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Search Results: 1 - 10 of 305099 matches for " Matthew J. Harrigan "
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Economic Conditions Predict Prevalence of West Nile Virus
Ryan J. Harrigan,Henri A. Thomassen,Wolfgang Buermann,Robert F. Cummings,Matthew E. Kahn,Thomas B. Smith
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0015437
Abstract: Understanding the conditions underlying the proliferation of infectious diseases is crucial for mitigating future outbreaks. Since its arrival in North America in 1999, West Nile virus (WNV) has led to population-wide declines of bird species, morbidity and mortality of humans, and expenditures of millions of dollars on treatment and control. To understand the environmental conditions that best explain and predict WNV prevalence, we employed recently developed spatial modeling techniques in a recognized WNV hotspot, Orange County, California. Our models explained 85–95% of the variation of WNV prevalence in mosquito vectors, and WNV presence in secondary human hosts. Prevalence in both vectors and humans was best explained by economic variables, specifically per capita income, and by anthropogenic characteristics of the environment, particularly human population and neglected swimming pool density. While previous studies have shown associations between anthropogenic change and pathogen presence, results show that poorer economic conditions may act as a direct surrogate for environmental characteristics related to WNV prevalence. Low-income areas may be associated with higher prevalence for a number of reasons, including variations in property upkeep, microhabitat conditions conducive to viral amplification in both vectors and hosts, host community composition, and human behavioral responses related to differences in education or political participation. Results emphasize the importance and utility of including economic variables in mapping spatial risk assessments of disease.
Statistical Properties of Blue Horizontal Branch Stars in the Spheroid: Detection of a Moving Group approximately 50 kpc from the Sun
Matthew J. Harrigan,Heidi Jo Newberg,Lee A. Newberg,Brian Yanny,Timothy C. Beers,Young Sun Lee,Paola Re Fiorentin
Physics , 2010, DOI: 10.1111/j.1365-2966.2010.16552.x
Abstract: A new moving group comprising at least four Blue Horizontal Branch (BHB) stars is identified at (l,b) = (65 deg, 48 deg). The horizontal branch at g0=18.9 magnitude implies a distance of 50 kpc from the Sun. The heliocentric radial velocity is RV = -157 +/- 4 km/s, corresponding to V(gsr) = -10 km/s; the dispersion in line-of-sight velocity is consistent with the instrumental errors for these stars. The mean metallicity of the moving group is [Fe/H] approximately -2.4, which is significantly more metal poor than the stellar spheroid. We estimate that the BHB stars in the outer halo have a mean metallicity of [Fe/H] = -2.0, with a wide scatter and a distribution that does not change much as a function of distance from the Sun. We explore the systematics of SDSS DR7 surface gravity metallicity determinations for faint BHB stars, and present a technique for estimating the significance of clumps discovered in multidimensional data. This moving group cannot be distinguished in density, and highlights the need to collect many more spectra of Galactic stars to unravel the merger history of the Galaxy.
Economic Freedom, Migration and Income Change among U.S. Metropolitan Areas  [PDF]
J. Matthew Shumway
Current Urban Studies (CUS) , 2018, DOI: 10.4236/cus.2018.61001
Abstract:
Even though metropolitan area governments have no control over state level monetary, labor, or fiscal policies, they are able to enact policies designed to enhance local living conditions—however determined. Such policies include local taxes, labor and wage policies, and regulations that can differ substantially from other metropolitan areas even within the same state. Collectively such policies create differing levels of economic freedom, as measured by standardized indices. We examine differences in levels of economic freedom across United States metropolitan areas and explore how these differences affect migration patterns and local aggregate and per capita income changes. We find that those metropolitan areas with higher levels of economic freedom tend to experience net in-migration and positive changes in aggregate and per capita income, although the balance between in-state and out-of-state migration confounds these patterns.
Iron Overdose during Pregnancy: Case and Treatment Review  [PDF]
Matthew J. Geraci, Haesuk Heagney
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.37A126
Abstract:

A 22-year-old pregnant female was transferred to the emergency department having ingested a bottle of iron-containing prenatal vitamins, ondansetron (Zofran?) tablets and alcohol. The patient was hemodynamically stable but suffered from intense bouts of brown, sandy emesis for the first few hours. Investigation revealed the patient ingested 13.57 mg/kg of elemental iron. Due to the initial iron level, history and presentation time whole bowel irrigation was initiated with polyethylene glycol solution. Acute iron toxicity in pregnancy is a medical emergency that can result in multisystem organ failure leading to maternal death and potential fetal demise. High maternal serum iron loads do not affect the developing fetus and are not associated with fetal malformations; however advanced poisoning can lead to maternal death, spontaneous abortions or preterm emergency deliveries. Initial treatment strategies may include whole bowel irrigation using polyethylene glycol electrolyte lavage solution and deferoxamine treatment along with necessary supportive care management. Despite concerns of teratogenicity deferoxamine does not cross the placenta and is regarded as safe for use during pregnancy. Maternal resuscitation must always be the primary objective in acute iron overdoses and, therefore such concern should not delay clinically indicated maternal treatment.

Have the Algae-Grazing Fish in the Back Reefs of Jamaica and Grand Cayman Changed in Size? A View across 36 Years  [PDF]
Matthew J. Draud, M. Itzkowitz
Open Journal of Marine Science (OJMS) , 2018, DOI: 10.4236/ojms.2018.82016
Abstract:
The island of Jamaica is often cited as an example of how overfishing has dramatically reduced the sizes of coral reef fishes. To examine the change in fish sizes over a 36-year period, we analyzed data from systematic surveys conducted in 1977 and 2013/14 of the sizes and relative abundances of four common algae-grazing fishes in the shallow backreef habitats of Jamaica and Grand Cayman. The four species are: striped parrotfish (Scarus iseri), stoplight parrotfish (Sparisoma viride), ocean surgeon (Acanthurus tractus) and the blue tang (Acanthurus coeruleus). We predicted that all four species would be larger in Grand Cayman than in Jamaica in 1977 as well as in 2013/14, because Grand Cayman has been cited as having less fishing pressure than Jamaica. For the same reason, we expected all four species would have declined in size over the 36 years in Jamaica but not in Grand Cayman. Furthermore, we predicted that the compressed body shape of the ocean surgeon and the blue tang would have made them especially vulnerable to net and trap fishing compared to the two parrotfishes, and that accordingly the effects of overfishing would be greater in these two species. We rejected this hypothesis. The size distributions of the laterally compressed species changed significantly on both islands over the 36-year time span, although not as predicted. At both islands, the blue tangs shifted toward smaller sizes and the ocean surgeons shifted toward larger sizes. There were no size distribution changes detected in the two fusiform species. There was also no support for the prediction that the sizes of these four species were larger in Grand Cayman than in Jamaica during either time period.
Anthropogenic emissions during Arctas-A: mean transport characteristics and regional case studies
D. L. Harrigan,H. E. Fuelberg,I. J. Simpson,D. R. Blake
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2011, DOI: 10.5194/acp-11-8677-2011
Abstract: The National Aeronautics and Space Administration (NASA) conducted the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission during 2008 as a part of the International Polar Year (IPY). The purpose of ARCTAS was to study the factors responsible for changes in the Arctic's atmospheric composition and climate. A major emphasis was to investigate Arctic haze, which is most pronounced during winter and early spring. This study focuses on the spring phase of ARCTAS (ARCTAS-A) that was based in Alaska during April 2008. Although anthropogenic emissions historically have been associated with Arctic haze, biomass burning emissions dominated the ARCTAS-A period and have been the focus of many ARCTAS related studies. This study determines mean transport characteristics of anthropogenic emissions during ARCTAS-A. Trajectories are initiated each day from three significant regions of anthropogenic emissions (Asia, North America, and Europe). The fifteen day forward trajectories are calculated using data from the Weather Research and Forecasting (WRF) model at 45 km horizontal resolution. The trajectory calculations indicate: origins of emissions that reach the Arctic (defined as north of 70° N) within fifteen days, pathways of these emissions, Arctic entry locations, and altitudes at which the trajectories enter the Arctic. Three cases during the ARCTAS-A period (one for each of the regions above) are examined using backward trajectories and chemical fingerprinting based on in situ data sampled from the NASA DC-8. The fingerprinting utilizes volatile organic compounds that represent pure anthropogenic tracers, Asian anthropogenic pollution, incomplete combustion, and natural gas emissions. We determine flight legs containing anthropogenic emissions and the pathways travelled by these emissions. Results show that the DC-8 sampled anthropogenic emissions from Asia, North America, and Europe during the spring phase of ARCTAS. The pathways travelled by these emissions agree with our derived transport characteristics and previous studies of Arctic transport. Meteorological analysis and trajectory calculations indicate that middle latitude cyclones and their associated warm conveyor belts play an important role in lofting the surface based emissions to their sampling altitude in all three cases.
Cardiac tamponade due to group a streptococcal pericarditis in a 10-month-old boy and a review of the literature  [PDF]
Matthew C. Schwartz, Matthew J. Gillespie, Paul Stephens, Brian Fisher
Open Journal of Pediatrics (OJPed) , 2011, DOI: 10.4236/ojped.2011.14020
Abstract: Group A streptococcus (GAS) is a rare cause of purulent pericarditis in pediatric patients as only 7 cases have been reported. We present a 10-month-old boy who developed cardiac tamponade from GAS and was successfully treated with subxiphoid tube drainage and 4 weeks of antibiotics at the Children’s Hospital of Philadelphia.
Metapopulation Dynamics Enable Persistence of Influenza A, Including A/H5N1, in Poultry
Parviez Rana Hosseini, Trevon Fuller, Ryan Harrigan, Delong Zhao, Carmen Sofia Arriola, Armandoe Gonzalez, Matthew Joshua Miller, Xiangming Xiao, Tom B. Smith, Jamie Holland Jones, Peter Daszak
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080091
Abstract: Highly pathogenic influenza A/H5N1 has persistently but sporadically caused human illness and death since 1997. Yet it is still unclear how this pathogen is able to persist globally. While wild birds seem to be a genetic reservoir for influenza A, they do not seem to be the main source of human illness. Here, we highlight the role that domestic poultry may play in maintaining A/H5N1 globally, using theoretical models of spatial population structure in poultry populations. We find that a metapopulation of moderately sized poultry flocks can sustain the pathogen in a finite poultry population for over two years. Our results suggest that it is possible that moderately intensive backyard farms could sustain the pathogen indefinitely in real systems. This fits a pattern that has been observed from many empirical systems. Rather than just employing standard culling procedures to control the disease, our model suggests ways that poultry production systems may be modified.
Hypertension may be the most important component of hyperdynamic therapy in cerebral vasospasm
Mark R Harrigan
Critical Care , 2010, DOI: 10.1186/cc8983
Abstract: In a previous issue of Critical Care, Dankbaar and colleagues [1] presented a systematic review of clinical studies of hyperdynamic therapy and its components on cerebral blood flow (CBF). Symptomatic cerebral vasospasm is defined as cerebral ischemia attributable to narrowing of intracranial arteries and loss of cerebral autoregulation, and afflicts some 20 to 25% of patients after rupture of an intracranial aneurysm [2,3]. The cornerstone of medical therapy for cerebral vasospasm is so-called hyperdynamic therapy. Also referred to as triple-H therapy, this strategy includes the use of hypertension, hypervolemia, and hemodilution to optimize cerebral perfusion. Introduced in the 1970s, this management strategy has become widely accepted as first-line treatment for symptomatic vasospasm and is probably used in one form or another in nearly all neurosurgical centers. Indeed, this author favors the use of induced hypertension and volume supplementation for primary treatment of symptomatic vasospasm, prior to endovascular treatment, and, anecdotally, has observed rapid neurological improvement - over the course of an hour or less - in such circumstances. This acceptance of hyperdynamic therapy has evolved despite a relatively modest amount of supportive clinical evidence. The recent American Heart Association Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage described hyperdynamic therapy only as 'one reasonable approach' for the treatment of symptomatic vasospasm (Class IIa treatment effect, level of evidence B) [4]. Hyperdynamic therapy, particularly hypervolemic therapy, also comes with a price in terms of complications (reported in up to 30% of cases [5,6]) and cost. Furthermore, it is not yet clear which components of hyperdynamic therapy are most important.Dankbaar and colleagues [1] provide a systematic review of clinical studies of hyperdynamic therapy and its components on CBF. Why focus on CBF instead of neurological or overall clinical outc
Qatar’s economy: Past, present and future
Ibrahim Ibrahim,Frank Harrigan
QScience Connect , 2012, DOI: 10.5339/connect.2012.9
Abstract: In this review, the story of Qatar’s economic emergence is told chronologically, beginning with Qatar’s independence and the discovery of the North Field gas reservoir in 1971 and ending with the steps that Qatar is now taking as it transitions towards a more diversified and innovative economy.
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