Dive Operator Use Patterns in the Designated No-Take Zones of the Florida Keys National Marine Sanctuary (FKNMS)

/ The Florida Keys National Marine Sanctuary (FKNMS), created by Congress in 1990, addressed the issue of resource protection partly by proposing 26 "no-take" zones. These areas, discussed in the 1995 Draft Management Plan, disallowed all extractive activities, and four of the zones also prohibited diving and snorkeling. Furthermore, the Draft Management Plan considered recreational carrying capacity, proposing that use densities be studied and eventually limited in high-use and sensitive areas. Conducted with 62 commercial dive operators from the Florida Keys in 1995-96, this study uses geographic information systems (GIS) to determine the extent of FKNMS zone use by dive operators, assess the regional importance of FKNMS zones to operators, and compare management strategies by which to allow use while minimizing impacts to the coral reef resource. Dive operators took almost 70% of their total trips and 77% of their total divers to FKNMS zones in 1995. Although zone use is generally related to the proximity of dive locations, dive operators do rely disproportionately on single sites in certain regions. The resulting profiles demonstrate that management strategies need to consider disproportionate use, as well as the average number of users per trip, to effectively protect the region's environmental resources. In addition to implementing a carrying capacity plan, the FKNMS should consider a limited-entry system for dive operators.     

The Use of Cluster Analysis in Distinguishing Farmland Prone to Residential Development: A Case Study of Sterling, Massachusetts

k -means nonhierarchical cluster analysis using farm size, slope, and distance to the nearest city center and highway as surrogates of farmland conversion. Discriminant analysis showed that the two groups derived from the cluster analysis were 98.8% accurate (P < 0.0000). Results from the statistical analysis may serve as a starting point for the identification of individual farms prone to residential development. To explain the driving forces of farmland conversion to residential uses, interviews should be conducted with farmers, landowners, and land buyers. The use of multivariate statistical techniques to identify farms in jeopardy of residential development, in conjunction with qualitative assessments that explain the probability of development of individual farms, may prove a useful strategy to understand and predict farmland conversion.     

Import demand for Brazilian ethanol: a cross-country analysis

This study presents an empirical analysis of the import demand for Brazilian ethanol by its six major foreign buyers. The primary objectives of this study were to identify the economic factors affecting the demand for ethanol imports and to derive long-run price and income elasticities of import demand. These elasticities could be used to analyze the impact of government policies such as mandatory gasoline/ethanol blends and import tariffs. Import demand models were estimated with ordinary least squares (OLS), using quarterly time series data for the 1997–2007 time period. The results suggest that the factors influencing the import demand for ethanol vary across countries. Markets adopting mandatory blends of renewable fuels tend to have less price elastic import demand schedules. Ethanol imports were found to be price elastic and statistically significant in the Caribbean region (?1.66), Mexico (?2.08), Japan (?1.44) and Nigeria (?1.38), while import demand was price inelastic and not statistically different from zero in the US (?0.76) and Europe (?0.21). The regression results could not determine the impacts of import tariffs for the United States, Mexico and Nigeria on the quantity of imports because tariffs did not vary during the time period studied. Results show that mandatory gasoline/ethanol blends have been an important determinant of ethanol imports.     

An overview of emissions trading and its prospects in Hong Kong

With the approval of the Chinese central government, the Government of the Hong Kong Special Administrative Region (HKSAR) decided to participate in a regional emissions trading (ET) pilot scheme in the Pearl River Delta (PRD) region. This scheme, instead of aiming to curb global warming, is geared mostly toward reducing air pollutant (that is, SO₂, NO_x, RSP, and VOCs) emissions by 20–55% by 2010, thus improving air quality in the region. Both the HKSAR and the Guangdong Provincial Governments will impose emission caps on their respective power plants in the region and allocate emissions credits to them. This study explores the background of this regional ET scheme and correlates it with the emissions reduction scenario to provide more details for assessing its applicability to Hong Kong and Guangdong Province. Although practicing ET in the PRD region presents many challenges, establishing an appropriate ET scheme is of paramount importance for Hong Kong, as well as other cities in the PRD region, to achieve a sustainable air quality.     

Nanosecond pulsed laser micromachining of PMMA-based microfluidic channels

This paper reports an investigation into the effects of nanosecond laser processing parameters on the geometry of microchannels fabricated from polymethylmethacrylate (PMMA). The Nd:YAG solid-state pulsed laser has a wavelength of 1064 nm and a measured maximum power of 4.15 W. The laser processing parameters are varied in a scanning speed range of 400–800 pulses/mm, a pulse frequency range of 5–11 Hz, a Q-switch delay time range of 170–180 μs. Main effects plots and microchannel images are utilized to identify the effects of the process parameters for improving material removal rate and surface quality simultaneously for laser micromachining of microchannels in PMMA polymer. It is observed that channel width and depth decreased linearly with increasing Q-switch delay time (hence average power) and increased non-linearly with higher scanning rates and not much affected by the increase in pulse frequency.     

The potential to encode sex,age, and individual identity in the alarm calls of three species of Marmotinae

In addition to encoding referential information and information about the sender’s motivation, mammalian alarm calls may encode information about other attributes of the sender, providing the potential for recognition among kin, mates, and neighbors. Here, we examined 96 speckled ground squirrels (Spermophilus suslicus), 100 yellow ground squirrels (Spermophilus fulvus) and 85 yellow-bellied marmots (Marmota flaviventris) to determine whether their alarm calls differed between species in their ability to encode information about the caller’s sex, age, and identity. Alarm calls were elicited by approaching individually identified animals in live-traps. We assume this experimental design modeled a naturally occurring predatory event, when receivers should acquire information about attributes of a caller from a single bout of alarm calls. In each species, variation that allows identification of the caller’s identity was greater than variation allowing identification of age or sex. We discuss these results in relation to each species’ biology and sociality.     

Grass–legume mixtures can yield more nitrogen than legume pure stands due to mutual stimulation of nitrogen uptake from symbiotic and non-symbiotic sources

Concerted use of legumes and of functional diversity in grassland forage systems can provide major contributions to the challenges of agricultural systems being productive yet environmental friendly. Acquisition and transformation of nitrogen (N) resources by legumes and grasses were studied in a temperate grassland experiment near Zurich (Switzerland) to investigate mechanisms driving effects of functional diversity in mixed swards and to optimise mixtures for efficient resource use.Grass–legume interactions and N availability were varied by manipulating legume percentage of the sward (0–100%) and N fertiliser application (50, 150 or 450 kg of N ha^?1 year^?1). ¹⁵N technology quantified N derived from symbiotic (Nsym) and non-symbiotic (Nnonsym) sources.Generally, acquisition of Nsym by the entire mixture was stimulated by grasses. As a result, strong overyielding of Nsym occurred (e.g. 75 and 114% for year 1 and 2 at N150) and mixtures with only 60% and 37% legumes (year 1 and 2) already attained the same Nsym yield as pure legume stands. Legumes stimulated Nnonsym acquisition by the entire mixture, largely via increased uptake by the grass component. Thus, overyielding of Nnonsym of 31% occurred in year 1 (N150).Mutual grass–legume interactions stimulated acquisition of Nsym, acquisition of Nnonsym and efficient transformation of N into biomass compared to either monocultures. These effects of functional diversity can substantially contribute to productive and resource efficient agricultural grassland systems and were maximised in mixtures with 40–60% legumes.     

A review of driving risks and impairments associated with attention-deficit/hyperactivity disorder and the effects of stimulant medication on driving performance

INTRODUCTION: Attention-Deficit/Hyperactivity Disorder (ADHD) may interfere with driving competence, predisposing those with the disorder to impaired driving performance and greater risk for adverse driving outcomes. Effective treatment may minimize the risk in those with ADHD. METHOD: We reviewed the scientific literature on driving risks and impairments associated with ADHD and the effects of stimulants on driving performance. Several lines of evidence were considered, including longitudinal studies and community-derived sample studies. The present review is based on a weekly review (by the first author) of all journals in the behavioral and social sciences indexed in the publication Current Contents spanning the past 15 years, as well as a search of the reference section of all studies found that pertained to driving risks associated with ADHD or to the treatment of ADHD as it relates to driving difficulties. RESULTS: The review of the scientific literature demonstrated well-documented driving risks and impairments associated with ADHD and the positive effects of stimulant medications on driving performance. CONCLUSIONS: Clinicians should educate patients/caregivers about the increased risk of adverse outcomes among untreated individuals with ADHD and the role of medication in potentially improving driving performance. IMPACT ON INDUSTRY: Owing to the significantly higher risk of adverse driving outcomes, the use of stimulant medications to treat people with ADHD who drive may reduce such safety risks.     

Irregular brood patterns and worker reproduction in social wasps

The potential for reproductive conflict among colony members exists in all social insect societies. For example, queens and workers may be in conflict over the production of males within colonies. Kin selection theory predicts that in a colony headed by a multiply-mated queen, worker reproduction is prevented by worker policing in the form of differential oophagy. However, few studies have demonstrated that workers actually lay eggs within queenright colonies. The purpose of this study was to determine if workers laid male eggs within unmanipulated queen-right colonies of the polyandrous social wasps Vespula maculifrons and V. squamosa. We focused our analysis on an unusual brood pattern within colonies, multiple egg cells. We were primarily interested in determining if individuals reared in these irregular circumstances were queen or worker offspring. To address this question, we genotyped 318 eggs from eight V. maculifrons and two V. squamosa colonies. No worker‑reproduction was detected in any of the queenright colonies; all of the eggs found in multiple egg cells were consistent with being queen‑produced. However, the frequency of multiple egg cells differed among colonies, suggesting that queens vary in the frequency of errors they make when laying eggs within cells. Finally, we suggest that workers may not be laying eggs within queenright colonies and that worker reproduction may be controlled through mechanisms other than differential oophagy in polyandrous Vespula wasps.