Prevalence of refractive errors in children of Puerto Rico

AIM:To determine the prevalence of refractive error in 5-to 17-year-old schoolchildren in Puerto Rico.METHODS:A quantitative descriptive study of 2867 children aged 5 to 17y from all seven educational regions of Puerto Rico was conducted from 2016–2019.Refractive error was determined via static and subjective refraction.Children with distance acuity≤20/40 or near visual acuity≤20/32 had a cycloplegic refraction.Data analysis included descriptive statistics,correlation coefficient,Kruskal-Wallis,Chi-square,and t test calculations.RESULTS:Twenty percent of the children had a spherical equivalent refractive error≤-0.50 D,3.2%had a spherical equivalent≥+2.00 D,and 10.4%had astigmatism≥1 D.There was a statistically(but non-clinically)significant myopic change in spherical equivalent refractive error with age(P<0.001).The prevalence of myopia increased with age(P<0.001)but not hyperopia(P=0.59)or astigmatism(P=0.51).Males had a significantly higher hyperopic spherical equivalent than females(P<0.001).Females had a higher prevalence of myopia(P<0.001)than males,but there was no difference in the hyperopia(P=0.74)or astigmatism prevalence(P=0.87).CONCLUSION:The prevalence of a spherical equivalent equal to or less than-0.50 D(myopia,20.7%)is one of the highest among similar-aged children worldwide.Further studies should explore the rate of myopia progression in children in Puerto Rico.Individual children must be monitored to examine the need for treatment of myopia progression.

Puerto Rico’s Water Supply: An Investigation of the Levels of Trihalomethanes and Other Contaminants

The US Commonwealth of Puerto Rico is comprised of 143 islands, atolls, cays, and islets. Of the 143 localities, only 3 islands are inhabited: The mainland (often referenced as Puerto Rico), Culebra, and Vieques. To properly analyze the water supply quality, the mainland will be the focal point for examining environmental and social injustices. Puerto Rico is a racially diverse but ethnically homogenous territory, with most of the commonwealth living below the poverty level. Access to clean water sources is always tenuous in Puerto Rico. Over 70 percent of the island is served by water, violating US health standards. However, the recent hurricanes made the situation even more detrimental. According to data reported between January 2015 and March 2018 by the Consumer Confidence Report (CCR), 97 percent of the population of Puerto Rico utilizes a common drinking water system with one or more recent violations of the Safe Drinking Water Act for its testing requirements for lead and copper levels. The amounts found were far higher than any US state, meaning that virtually everyone on the island gets water from systems that violated testing or reporting requirements. In this study, we have collected and analyzed the levels of trihalomethanes (THMs), haloacetic acids (HAAs), copper, lead, and total organic compounds (TOCs) in drinking water providing systems in Puerto Rico and compared them with the recommended levels of contaminants provided by the US Environmental Protection Agency (EPA) guidelines. Many of these reported contaminants can have serious and detrimental health effects after prolonged exposure to higher concentrations of the contaminants found in the drinking water sources of Puerto Rico.

Simulation of Regional Karst Aquifer System and Assessment of Groundwater Resources in Manatí-Vega Baja, Puerto Rico

The North Coast karst aquifer system of Puerto Rico, the most productive aquifer of the island, is a vital water source for drinking water and local ecosystems. High freshwater demands alter the coastal groundwater system that impacts both human populations and coastal ecosystems of the island. To predict how this system might respond to rainfall events and high pumping demands, we used the equivalent porous medium (EPM) technique to develop a three-dimensional groundwater flow model to estimate hydrogeological parameters and assess groundwater resources in the Manatí-Vega Baja karst aquifer. The approach is based on the hypothesis that the simplified EPM approach will reproduce groundwater hydrodynamics in this complex karst environment. The steady-state model was calibrated with trial and error and parameter estimation methods using an observed groundwater table of 1995 (r = 0.86, p < 0.0001, n = 39). The large-scale simulation suggested that groundwater flow roughly follows the elevation slope (i.e. south to north). Calibrated hydraulic conductivities range from 0.5 to 86 m/d, whereas the hydro-geologic data strongly suggest higher permeability in the middle karst section of the study area. The transient model adequately estimates the observed groundwater fluctuations in response to rainfall events from 1980 until 2014. The transient results indicate that the conceptual model accuracy is more acceptable with a mean error (ME) of -0.132 m, mean absolute error (MAE) of 0.542 m and root mean square (RMSE) error of 0.365 m. The results of water budget simulation show that the total recharge satisfies the total groundwater withdrawal rate in the past, but continuous closure of more contaminated wells causes groundwater levels to increase in the future. The results indicate that the assumption of applicability of EPM approach is sustained and supported by measured data in the study area. Taking future water demands into account, this model could be applied further to predict the changes of groundwater levels and mass balance under different exploitation scenarios.

An Assessment of Water Quality Parameters at the Cerrillos Reservoir, Ponce, Puerto Rico in the Aftermath of Hurricane Maria

Maintaining the water quality of lakes and reservoirs is part of the 2030 Agenda for Sustainable Development, an initiative promoted by the United Nations, including anthropogenic and natural factors that may influence water quality. The water reservoirs of Puerto Rico were built in watersheds to provide runoff control and for primary uses. The Cerrillos Reservoir is one of the largest water reservoirs in southern Puerto Rico, and is used as a source of potable water and for recreational activities. After hurricane Maria, in September 2017, many communities were without public water service and have obtained their drinking water from local rivers or their tributaries, without filtration or purification treatment. This research explored the physical-chemical parameters of Cerrillos Reservoir’s surface water from May 2018 to January 2019. The objective of the present study is to assess seasonal variations in surface water quality with respect to physical (temperature, turbidity, and conductivity), chemical (nutrient concentrations: (Phosphorus (P) (Soluble Reactive Phosphorus, phosphate, or orthophosphate) and Nitrogen (N) (nitrate, nitrite, and ammonia)), pH, and dissolved oxygen), and biological (total coliforms and Escherichia coli) parameters. Results suggest that Cerrillos Reservoir did not exceed the parameters of temperature, turbidity, conductivity, pH and DO, established by the Puerto Rico Department of Natural and Environmental Resources (PRDNER). The reservoir showed a stable trophic state in relation to inorganic phosphorus and nitrogen as N and P concentrations did not increase sufficiently to disrupt this ecosystem. However, total coliforms exceeded the maximum parameter (23 MPN/100mL - 994 MPN/100mL) established for the Puerto Rico Department of Natural and Environmental Resources and are likely to be the results of the disruption caused by hurricane Maria.

Perceptions of Climate Change in Puerto Rico before and after Hurricane Maria

This article analyzes the perceptions of Puerto Rican citizens of global climate change (GCC) before and after an extreme weather event, specifically Hurricane Maria (HM). The purpose of the current article is to evaluate Puerto Ricans’ perceptions of the impact of extreme meteorological phenomena and of GCC before and after HM. This tropical cyclone entered the island as a category IV hurricane on September 17, 2017, causing enormous destruction, loss of life, and economic damage. In this study, two data samples were collected before and after HM struck Puerto Rico (PR) (the second sample was collected approximately six months after the hurricane). Surveyed citizens with general knowledge of GCC increased from 43% to 62%, which the researchers consider a small increase, considering the severe destruction caused by HM. This study also found that Puerto Ricans trust non-profit institutions and the scientific community more than state authorities. Furthermore, 85% of citizens believe that public policies on GCC should be directed by the state (federal, state, and municipal governments);this did not change after HM. In addition, this study found that the poor response of the federal and state governments to the destruction caused by HM increased citizens’ trust in the scientific community.

Effect of Ambient Temperature on PUF Passive Samplers and PAHs Distribution in Puerto Rico

Passive sampling for the monitoring of organic pollutants (PAHs, PCBs, PBDEs) in ambient air has received increased attention in the last two decades. However, the accuracy of the concentration of organics obtained with passive samplers under varying environmental conditions is a subject of controversy. In this study, effect of ambient temperature on passive samplers was evaluated by using three different sampler configurations. Additionally, passive samplers with polyurethane disks (PUF) were applied throughout the Island for the determination of the airborne concentration of polycyclic aromatic hydrocarbons (PAHs). The passive samplers were deployed in seven municipalities for three-month periods in two different sampling campaigns, representing hurricane and non-hurricane seasons. Here we present preliminary results obtained from those sampling campaigns. The total concentrations of 15 PAHs varied from 3.1 to 19.6 and from 5.5 to 38.5 ng/m3 for hurricane and non-hurricane seasons, respectively. Hurricane and non-hurricane season concentrations of PAH were significantly different for the samples taken in the northern municipalities of the Island. However, there was no significant difference in PAH concentrations between the hurricane and non-hurricane seasons for the southern sites. Increased rainfall and high-relative humidity during the hurricane season had an influence on the concentrations of PAHs derived by the passive PUF sampler.

The Motivations and Experiences of Young Women in a Microbicide Trial in the USA and Puerto Rico

Young women are an important target group in microbicide research, yet little is known about why they participate and stay in microbicide trials. Our study examined motivations for participating in a Phase I microbicide trial among 61 women ages 18 - 24 years in the continental USA and Puerto Rico. We also examined their perspectives on study participation. Participants underwent a semi-structured in-depth interview in which they were asked about factors that motivated enrollment and their experiences while participating. They also completed a Web-based Computer Assisted Self Interview in which they were asked to rate study burden (1 = low to 4 = high). Factors that motivated enrollment were altruism (29%), compensation (17%), a combination of altruism and compensation (37%) and free medical exams (17%). Factors that encouraged participants to stay in the study were study staff (95%), confirmation of good health (41%), and the opportunity to learn about their bodies (17%). Mean ratings of study burden ranged from 1.83 (having to travel to site) to 2.41 (colposcopy), indicating that participants were not highly bothered by visits or procedures. Although Phase I trials require invasive procedures, participants were not highly bothered by them and recognized them as necessary. Good relationships with staff and clear information about how procedures contribute to study goals may encourage participants to remain in trials. Young women may be motivated to enter microbicide trials by stressing the role they will play in discovering better HIV-prevention methods and highlighting the comprehensive preventive exams they will receive.

急性心肌梗死患者复杂病变的预测因素和预后:来自RICO研究的数据

背景:作者旨在探明急性心肌梗死患者中冠状动脉造影可见多个复杂病变(MCL)的决定因素和预后。方法:对1152例在入院后24h内进行冠状动脉造影的连续未经选择的心肌梗死患者进行分析。复杂病变定义为出现血栓、溃疡、不规则斑块和血流受损。具有≤1处复杂病变的患者被认为是单一复杂病变(SCL)患者。

Rico Lee户外科技

不久之前,Rico Lee品牌新作《新·户外》粉墨登场,相交于多数设计师选择张扬个性理念,追寻前沿潮流的时装领域,李伟刚（Rico Lee）选择了户外服装领域。户外服装所蕴含的科技性、专业性、功能性让有着十余年的时尚设计经历的李伟刚沉醉其中。2009年,李伟刚从时装设计转入户外服装设计,随着深入研究,李伟刚感叹户外就是一座宝矿,但传统户外服装的单调与缺乏变化,使得太多的科技和潜力都被禁锢在那单调的外形之下。

美国岛屿案件发展探析

岛屿案件是一项具有重大意义的司法裁决,其深远影响体现在对美国领土政策的塑造上,并对美国领土治理方法的形成和持续演进产生了持久的影响。19世纪末和20世纪初,美西战争后,美国获得波多黎各、关岛和菲律宾等领土,岛屿案件随之出现。这些裁决建立了管理非相邻领土居民的政治地位、权利和义务的法律框架。在岛屿案的审理过程中,美国最高法院就美国主权如何延伸至其获取的领土,以及这些领土上居民所享有的基本权利的宪法解释问题进行了探讨,展示了领土主权和公民权概念的演变。岛屿案件裁决为管理获得的领土的复杂性和平衡国家利益与正义和民主原则提供了有价值的见解。

Seasonal abundance of Pyrodinium bahamense(order Peridiniales,family Gonyaulacaceae)in Mosquito Bay,Vieques,Puerto Rico

Objective:To determine the presence of consistent spatial or temporal patterns to the abundance of Pyrodinium bahamense(P.bahamense)in Mosquito Bay,Vieques,Puerto Rico.Methods:Measurements of dissolved oxygen,pH,salinity,water temperature,tide level,wind speed,and density counts of P.bahamense were taken at six sites in the bay over approximately one year.The data were analyzed statistically to determine if spatial or temporal patterns were present.Results:There were statistically significant patterns of P.bahamense seasonally,which was similar to other studies done in other subtropical locations with phytoplankton.Also,trends were seen that rain events caused short-term increases in abundance and shallow areas of the bay had lower abundance than that of deeper areas.The average number of organisms from 736 samples was 26.8 per mL.The average water temperature was 29.0℃,the average salinity was 36.8 ppt,the average pH was 8.11,and the average dissolved oxygen level was 4.27 mg/L.Conclusions:The abundance of P.bahamense varies seasonally over shorter time periods.The abundance also varies over a few meters in small coastal bays.This information indicates that economically important bioluminescent bays are vulnerable to changes in freshwater input,water temperature,water circulation patterns and possibly the nutrient inputs from the land surrounding such bays.

Determination of the burrow shapes of Cardisoma guanhumi on Vieques,Puerto Rico

Objective:To determine the burrow morphology of Cardisoma guanhumi and to determine if a battery-powered fiber optic camera could be used to investigate these burrows.Methods:A portable fiber optic camera was used to investigate 116 active burrows.All burrows were categorized according to shape.The diameter of each burrow was also recorded and biomass calculations were completed at each study site.Results:Analysis showed that different study sites were more likely to have particular burrow shapes than expected.Three main types of burrows were classified as horizontal slide,short and shallow,and inverted-S.A Pearson Chi-square analysis revealed that burrow shape was not equally distributed across study sites(χ^(2)=61.05,df=18,P<0.0001).Biomass calculations showed that different sized animals inhabited different study sites(ANOVA;df=7,MS=158.3,F=13.9,P<0.0001).The fiber optic camera was useful in determining burrow morphology and occupancy non-destructively.Conclusions:As the locations of juvenile individuals of this species are poorly known,and the species is both ecologically and economically important where it occurs,a greater understanding of burrow morphology and size segregation may help agencies be responsible for managing this natural resource to do so effectively.

Effect of Particle Size and Pesticide Contamination on Preference and Ingestion Rates by the Tropical Freshwater Shrimp Xiphocaris elongata

In tropical streams, freshwater shrimp are essential to preserve the structure and function of lotic ecosystems. Shredder shrimp play a fundamental role in organic matter decomposition because these feed on detritus. In addition, they are especially important organisms as they connect all trophic levels at food webs. In natural environments, decaying leaf material may accumulate contaminants, including insecticides and herbicides. At these, shredder shrimp can be exposed to these contaminants through ingestion of leaf litter material. The objectives of this study were to evaluate if the shredder shrimp Xiphocaris elongata display a preference for feeding on different plant species and leaf size areas while also assessing their consumption of leaves contaminated with pesticides. We also evaluated acetylcholinesterase (AChE) activity as a possible biomarker of pesticide contamination using an immunofluorescence and microscopy imaging approach. Our results revealed that the leaf area and plant species more appropriate for future toxicological studies is Spathodea campanulata leaves, with a leaf area of 0.65 cm2. This study also showed that sublethal concentrations of malathion and permethrin in leaves seem to have a significant effect on the ingestion rates of X. elongata, which suggests that the presence of these contaminants influenced feeding behavior. Immunofluorescence in cephalothorax ganglia showed a decline in AChE activity when the sublethal dose of malathion and permethrin increased. The observed results suggest that AChE activity can be used as a biomarker to detect and assess permethrin and malathion exposure on shredder shrimp.

神华长焰煤大分子结构特征的研究

利用ASE 350型超声快速溶剂抽提仪,在高温高压下对神华长焰煤(SH)进行二硫化碳/N-甲基吡咯烷酮(CS2/NMP)混合溶剂抽提,抽提率约为25%(质量分数)。将得到的抽提残渣(SHC)进行钌离子催化氧化(RICO)降解反应,并对产物进行了离子色谱(IC)检测和以四甲基氢氧化铵(TMAH,25%甲醇溶液)为衍生化试剂的热辅助-在线甲酯化后的气质联用仪(GC-MS)检测分析。结果表明,神华长焰煤大分子结构中含有C2～28烷基侧链,C2～22的连接芳环的烷基桥链,有相对较多的醚键链接的芳环结构存在,芳环缩合程度相对较低(主要以含有2～4个苯环的共轭结构为主),有较多的醚键链接的芳环结构及羟基(-OH)、羰基(=C=O)和甲氧基(-OCH3)等形式含氧基团以及含硫和氮等杂原子化合物的存在。

大港减压渣油超临界萃取残渣极性组分的化学结构特征

将大港减压渣油超临界萃取(SFEF)的残渣利用中性Al2O3色谱柱进行四组分(SARA)分离,得到饱和分、芳香分、胶质和沥青质。然后对其中的芳香分、胶质和沥青质3个极性组分进行钌离子催化氧化反应(RICO)选择性降解,生成的混合物分离处理后,非挥发性羧酸用CH2N2-乙醚溶液酯化,挥发性羧酸用苯甲酰甲基溴酯化。采用GC-MS、GC、FT-IR等手段对这些酯化产物进行定性和定量分析,检测到各组分的降解产物含有一系列的一元正构脂肪酸、α,ω-二元正构脂肪酸和多种芳羧酸,以此可了解各组分的结构特征。结果表明,3个组分的RICO产物中,芳环上的正构烷基侧链含量和连接2个不同芳碳的聚亚甲基桥含量均随着碳链增长呈递减趋势。沥青质组分的芳核中迫位缩合结构比芳香分要多,而芳香分中的联苯和渺位缩合结构比沥青质中的比例要大,胶质中各种结构的分布介于两者之间。

基于Ajax的门户框架的研究与实现

提出了一种基于Ajax的门户框架设计方案.详细分析了该方案设计的门户框架的体系结构和组成模块以及模块之间的关系,并利用Spring MVC和一种Ajax库Rico实现了该方案.工程实践表明,采用该方案设计的门户框架系统,层次结构清晰,代码复用率高,并能有效地提高门户系统的运行效率及改善用户的交互体验.

轮南、塔河油田稠油油源对比

运用GC ,GC -MS ,GC -MS -MS、配比实验、沥青质钌离子催化氧化技术 ,研究了塔里木盆地轮南、塔河稠油油源。轮南、塔河油田稠油中含有 2 5 降藿烷 ,但正构烷烃分布完整 ,色谱基线呈不同程度抬升 ,油藏经历了两期成藏过程。稠油具有三环萜烷含量高、C2 4四环萜烷含量低、伽马蜡烷含量低、C2 8甾烷含量低、甲藻甾烷及三芳甲藻甾烷含量低、4 甲基 2 4 乙基胆甾烷及其芳构化甾烷含量低、2 4 降甾烷含量低的特点。油源对比表明轮南、塔河稠油来源中、上奥陶统烃源岩。配比实验表明 ,原油中若混入了 2 5 %寒武系生源的TD2井原油 ,混源油也会呈现寒武系生源的特点 ,表明寒武系烃源岩生成的原油并未大规模混入到轮南、塔河油藏中。轮南、塔河稠油沥青质钌离子氧化降解产物在一元酸及甾烷酸、4 甲基甾烷酸的分布与TD2井稠油明显不同 ,进一步证明中、上奥陶统烃源岩可能为轮南、塔河稠油的主力源岩。

塔里木盆地原油沥青质钌离子催化氧化及油源

运用钌离子催化氧化(RICO)技术研究了塔里木盆地轮南、塔河、哈得逊地区及TD2井原油沥青质。其RICO产物包括一元酸、二元酸、支链酸、三环萜烷酸、藿烷酸、甾烷酸和4 甲基甾烷酸。键合在沥青质中的烷基侧链和生物标志物不易遭受生物降解作用,特别是甾烷与饱和烃中分布相似。沥青质的RICO研究结果表明,中、上奥陶统烃源岩为轮南、塔河、哈得逊原油的主力烃源岩。沥青质RICO技术为严重生物降解原油的油源对比提供了一种新的途径。

生物降解原油研究的新方法

利用沥青质包裹烃和沥青质钌离子催化氧化(RICO)产物中的生标对生物降解原油进行了研究。研究表明,虽然原油中的生标受到了严重破坏,但利用这两种方法在沥青质中均可以获得较为完整的生标系列。与其它方法相比,这两种方法简单方便,结果较为可靠、准确,可能是生物降解原油研究的发展方向。

东营凹陷草桥油田生物降解原油沥青质钌离子催化氧化研究——生标分布及地质意义

运用钌离子催化氧化技术(RICO)研究了渤海湾盆地东营凹陷草桥油田生物降解原油沥青质。原油沥青质RICO产物主要包括一元酸、二元酸、三环萜烷酸、藿烷酸、伽马蜡烷酸、孕甾烷酸、甾烷酸等,键合在沥青质芳核结构中的生物标志物以特定碳位与沥青质结合。草桥生物降解原油沥青质RICO产物中具有较高的伽马蜡烷酸/C30藿烷酸比值,具有完整的4-甲基、4,4-二甲基甾烷酸系列,表明原油为沙四段、沙三段的混源油;生标酸异构化参数低表明原油成熟度不高。沥青质钌离子催化氧化技术对于强烈生物降解原油的油-油对比、油-源对比提供了一种新的途径。