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is it growing exponentially fast? -impact of assuming exponential growth for characterizing and forecasting epidemics with initial near-exponential growth dynamics

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infectious Disease Modelling 2016年第1期1卷 71-78页

作者： gerardo Chowell Cecile Viboud School of Public Health Georgia State UniversityAtlantaGAUSA Division of international Epidemiology and Population Studies Fogarty International CenterNational Institutes of HealthBethesdaMDUSA

The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing models that capture the baseline transmission characteristics in order to generate reliable epidemic *** models for epidemic forecasting could be achieved by identifying signature features of epidemic growth,which could inform the design of models of disease spread and reveal important characteristics of the transmission *** particular,it is often taken for granted that the early growth phase of different growth processes in nature follow early exponential growth *** the context of infectious disease spread,this assumption is often convenient to describe a transmission process with mass action kinetics using differential equations and generate analytic expressions and estimates of the reproduction *** this article,we carry out a simulation study to illustrate the impact of incorrectly assuming an exponential-growth model to characterize the early phase(e.g.,3e5 disease generation intervals)of an infectious disease outbreak that follows near-exponential growth ***,we assess the impact on:1)goodness of fit,2)bias on the growth parameter,and 3)the impact on short-term epidemic *** findings indicate that devising transmission models and statistical approaches that more flexibly capture the profile of epidemic growth could lead to enhanced model fit,improved estimates of key transmission parameters,and more realistic epidemic forecasts.

关键词： dynamics. process. exponential

Cancer stem cell hypothesis and gastric carcinogenesis: Experimental evidence and unsolved questions

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World Journal of Gastrointestinal Oncology 2012年第3期4卷 54-59页

作者： Alba Rocco Debora Compare gerardo Nardone Department of Clinical and Experimental Medicine Gastroenterology Unit University Federico Ⅱ of Naples

Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continually diversifying cells. This heterogeneity enables the survival of different clones under particular conditions allowing growth at metastatic locations or resistance to chemotherapeutics. Cancer stem cell (CSC) theory completely overturns this traditional understanding of cancer suggesting that only CSCs can self-renew and promote tumor growth. CSCs are relatively refractory to conventional therapies, thus explaining why anti-cancer therapies are far from curative and why relapses of cancer are frequent. The identification of the CSC component of a tumor might, thus, open new therapeutic perspective based on the selective targeting of this small population of cells. in this review we examine the current scientific evidence supporting the existence of CSC in gastric tumors and analyze the main unsolved questions of this difficult field of cancer research.

关键词： Cancer stem cells Gastric cancer CD133 CD44

A primer on stable parameter estimation and forecasting in epidemiology by a problem-oriented regularized least squares algorithm

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infectious Disease Modelling 2017年第2期2卷 268-275页

作者： Alexandra Smirnova gerardo Chowell Department of Mathematics and Statistics Georgia State UniversityAtlantaUSA School of Public Health Georgia State UniversityAtlantaUSA Division of international Epidemiology and Population Studies Fogarty International CenterNational Institutes of HealthBethesdaMDUSA

Public health officials are increasingly recognizing the need to develop disease-forecasting systems to respond to epidemic and pandemic *** instance,simple epidemic models relying on a small number of parameters can play an important role in characterizing epidemic growth and generating short-term epidemic *** the absence of reliable information about transmission mechanisms of emerging infectious diseases,phenomenological models are useful to characterize epidemic growth patterns without the need to explicitly model transmission mechanisms and the natural history of the *** this article,our goal is to discuss and illustrate the role of regularization methods for estimating parameters and generating disease forecasts using the generalized Richards model in the context of the 2014e15 Ebola epidemic in West Africa.

关键词： Generalized Richards model Parameter estimation Regularization methods Epidemic forecasting Ebola

Seismic hazard prediction using multispectral amplification maps in a complex topographic area: A case study of Qiaozhuang town, Sichuan Province, Southwest China

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Journal of Mountain Science 2022年第3期19卷 726-739页

作者： LUO Yong-hong XU Qiang ZHAN Wei-wei GRELLE gerardo State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection Chengdu University of TechnologyChengdu 610059China Department of Civil and Environmental Engineering Tufts UniversityMedfordMA 02155USA Department of Civil and Environment Engineering University of RomeRome 00184Italy

Earthquakes can cause widely distributed slope failures and damage in mountainous *** accurate prediction of ground motions in mountainous areas is essential for managing the seismic risk of urban cities near mountains but is restricted primarily by complex seismic site amplification effects in areas of uneven *** study selected Qiaozhuang town located in the Qingchuan–Pingwu fault zone,Southwest China,as a case study.A simulator for mapped seismic responses using a hybrid model(Si Se RHMap)was applied to compute the multispectral seismic topographic amplification maps at the three slope units surrounding Qiaozhuang town(Weigan hill,***,and ***).Post-earthquake damage survey maps,1 D seismic site response spectral ratios,and H/V spectral ratios of earthquake data were used to validate the computed seismic site amplification factors and resonance *** results suggest that strong topographic amplification effects usually occur at distinct slope locations,such as hilltops,convex slope positions,upslope,and narrow *** computed topographic amplification factors in the study area reached up to 2.4 at upslope or hilltops,and the resonance frequencies were between 3 and 10 *** effects can be as important as stratigraphic effects when assessing seismic amplification effects in the study *** conclude that both topographic and stratigraphic effects should be considered in the comprehensive seismic hazard assessment of the study area or other similar mountain towns.

关键词： Seismic hazard prediction Multispectral amplification map topographic effects Stratigraphic effects SiSeRHMap Wenchuan earthquake

Positive frequency of autoantibodies in multiple sclerosis patients Are they associated with therapy?

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Neural Regeneration Research 2010年第4期5卷 257-260页

作者： gerardo iuliano Luigi Cinquanta Anna Maria Ferruzzi Rosa Napoletano Azienda Ospedaliera Ospedali Riuniti di SalernoU.O.NeurologiaCentro Provinciale Sclerosi Multipla Azienda Ospedaliera Ospedali Riuniti di SalernoU.O.Laboratorio Patologia Clinica Azienda Ospedaliera Ospedali Riuniti di Salerno

BACKGROUND： Humoral autoimmunity in patients with multiple sclerosis is often asymptomatic and transient during interferon therapy. OBJECTiVE： To analyze the frequency of positivity to autoantibodies in multiple sclerosis patients and to clarify whether it is modified by immunomodulating therapy. DESiGN： A retrospective *** AND SE＇rrlNG： The study was performed at the Multiple Sclerosis Center, Department of Neurosciences, Salerno Hospital, italy, between 2005 and 2007. PARTiCiPANTS： A total of 169 multiple sclerosis patients were included, 57 males and 112 females individuals were mainly outpatients and were usually tested yearly for autoantibodies. Patients with previous immunological diseases were excluded from statistical evaluation. METHODS： The frequency of positivity was calculated in patients grouped for gender, multiple sclerosis clinical parameters, magnetic resonance imaging features and disease modifying therapy. A total of 113 patients were treated with beta interferons. MAiN OUTCOME MEASURES： Frequency of positivity to any autoantibody. Prevalences and incidences were ***： The overall prevalence of autoantibodies within 3 years was 47.3%. in multiple sclerosis patients who were untreated or treated with drugs other than interferons, the prevalence was higher, and greater positivity to autoantibodies was seen in patients treated with interferons [odds ratio （95% confidence interval）, 2.87 （1.5 - 5.2）, P 〈 0.05 - 0.01]. Multiple regression analysis showed a significant association of the positivity to autoantibodies with interferon therapy, rather than gender, relapse or magnetic resonance imaging. CONCLUSiON： interferon therapy is associated with significantly higher frequency of autoantibodies in patients with multiple sclerosis. The differences among the therapies are not influenced by other variables such as gender or clinical pattern.

关键词： multiple sclerosis autoimmunity autoantibodies immunomodulation interferon

alcohol drinking and mammary cancer: pathogenesis and potential dietary preventive alternatives

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World Journal of Clinical Oncology 2014年第4期5卷 713-729页

作者： gerardo Daniel Castro José A Castro Centro de investigaciones Toxicológicas CITEDEF B1603ALO Villa Martelli province of Buenos Aires Argentina instituto de investigación e ingeniería Ambiental Universidad Nacional de General San Martín B1650ANQ San Martín province of Buenos Aires Argentina

Alcohol consumption is associated with an increased risk of breast cancer, increasing linearly even with a moderate consumption and irrespectively of the type of alcoholic beverage. it shows no dependency from other risk factors like menopausal status, oral contraceptives, hormone replacement therapy, or genetic history of breast cancer. The precise mechanism for the effect of drinking alcohol in mammary cancer promotion is still far from being established. Studies by our laboratory suggest that acetaldehyde produced in situ and accumulated in mammary tissue because of poor detoxicating mechanisms might play a role in mutational and promotional events. Additional studies indicated the production of reactive oxygen species accompanied of decreases in vitamin E and GSH contents and of glutathione transferase activity. The resulting oxidative stress might also play a relevant role in several stages of the carcinogenic process. There are reported in literature studies showing that plasmatic levels ofestrogens significantly increased after alcohol drinking and that the breast cancer risk is higher in receptor ERpositive individuals. Estrogens are known that they may produce breast cancer by actions on ER and also as chemical carcinogens, as a consequence of their oxidation leading to reactive metabolites. in this review we introduce our working hypothesis integrating the acetaldehyde and the oxidative stress effects with those involving increased estrogen levels. We also analyze potential preventive actions that might be accessible. There remains the fact that alcohol drinking is just one of the avoidable causes of breast cancer and that, at present, the suggested acceptable dose for prevention of this risk is of one drink per day.

关键词： Alcohol Ethanol Acetaldehyde Free radicals Mammary cancer Oxidative stress Estrogens Polyphenols

AN iNTEGRATED DESiGN PROCESS OF LOW-COST HOUSiNG iN CHiLE

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Journal of Green Building 2019年第3期14卷 81-93页

作者： Maureen Trebilcock-Kelly gerardo Saelzer-Fica Ariel Bobadilla-Moreno Dept.Diseño y Teoría de la Arquitectura Universidad del Bío-Bío Centro de investigación en Tecnologías de la Construcción CiTEC UBB Universidad del Bío-Bío

This paper discusses the application of integrated Design Process for the design of low-cost housing in *** aims to question common practice for the development of housing based on prescriptive regulations and non-interdisciplinary work,which has resulted in poor quality building *** first stage consisted in defining performance requirements for aspects such as energy demand,U value,air tightness and indoor air quality for a specific case of low-cost houses located in the city of *** integrated design process was carried out by an interdisciplinary team of professionals specialized in each of the performance aspects that were taken into *** construction and post-occupancy stages were characterized by verifying the performance requirements,which resulted in a low-cost house prototype that included strategies for energy efficiency and a healthy indoor environment.

关键词： integrated Design Process low-cost housing performance requirements interdisciplinary work

Focus on acute diarrhoeal disease

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World Journal of Gastroenterology 2009年第27期15卷 3341-3348页

作者： Fabio Baldi Maria Antonia Bianco gerardo Nardone Alberto Pilotto Emanuela Zamparo Gastroenterology Unit S. Orsola-Malpighi HospitalVia Massarenti 9 40138 Bologna Italy

Diarrhoea is an alteration of normal bowel movement characterized by an increase in the water content, volume, or frequency of stools. Diarrhoea needs to be classified according to the trends over time （acute or chronic） and to the characteristics of the stools （watery, fatty, inflammatory）. Secretory diarrhoeas, mostly acute and of viral aetiology in more than 70% of cases, are by far the most important subtype of diarrhoeas in terms of frequency, incidence and mortality （over 2.5 million deaths/year in developing countries）. Natural and synthetic opiates such as morphine, codeine, and ioperamide which react with endogenous opiates （enkephalins, beta-endorphins, dynorphins） mainly act on intestinal motility and slow down transit. An antidiarrhoeal drug developed in recent years, racecadotril, acts as an enkephalinase inhibitor. Clinical studies have shown that it is just as effective as ioperamide in resolving acute diarrhoea but with greater reduction in pain and abdominal distension. Some studies have explored the prevalence of diarrhoea in old age. An epidemiological study carried out in italy by 133 General Practitioners on 5515 elderly outpatients reported a prevalence of diarrhoea, defined according to the Rome criteria, of 9.1%. infectious diseases （19%） and drug use （16%） were the most common causes of diarrhoea in old age. Regardless of the cause, the treatment of elderly patients with diarrhoea must include rehydration and nutritional support. Every year, more than 50 million tourists travel from industrialized countries to places where hygiene levels are pool. At least 75% of those travelling for short periods mention health problems, and in particular traveller＇s diarrhoea.

关键词： Diarrhoea Secretory diarrhoeas Elderly patients Traveller's diarrhoea Antidiarrhoeal drugs Enkephalinase inhibitor Racecadotril Efficacy Tolerability

Effects of corn gluten feed inclusion at graded levels in a corn-soybean diet on the ileal and fecal digestibility of growing pigs

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Journal of Animal Science and Biotechnology 2015年第1期6卷 63-68页

作者： gerardo Mariscal Landin Tercia Cesaria Reis de Souza Ericka Ramirez Rodriguez Centro Nacional de investigacion en Fisiologia Animal Instituto Nacional de Investigaciones Forestales Agricolas y PecuariasKm 1Carretera a ColonAjuchitlan ColonQueretaro 76280Mexico Facultad de Ciencias Naturales Universidad Autonoma de QueretaroSantiago de QueretaroAv.De las Ciencias s/n Juriquilla 76000QueretaroQueretaroMexico

Background： This study aimed to determine the effect of the inclusion of corn gluten feed （CGF） on the apparent and standardized ileal digestibility of protein and amino acids and the apparent ileal and total tract digestibility of energy in growing pigs. The study was performed using 16 barrows （weight, 45.3 ±4.5 kg） that were fitted with a T cannula at the terminal ileum. There were four treatments： a corn-soybean diet without CGF and three corn-soybean diets containing increasing levels of CGF （65, 130, and 195 g/kg）. Data were analyzed according to a randomized complete block design, four blocks with four pigs each （one pig per treatment）. The trend of the response （linear or quadratic） was determined using orthogonal contrasts, and when a linear effect was determined, a linear equation was obtained. Results： The results showed that the inclusion up to 195 g/kg of CGF in the corn-soybean diet did not diminish the ileal digestibility （apparent and standardized） of protein and amino acids （P 〉 0.05）, except that of phenylalanine, cystine, and proline. A linear decrease （P 〈 0.05） per gram of CGF added to the diet in the apparent and standardized ileal digestibility of phenylalanine （0.011 and 0.015 percentage units, respectively）, cystine （0.048 and 0.043 percentage units, respectively）, and proline （0.045 and 0.047 percentage units, respectively） was noted. Similarly, ileal digestibility of dry matter and energy were adversely affected （reduced by 0.028 and 0.025 percentage units, respectively, per gram of CGF increment in the diet）. A significant （P 〈 0.05） linear reduction in total tract digestibility with increase in CGF amount in the diet was observed for energy （0.027 percentage units）, dry matter （0.027 percentage units）, crude protein （0.020 percentage units）, and neutral detergent fiber （0.041 percentage units） per gram of CGF added to the diet. Conclusion： CGF did not affect the ileal digestibility of protein and most amino acids but reduced the ileal an

关键词： Amino acids Corn gluten feed Energy ileal digestibility Pigs Total tract digestibility