62 research outputs found

    Hybrid LSTM and Encoder-Decoder Architecture for Detection of Image Forgeries

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    With advanced image journaling tools, one can easily alter the semantic meaning of an image by exploiting certain manipulation techniques such as copy-clone, object splicing, and removal, which mislead the viewers. In contrast, the identification of these manipulations becomes a very challenging task as manipulated regions are not visually apparent. This paper proposes a high-confidence manipulation localization architecture which utilizes resampling features, Long-Short Term Memory (LSTM) cells, and encoder-decoder network to segment out manipulated regions from non-manipulated ones. Resampling features are used to capture artifacts like JPEG quality loss, upsampling, downsampling, rotation, and shearing. The proposed network exploits larger receptive fields (spatial maps) and frequency domain correlation to analyze the discriminative characteristics between manipulated and non-manipulated regions by incorporating encoder and LSTM network. Finally, decoder network learns the mapping from low-resolution feature maps to pixel-wise predictions for image tamper localization. With predicted mask provided by final layer (softmax) of the proposed architecture, end-to-end training is performed to learn the network parameters through back-propagation using ground-truth masks. Furthermore, a large image splicing dataset is introduced to guide the training process. The proposed method is capable of localizing image manipulations at pixel level with high precision, which is demonstrated through rigorous experimentation on three diverse datasets

    Human subjects protection issues in QUERI implementation research: QUERI Series

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    <p>Abstract</p> <p>Background</p> <p>Human Subjects protections approaches, specifically those relating to research review board oversight, vary throughout the world. While all are designed to protect participants involved in research, the structure and specifics of these institutional review boards (IRBs) can and do differ. This variation affects all types of research, particularly implementation research.</p> <p>Methods</p> <p>In 2001, we began a series of inter-related studies on implementing evidence-based collaborative care for depression in Veterans Health Administration primary care. We have submitted more than 100 IRB applications, amendments, and renewals, and in doing so, we have interacted with 13 VA and University IRBs across the United States (U.S.). We present four overarching IRB-related themes encountered throughout the implementation of our projects, and within each theme, identify key challenges and suggest approaches that have proved useful. Where applicable, we showcase process aids developed to assist in resolving a particular IRB challenge.</p> <p>Results</p> <p>There are issues unique to implementation research, as this type of research may not fit within the traditional Human Subjects paradigm used to assess clinical trials. Risks in implementation research are generally related to breaches of confidentiality, rather than health risks associated with traditional clinical trials. The implementation-specific challenges discussed are: external validity considerations, Plan-Do-Study-Act cycles, risk-benefit issues, the multiple roles of researchers and subjects, and system-level unit of analysis.</p> <p>Discussion</p> <p>Specific aspects of implementation research interact with variations in knowledge, procedures, and regulatory interpretations across IRBs to affect the implementation and study of best methods to increase evidence-based practice. Through lack of unambiguous guidelines and local liability concerns, IRBs are often at risk of applying both variable and inappropriate or unnecessary standards to implementation research that are not consistent with the spirit of the Belmont Report (a summary of basic ethical principles identified by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research), and which impede the conduct of evidence-based quality improvement research. While there are promising developments in the IRB community, it is incumbent upon implementation researchers to interact with IRBs in a manner that assists appropriate risk-benefit determinations and helps prevent the process from having a negative impact on efforts to reduce the lag in implementing best practices.</p

    Winter territory prospecting is associated with life-history stage but not activity in a passerine

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    Finding a high quality territory is essential for many animals to reproduce successfully. Despite its importance for fitness, we know little about the process of territory prospecting in wild birds, and whether individual traits and behaviours, such as personality, co-vary with territory prospecting. Here, we use long-term data from a wild, insular house sparrow Passer domesticus population to test three hypotheses about territory fidelity and prospecting: (1) House sparrows show high territory fidelity between years and also during winter. (2) Individuals will prospect for a breeding territory during their first winter whereas older, more experienced individuals will keep a territory from previous years and will, therefore, show no or reduced winter territory prospecting. (3) More active behavioural types will prospect more than less active behavioural types. We use data from four winters from automatically, daily recorded nest-box visits of 188 birds of known age. The number of nest-boxes that each individual visited within each winter was used as a proxy of winter territory prospecting. We show that house sparrows visit multiple nest-boxes during their first winter, whereas older individuals keep territories year-round and, potentially because of this, indeed show reduced winter territory prospecting. Activity was not associated with the number of nest-boxes visited. Further research is needed to investigate whether time of territory and mate acquisition differs among individuals and the possible effect on lifetime fitness

    Disturbance and Plant Succession in the Mojave and Sonoran Deserts of the American Southwest

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    Disturbances such as fire, land clearing, and road building remove vegetation and can have major influences on public health through effects on air quality, aesthetics, recreational opportunities, natural resource availability, and economics. Plant recovery and succession following disturbance are poorly understood in arid lands relative to more temperate regions. This study quantitatively reviewed vegetation reestablishment following a variety of disturbances in the Mojave and Sonoran Deserts of southwestern North America. A total of 47 studies met inclusion criteria for the review. The time estimated by 29 individual studies for full reestablishment of total perennial plant cover was 76 years. Although long, this time was shorter than an estimated 215 years (among 31 individual studies) required for the recovery of species composition typical of undisturbed areas, assuming that recovery remains linear following the longest time since disturbance measurement made by the studies

    Technologies of contraception and abortion

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    Soon to turn 60, the oral contraceptive pill still dominates histories of technology in the ‘sexual revolution’ and after. ‘The pill’ was revolutionary for many, though by no means all, women in the west, but there have always been alternatives, and looking globally yields a different picture. The condom, intrauterine device (IUD), surgical sterilization (male and female) and abortion were all transformed in the twentieth century, some more than once. Today, female sterilization (tubal ligation) and IUDs are the world's most commonly used technologies of contraception. The pill is in third place, followed closely by the condom. Long-acting hormonal injections are most frequently used in parts of Africa, male sterilization by vasectomy is unusually prevalent in Britain, and about one in five pregnancies worldwide ends in induced abortion. Though contraceptive use has generally increased in recent decades, the disparity between rich and poor countries is striking: the former tend to use condoms and pills, the latter sterilization and IUDs. Contraception, a term dating from the late nineteenth century and since then often conflated with abortion, has existed in many forms, and techniques have changed and proliferated over time. Diverse local cultures have embraced new technologies while maintaining older practices. Focusing on Britain and the United States, with excursions to India, China and France, this chapter shows how the patterns observed today were established and stabilized, often despite persistent criticism and reform efforts. By examining past innovation, and the distribution and use of a variety of tools and techniques, it reconsiders some widely held assumptions about what counts as revolutionary and for whom. Analytically, it takes up and reflects on one of the main issues raised by feminists and social historians: the agency of users as patients and consumers faced with choice and coercion. By examining practices of contraception alongside those of abortion, it revisits the knotty question of technology in the sexual revolution and the related themes of medical, legal, religious and political forms of control

    Physician assistant education program director attrition and consideration to leave

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    Abstract Background This study explores factors related to physician assistant (PA) education program directors’ (PD) consideration to leave their leadership role. This is important to better understand, with the need for additional PA education PDs as the number of PA programs grows in addition to current PA program leaders considering leaving their PD role. Methods Data from the 2019 Physician Assistant Education Association (PAEA) Faculty and Directors Survey were used to analyze factors related to consideration for leaving the PD position. Multiple logistic regression analyses were utilized to identify predictors of PD consideration for leaving their position. Multiple regression analyses were also used to explore factors related to burnout. Results The study found burnout was a modest predictor for consideration of leaving the PD position, while underrepresented minority status was not. Additional job stress, job satisfaction, and job experience variables were found to have a modest relationship with consideration of leaving, with odds ratios between 0.28 (lack of faculty respecting each other) and 5.29 (stress from lack of personal time) for those with statistically significant relationships. Conclusions PD consideration of leaving is a complex phenomenon with many variables and confounding factors likely at play, including, as demonstrated by this study, level of burnout. Study implications include a further understanding of how effective strategies might be designed and implemented to address the drivers of PA PD attrition. Further exploration of burnout as a possible mediating variable as well as more specific data collection directed at better understanding predictors of PD attrition would be valuable future research directions
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