521 research outputs found
Interface Development for Static Multimedia Documents
We propose to create a set of software technologies and encoding practices that will allow for the encoding, displaying, and searching of static documents that mix print, manuscript, and visual images--documents such as printed texts or images bearing handwritten annotations. The technologies we plan to build include standards for encoding coordinates in XML transcriptions so that search engines can visually display results of user searches for manuscript words and phrases; software for linking XML editing programs to an image display to allow encoders to relate bitmap images to XML text; and model stylesheets capable of displaying transcriptions of annotated documents together with digital images of those documents. The goal will be to create a software suite that is simple enough to be used by transcribers with little familiarity with information encoding and portable enough to work in multiple computing environments for widely different kinds of archival projects
Communication Lower Bounds for Cryptographic Broadcast Protocols
Broadcast protocols enable a set of parties to agree on the input of a
designated sender, even facing attacks by malicious parties. In the
honest-majority setting, randomization and cryptography were harnessed to
achieve low-communication broadcast with sub-quadratic total communication and
balanced sub-linear cost per party. However, comparatively little is known in
the dishonest-majority setting. Here, the most communication-efficient
constructions are based on Dolev and Strong (SICOMP '83), and sub-quadratic
broadcast has not been achieved. On the other hand, the only nontrivial
communication lower bounds are restricted to deterministic
protocols, or against strong adaptive adversaries that can perform "after the
fact" removal of messages.
We provide new communication lower bounds in this space, which hold against
arbitrary cryptography and setup assumptions, as well as a simple protocol
showing near tightness of our first bound.
1) We demonstrate a tradeoff between resiliency and communication for
protocols secure against static corruptions. For example,
messages are needed when the number of honest
parties is ; messages are needed for
honest parties; and messages are needed for
honest parties.
Complementarily, we demonstrate broadcast with
total communication facing any constant fraction of static corruptions.
2) Our second bound considers corruptions and a weakly adaptive
adversary that cannot remove messages "after the fact." We show that any
broadcast protocol within this setting can be attacked to force an arbitrary
party to send messages to other parties. This rules out, for example,
broadcast facing 51% corruptions in which all non-sender parties have sublinear
communication locality.Comment: A preliminary version of this work appeared in DISC 202
Neighborhood Climate Action Planning Handbook
The City of Portland and Multnomah County are developing new plans and policies to meet greenhouse gas reduction goals of 80% below 1990 levels by 2050. To meet these new steep reduction targets, actions will be needed at every level of society. While neighborhoods have historically received little attention as a means of addressing climate change, they are ideally suited to bring people together to bridge the gap between individual actions and higher level government policies. To help neighborhoods develop strategies and actions to address climate change, C-Change Consultants worked with the Southeast Uplift Neighborhood Coalition to create a Neighborhood Climate Action Planning Handbook. Through the course of developing the Handbook, C-Change consultants found that southeast neighborhoods see taking collective action on climate change as a way to build stronger communities, save money, and increase neighborhood involvement. The Neighborhood Climate Action Planning Handbook features three main sections: a process section that includes various strategies for how neighborhoods can address climate change; an actions section that includes examples of successful projects that neighborhoods can use to reduce their carbon footprint; and an appendix that includes useful tools and resources neighborhoods can use as they move throughout the neighborhood climate action planning process. This project was conducted under the supervision of Sy Adler, Ethan Seltzer, Ellen Basset, and Vivek Shandas
Functional cis-regulatory modules encoded by mouse-specific endogenous retrovirus
Cis-regulatory modules contain multiple transcription factor (TF)-binding sites and integrate the effects of each TF to control gene expression in specific cellular contexts. Transposable elements (TEs) are uniquely equipped to deposit their regulatory sequences across a genome, which could also contain cis-regulatory modules that coordinate the control of multiple genes with the same regulatory logic. We provide the first evidence of mouse-specific TEs that encode a module of TF-binding sites in mouse embryonic stem cells (ESCs). The majority (77%) of the individual TEs tested exhibited enhancer activity in mouse ESCs. By mutating individual TF-binding sites within the TE, we identified a module of TF-binding motifs that cooperatively enhanced gene expression. Interestingly, we also observed the same motif module in the in silico constructed ancestral TE that also acted cooperatively to enhance gene expression. Our results suggest that ancestral TE insertions might have brought in cis-regulatory modules into the mouse genome
Are There Nutrient-based Poverty Traps? Evidence on Iron Deficiency and Schooling Attainment in Peru
A key question in development economics is whether nutritional deficiencies generate intergenerational
poverty traps by reducing the earnings potential of children born into poverty. To assess the causal influence on human capital of one of the most widespread micronutrient
deficiencies, supplemental iron pills were made available at a local health center in rural Peru and adolescents were encouraged to take them up via classroom media messages. Results from school administrative records provide novel evidence that reducing iron deficiency results almost immediately in a large and significant improvement in school performance. For anemic students, an average of 10 100mg iron pills over three months improves average
test scores by 0.4 standard deviations and increases the likelihood of grade progression by 11%. Supplementation also raises anemic students’ aspirations for the future. Both results indicate that cognitive deficits from iron-deficiency anemia contribute to a nutrition-based
poverty trap. Our findings also demonstrate that, with low-cost outreach efforts in schools, supplementation programs offered through a public clinic can be both affordable and effective in reducing rates of adolescent IDA
Communication Lower Bounds for Cryptographic Broadcast Protocols
Broadcast protocols enable a set of parties to agree on the input of a designated sender, even facing attacks by malicious parties. In the honest-majority setting, a fruitful line of work harnessed randomization and cryptography to achieve low-communication broadcast protocols with sub-quadratic total communication and with balanced sub-linear communication cost per party.
However, comparatively little is known in the dishonest-majority setting. Here, the most communication-efficient constructions are based on the protocol of Dolev and Strong (SICOMP \u2783), and sub-quadratic broadcast has not been achieved even using randomization and cryptography. On the other hand, the only nontrivial communication lower bounds are restricted to deterministic protocols, or against strong adaptive adversaries that can perform after the fact removal of messages.
We provide new communication lower bounds in this space, which hold against arbitrary cryptography and setup assumptions, as well as a simple protocol showing near tightness of our first bound.
1) We demonstrate a tradeoff between resiliency and communication for randomized protocols secure against static corruptions. For example, messages are needed when the number of honest parties is ; messages are needed for honest parties; and messages are needed for honest parties.
Complementarily, we demonstrate broadcast with total communication facing any constant fraction of static corruptions.
2) Our second bound considers corruptions and a weakly adaptive adversary that cannot remove messages after the fact. We show that any broadcast protocol within this setting can be attacked to force an arbitrary party to send messages to other parties. Our bound rules out, for example, broadcast facing corruptions, in which all non-sender parties have sublinear communication locality
Are There Nutrient-based Poverty Traps? Evidence on Iron Deficiency and Schooling Attainment in Peru
A key question in development economics is whether nutritional deficiencies generate intergenerational
poverty traps by reducing the earnings potential of children born into poverty. To assess the causal influence on human capital of one of the most widespread micronutrient
deficiencies, supplemental iron pills were made available at a local health center in rural Peru and adolescents were encouraged to take them up via classroom media messages. Results from school administrative records provide novel evidence that reducing iron deficiency results almost immediately in a large and significant improvement in school performance. For anemic students, an average of 10 100mg iron pills over three months improves average
test scores by 0.4 standard deviations and increases the likelihood of grade progression by 11%. Supplementation also raises anemic students’ aspirations for the future. Both results indicate that cognitive deficits from iron-deficiency anemia contribute to a nutrition-based
poverty trap. Our findings also demonstrate that, with low-cost outreach efforts in schools, supplementation programs offered through a public clinic can be both affordable and effective in reducing rates of adolescent IDA
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Lung Injury Prediction Score for the Emergency Department: First Step Towards Prevention in Patients at Risk
Background: Early identification of patients at risk of developing acute lung injury (ALI) is critical for potential preventive strategies. We aimed to derive and validate an acute lung injury prediction score (EDLIPS) in a multicenter sample of emergency department (ED) patients. Methods: We performed a subgroup analysis of 4,361 ED patients enrolled in the previously reported multicenter observational study. ED risk factors and conditions associated with subsequent ALI development were identified and included in the EDLIPS model. Scores were derived and validated using logistic regression analyses. The model was assessed with the area under the receiver-operating curve (AUC) and compared to the original LIPS model (derived from a population of elective high-risk surgical and ED patients) and the Acute Physiology and Chronic Health Evaluation (APACHE II) score. Results: The incidence of ALI was 7.0% (303/4361). EDLIPS discriminated patients who developed ALI from those who did not with an AUC of 0.78 (95% CI 0.75, 0.82), better than the APACHE II AUC 0.70 (p ≤ 0.001) and similar to the original LIPS score AUC 0.80 (p = 0.07). At an EDLIPS cutoff of 5 (range −0.5, 15) positive and negative likelihood ratios (95% CI) for ALI development were 2.74 (2.43, 3.07) and 0.39 (0.30, 0.49), respectively, with a sensitivity 0.72(0.64, 0.78), specificity 0.74 (0.72, 0.76), and positive and negative predictive value of 0.18 (0.15, 0.21) and 0.97 (0.96, 0.98). Conclusion: EDLIPS may help identify patients at risk for ALI development early in the course of their ED presentation. This novel model may detect at-risk patients for treatment optimization and identify potential patients for ALI prevention trials
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Towards Prevention of Acute Lung Injury: Frequency and Outcomes of Emergency Department Patients At-Risk: A Multicenter Cohort Study
Background: Few emergency department (ED) evaluations on acute lung injury (ALI) have been carried out; hence, we sought to describe a cohort of hospitalized ED patients at risk for ALI development. Methods: Patients presenting to the ED with at least one predisposing condition to ALI were included in this study, a subgroup analysis of a multicenter observational cohort study (USCIITG-LIPS 1). Patients who met ALI criteria within 6 h of initial ED assessment, received end-of-life care, or were readmitted during the study period were excluded. Primary outcome was frequency of ALI development; secondary outcomes were ICU and hospital mortality. Results: Twenty-two hospitals enrolled 4,361 patients who were followed from the ED to hospital discharge. ALI developed in 303 (7.0 %) patients at a median onset of 2 days (IQR 2–5). Of the predisposing conditions, frequency of ALI development was highest in patients who had aortic surgery (43 %) and lowest in patients with pancreatitis (2.8 %). Compared to patients who did not develop ALI, those who did had higher ICU (24 % vs. 3.0 %, p < 0.001) and hospital (28 % vs. 4.6 %, p < 0.001) mortality, and longer hospital length of stay (16 vs. 5 days, p < 0.001). Among the 22 study sites, frequency of ALI development varied from less than 1 % to more than 12 % after adjustment for APACHE II. Conclusions: Seven percent of hospitalized ED patients with at least one predisposing condition developed ALI. The frequency of ALI development varied significantly according to predisposing conditions and across institutions. Further research is warranted to determine the factors contributing to ALI development
Higher BMI is associated with reduced brain volume in heart failure
Abstract
Background
Heart failure (HF) patients are at risk for structural brain changes due to cerebral hypoperfusion. Past work shows obesity is linked with reduced cerebral blood flow and associated with brain atrophy in healthy individuals, although its effects on the brain in HF are unclear. This study examined the association among body mass index (BMI), cerebral perfusion, and brain volume in HF patients.
Results
Eighty HF patients underwent transcranial Doppler sonography to quantify cerebral blood flow velocity of the middle cerebral artery (CBF-V of the MCA) and brain magnetic resonance imaging (MRI) to quantify total brain, total and subcortical gray matter, white matter volume, and white matter hyperintensities. Body mass index (BMI) operationalized weight status. Nearly 45% of HF patients exhibited a BMI consistent with obesity. Regression analyses adjusting for medical variables, demographic characteristics, and CBF-V of the MCA, showed increased BMI was associated with reduced white matter volume (p \u3c .05). BMI also interacted with cerebral perfusion to impact total gray matter volume, but this pattern did not emerge for any other MRI indices (p \u3c 0.05).
Conclusions
Our findings suggest increased BMI negatively affects brain volume in HF, and higher BMI interacts with cerebral perfusion to impact gray matter volume. The mechanisms for these findings remain unclear and likely involve multiple physiological processes. Prospective studies are needed to elucidate the exact pattern and rates of brain changes in obese HF persons
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