ABSTRACT
With the development of urbanization, the effect of urban heat island has become increasingly evident. As an essential component of the urban natural landscapes, urban green space plays an important role in mitigating the effect of urban heat island. However, facing the rapid urbanization and changing environment, how to rationally plan and design the green space and realize its best cooling effect which can improve the urban environment and microclimate is still an urgent problem to be solved. So there is a strong need for mulitiscale researches on the cooling effect of urban green space. This paper systematically gave a review on the cooling effect of urban green space based on field measurement of air temperature, the main factors that influenced the cooling effect of green space were explored from three aspects including the area and shape characteristics of urban green space, the structure characteristics of vegetation and the external factors which affected the cooling effect, and the characteristics of the cooling effect of the green space were summarized from the aspect of time variation and distance decay. Then, the main problems and future research prospects of urban green space cooling effect were put forward.
Subject(s)
Microclimate , Urbanization , Cities , Cold Temperature , Hot Temperature , TemperatureABSTRACT
OBJECTIVE: To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. METHODS: Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. RESULTS: The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. CONCLUSION: This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.
Subject(s)
Hantavirus Infections/veterinary , Leptospirosis/virology , Rodent Diseases/epidemiology , Rodentia , Water Supply , Animal Distribution , Animals , China/epidemiology , Disease Reservoirs , Hantavirus Infections/epidemiology , Leptospirosis/epidemiology , Population Density , Rodent Diseases/microbiology , Rodent Diseases/virology , Seasons , Time Factors , ZoonosesABSTRACT
Olfactory dysfunction is a common and early symptom of many neurodegenerative diseases, particularly of Alzheimer's disease (AD) and mild cognitive impairment, pointing to the progression to dementia. Recent studies have revealed that valproic acid (VPA) has neuroprotective effects in rodent models of AD. In this study, we investigated the effects of VPA on olfactory dysfunction of APP/PS1 double transgenic mouse models of AD. After continuous treatment with a 100mg/kg daily dose of VPA for 3 months, APP/PS1 mice showed improved olfactory performances. In agreement with the behavioral findings, VPA treatment reduced amyloid ß (Aß) burden in the olfactory epithelium (OE) of transgenic mice. And, VPA increased epithelial thickness of the olfactory mucosa through decreased cell apoptosis and increased cell proliferation. In the olfactory bulb (OB), VPA administration also reduced senile plaques and levels of soluble and insoluble Aß42 peptides. Besides, VPA promoted the increase of mitral cells and decrease of neurofilament immunostaining. In hence, VPA treatment completely improved the olfactory performances and prevented degenerative changes of the OE and OB. Our study raises the possibility of AD diagnosis by OE biopsy. Moreover, VPA may provide a novel therapeutic strategy for the treatment of olfactory dysfunction in AD patients.
