The economic control of infectious diseases

Despite interesting work on infectious diseases by such economists as Peter Francis, Michael Kremer, and Tomas Philipson, the literature does not set out the general structure of externalities involved in the prevention, and care of such diseases. The authors identify two kinds of externality. First, infectious people can infect other people, who in turn can infect others, and so on, in what the authors call the pure infection externality. In controlling their own infection, people do not take into account the social consequence of their infection. Second, in the pure prevention externality, one individual's preventive actions (such as killing mosquitoes) may directly affect the probability of others becoming infected, whether or not the preventive action succeeds for the individual undertaking it. The authors provide a general framework for discussing these externalities, and the role of government interventions to offset them. They move the discussion away from its focus on HIV (a fatal infection for which there are few interventions), and on vaccinations (which involve plausibly discrete decisions), to more general ideas of prevention, and cure applicable to many diseases for which interventions exhibit a continuum of intensities, subject to diminishing marginal returns. Infections, and actions to prevent, or cure them entail costs. Individuals balance those parts of different costs that they can actually control. In balancing costs to society, government policy should take individual behavior into account. Doing so requires a strategy combining preventive, and curative interventions, to offset both the pure infection externality, and the pure prevention externality. The relative importance of the strategy's components depends on: 1) The biology of the disease - including whether an infection is transmitted from person to person, or by vectors. 2) The possible outcomes of infection: death, recovery with susceptibility, or recovery with immunity. 3) The relative costs of the interventions. 4) Whether interventions are targeted at the population as a whole, the uninfected, the infected, or contacts between the uninfected, and the infected. 5) The behavior of individuals that leads to the two types of externalities.Disease Control&Prevention,Economic Theory&Research,Environmental Economics&Policies,Decentralization,Poverty Impact Evaluation,Economic Theory&Research,Environmental Economics&Policies,Poverty Impact Evaluation,Health Monitoring&Evaluation,Agricultural Knowledge&Information Systems

Review of \u3ci\u3ePieces of the Plains: Memories and Predictions from the Heart of America.\u3c/i\u3e By John Janovy, Jr.

John Janovy, Jr., author, parasitologist, and Varner Professor of Biological Sciences at the University ofNebraska- Lincoln, describes his book as sort of a memoir, but one in which experience is the main character, instead of the writer. Janovy divides this experience into three sections describing his past, his present, and humanity\u27s future. Janovy the teacher is never far from each chapter\u27s storyline. Describing his central theme as education in the broadest sense, a constant learning derived from exploration of things and places, he sets out in the book\u27s pages to engage in a discussion of big ideas just as he does in his classroom. Janovy\u27s love of teaching is evident throughout and ought to inspire other college and university teachers

Review of \u3ci\u3ePieces of the Plains: Memories and Predictions from the Heart of America.\u3c/i\u3e By John Janovy, Jr.

John Janovy, Jr., author, parasitologist, and Varner Professor of Biological Sciences at the University ofNebraska- Lincoln, describes his book as sort of a memoir, but one in which experience is the main character, instead of the writer. Janovy divides this experience into three sections describing his past, his present, and humanity\u27s future. Janovy the teacher is never far from each chapter\u27s storyline. Describing his central theme as education in the broadest sense, a constant learning derived from exploration of things and places, he sets out in the book\u27s pages to engage in a discussion of big ideas just as he does in his classroom. Janovy\u27s love of teaching is evident throughout and ought to inspire other college and university teachers

Eutrophication Of Small Reservoirs In Eastern Nebraska

Numerous small reservoirs constructed in Nebraska are used for recreation and many more are being planned. While these impoundments seemingly alleviate the long standing need for recreational waters, many existing impoundments exhibit symptoms of accelerated eutrophication after only a few years of existence. It is natural that such lakes, impounding nutrient-rich water, should be productive and generate nuisances that interfere with projected recreational uses. Unfortunately, neither this fact nor the lack of feasible methods for nutrient control were perceived prior to providing recreational facilities at the reservoir sites. Rates of eutrophication, nutrient sources, and eutrophication control have been examined in a study of five eastern Nebraska reservoirs. The following conclusions have been established by the research studies: Runoff waters impounded in the Salt Valley reservoirs have sufficient nutrient salts to support abundant growths of aquatic plants; reservoirs that are light-limited by soil turbidity support neither abundant growths of aquatic plants nor dense blue-green algal blooms; clear water reservoirs are very eutrophic - shorelines choked with rooted aquatics, dense blooms of blue-green algae, odorous emissions, and occasional fish kills are typical characteristics of these impoundments; and in clear water reservoirs the rate of eutrophication is very rapid and appears to be directly related to age. Projections based upon existing data indicate that the useful life of these reservoirs for body-contact recreation is only a few years

Eutrophication Of Small Reservoirs In Eastern Nebraska

Numerous small reservoirs constructed in Nebraska are used for recreation and many more are being planned. While these impoundments seemingly alleviate the long standing need for recreational waters, many existing impoundments exhibit symptoms of accelerated eutrophication after only a few years of existence. It is natural that such lakes, impounding nutrient-rich water, should be productive and generate nuisances that interfere with projected recreational uses. Unfortunately, neither this fact nor the lack of feasible methods for nutrient control were perceived prior to providing recreational facilities at the reservoir sites. Rates of eutrophication, nutrient sources, and eutrophication control have been examined in a study of five eastern Nebraska reservoirs. The following conclusions have been established by the research studies: Runoff waters impounded in the Salt Valley reservoirs have sufficient nutrient salts to support abundant growths of aquatic plants; reservoirs that are light-limited by soil turbidity support neither abundant growths of aquatic plants nor dense blue-green algal blooms; clear water reservoirs are very eutrophic - shorelines choked with rooted aquatics, dense blooms of blue-green algae, odorous emissions, and occasional fish kills are typical characteristics of these impoundments; and in clear water reservoirs the rate of eutrophication is very rapid and appears to be directly related to age. Projections based upon existing data indicate that the useful life of these reservoirs for body-contact recreation is only a few years

Dephosphorylation of the Thylakoid Membrane Light-Harvesting Complex-II by a Stromal Protein Phosphatase

Light-harvesting complex-II (LHC-II) phosphatase activity has generally been examined in the intact thylakoid membrane. A recent report of peptide-phosphatase activity associated with the chloroplast stromal fraction (Hammer, M.E et al. (1995) Photosynth Res 44:107–115) has led to the question of whether this activity is capable of dephosphorylating membrane-bound LHC-II. To this end, heat-treated thylakoid membranes were examined as a potential LHC-II phosphatase substrate. Following incubation of the thylakoid membrane at 60 °C for 15 min, the endogenous protein phosphatase and kinase activities were almost eliminated. Heat-inactivated phosphomembranes exhibited minimal dephosphorylation of the light harvesting complex-II. Peptide-phosphatase activities isolated from the thylakoid and stromal fraction were able to dephosphorylate LHC-II in heat-inactivated phosphomembranes. The stromal phosphatase showed highest activity against LHC-II at pH 9. Dephosphorylation of the LHC-II by the stromal enzyme was not inhibited by molybdate, vanadate or tungstate ions, but was partially inhibited by EDTA and a synthetic phosphopeptide mimicking the LHC-II phosphorylation site. Thus, the previously identified stromal phosphatase does appear capable of dephosphorylating authentic LHC-II in vivo

Balancing problems in acyclic networks

A directed acyclic network with nonnegative integer arc lengths is called balanced if any two paths with common endpoints have equal lengths. In the buffer assignment problem such a network is given, and the goal is to balance it by increasing arc lengths by integer amounts (called buffers), so that the sum of the amounts added is minimal. This problem arises in VLSI design, and was recently shown to be polynomial for rooted networks. Here we give simple procedures which solve several generalizations of this problem in strongly polynomial time, using ideas from network flow theory. In particular, we solve a weighted version of the problem, extend the results to nonrooted networks, and allow upper bounds on buffers. We also give a strongly polynomial algorithm for solving the min-max buffer assignment problem, based on a strong proximity result between fractional and integer balanced solutions. Finally, we show that the problem of balancing a network while minimizing the number of arcs with positive buffers is NP-hard

Simple quantitative chest CT for pulmonary edema

Purpose: To determine the accuracy of quantitative CT to diagnose pulmonary edema compared to qualitative CT and CXR and to determine a threshold Hounsfield unit (HU) measurement for pulmonary edema on CT examinations. Method: Electronic medical records were searched for patients with a billing diagnosis of heart failure and a Chest CT and CXR performed within three hours between 1/1/2016 to 10/1/2016, yielding 100 patients. CXR and CT examinations were scored for the presence and severity of edema, using a 0-5 scale, and CT HU measurements were obtained in each lobe. Polyserial correlation coefficients evaluated the association between CT HUs and CXR scores, and receiver operating characteristic (ROC) curve analysis determined a cutoff CT HU value for identification of pulmonary edema. Results: Correlation between CT HU and CXR score was moderately strong (r=0.585-0.685) with CT HU measurements demonstrating good to excellent accuracy in differentiating between no edema (grade 0) and mild to severe edema (grades 1-5) in every lobe, with AUCs ranging between 0.869 and 0.995. The left upper lobe demonstrated the highest accuracy, using a cutoff value of -825 HU (AUC of 0.995, sensitivity=100 % and specificity=95.1 %). Additionally, qualitative CT evaluation was less sensitive (84 %) than portable CXR in identifying pulmonary edema. However, quantitative CT evaluation was as sensitive as portable CXR (100 %) and highly specific (95 %). Conclusions: Quantitative CT enables the identification of pulmonary edema with high accuracy and demonstrates a greater sensitivity than qualitative CT in assessment of pulmonary edema

Effect of Shear Stress on Platelet Activation via the Glycoprotein VI Receptor

Cardiovascular diseases are the nation\u27s leading cause of death. Such diseases are caused by platelet response to collagen especially in the event of vascular injury leading to thrombosis. One of the platelet receptors known to bind to the collagen ligand is glycoprotein VI (GPVI) with co-receptor Fc receptor γ chain (FcRγ). By stably expressing the GPVI receptor in rat basophilic leukemia cells (RBL-2H3), which abundantly express FcRγ, but endogenously lack GPVI, studies have shown that GPVI-FcRγ is sufficient to confer adhesion as well as signaling responses to collagen as long as the receptor density is equivalent to that found on human platelets. While those investigations confirm that the GPVI receptor mediate binding to collagen under static conditions, they do not provide information on how the GPVI receptor interacts with collagen under dynamic conditions. In the present study we have used the GPVI-expressing RBL-2H3 cells to observe the kinetics of adhesion to collagen under hydrodynamic flow conditions in vitro using a parallel plate flow chamber coupled with video microscopy. We demonstrate that these cells do adhere to the surface at a low shear rate and do so at a greater adherent cell density than wild-type RBL-2H3 (WT-RBL) cells

IGF-I increases bone marrow contribution to adult skeletal muscle and enhances the fusion of myelomonocytic precursors

Muscle damage has been shown to enhance the contribution of bone marrow–derived cells (BMDCs) to regenerating skeletal muscle. One responsible cell type involved in this process is a hematopoietic stem cell derivative, the myelomonocytic precursor (MMC). However, the molecular components responsible for this injury-related response remain largely unknown. In this paper, we show that delivery of insulin-like growth factor I (IGF-I) to adult skeletal muscle by three different methods—plasmid electroporation, injection of genetically engineered myoblasts, and recombinant protein injection—increases the integration of BMDCs up to fourfold. To investigate the underlying mechanism, we developed an in vitro fusion assay in which co-cultures of MMCs and myotubes were exposed to IGF-I. The number of fusion events was substantially augmented by IGF-I, independent of its effect on cell survival. These results provide novel evidence that a single factor, IGF-I, is sufficient to enhance the fusion of bone marrow derivatives with adult skeletal muscle