Browsing by Subject "CHALLENGES"

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  • Wannasarit, Saowanee; Wang, Shiqi; Figueiredo, Patricia; Trujillo Olvera, Claudia Ximenia; Eburnea, Francesca; Simón-Gracia, Lorena; Correia, Alexandra; Ding, Yaping; Teesalu, Tambet; Liu, Dongfei; Wiwattanapatapee, Ruedeekorn; Santos, Hélder A.; Li, Wei (2019)
    Achieving cellular internalization and endosomal escape remains a major challenge for many antitumor therapeutics, especially macromolecular drugs. Viral drug carriers are reported for efficient intracellular delivery, but with limited choices of payloads. In this study, a novel polymeric nanoparticle (ADMAP) is developed, resembling the structure and functional features of a virus. ADMAP is synthesized by grafting endosomolytic poly(lauryl methacrylate‐co‐methacrylic acid) on acetalated dextran. The endosomolytic polymer mimics the capsid protein for endosomal escape, and acetalated dextran resembles the viral core for accommodating payloads. After polymer synthesis, the subsequent controlled nanoprecipitation on a microfluidic device yields uniform nanoparticles with high encapsulation efficiency. At late endosomal pH (5.0), the ADMAP particles successfully destabilize endosomal membranes and release the drug payloads synergistically, resulting in a greater therapeutic efficacy compared with that of free anticancer drugs. Further conjugation of a tumor‐penetrating peptide enhances the antitumor efficacy toward 3D spheroids and finally leads to spheroid disintegration. The unique structure along with the synergistic endosomal escape and drug release make ADMAP nanoparticles favorable for intracellular delivery of antitumor therapeutics.
  • Kemppainen, Petri; Husby, Arild (2018)
    A fundamental assumption in quantitative genetics is that traits are controlled by many loci of small effect. Using genomic data, this assumption can be tested using chromosome partitioning analyses, where the proportion of genetic variance for a trait explained by each chromosome (h(c)(2)), is regressed on its size. However, as h(c)(2)-estimates are necessarily positive (censoring) and the variance increases with chromosome size (heteroscedasticity), two fundamental assumptions of ordinary least squares (OLS) regression are violated. Using simulated and empirical data we demonstrate that these violations lead to incorrect inference of genetic architecture. The degree of bias depends mainly on the number of chromosomes and their size distribution and is therefore specific to the species; using published data across many different species we estimate that not accounting for this effect overall resulted in 28% false positives. We introduce a new and computationally efficient resampling method that corrects for inflation caused by heteroscedasticity and censoring and that works under a large range of dataset sizes and genetic architectures in empirical datasets. Our new method substantially improves the robustness of inferences from chromosome partitioning analyses.
  • Jones, Marjaana; Pietilä, Ilkka Veikko (2020)
    Health policies and strategies promote the involvement of people with illness experiences in service development and production, integrating them into settings that have traditionally been domains of health professionals. In this study, we focus on the perspectives of people with personal illness experiences and explore how they justify involvement, position themselves as legitimate actors and forge collaborative relationships with health professionals. We have used discourse analysis in analysing individual interviews conducted with peer support workers and experts by experience (n = 17) who currently work in Finnish health services. The interviewees utilised discourses of empowerment, efficiency and patient-centeredness, aligning themselves with the justifications constructed by patient movements additionally to those found in current health policies. Both groups wanted to retain critical distance from professionals in order to voice criticisms of current care practices, yet they also frequently aligned themselves with professionals in order to gain legitimacy for their involvement. They adopted professional traits that moved them further from being lay participants sharing personal experiences and adopted an expert position. Although national-level policies provided backing and legitimacy for involvement, the lack of local-level guidance could hinder the practical implementation and make involvement largely dependent of professionals' discretion.
  • Wirehn, Lotten; Käyhkö, Janina; Neset, Tina-Simone; Juhola, Sirkku (2020)
    In light of the increased focus on climate change adaptation, there is a need to understand when and how adaptation decision-making generates trade-offs. This study presents a novel framework for adaptation trade-off assessments, which integrates (I) two trade-off mechanisms (direct and interactions) and (II) two types of trade-off characteristics (substantive and processual). Perspectives on adaptation trade-offs were collected from 37 Swedish and Finnish agricultural experts through semi-structured interviews supported by serious gaming and visualization. The data were thematically analysed based on the provided analytical framework. The results show that trade-offs in agricultural adaptation decision-making processes involve balancing a number of socio-ecological system aspects that are of different character and have different functions. The study identified 20 aspects generating trade-offs related to adaptation management in Swedish and Finnish agriculture, among which 'crop yield and profitability', 'farm economy', 'pest and weed robustness' and 'soil quality' were discussed as the most prominent by respondents. The framework enables an examination of complex trade-off structures that can have implications for adaptation management decisions. The results show that the identified aspects constitute different components and functions of trade-offs, including both processual and/or substantive ones. In conclusion, the 20 identified aspects and the framework together demonstrate the importance of the two types of adaptation trade-offs and the resulting complexity of climate change adaptation decision-making in Swedish and Finnish agriculture. Furthermore, the study asserts the potential of applying the framework for various strategic contexts-to recognize and cope with trade-offs in adaptation management.
  • Cardoso, Pedro; Branco, Vasco V.; Borges, Paulo A.; Carvalho, Jose C.; Rigal, Francois; Gabriel, Rosalina; Mammola, Stefano; Cascalho, Jose; Correia, Luis (2020)
    Ecological systems are the quintessential complex systems, involving numerous high-order interactions and non-linear relationships. The most used statistical modeling techniques can hardly accommodate the complexity of ecological patterns and processes. Finding hidden relationships in complex data is now possible using massive computational power, particularly by means of artificial intelligence and machine learning methods. Here we explored the potential of symbolic regression (SR), commonly used in other areas, in the field of ecology. Symbolic regression searches for both the formal structure of equations and the fitting parameters simultaneously, hence providing the required flexibility to characterize complex ecological systems. Although the method here presented is automated, it is part of a collaborative human-machine effort and we demonstrate ways to do it. First, we test the robustness of SR to extreme levels of noise when searching for the species-area relationship. Second, we demonstrate how SR can model species richness and spatial distributions. Third, we illustrate how SR can be used to find general models in ecology, namely new formulas for species richness estimators and the general dynamic model of oceanic island biogeography. We propose that evolving free-form equations purely from data, often without prior human inference or hypotheses, may represent a very powerful tool for ecologists and biogeographers to become aware of hidden relationships and suggest general theoretical models and principles.
  • Aalto, Juha; Scherrer, Daniel; Lenoir, Jonathan; Guisan, Antoine; Luoto, Miska (2018)
    Soil temperature (ST) has a key role in Arctic ecosystem functioning and global environmental change. However, soil thermal conditions do not necessarily follow synoptic temperature variations. This is because local biogeophysical processes can lead to a pronounced soil-atmosphere thermal offset (Delta T) while altering the coupling (beta Tau) between ST and ambient air temperature (AAT). Here, we aim to uncover the spatiotemporal variation in these parameters and identify their main environmental drivers. By deploying a unique network of 322 temperature loggers and surveying biogeophysical processes across an Arctic landscape, we found that the spatial variation in Delta T during the AAT 0 period, Delta T was controlled by soil characteristics, vegetation and solar radiation (Delta T = -0.6 degrees C +/- 1.0 degrees C). Importantly, Delta T was not constant throughout the seasons reflecting the influence of beta Tau on the rate of local soil warming being stronger after (mean beta Tau = 0.8 +/- 0.1) than before (beta Tau = 0.2 +/- 0.2) snowmelt. Our results highlight the need for continuous microclimatic and local environmental monitoring, and suggest a potential for large buffering and non-uniform warming of snow-dominated Arctic ecosystems under projected temperature increase.
  • Kaikkonen, Laura; Helle, Inari; Kostamo, Kirsi; Kuikka, Sakari; Törnroos, Anna; Nygård, Henrik; Venesjärvi, Riikka; Uusitalo, Laura (2021)
    Mineral deposits containing commercially exploitable metals are of interest for seabed mineral extraction in both the deep sea and shallow sea areas. However, the development of seafloor mining is underpinned by high uncertainties on the implementation of the activities and their consequences for the environment. To avoid unbridled expansion of maritime activities, the environmental risks of new types of activities should be carefully evaluated prior to permitting them, yet observational data on the impacts is mostly missing. Here, we examine the environmental risks of seabed mining using a causal, probabilistic network approach. Drawing on a series of expert interviews, we outline the cause-effect pathways related to seabed mining activities to inform quantitative risk assessments. The approach consists of (1) iterative model building with experts to identify the causal connections between seabed mining activities and the affected ecosystem components and (2) quantitative probabilistic modeling. We demonstrate the approach in the Baltic Sea, where seabed mining been has tested and the ecosystem is well studied. The model is used to provide estimates of mortality of benthic fauna under alternative mining scenarios, offering a quantitative means to highlight the uncertainties around the impacts of mining. We further outline requirements for operationalizing quantitative risk assessments in data-poor cases, highlighting the importance of a predictive approach to risk identification. The model can be used to support permitting processes by providing a more comprehensive description of the potential environmental impacts of seabed resource use, allowing iterative updating of the model as new information becomes available.
  • Hällfors, Maria H.; Vaara, Elina M.; Hyvärinen, Marko; Oksanen, Markku; Schulman, Leif E.; Siipi, Helena; Lehvävirta, Susanna (2014)
    Intentional moving of species threatened by climate change is actively being discussed as a conservation approach. The debate, empirical studies, and policy development, however, are impeded by an inconsistent articulation of the idea. The discrepancy is demonstrated by the varying use of terms, such as assisted migration, assisted colonisation, or managed relocation, and their multiple definitions. Since this conservation approach is novel, and may for instance lead to legislative changes, it is important to aim for terminological consistency. The objective of this study is to analyse the suitability of terms and definitions used when discussing the moving of organisms as a response to climate change. An extensive literature search and review of the material (868 scientific publications) was conducted for finding hitherto used terms (N = 40) and definitions (N = 75), and these were analysed for their suitability. Based on the findings, it is argued that an appropriate term for a conservation approach relating to aiding the movement of organisms harmed by climate change is assisted migration defined as follows: Assisted migration means safeguarding biological diversity through the translocation of representatives of a species or population harmed by climate change to an area outside the indigenous range of that unit where it would be predicted to move as climate changes, were it not for anthropogenic dispersal barriers or lack of time. The differences between assisted migration and other conservation translocations are also discussed. A wide adoption of the clear and distinctive term and definition provided would allow more focused research on the topic and enable consistent implementation as practitioners could have the same understanding of the concept.
  • Syyrilä, Tiina; Vehviläinen-Julkunen, Katri; Härkänen, Marja (2020)
    Abstract Aim To identify the types and frequencies of communication issues (communication pairs, person related, institutional, structural, process, and prescription-related issues) detected in medication incident reports and to compare communication issues that caused moderate or serious harm to patients. Background Communication issues have been found to be amongst the main contributing factors of medication incidents, thus necessitating communication enhancement. Design A sequential exploratory mixed-method design. Methods Medication incident reports from Finland (n=500) for the year 2015 in which communication was marked as a contributing factor were used as the data source. Indicator phrases were used for searching communication issues from free texts of incident reports. The detected issues were analysed statistically, qualitatively, and considering the harm caused to the patient. Citations from free texts were extracted as evidence of issues and were classified following main categories of indicator phrases. The EQUATOR?s SRQR checklist was followed in reporting. Results Twenty-eight communication pairs were identified, with nurse-nurse (68.2%; n=341), nurse-physician (41.6%; n=208), and nurse-patient (9.6%; n=48) pairs being the most frequent. Communication issues existed mostly within unit (76.6%, n=383). The most commonly identified issues were digital communication (68.2%; n=341), lack of communication within a team (39.6%; n=198), false assumptions about work processes (25.6%; n=128) and being unaware of guidelines (25.0%; n=125). Collegial feedback, and communication from patients and relatives were the preventing issues. Moderate harm cases were often linked with lack of communication within the unit, digital communication and not following guidelines. Conclusions The interventions should be prioritized to (a) enhancing communication about work-processes, (b) verbal communication about digital prescriptions between professionals, (c) feedback among professionals, and (f) encouraging patients to communicate about medication. Relevance to clinical practice Upon identifying the most harmful and frequent communication issues, interventions to strengthen medication safety can be implemented.
  • Gurarie, Eliezer; Fleming, Christen H.; Fagan, William F.; Laidre, Kristin L.; Hernandez-Pliego, Jesus; Ovaskainen, Otso (2017)
    Background: Continuous time movement models resolve many of the problems with scaling, sampling, and interpretation that affect discrete movement models. They can, however, be challenging to estimate, have been presented in inconsistent ways, and are not widely used. Methods: We review the literature on integrated Ornstein-Uhlenbeck velocity models and propose four fundamental correlated velocity movement models (CVM's): random, advective, rotational, and rotational-advective. The models are defined in terms of biologically meaningful speeds and time scales of autocorrelation. We summarize several approaches to estimating the models, and apply these tools for the higher order task of behavioral partitioning via change point analysis. Results: An array of simulation illustrate the precision and accuracy of the estimation tools. An analysis of a swimming track of a bowhead whale (Balaena mysticetus) illustrates their robustness to irregular and sparse sampling and identifies switches between slower and faster, and directed vs. random movements. An analysis of a short flight of a lesser kestrel (Falco naumanni) identifies exact moments when switches occur between loopy, thermal soaring and directed flapping or gliding flights. Conclusions: We provide tools to estimate parameters and perform change point analyses in continuous time movement models as an R package (smoove). These resources, together with the synthesis, should facilitate the wider application and development of correlated velocity models among movement ecologists.
  • Tedersoo, Leho; Kungas, Rainer; Oras, Ester; Köster, Kajar; Eenmaa, Helen; Leijen, Ali; Pedaste, Margus; Raju, Marju; Astapova, Anastasiya; Lukner, Heli; Kogermann, Karin; Sepp, Tuul (2021)
    Data sharing is one of the cornerstones of modern science that enables large-scale analyses and reproducibility. We evaluated data availability in research articles across nine disciplines in Nature and Science magazines and recorded corresponding authors' concerns, requests and reasons for declining data sharing. Although data sharing has improved in the last decade and particularly in recent years, data availability and willingness to share data still differ greatly among disciplines. We observed that statements of data availability upon (reasonable) request are inefficient and should not be allowed by journals. To improve data sharing at the time of manuscript acceptance, researchers should be better motivated to release their data with real benefits such as recognition, or bonus points in grant and job applications. We recommend that data management costs should be covered by funding agencies; publicly available research data ought to be included in the evaluation of applications; and surveillance of data sharing should be enforced by both academic publishers and funders. These cross-discipline survey data are available from the plutoF repository.
  • Rochette, Anne-Julie; Akpona, Jean Didier T.; Akpona, Hugues Adeloui; Akouehou, Gaston S.; Kwezi, Blanchard Mayundo; Djagoun, Chabi A. M. S.; Habonimana, Bernadette; Idohou, Rodrigue; Legba, Ingride S.; Nzigidahera, Benoit; Matilo, Augustin Orou; Taleb, Mohammed Sghir; Bamoninga, Benjamin Toirambe; Ivory, Sarah; de Bisthoven, Luc Janssens; Vanhove, Maarten P. M. (2019)
    There is an increasing need for monitoring schemes that help understand the evolution of the global biodiversity crisis and propose solutions for the future. Indicators, including temporal baselines, are crucial to measure the change in biodiversity over time, to evaluate progress towards its conservation and sustainable use and to set conservation priorities. They help design and monitor national and regional policies on biodiversity; they also feed into national reporting on international agreements such as the Convention on Biological Diversity and the Sustainable Development Goals. We analyse the methodological approach of five small African projects resulting from a call to promote indicator development, improve monitoring capacity and strengthen the science-policy interface in the field of biodiversity. We compared their approach to existing guidance provided by the international community, specifically the Biodiversity Indicators Partnership. To this end, we assess whether internationally recommended steps are effectively applied to national/local biodiversity monitoring in selected developing countries. We also present lessons learnt from workshop interactions between partners involved in these projects. Through our pilot projects we identified data availability and data accessibility, together with the involvement of stakeholders, as critical steps in indicator development. Moreover, there is a need for a better awareness and a wider application of the indicator concept itself. Hence, training of key actors both in the policy and science spheres is needed to operationalize indicators and ensure their continuity and sustainability. We hope that these case studies and lessons learnt can stimulate and support countries in the Global South to formulate policy-relevant biodiversity indicators.
  • Elf, Sonja; Auvinen, Pauliina; Jahn, Lisa; Liikonen, Karoliina; Sjöblom, Solveig; Saavalainen, Päivi; Mäki, Minna; Eboigbodin, Kevin E. (2018)
    Isothermal nucleic acid amplification methods can potentially shorten the amount of time required to diagnose influenza. We developed and evaluated a novel isothermal nucleic acid amplification method, RT-SIBA to rapidly detect and differentiate between influenza A and B viruses in a single reaction tube. The performance of the RT-SIBA Influenza assay was compared with two established RT-PCR methods. The sensitivities of the RT-SIBA, RealStar RT-PCR, and CDC RT-PCR assays for the detection of influenza A and B viruses in the clinical specimens were 98.8%, 100%, and 89.3%, respectively. All three assays demonstrated a specificity of 100%. The average time to positive result was significantly shorter with the RT-SIBA Influenza assay (90 min). The method can be run using battery-operated, portable devices with a small footprint and therefore has potential applications in both laboratory and near-patient settings. (C) 2018 Elsevier Inc. All rights reserved.
  • Savela, Nina; Oksanen, Atte; Kaakinen, Markus; Noreikis, Marius; Xiao, Yu (2020)
    Augmented reality (AR) applications have recently emerged for entertainment and educational purposes and have been proposed to have positive effects on social interaction. In this study, we investigated the impact of a mobile, indoor AR feature on sociability, entertainment, and learning. We conducted a field experiment using a quiz game in a Finnish science center exhibition. We divided participants (N = 372) into an experimental group (AR app users) and two control groups (non-AR app users; pen-and-paper participants), including 28 AR users of follow-up interviews. We used Kruskal-Wallis rank test to compare the experimental groups and the content analysis method to explore AR users' experiences. Although interviewed AR participants recognized the entertainment value and learning opportunities for AR, we did not detect an increase in perceived sociability, social behavior, positive affect, or learning performance when comparing the experimental groups. Instead, AR interviewees experienced a strong conflict between the two different realities. Despite the engaging novelty value of new technology, performance and other improvements do not automatically emerge. We also discuss potential conditional factors. Future research and development of AR and related technologies should note the possible negative effects of dividing attention to both realities.
  • Li, Yuhong; Su, Xiang; Ding, Aaron Yi; Lindgren, Anders; Liu, Xiaoli; Prehofer, Christian; Riekki, Jukka; Rahmani, Rahim; Tarkoma, Sasu; Hui, Pan (2020)
    The Internet of Things (IoT) connects smart devices to enable various intelligent services. The deployment of IoT encounters several challenges, such as difficulties in controlling and managing IoT applications and networks, problems in programming existing IoT devices, long service provisioning time, underused resources, as well as complexity, isolation and scalability, among others. One fundamental concern is that current IoT networks lack flexibility and intelligence. A network-wide flexible control and management are missing in IoT networks. In addition, huge numbers of devices and large amounts of data are involved in IoT, but none of them have been tuned for supporting network management and control. In this paper, we argue that Software-defined Networking (SDN) together with the data generated by IoT applications can enhance the control and management of IoT in terms of flexibility and intelligence. We present a review for the evolution of SDN and IoT and analyze the benefits and challenges brought by the integration of SDN and IoT with the help of IoT data. We discuss the perspectives of knowledge-driven SDN for IoT through a new IoT architecture and illustrate how to realize Industry IoT by using the architecture. We also highlight the challenges and future research works toward realizing IoT with the knowledge-driven SDN.
  • Bissell, Karen; Ellwood, Philippa; Ellwood, Eamon; Chiang, Chen-Yuan; Marks, Guy B.; El Sony, Asma; Asher, Innes; Billo, Nils; Perrin, Christophe; Global Asthma Network Study Grp; Mäkelä, M. (2019)
    Patients with asthma need uninterrupted supplies of affordable, quality-assured essential medicines. However, access in many low- and middle-income countries (LMICs) is limited. The World Health Organization (WHO) Non-Communicable Disease (NCD) Global Action Plan 2013-2020 sets an 80% target for essential NCD medicines' availability. Poor access is partly due to medicines not being included on the national Essential Medicines Lists (EML) and/or National Reimbursement Lists (NRL) which guide the provision of free/subsidised medicines. We aimed to determine how many countries have essential asthma medicines on their EML and NRL, which essential asthma medicines, and whether surveys might monitor progress. A cross-sectional survey in 2013-2015 of Global Asthma Network principal investigators generated 111/120 (93%) responses41 high-income countries and territories (HICs); 70 LMICs. Patients in HICs with NRL are best served (91% HICs included ICS (inhaled corticosteroids) and salbutamol). Patients in the 24 (34%) LMICs with no NRL and the 14 (30%) LMICs with an NRL, however no ICS are likely to have very poor access to affordable, quality-assured ICS. Many LMICs do not have essential asthma medicines on their EML or NRL. Technical guidance and advocacy for policy change is required. Improving access to these medicines will improve the health system's capacity to address NCDs.
  • Muurinen, Johanna; Pasupulate, Avinash; Lappalainen, Juha; Virta, Marko (2019)
    Whole-cell bioreporters are living organisms and thus using them for detecting environmental contaminants would reflect biological effects of these pollutants. However, bioreporters are not widely used in field studies. Many of the bioreporter field protocols are suitable for liquid samples or include pipetting steps, which is a demanding task outside the laboratory. We present a bioreporter protocol without pipetting or sample type requirements. The protocol utilizes polyester swabs, commonly used in cleanroom technology. As an example contaminant, we used tetracycline and generated test samples with known concentrations up to the maximum tetracycline residue limit of milk set by the European Union (EU) regulation. The matrices of the test samples were Milli-Q water, milk and soil. The swabs were first dipped in the bioreporter cell cultures and then to test samples and luminescence was measured after incubation. The standard deviation of measurements from ten replicate swabs was in the same range as commonly in pipetting protocols (4-19%). The test samples with lowest tetracycline concentration (5 ng mL(-1)) were distinguished from the control samples (0 ng mL(-1) tetracycline). Our results show that swabs can be used together with luminescent whole cell bioreporters, making it possible to conduct the measurements in field conditions.
  • Räsänen, Aleksi; Nygren, Anja; Monge Monge, Adrian Antonio; Käkönen, Mira; Kanninen, Markku; Juhola, Sirkku (2018)
    Land use changes have been recognized to have considerable impacts on water; and vice versa, changes in water use and governance may have implications on land use and governance. This study analyzes recent land use/land cover (LULC) changes, and how changes in land use and water governance are perceived to affect land use and water-related risks in three case-study areas exposed to frequent flooding and inadequate or deteriorating water quality. The areas studied included the Vantaa basin in Finland, a section of the Grijalva basin in Mexico, and the Lower Xe Bang Fai basin in Laos. We show how there are complex and context-specific interrelationships between land use, water governance, and water-related risks in each study area. In a remote sensing analysis of LULC changes during the past 30 years, we found that LULC changes have been the most dramatic in Xe Bang Fai, Laos in the form of expanding agriculture and built-up areas; however, there has also been an expansion of built-up areas in the two other sites. According to our stakeholder scenario workshop data, analysis of policy documents and field visits, the nexus between land, water and risks is recognized to some extent in each study area. There have been modest shifts toward more integrated land use and water governance in Vantaa and Grijalva, while the integrated governance seems to have been most absent in Xe Bang Fai. Tighter integration of land and water policies is needed in all the three cases to manage the land use changes in a way that their effects on water-related risks will be minimized.
  • GBD 2017 HIV Collaborators; Frank, Tahvi D.; Carter, Austin; Meretoja, Tuomo J. (2019)
    Background Understanding the patterns of HIV/AIDS epidemics is crucial to tracking and monitoring the progress of prevention and control efforts in countries. We provide a comprehensive assessment of the levels and trends of HIV/AIDS incidence, prevalence, mortality, and coverage of antiretroviral therapy (ART) for 1980-2017 and forecast these estimates to 2030 for 195 countries and territories. Methods We determined a modelling strategy for each country on the basis of the availability and quality of data. For countries and territories with data from population-based seroprevalence surveys or antenatal care clinics, we estimated prevalence and incidence using an open-source version of the Estimation and Projection Package-a natural history model originally developed by the UNAIDS Reference Group on Estimates, Modelling, and Projections. For countries with cause-specific vital registration data, we corrected data for garbage coding (ie, deaths coded to an intermediate, immediate, or poorly defined cause) and HIV misclassification. We developed a process of cohort incidence bias adjustment to use information on survival and deaths recorded in vital registration to back-calculate HIV incidence. For countries without any representative data on HIV, we produced incidence estimates by pulling information from observed bias in the geographical region. We used a re-coded version of the Spectrum model (a cohort component model that uses rates of disease progression and HIV mortality on and off ART) to produce age-sex-specific incidence, prevalence, and mortality, and treatment coverage results for all countries, and forecast these measures to 2030 using Spectrum with inputs that were extended on the basis of past trends in treatment scale-up and new infections. Findings Global HIV mortality peaked in 2006 with 1.95 million deaths (95% uncertainty interval 1.87-2.04) and has since decreased to 0.95 million deaths (0.91-1.01) in 2017. New cases of HIV globally peaked in 1999 (3.16 million, 2.79-3.67) and since then have gradually decreased to 1.94 million (1.63-2.29) in 2017. These trends, along with ART scale-up, have globally resulted in increased prevalence, with 36.8 million (34.8-39.2) people living with HIV in 2017. Prevalence of HIV was highest in southern sub-Saharan Africa in 2017, and countries in the region had ART coverage ranging from 65.7% in Lesotho to 85.7% in eSwatini. Our forecasts showed that 54 countries will meet the UNAIDS target of 81% ART coverage by 2020 and 12 countries are on track to meet 90% ART coverage by 2030. Forecasted results estimate that few countries will meet the UNAIDS 2020 and 2030 mortality and incidence targets. Interpretation Despite progress in reducing HIV-related mortality over the past decade, slow decreases in incidence, combined with the current context of stagnated funding for related interventions, mean that many countries are not on track to reach the 2020 and 2030 global targets for reduction in incidence and mortality. With a growing population of people living with HIV, it will continue to be a major threat to public health for years to come. The pace of progress needs to be hastened by continuing to expand access to ART and increasing investments in proven HIV prevention initiatives that can be scaled up to have population-level impact. Copyright (C) 2019 The Author(s). Published by Elsevier Ltd.
  • Karonen, Maarit; Murtonen, Mari; Södervik, Ilona; Manninen, Marianna; Salomäki, Mikko (2021)
    Understanding chemical models can be challenging for many university students studying chemistry. This study analysed students’ understanding of molecular structures using the Lewis structure as a model, and examined what hinders their understanding. We conducted pre- and post-tests to analyse students’ conceptions and changes in them. The measures contained multiple-choice questions and drawing tasks testing their understanding of concepts, such as polarity, geometry, charge or formal charge and expanded octet. The pre-test revealed a lack of knowledge and several misconceptions in students’ prior knowledge. For example, the concept of polarity was well-known, but the combination of polarity and geometry appeared to be difficult. For some students, the representation of molecules was intuitive and lacking a systematic approach. Certain students used mnemonics and draw ball-and-stick models connected to surficial representations. After the chemistry courses, the conceptions and drawings had generally changed, and the level of the students’ knowledge increased markedly. Although, fewer ball-and-stick models were drawn in the post-test, some students still used them. The main result was that students who drew ball-and-stick models in the pre-test were less capable of drawing the correct Lewis structures with electrons in the post-test. In addition, heuristics seem to hinder learning and some concepts, such as resonance, remained difficult. This is probably due to the fact that understanding molecular structures requires systemic understanding, where several matters must be understood at the same time. Our study highlights that the understanding of molecular structures requires conceptual change related to several sub-concepts.