The Ramifications of Revolution: Haiti and the Influence of U.S. Policy

The Haitian Revolution, lasting from 1791 to 1804, was the first successful slave-led insurrection against France in Saint-Domingue. Influenced by United States foreign policy, the fight to establish a free nation led the U.S. to question future economic and diplomatic relationships with an independent Haiti. Through excerpts from various sources, including a Pennsylvania Gazette article outlining violence in Saint-Domingue, the 1793 French Emancipation Decree and Laurent Dubois’ historical narrative, this essay explores the precarious relationship between the U.S. and Haiti during the late eighteenth and early nineteenth centuries. The vehement and successful rejection of foreign rule by an enslaved population swayed the American government to attempt to prevent a similar uprising within the states. The U.S. denial to recognize Haitian independence exemplifies the notion that the U.S. government denied Black autonomy to preserve its economy and power structures

Study in supply chain design

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 82-83).Corporations are increasingly looking at ways to incorporate environmental sustainability initiatives into their businesses to lower operating costs and improve the value of their brands for customers that expect higher social responsibility from corporations. These environmental initiatives, often called "win-win" for their dual effect on long-term shareholder value, are easy to identify but often hard to incorporate into existing operations. One such initiative in the retail industry involves delivering products to customers in reusable plastic cartons, rather than corrugated cardboard. One of the largest challenges when designing and implementing this type of supply chain system is developing a reverse logistics strategy that ensures carton return by the consumers, whom the corporation must convince to participate in closing the logistics loop. This thesis analyzes a pilot program conducted by a consumer products company, referred to as the Sponsor, where reusable plastic cartons were used to deliver orders to one of their corporate customers. Process mapping, qualitative interviews, and data analysis were utilized to understand factors contributing to the unacceptably high rate of carton attrition. Using the results of this analysis, two new design tracks are proposed for the delivery of the Sponsor's products at MIT. One design relies on the current operating systems and structures to minimize investment by the Sponsor, while the other design is aimed at maximizing effort to optimize the system. The proposed programs consider both operational practicalities in the logistical design and communication and incentive efforts that are needed to drive consumer behavior to maximize carton return and lower attrition rates. We believe the recommended implementation of the maximized effort design will result in lower carton attrition, which will provide the necessary proof of concept for the Sponsor to roll the program out to additional customers.by Erin Mulvey Connolly and Emily Keane.M.Eng.in Logistic

The Impact of Vitamin D Levels on Inflammatory Status: A Systematic Review of Immune Cell Studies.

Chronic low-grade inflammation accompanies obesity and its related chronic conditions. Both peripheral blood mononuclear cells (PBMCs) and cell lines have been used to study whether vitamin D has immune modulating effects; however, to date a detailed systematic review describing the published evidence has not been completed. We therefore conducted a systematic review on the effect of vitamin D on the protein expression and secretion of inflammatory markers by human-derived immune cells. The review was registered at the International Prospective Register for Systematic Reviews (PROSPERO, Registration number CRD42015023222). A literature search was conducted using Pubmed, Science Direct, Scopus, Web of Science and Medline. The search strategy used the following search terms: Vitamin D or cholecalciferol or 1,25-dihydroxyvitamin or 25-hydroxy-Vitamin D and Inflam* or cytokine* and supplement* or cell*. These terms were searched in the abstract, title and keywords. Inclusion criteria for study selection consisted of human-derived immune cell lines or cellular studies where PBMCs were obtained from humans, reported in the English language, and within the time period of 2000 to 2015. The selection protocol was mapped according to PRISMA guidelines. Twenty three studies (7 cell line and 16 PBMCs studies) met our criteria. All studies selected except one used the active metabolite 1,25(OH)2, with one study using cholecalciferol and two studies also using 25(OH)D. Four out of seven cell line studies showed an anti-inflammatory effect where suppression of key markers such as macrophage chemotactic protein 1, interleukin 6 and interleukin 8 were observed. Fourteen of sixteen PBMC studies also showed a similar anti-inflammatory effect based on common inflammatory endpoints. Mechanisms for such effects included decreased protein expression of toll-like receptor-2 and toll-like receptor-4; lower levels of phosphorylated p38 and p42/42; reduced expression of phosphorylated signal transducer and activator of transcription 5 and decreased reactive oxygen species. This review demonstrates that an anti-inflammatory effect of vitamin D is a consistent observation in studies of cell lines and human derived PBMCs

Computed tomography in veterinary medicine: currently published and tomorrow’s vision

The utilisation of Computed Tomography (CT) in veterinary practice has been increasing rapidly in line with reduced cost, improved availability and the increase in expertise and technology. This review briefly examines the recent technological advancements in imaging in the veterinary sector, and explores how CT and micro-CT (μCT) have furthered basic understanding and knowledge, and influenced clinical practice and medicine. The uses of CT technology in veterinary research, especially in relation to bone, vasculature and soft tissues, are explored and compared in relation to the different species. CT is essential not only for the diagnosis and treatment of many disorders, but it is now being used to understand areas ranging from drug delivery and surgical advancements through to anatomical and educational uses throughout the world

Hypoxia promotes production of neural crest cells in the embryonic head

ABSTRACT Hypoxia is encountered in either pathological or physiological conditions, the latter of which is seen in amniote embryos prior to the commencement of a functional blood circulation. During the hypoxic stage, a large number of neural crest cells arise from the head neural tube by epithelial-to-mesenchymal transition (EMT). As EMT-like cancer dissemination can be promoted by hypoxia, we investigated whether hypoxia contributes to embryonic EMT. Using chick embryos, we show that the hypoxic cellular response, mediated by hypoxia-inducible factor (HIF)-1α, is required to produce a sufficient number of neural crest cells. Among the genes that are involved in neural crest cell development, some genes are more sensitive to hypoxia than others, demonstrating that the effect of hypoxia is gene specific. Once blood circulation becomes fully functional, the embryonic head no longer produces neural crest cells in vivo, despite the capability to do so in a hypoxia-mimicking condition in vitro, suggesting that the oxygen supply helps to stop emigration of neural crest cells in the head. These results highlight the importance of hypoxia in normal embryonic development.</jats:p

Hybrid Thermal Lance

The Hybrid Thermal Lance (HTL) is a device used to burn through landmines to destroy them safely. Designed for the team’s client, The HALO Trust, the HTL has proven to work well in destroying explosives, which has been demonstrated by field trials conducted in a number of countries including but not limited to Afghanistan and the Republic of Georgia. The HTL works by igniting acrylic burn tubes, which act as a fuel source and also focus the flame on a specific location on an explosive device. The system is controlled via a user-friendly, rugged control box that can run the HTL automatically and allow the device to burn for different lengths of time upon user command. The team was asked by HALO to make the HTL as user-friendly as possible. In order to do this, the team has been researching ways to make the ignition system as reliable as possible so the device works every time. The team plans to move forward in testing and refining the ignition system and the control circuit in order to give the client a trouble-free device. Future plans include designing a fixture that can be fitted over the end of the HTL burn tube which can focus the heat of the flame for a more concentrated burn.https://mosaic.messiah.edu/engr2020/1022/thumbnail.jp

‘Eastern African paradox’ rainfall decline due to shorter not less intense long rains

An observed decline in the Eastern African Long Rains from the 1980s to late 2000s appears contrary to the projected increase under future climate change. This “Eastern African climate paradox” confounds use of climate projections for adaptation planning across Eastern Africa. Here we show the decline corresponds to a later onset and earlier cessation of the long rains, with a similar seasonal maximum in area-averaged daily rainfall. Previous studies have explored the role of remote teleconnections, but those mechanisms do not sufficiently explain the decline or the newly identified change in seasonality. Using a large ensemble of observations, reanalyses and atmospheric simulations, we propose a regional mechanism that explains both the observed decline and the recent partial recovery. A decrease in surface pressure over Arabia and warmer north Arabian Sea is associated with enhanced southerlies and an earlier cessation of the long rains. This is supported by a similar signal in surface pressure in many atmosphere-only models giving lower May rainfall and an earlier cessation. Anomalously warm seas south of Eastern Africa delay the northward movement of the tropical rain-band, giving a later onset. These results are key in understanding the paradox. It is now a priority to establish the balance of mechanisms that have led to these trends, which are partially captured in atmosphere-only simulations

Optical follow-up observation of Fast Radio Burst 151230

The origin of fast radio bursts (FRBs), bright millisecond radio transients, is still somewhat of a mystery. Several theoretical models expect that the FRB accompanies an optical afterglow (e.g., Totani 2013; Kashiyama et al. 2013). In order to investigate the origin of FRBs, we perform $gri$-band follow-up observations of FRB~151230 (estimated $z \lesssim 0.8$) with Subaru/Hyper Suprime-Cam at $8$, $11$, and $14$~days after discovery. The follow-up observation reaches a $50\%$ completeness magnitude of $26.5$~mag for point sources, which is the deepest optical follow-up of FRBs to date. We find $13$ counterpart candidates with variabilities during the observation. We investigate their properties with multicolor and multi-wavelength observations and archival catalogs. Two candidates are excluded by the non-detection of FRB~151230 in the other radio feed horns that operated simultaneously to the detection, as well as the inconsistency between the photometric redshift and that derived from the dispersion measure of FRB~151230. Eight further candidates are consistent with optical variability seen in AGNs. Two more candidates are well fitted with transient templates (Type IIn supernovae), and the final candidate is poorly fitted with all of our transient templates and is located off-center of an extended source. It can only be reproduced with rapid transients with a faint peak and rapid decline and the probability of chance coincidence is $\sim3.6\%$. We also find that none of our candidates are consistent with Type Ia supernovae, which rules out the association of Type Ia supernovae to FRB~151230 at $z\leq0.6$ and limits the dispersion measure of the host galaxy to $\lesssim300$~pc~cm$^{-3}$ in a Type Ia supernova scenario.Comment: 22 pages, 11 figures. Accepted for publication in PASJ (Publications of the Astronomical Society of Japan

Clinician-Driven AI: Code-Free Self-Training on Public Data for Diabetic Retinopathy Referral

Importance: Democratizing artificial intelligence (AI) enables model development by clinicians with a lack of coding expertise, powerful computing resources, and large, well-labeled data sets. // Objective: To determine whether resource-constrained clinicians can use self-training via automated machine learning (ML) and public data sets to design high-performing diabetic retinopathy classification models. // Design, Setting, and Participants: This diagnostic quality improvement study was conducted from January 1, 2021, to December 31, 2021. A self-training method without coding was used on 2 public data sets with retinal images from patients in France (Messidor-2 [n = 1748]) and the UK and US (EyePACS [n = 58 689]) and externally validated on 1 data set with retinal images from patients of a private Egyptian medical retina clinic (Egypt [n = 210]). An AI model was trained to classify referable diabetic retinopathy as an exemplar use case. Messidor-2 images were assigned adjudicated labels available on Kaggle; 4 images were deemed ungradable and excluded, leaving 1744 images. A total of 300 images randomly selected from the EyePACS data set were independently relabeled by 3 blinded retina specialists using the International Classification of Diabetic Retinopathy protocol for diabetic retinopathy grade and diabetic macular edema presence; 19 images were deemed ungradable, leaving 281 images. Data analysis was performed from February 1 to February 28, 2021. // Exposures: Using public data sets, a teacher model was trained with labeled images using supervised learning. Next, the resulting predictions, termed pseudolabels, were used on an unlabeled public data set. Finally, a student model was trained with the existing labeled images and the additional pseudolabeled images. Main Outcomes and Measures: The analyzed metrics for the models included the area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity, and F1 score. The Fisher exact test was performed, and 2-tailed P values were calculated for failure case analysis. // Results: For the internal validation data sets, AUROC values for performance ranged from 0.886 to 0.939 for the teacher model and from 0.916 to 0.951 for the student model. For external validation of automated ML model performance, AUROC values and accuracy were 0.964 and 93.3% for the teacher model, 0.950 and 96.7% for the student model, and 0.890 and 94.3% for the manually coded bespoke model, respectively. // Conclusions and Relevance: These findings suggest that self-training using automated ML is an effective method to increase both model performance and generalizability while decreasing the need for costly expert labeling. This approach advances the democratization of AI by enabling clinicians without coding expertise or access to large, well-labeled private data sets to develop their own AI models

Probing the extragalactic fast transient sky at minute timescales with DECam

Searches for optical transients are usually performed with a cadence of days to weeks, optimised for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on the detection of extragalactic transients evolving at sub-hour timescales. Here, we present the results of deep searches for dim, minute-timescale extragalactic fast transients using the Dark Energy Camera, a core facility of our all-wavelength and all-messenger Deeper, Wider, Faster programme. We used continuous 20s exposures to systematically probe timescales down to 1.17 minutes at magnitude limits $g > 23$ (AB), detecting hundreds of transient and variable sources. Nine candidates passed our strict criteria on duration and non-stellarity, all of which could be classified as flare stars based on deep multi-band imaging. Searches for fast radio burst and gamma-ray counterparts during simultaneous multi-facility observations yielded no counterparts to the optical transients. Also, no long-term variability was detected with pre-imaging and follow-up observations using the SkyMapper optical telescope. We place upper limits for minute-timescale fast optical transient rates for a range of depths and timescales. Finally, we demonstrate that optical $g$-band light curve behaviour alone cannot discriminate between confirmed extragalactic fast transients such as prompt GRB flashes and Galactic stellar flares.Comment: Published in MNRA