD who completed the same paradigm (without adaptation). Reliability analysis showed that responses in the representation of the lesion were generally consistent irrespective of whether positive or negative. We provide some evidence that peripheral visual stimulation can also produce responses in central representations in controls while performing a task. This suggests that the 'signature of reorganization of visual processing', is not found solely in patients with retinal lesions, consistent with the idea that activity may be driven by unmasked top-down feedback
Citizen science can improve conservation science, natural resource management, and environmental protection
Citizen science has advanced science for hundreds of years, contributed to many peer-reviewed articles, and informed
land management decisions and policies across the United States. Over the last 10 years, citizen science
has grown immensely in the United States and many other countries. Here, we show how citizen science is a
powerful tool for tackling many of the challenges faced in the field of conservation biology. We describe the
two interwoven paths bywhich citizen science can improve conservation efforts, natural resource management,
and environmental protection. The first path includes building scientific knowledge, while the other path involves
informing policy and encouraging public action. We explore how citizen science is currently used and describe
the investments needed to create a citizen science program. We find that:
1. Citizen science already contributes substantially to many domains of science, including conservation, natural
resource, and environmental science. Citizen science informs natural resource management, environmental
protection, and policymaking and fosters public input and engagement.
2. Many types of projects can benefit fromcitizen science, but one must be careful tomatch the needs for science
and public involvement with the right type of citizen science project and the right method of public
participation.
3. Citizen science is a rigorous process of scientific discovery, indistinguishable from conventional science apart
from the participation of volunteers.When properly designed, carried out, and evaluated, citizen science can
provide sound science, efficiently generate high-quality data, and help solve problems
Phytoplankton functional types from Space.
The concept of phytoplankton functional types has emerged as a useful approach to
classifying phytoplankton. It finds many applications in addressing some serious
contemporary issues facing science and society. Its use is not without challenges,
however. As noted earlier, there is no universally-accepted set of functional types,
and the types used have to be carefully selected to suit the particular problem being
addressed. It is important that the sum total of all functional types matches all
phytoplankton under consideration. For example, if in a biogeochemical study,
we classify phytoplankton as silicifiers, calcifiers, DMS-producers and nitrogen fix-
ers, then there is danger that the study may neglect phytoplankton that do not
contribute in any significant way to those functions, but may nevertheless be a
significant contributor to, say primary production. Such considerations often lead
to the adoption of a category of âother phytoplanktonâ in models, with no clear
defining traits assigned them, but that are nevertheless necessary to close budgets
on phytoplankton processes. Since this group is a collection of all phytoplankton
that defy classification according to a set of traits, it is difficult to model their physi-
ological processes. Our understanding of the diverse functions of phytoplankton is
still growing, and as we recognize more functions, there will be a need to balance the
desire to incorporate the increasing number of functional types in models against
observational challenges of identifying and mapping them adequately. Modelling
approaches to dealing with increasing functional diversity have been proposed,
for example, using the complex adaptive systems theory and system of infinite
diversity, as in the work of Bruggemann and Kooijman (2007). But it is unlikely that
remote-sensing approaches might be able to deal with anything but a few prominent
functional types. As long as these challenges are explicitly addressed, the functional-
type concept should continue to fill a real need to capture, in an economic fashion,
the diversity in phytoplankton, and remote sensing should continue to be a useful
tool to map them.
Remote sensing of phytoplankton functional types is an emerging field, whose
potential is not fully realised, nor its limitations clearly established. In this report,
we provide an overview of progress to date, examine the advantages and limitations
of various methods, and outline suggestions for further development. The overview
provided in this chapter is intended to set the stage for detailed considerations of
remote-sensing applications in later chapters.
In the next chapter, we examine various in situ methods that exist for observing
phytoplankton functional types, and how they relate to remote-sensing techniques.
In the subsequent chapters, we review the theoretical and empirical bases for the
existing and emerging remote-sensing approaches; assess knowledge about the
limitations, assumptions, and likely accuracy or predictive skill of the approaches;
provide some preliminary comparative analyses; and look towards future prospects
with respect to algorithm development, validation studies, and new satellite mis-
sions
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