Resilience of Self-Organised and Top-Down Planned Cities—A Case Study on London and Beijing Street Networks

The success or failure of the street network depends on its reliability. In this article, using resilience analysis, the author studies how the shape and appearance of street networks in self-organised and top-down planned cities influences urban transport. Considering London and Beijing as proxies for self-organised and top-down planned cities, the structural properties of London and Beijing networks first are investigated based on their primal and dual representations of planar graphs. The robustness of street networks then is evaluated in primal space and dual space by deactivating road links under random and intentional attack scenarios. The results show that the reliability of London street network differs from that of Beijing, which seems to rely more on its architecture and connectivity. It is found that top-down planned Beijing with its higher average degree in the dual space and assortativity in the primal space is more robust than self-organised London using the measures of maximum and second largest cluster size and network efficiency. The article offers an insight, from a network perspective, into the reliability of street patterns in self-organised and top-down planned city systems.     

The Preliminary Study on DNA Barcoding of Mosses——A Case of Part of Genera of Meteoriaceae

We compared the performances of the candidate loci for moss DNA barcoding and the primers used in amplifying the loci. Primers for three coded loci (matK, rps4 and rbcL a) and four non coded loci (atpB rbcL, atpF H, psbK I and trnH psbA) of the chloroplast genome, one from the mitochondrial genome (nad5), and one from the nucleus genome (ITS2) were evaluated. Seventy four samples representing 14 species belonging to five genera of Trachypodoaceae (or Meteoriaceae) were screened. All primers for matK and a pair of primers for trnH psbA failed. Low successes were encountered with the primers for atpF H and psbK I. The primers for psbK I produced several bands and the PCR products of atpF H were difficult to sequence. The powers of the remaining six loci were compared using the variability, identification success and the resolutions. It was found that ITS2 is the most promising candidate for DNA barcoding for mosses. Among the chloroplast genes, atpB rbcL exhibited the highest resolution. Although trnH psbA is very variable, it is too short to be an ideal barcode alone. Combinations of chloroplast genes were also tried and Ps of both atpB rbcL+trnH psbA and rbcL a++trnH psbA were 64% using NJ method. More additions of loci did not increase the resolution. No barcoding gap exists for all these loci. Phylogenetic analyses were carried out prior to the DNA barcoding evaluation and some taxonomic problems do exist. This study exemplifies the necessity of correct species delimitation and the adoption of both plastid and nuclear loci in plant DNA barcoding.     

Hybrid Epidemics—A Case Study on Computer Worm Conficker

Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm’s spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm’s effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.     

Sampling-Design Effects on Properties of Species-Area Relationships – A Case Study from Estonian Dry Grassland Communities

Despite widespread use of species-area relationships (SARs), dispute remains over the most representative SAR model. Using data of small-scale SARs of Estonian dry grassland communities, we address three questions: (1) Which model describes these SARs best when known artifacts are excluded? (2) How do deviating sampling procedures (marginal instead of central position of the smaller plots in relation to the largest plot; single values instead of average values; randomly located subplots instead of nested subplots) influence the properties of the SARs? (3) Are those effects likely to bias the selection of the best model? Our general dataset consisted of 16 series of nested-plots (1 cm²–100 m², any-part system), each of which comprised five series of subplots located in the four corners and the centre of the 100-m² plot. Data for the three pairs of compared sampling designs were generated from this dataset by subsampling. Five function types (power, quadratic power, logarithmic, Michaelis-Menten, Lomolino) were fitted with non-linear regression. In some of the communities, we found extremely high species densities (including bryophytes and lichens), namely up to eight species in 1 cm² and up to 140 species in 100 m², which appear to be the highest documented values on these scales. For SARs constructed from nested-plot average-value data, the regular power function generally was the best model, closely followed by the quadratic power function, while the logarithmic and Michaelis-Menten functions performed poorly throughout. However, the relative fit of the latter two models increased significantly relative to the respective best model when the single-value or random-sampling method was applied, however, the power function normally remained far superior. These results confirm the hypothesis that both single-value and random-sampling approaches cause artifacts by increasing stochasticity in the data, which can lead to the selection of inappropriate models.     

“Sharks in Your Hands”—A Case Study on Effects of Teaching Strategies to Change Knowledge and Attitudes Towards Sharks

This study was designed to exemplify how hands-on based teaching strategies enhanced students’ knowledge and positive attitudes towards sharks. Hands-on activities for sharks’ biological and morphological features were carried out. Eleven elementary school students from a remote area in Taiwan were recruited and assigned to the hands-on condition. They were encouraged to draw pictures of sharks before and after the instruction as the main data for pre- and post-test comparison. Two years later, the retention test and attitude inventory towards sharks were implemented. The results revealed that large effect size emerged for both the post-test and retention test. In regards to attitude inventory, students involved in hands-on activities also significantly outperformed the baseline group. Many of them have taken notice of television programs and books about sharks or marine ecology since the hands-on activities, indicating the instruction had a beneficial impact on their extracurricular lives. Empirical findings of this study suggest hands-on instruction is a powerful strategy for learning, both for immediate and prolonged effects on improving students’ knowledge and attitudes toward sharks.     

A Lipidomic Study of the Effects of N-methyl-N′-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism

Systems biology is a new and rapidly developing research area in which,by quantitativelydescribing the interaction among all the individual components of a cell,a systems-level understanding of abiological response can be achieved.Therefore,it requires high-throughput measurement technologies forbiological molecules,such as genomic and proteomic approaches for DNA/RNA and protein,respectively.Recently,a new concept,lipidomics,which utilizes the mass spectrometry(MS)method for lipid analysis,has been proposed.Using this lipidomic approach,the effects of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)on sphingomyelin metabolism,a major class of sphingolipids,were evaluated.Sphingomyelin moleculeswere extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight MS.Itwas found that MNNG induced profound changes in sphingomyelin metabolism,including the appearance ofsome new sphingomyelin species and the disappearance of some others,and the concentrations of severalsphmgomyelin species also changed.This was accompanied by the redistribution of acid sphingomyelinase(ASM),a key player in sphingomyelin metabolism.On the other hand,imipramine,an inhibitor of ASM,caused the accumulation of sphingomyelin.It also prevented some of the effects of MNNG,as well as theredistribution of ASM.Taken together,these data suggested that the lipidomic approach is highly effectivefor the systematic analysis of cellular lipids metabolism.     

A Lipidomic Study of the Effects of N-methyl-N＇-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism

Systems biology is a new and rapidly developing research area in which, by quantitatively describing the interaction among all the individual components of a cell, a systems-level understanding of a biological response can be achieved. Therefore, it requires high-throughput measurement technologies for biological molecules, such as genomic and proteomic approaches for DNA/RNA and protein, respectively.Recently, a new concept, lipidomics, which utilizes the mass spectrometry （MS） method for lipid analysis,has been proposed. Using this lipidomic approach, the effects of N-methyl-N＇-nitro-N-nitrosoguanidine （MNNG） on sphingomyelin metabolism, a major class of sphingolipids, were evaluated. Sphingomyelin molecules were extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight MS. It was found that MNNG induced profound changes in sphingomyelin metabolism, including the appearance of some new sphingomyelin species and the disappearance of some others, and the concentrations of several sphingomyelin species also changed. This was accompanied by the redistribution of acid sphingomyelinase （ASM）, a key player in sphingomyelin metabolism. On the other hand, imipramine, an inhibitor of ASM,caused the accumulation of sphingomyelin. It also prevented some of the effects of MNNG, as well as the redistribution of ASM. Taken together, these data suggested that the lipidomic approach is highly effective for the systematic analysis of cellular lipids metabolism.     

Environmental Effects of Steam Explosion Pretreatment on Biogas from Maize—Case Study of a 500-kW Austrian Biogas Facility

Potential environmental impacts of biogas electricity from agricultural residues (maize stover) with steam explosion (SE) pretreatment were compared to a typical Austrian biogas system (maize silage) using the method of life cycle assessment. Besides the biogas plant, the system includes substrate production, a combined heat-and-power (CHP) unit, digestate management, and transportation. The stover scenario (including construction and operation of the SE unit) results in lower total climate change impacts than those of the typical biogas system (239 g CO₂-eq/kWh electricity vs. 287 g CO₂-eq/kWh electricity; 100-year global warming potential (GWP)), and this holds also for the other impact categories (e.g., cumulative energy demand, acidification, eutrophication). While uncertainties in other areas could change the results, based on the uncertainty information considered, the overall results for the two scenarios were significantly different. Methane slip emissions from the CHP exhaust account for the largest GWP share in both scenarios. Other large GWP contributions are from substrate production and grid electricity for plant operations. The findings were robust against worst-case assumptions about the energy requirements of the SE pretreatment.     

Are We Biologically Safe with Snow Precipitation? A Case Study in Beijing

In this study, the bacterial and fungal abundances, diversities, conductance levels as well as total organic carbon (TOC) were investigated in the snow samples collected from five different snow occurrences in Beijing between January and March, 2010. The collected snow samples were melted and cultured at three different temperatures (4, 26 and 37°C). The culturable bacterial concentrations were manually counted and the resulting colony forming units (CFUs) at 26°C were further studied using V3 region of 16 S rRNA gene-targeted polymerase chain reaction -denaturing gradient gel electrophoresis (PCR-DGGE). The clone library was constructed after the liquid culturing of snow samples at 26°C. And microscopic method was employed to investigate the fungal diversity in the samples. In addition, outdoor air samples were also collected using mixed cellulose ester (MCE) filters and compared with snow samples with respect to described characteristics. The results revealed that snow samples had bacterial concentrations as much as 16000 CFU/ml for those cultured at 26°C, and the conductance levels ranged from 5.6×10⁻⁶ to 2.4×10⁻⁵ S. PCR-DGGE, sequencing and microscopic analysis revealed remarkable bacterial and fungal diversity differences between the snow samples and the outdoor air samples. In addition, DGGE banding profiles for the snow samples collected were also shown distinctly different from one another. Absent from the outdoor air, certain human, plant, and insect fungal pathogens were found in the snow samples. By calculation, culturable bacteria accounted for an average of 3.38% (±1.96%) of TOC for the snow samples, and 0.01% for that of outdoor air samples. The results here suggest that snow precipitations are important sources of fungal pathogens and ice nucleators, thus could affect local climate, human health and agriculture security.     

Traffic Deaths—A Preliminary Study of Urban and Rural Fatalities in California

An analysis by the California Department of Public Health of California Highway Patrol reports for 1961 showed that traffic accidents injured one and one-half times as many people per 1,000 population in rural California counties (under 50,000 people) as in urban counties (over 500,000 people), also persons injured in rural counties were almost four times as likely to die of their injuries as those injured in urban counties.A death certificate study was undertaken of 782 traffic deaths (excluding pedestrians) occurring in rural and urban California counties during 1961. Accidents occurring in rural counties tended to be single vehicle accidents which resulted in less severe injuries, while those in urban counties tended to be two vehicle and multiple vehicle accidents resulting in more serious injuries. The anatomic distribution of injuries was the same for both urban and rural accidents. However, people dying in rural accidents more frequently died at the scene of the accident, died sooner after injury, and died of less serious injuries than did those injured in urban accidents. For injuries where theoretically few lives should be salvaged by prompt emergency care, the time between injury and death was about the same in urban as in rural counties. Where such care should delay or prevent death because the injury was possibly or probably salvageable, those injured in rural counties died more quickly.Thirty-two per cent of fatalities in rural counties happened to urban and out-of-state residents, while only 12 per cent of fatalities in urban counties were to rural or out-of-state residents, suggesting that traffic accidents to non-residents may place an excessive load upon medical care resources in rural areas.     

What Role Do Local Grocery Stores Play in Urban Food Environments? A Case Study of Hartford-Connecticut

Introduction

Research on urban food environments emphasizes limited access to healthy food, with fewer large supermarkets and higher food prices. Many residents of Hartford, Connecticut, which is often considered a food desert, buy most of their food from small and medium-sized grocery stores. We examined the food environment in greater Hartford, comparing stores in Hartford to those in the surrounding suburbs, and by store size (small, medium, and large).

Methods

We surveyed all small (over 1,000 ft²), medium, and large-sized supermarkets within a 2-mile radius of Hartford (36 total stores). We measured the distance to stores, availability, price and quality of a market basket of 25 items, and rated each store on internal and external appearance. Geographic Information System (GIS) was used for mapping distance to the stores and variation of food availability, quality, and appearance.

Results

Contrary to common literature, no significant differences were found in food availability and price between Hartford and suburban stores. However, produce quality, internal, and external store appearance were significantly lower in Hartford compared to suburban stores (all p<0.05). Medium-sized stores had significantly lower prices than small or large supermarkets (p<0.05). Large stores had better scores for internal (p<0.05), external, and produce quality (p<0.01). Most Hartford residents live within 0.5 to 1 mile distance to a grocery store.

Discussion

Classifying urban areas with few large supermarkets as ‘food deserts’ may overlook the availability of healthy foods and low prices that exist within small and medium-sized groceries common in inner cities. Improving produce quality and store appearance can potentially impact the food purchasing decisions of low-income residents in Hartford.     

A Life-Course Study on Effects of Parental Markers of Morbidity and Mortality on Offspring’s Suicide Attempt

Background

Research on the temporal relationship of parental risk factors with offspring’s suicide attempt is scarce and a life course approach has not been applied to date. We investigated the temporal relationship of parental morbidity and mortality with offspring’s suicide attempt and whether any such association was modified by offspring’s age at attempt.

Methods

We designed a case-control study through linkage of Swedish registers. Cases comprised all individuals in Sweden born 1973–1983 with inpatient care due to suicide attempt (15–31 years of age) and with information on both biological parents (N = 15 193). Ten controls were matched to each case (National Patient register with national complete coverage). Conditional logistic and spline regressions were applied.

Results

Particularly for women, most parental markers showed the strongest effect sizes if exposure was short-term (within 2 years after exposure) and related to the mother. Especially short-term exposure to maternal inpatient care due to psychiatric diagnoses had a significantly stronger effect on suicide attempt risk in women compared to men. Regarding exposure to parental inpatient care due to psychiatric diagnoses, short-term as opposed to long-term (exceeding 2 years after exposure) effects were highest during adolescence and decreased significantly with age for female and male offspring, respectively.

Conclusions

Although limited by the fact that data on parental morbidity and the outcome of suicidality were based on in-patient data only, the data suggest that the high risks of suicide attempt in case of exposure to parental psychopathology and suicidal behavior particularly during adolescence and the strong short-term effects associated with maternal psychopathology for female offspring are of direct clinical importance.     

Influence of Critical Parameters of Nanosuspension Formulation on the Permeability of a Poorly Soluble Drug through the Skin—A Case Study

In transdermal drug delivery systems, it is always a challenge to achieve stable and prolonged high permeation rates across the skin since the concentrations of the drug dissolved in the matrix have to be high in order to maintain zero order release kinetics. Several attempts have been reported to improve the permeability of poorly soluble drug compounds using supersaturated systems. However, due to thermodynamic challenges, there was a high tendency for the drug to nucleate immediately after formulating or even during storage. The present study focuses on the efficiency of nanoparticles and influence of different concentrations of solubilizer such as vitamin E TPGS (d-a-tocopheryl polyethylene glycol 1000 succinate) to improve the permeation rate through the skin. Effects of several formulation factors were studied on the nanosuspension systems using ibuprofen as a model drug. The overall permeation enhancement process through the skin was influenced mostly by the solubilizer and also by the size of nanoparticles. The gel formulation developed with vitamin E TPGS + HPMC nanosuspension, consequently represent a promising approach aiming to improve the permeability performance of a poorly water soluble drug candidate.KEY WORDS: dermal drug delivery, human skin, nanosuspension, permeation rate, porcine skin, vitamin E TPGS     

Does Landscape Fragmentation Influence Sex Ratio of Dioecious Plants? A Case Study of Pistacia chinensis in the Thousand-Island Lake Region of China

The Thousand-Island Lake region in Zhejiang Province, China is a highly fragmented landscape with a clear point-in-time of fragmentation as a result of flooding to form the reservoir. Islands in the artificial lake were surveyed to examine how population sex ratio of a dioecious plant specie Pistacia chinensis B. was affected by landscape fragmentation. A natural population on the mainland near the lake was also surveyed for comparison. Population size, sex ratio and diameter at breast height (DBH) of individuals were measured over 2 years. More than 1,500 individuals, distributed in 31 populations, were studied. Soil nitrogen in the different populations was measured to identify the relationship between sex ratio and micro-environmental conditions. In accordance with the results of many other reports on biased sex ratio in relation to environmental gradient, we found that poor soil nitrogen areas fostered male-biased populations. In addition, the degree of sex ratio bias increased with decreasing population size and population connectivity. The biased sex ratios were only found in younger individuals (less than 50 years old) in small populations, while a stable 1∶1 sex ratio was found in the large population on the mainland. We concluded that the effects of landscape fragmentation on the dioecious population sex ratio were mainly achieved in relation to changing soil nitrogen conditions in patches and pollen limitation within and among populations. Large populations could maintain a more suitable environment in terms of nutrient conditions and pollen flow, subsequently maintaining a stable sex ratio in dioecious plant populations. Both micro-environmental factors and spatial structure should be considered in fragmented landscape for the conservation of dioecious plant species.     

A Basic Study on the Biological Monitoring for Vanadium—Effects of Vanadium on Vero Cells and the Evaluation of Intracellular Vanadium Contents

A high concentration of vanadium (V) has toxic effects on human and animals and is one of environmental pollutants. In the present study, we have conducted a fundamental study using cultured Vero cells from monkey kidney for the future environmental monitoring. Orthovanadate (VAN), one of V compounds, of 10⁻¹⁰ and 10⁻⁸ M did not affect the cell growth although the higher concentration of above 10⁻⁶ M VAN inhibited the cell growth accompanied with the decrease in cell numbers and morphological changes. Given that the washing method with ice-cold Li is also effective for determination of the cellular Na content, we used this method for the determination of the V content of the Vero cells. The V distributions in Vero cell; in the 10⁻³ M VAN solution, extracellular and intracellular were obtained as 1:0.564:0.036 and 1:0.662:0.098 at 60 and 120 min after the treatment of VAN. The intracellular V content was 10% of the applied concentration of VAN. Consequently, it was suggested that V concentration of 10⁻⁷ and 10⁻⁶ M in the tissue and environment, respectively, might become the threshold concentration; a criterion of the environmental contamination when we carry out environmental monitoring.     

The Preference and Actual Use of Different Types of Rural Recreation Areas by Urban Dwellers—The Hamburg Case Study

In the wake of urbanisation processes and the constitution of metropolitan regions, the role of the city''s rural surroundings is receiving more attention from researchers and planners as rural areas offer various (cultural) ecosystem services for the urban population. Urban dwellers increasingly desire recreation and landscape experience. Although this need for recreation is generally recognized, few studies have focused on the question of people''s preferences for certain types and characteristics of outdoor recreation areas in relation to the frequency of use. In order to acquire baseline data on this subject, the main objectives of this study were to explore recreation preferences of urban dwellers and the relation between actual use and perceived value of recreation areas in a case study in the Hamburg Metropolitan Region (Germany). In a social survey, Hamburg residents (n = 400) were asked about their preferences and use of four important regional recreation areas with different landscape characteristics in face-to-face interviews in different locations in the city. We found that both outdoor recreation within and outside of the city were fairly or very important for more than 70% of the questioned urban dwellers. Interestingly, the preference for a recreation area outside of the city did not depend on the frequency of use, which indicates that certain recreation areas had a symbolic value besides their use value. When people were questioned on the characteristics of recreation areas, perceived naturalness was found to be strongly related to preference. Respondents considered the diversity, uniqueness, and naturalness of the landscape to be far more important than the accessibility of the recreation areas and the provision of service facilities.     

Environmental Risks at Finnish Shooting Ranges—A Case Study

We studied three Finnish shooting ranges in order to define the extent of the risks associated with elevated environmental concentrations of metals and PAHs. A scoring system revealed that lead, arsenic, and antimony were the most critical contaminants. On Site 3, the concentration of lead in groundwater exceeded the drinking water standard indicating evident health risks. For the remaining two sites we calculated Acceptable Daily Doses (ADD) based on the Reasonable Maximum Exposure (RME) approach and compared them with safe exposure levels. We also used a pharmacokinetic model to determine blood lead levels (PbBs). Risks to biota were assessed using ecological benchmarks and exposure and accumulation models. Prediction of leaching was based on laboratory tests and a distribution model. The health risk assessment for lead resulted in the maximum hazard quotient (HQ) of 1.2 whereas the HQs of As and Sb remained less than 1. Some exposure scenarios produced PbB estimates exceeding 10 μ g dl^?1 but based on the uncertainty analysis we expect the health risks to remain insignificant. However, leaching of contaminants presents a risk to groundwater quality. At site 1 the ecotoxicity-based HQs demonstrate high risks to soil biota, small mammals, terrestrial plants and aquatic organisms.