The Response of Plant Species Diversity to the Interrelationships between Soil and Environmental Factors in the Limestone Forests of Southwest China

An understanding of the spatial patterns of plant diversity is essential in deciding conservation priorities. Identifying these patterns may rely on our ability to predict how species respond to environmental variables. The present study examined plant species diversity variations and their ecological correlates in the limestone forest of Longhushan Nature Reserve, SW China. Species diversity was examined using statistical analyses and modellings to establish its response to the single or combined influence of the environmental habitat factors. The results showed that variations in diversity were dependent on complex relationships between karst habitat factors. The geological factor played an important role as its inclusion in the analysis with soil and environmental factors greatly improved the overall predictability of plant diversity. Species diversity was significantly predicted (F=13.330, p<0.001) with over 79% of its variance explained by the model (adjusted R2=0.794). Trends in diversity were mainly related to moisture, rock type in association with slope gradient and temperature. The influence of rock type was related to dolomite as diversity had a positive trend in high dolomite percentage areas and the inverse trend in calcium rich areas. The dominant species responded differently to the significant factors, but a number of those species were found typically well adapted to the special karst habitats. Sterculia nobilis, Albizia chinensis, Ficus oligodon, and Psychotria rubra were found adapted to all habitats conditions, suggesting they could be appropriate species for restoration and forest amelioration measures. It was clearly demonstrated that the evidence of significant variations in species diversity was provided after combining variables from soil, geological, and environmental factors, suggesting their interactions influence on plants. Keywords: plant species diversity, rock type, soil characteristics, environmental factors, interactions, karst fores

Manufacturer competition in the nanostore retail channel

In emerging markets, a significant share of the revenue of Consumer Packaged Goods (CPG) manufacturers comes from the traditional retail channel, composed of millions of independent family-owned nanostores. Nanostore owners typically have limited cash flow and are driven by the modest goal of making a living. It is common practice for manufacturers to dispatch sales representatives to visit nanostores directly in order to drive product sales. We study the sales visit and pricing decisions of manufacturers supplying to a nanostore over an infinite time horizon. We first consider the case of a single manufacturer and show that the manufacturer should price the product such that the nanostore can earn enough to pay for his subsistence spending. Such a supplier-retailer mutual reliance relationship continues to hold for the two-manufacturer model where the manufacturers compete for the nanostore's cash resources under shelf space limitations. Further, under some conditions, the two manufacturers can mutually benefit, that is, instead of jeopardizing each other through competition, they contribute collectively to satisfy the nanostore family's subsistence needs such that nanostores are more likely to survive; besides, each can earn more profit than in a single-supplier setting. The results can help us understand the current industry dynamics in this vital sector.</p

Nanoretail operations in developing markets

Across much of the developing world, family-operated nanostores provide daily grocery needs to billions of poorly paid consumers. This highly fragmented retail channel is of critical importance to consumer brands as in many markets this is the largest retail channel. We characterize the empirical context in which these stores operate, as well as the intricate operations that manufacturers and distributors put in place to supply them with their goods. We then elaborate on modeling operations execution and operations strategies to expose critical tradeoffs that are distinct from those in organized retail in developed markets. We discuss research results that have demonstrated why many manufacturers choose to serve this market directly and at high frequency, why manufacturers invest considerable effort in deploying sales agents networks, how this channel manages to remain competitive with modern organized retail such as convenience store chains, and how digitization and novel financing solutions provide a further competitive advantage to the nanoretail channel. Finally, we discuss how to conduct research in this retail segment and provide examples of novel contexts and business models that may open up new areas of nanoretail researc

Water Quality Assessment of Gufu River in Three Gorges Reservoir (China) Using Multivariable Statistical Methods

Abstract: To provide the reasonable basis for scientific management of water resources and certain directive significance for sustaining health of Gufu River and even maintaining the stability of water ecosystem of the ThreeGorge Reservoir of Yangtze River, central China, multiple statistical methods including Cluster Analysis (CA), Discriminant Analysis (DA) and Principal Component Analysis (PCA) were performed to assess the spatialtemporal variations and interpret water quality data. The data were obtained during one year (2010~2011) of monitoring of 13 parameters at 21 different sites (3003 observations), Hierarchical CA classified 11 months into 2 periods (the first and second periods) and 21 sampling sites into 2 clusters, namely, respectively upper reaches with little anthropogenic interference (UR) and lower reaches running through the farming areas and towns that are subjected to some human interference (LR) of the sites, based on similarities in the water quality characteristics. Eight significant parameters (total phosphorus, total nitrogen, temperature, nitrate nitrogen, total organic carbon, total hardness, total alkalinity and silicon dioxide) were identified by DA, affording 100% correct assignations for temporal variation analysis, and five significant parameters (total phosphorus, total nitrogen, ammonia nitrogen, electrical conductivity and total organic carbon) were confirmed with 88% correct assignations for spatial variation analysis. PCA (varimax functionality) was applied to identify potential pollution sources based on the two clustered regions. Four Principal Components (PCs) with 91.19 and 80.57% total variances were obtained for the Upper Reaches (UR) and Lower Reaches (LR) regions, respectively. For the UR region, the rainfall runoff, soil erosion, scouring weathering of crustal materials and forest areas are the main sources of pollution. The pollution sources for the LR region are anthropogenic sources (domestic and agricultural runoff, hydropower exploitation and municipal waste). The study demonstrates the utility of multivariate statistical techniques for river water quality assessment, identification of pollution sources, and exploring spatial and temporal variations of water quality

The Status of Musculoskeletal Disorders and Its Influence on the Working Ability of Oil Workers in Xinjiang, China

The purpose of this study was to investigate the status of musculoskeletal disorders (MSDs) and its influence on the working ability of oil workers, and to provide a theoretical basis for helping lessen the burden of MSDs and improve the man-machine environment of oil workers. The cluster sampling method was used to study 2000 workers who had been employed for more than 1 year in this field. We investigated the prevalence rate and the work ability index (WAI). A total of 1935 valid questionnaires were collected, a response rate of 96.75%. There were 1639 people who had suffered from MSDs in the past year, a prevalence rate of 84.7%. The damage detection rate in female oil workers was higher than in males, and the damage detection rate in workers aged 30 to 45 years was higher than that in the other two age groups. The detection rate in less highly-educated oil workers was higher than that in more highly-educated workers. The detection rate in divorced workers was higher than that in other groups. The detection rate in workers between the number of working years of 18 to 25 years was higher than in the other two groups. The detection rate in workers with a high professional title was significantly higher than that in lower-titled workers (p &lt; 0.05). The results showed that the WAI scores of the subjects with MSDs were significantly lower than for subjects without MSDs (p &lt; 0.05). In a logistic regression analysis, sex, number of working years and WAI index all had an impact on MSDs. We concluded that due to the demands of their role, the oil workers had serious MSDs that influenced their working ability

Supplying to mom and pop: traditional retail channel selection in megacities

Nanostores are traditional, small independent retailers that are present in large numbers in the megacities of the developing world. CPG Manufacturers can choose to deliver to nanostores either directly - visiting thousands of stores per day - or via wholesalers - saving on distribution cost but forfeiting the direct access to the store owners to develop demand. We study a manufacturer’s channel strategy within a finite time horizon. The channel strategy in emerging markets has both marketing and operational elements which lead to a newly formulated problem with novel characteristics. High costs are involved in nanostore distribution and the difference in wholesale price, logistics cost, product availability and market growth leads to a multi-dimensional problem that is not trivial to analyze. We develop an analytical model to derive the optimal channel policy. We conduct a numerical study with parameters tuned by field data. We develop managerial insights based on our formal results and our numerical analysis. The optimal channel policy structure depends mainly on two channel metrics: the gross profitability, which is the gross margin at a particular moment in time and the growth-adjusted profitability, which includes the growth potential of a particular channel strategy to develop the market and realize future profits. With demand growth over time, we show that, in the optimal policy, there is at most one switch between the wholesale and direct channel strategies within the time horizon. Depending on the two metrics, it may be optimal to first expand the market using the direct channel and then switch to the wholesale channel to exploit the expanded market. In other cases, it may be optimal to first expand the market slowly using the wholesale channel then switch to the direct channel to benefit from high demand growth. The optimal channel strategy is also dependent on the time horizon, with a longer time horizon leading to a relatively longer use of the direct channel