Floristics, structure and site characteristics of "Melaleuca viridiflora" (Myrtaceae) dominated open woodlands of the wet tropics lowlands

Tropical lowland plant communities in north-eastern Queensland remain under pressure from continuing clearing, fragmentation, exotic species invasion, inappropriate fire regimes, and altered hydrological patterns. Comparatively little scientific research has been conducted on the highly diverse and ecologically significant range of remnant vegetation types. Additionally, most plant communities remain very poorly represented in the existing conservation reserve system. Melaleuca viridiflora Sol. ex Gaertn. open woodlands were selected for investigation based on their relatively simple structure, compared to other lowland communities, and the large extent to which they have been affected by past clearing patterns. A detailed analysis of community structure and composition was conducted at 24 sites throughout the wet-tropics coastal region between Townsville and Cooktown. Surprisingly, a high diversity of structural and floristic types was recorded, with a total of 127 species documented across the 24 sites. Classification analyses of species composition data produced seven or eight main groups of sites (dependent on the statistical technique used), essentially related to a gradient of latitude and rainfall. These floristic groups were not well explained by either species richness, past fire frequencies or soil types. Structural classification analyses based upon DBH data identified six or seven main groups, the singularly most striking of which were sites with annual fire histories. Ordinations based on both the DBH and species composition data produced groupings that supported those detected by the classification techniques. On closer examination of sites with similar fire histories, soil moisture and soil type were both found to have significant effects on community structure and composition. Many of the woodland types recorded are not adequately included (some not at all) in the existing conservation reserve system

This little piggy went running, that little piggy stayed home : a forelimb perspective of limb loading [abstract]

Variation in mechanical loading is known to influence chondral modeling. However, the interaction between chondrocyte behavior, skeletal morphology, and ontogenetic variation in activity patterns are variably understood. This hinders our knowledge of limb formation and function, whether plasticity varies within/among skeletal joints, and the limits of paleobiological inference. Here, the role of endurance exercise on the development of articular and growth plate cartilage in the humeral head was examined in 14 miniature swine (Sus scrofa domesticus). One group (n=7) was subjected to graded treadmill running over a period of 17 weeks. A matched group (n=7) was kept pen-confined sedentary. Gross and microanatomical dimensions between groups were compared multivariately. H&E and Safranin-O staining were performed for histomorphometry and evaluation of variation in proteoglycan content of the cartilage extracellular matrix, respectively. Versus sedentary pigs, exercised pigs possessed relatively increased cellularity, thinner cartilage zones, larger chondrocytes, and greater humeral proportions. While articular and growth plate cartilage demonstrated between-cohort differences, growth plate cartilage in the humerus exhibited a greater load-induced response. Likewise, external measures were less effective than histomorphometry in diagnosing group membership. When compared to similar data on the femur from the same individuals, humerus parameters evinced similar patterns of variation between loading cohorts. Given the primary role of growth plate cartilage in limb elongation, this constitutes further experimental evidence that ontogenetic variation in locomotor activity can influence limb length in mammals. These findings regarding joint plasticity during high endurance behaviors have important implications for understanding limb biomechanics and joint development

The Effect of Inventions Upon Social Problems

A study of the most notable effects of new inventions upon social issues, including employment opportunities, distribution of industry and the life of a laborer

Blanding’s Turtle (\u3ci\u3eEmydoidea blandingii\u3c/i\u3e): A Technical Conservation Assessment

Blanding’s turtles (Emydoidea blandingii) are secure in Nebraska, and they range from being vulnerable to threatened, or endangered throughout most of the rest of their distribution. In Region 2, they have not been reported from Kansas, they are extremely rare in South Dakota, and they occupy wetlands in the northern half of Nebraska. The largest population known within the range of Blanding’s turtles is at Valentine National Wildlife Refuge, Nebraska. The core habitat of Blanding’s turtles has an aquatic component that consists of a permanent wetland and a suite of other, usually smaller and more temporary, wetlands such as vernal pools that are used by adults and hatchlings as temporary refugia and seasonal food sources. Blanding’s turtle habitat also has a large terrestrial component that consists of nesting areas and movement corridors. The terrestrial component of the core habitat is larger than that of many other aquatic turtle species, and both sexes use terrestrial corridors for movements among wetlands and for nesting migrations. A host of things can affect Blanding’s turtles through their impact on either (or both) the wetland or terrestrial portions of their required habitat. Given the wide range of possible threats to populations of Blanding’s turtles, three categories of threat appear most important. In rough order of decreasing priority, they are as follows: loss and degradation of wetland and terrestrial habitats; road mortality; collection Loss and degradation of wetland and terrestrial habitats: Destruction of resident aquatic habitat is of primary conservation concern because it impacts all stages of the life cycle. Reduction in the numbers of such wetlands can increase risks of mortality for adults and reduce hatchling recruitment into populations. Cultivation to the edge of wetlands and the use of fertilizers, pesticides, and herbicides that wash into wetlands can degrade aquatic habitats. Water management activities related to fish management and agriculture can be detrimental to overwintering Blanding’s turtle populations if they are conducted during winter. Loss or degradation of terrestrial movement corridors can increase the risks of injury and mortality, and in addition may lead to isolation of populations and a subsequent reduction in genetic variation through drift and inbreeding. Reduction in the amount or number of nesting areas through agriculture, forestry, forest succession, introduction of exotics, or development can result in increased risks to females during nesting migrations of longer length or duration. Despite their importance to Blanding’s turtles and the amphibian larvae that they feed on, small and temporary wetlands have minimal or no legal protection in many areas. However, conservation easements, local zoning, and education of private and public landowners can help reduce the loss of Blanding’s turtle habitat. Such protection must focus on both wetlands (including small wetlands such as vernal pools) and key terrestrial areas near those wetlands. Road mortality: The propensity for terrestrial movement by Blanding’s turtles results in added risk of adult mortality associated with roads and other human activities, problems that tend to impact females more than males because of their extensive nesting migrations. In Michigan we have found females killed by farm equipment such as tractors, hay mowers, and road graders, and some stuck in stock fences. Communicating conservation issues to transportation planners may reduce construction of new roads in movement corridors and between nesting areas and aquatic habitats. Designs for new roads with high traffic volumes should include both barriers and culverts to control turtle movements. Barriers should block access to risky areas and encourage use of culverts that allow turtles safe passage under roads. Road signs can be placed along roadways with high volumes of traffic of both Blanding’s turtles and vehicles. In areas with high levels of mortality associated with existing roads, fencing and ecopassages (e.g., culverts, tunnels, bridges) should be installed. Collecting: In conjunction with their extended longevity and long reproductive lives, collection of adults, juveniles, and hatchlings from small and isolated populations for the pet trade can result in severe reductions and extirpation of populations. Gravid females were collected on roads by motorists during nesting migrations; one was subsequently returned to the University of Michigan’s Edwin S. George Reserve (ESGR) when it was found to be marked. The presence of these threats is exacerbated by a number of factors that make Blanding’s turtles particularly susceptible to disturbance. First, Blanding’s turtles and many other turtle species have temperature-dependent sex determination and some populations have biased adult sex ratios (e.g., the ESGR population in southeastern Michigan has an adult sex ratio close to 1 male to 4 females). Biased sex ratios are one of the factors that reduce effective population size and can contribute to population instability and reduce the probability of population persistence, particularly for small populations. Further, head-starting programs that include protecting or moving nests to artificial nesting areas run the risk of producing highly biased hatchling sex ratios. Second, reproductive output of Blanding’s turtles is low. Females do not begin to reproduce until they are between 14 and 20 years old, do not reproduce every year, and have small clutch sizes, thus resulting in low fecundity. This means that annual survivorship between ages 1 and maturity must average at least 60 percent to maintain population stability. Third, Blanding’s turtles are long-lived (even compared to other turtles), and older females appear to have higher survivorship and reproductive output than do younger females. This places primary reproductive importance on a small segment of the population, and because potential reproduct

Workers\u27 Responses to Incentives: The Case of Pending MLB Free Agents

This study examines ways in which workers respond to implicit incentives. Specifically, we examine the extent to which workers shift their effort to activities that are measured and which have been previously rewarded in the labor market. To examine this question, we examine the changes in the performance measures of professional baseball players in the season prior to the opportunity to freely negotiate their contract (free agency). We will examine different eras in baseball to examine if we can identify changes in behavior in this pivotal year based on changes to the current premium outputs for each time period

Beyond Moneyball: Changing Compensation in MLB

This study examines the changes in player compensation in Major League Baseball during the last three decades. Specifically, we examine the extent to which recently documented changes in players’ compensation structure based on certain types of productivity fits in with the longer term trends in compensation, and identify the value of specific output activities in different time periods. We examine free agent contracts in three-year periods across three decades and find changes to which players’ performance measures are significantly rewarded in free agency. We find evidence that the compensation strategies of baseball teams increased the rewards to “power” statistics like home runs and doubles in the 1990s when compared to a model that focused on successfully reaching base with a batted ball without a significant regard for the number of bases reached. Similarly, we confirm and expand upon the increased financial return to bases-on-balls in the late 2000s as found in previous research

Pretreatment of Spores as a Factor in Dimensional Analysis of Two Species of Histozoic Myxosporida

Spores of Henneguya exilis, taken during the summer of 1968 from the gills of Ictalurus punctatus caught in the Des Moines River near Knoxville, Iowa, and of a species of Myxosoma apparently closely related to Myxosoma ovalis, taken from the gills of Carpiodes velifer from the same locality, were subjected to storage at room temperatures, 4° C, and deep freezing. Repeated measurements of spores under different pretreatment showed that the dimensions of the spores and polar capsules remained remarkably stable, as did ratios of the dimensions of spore parts. Abnormalities in the details of spore architecture were seen under conditions under which dimensions remained stable. It is recommended that, wherever possible, unfixed spores be used for measurements, and preserved spores be used for other observations on which species descriptions are to be based

Population structure of palms in rainforests frequently impacted by cyclones

Tropical cyclones may act as important ecological drivers in northern Australia including north Queensland, as several cyclones impact this region each year between November and May. Extensive research has been conducted to investigate how the population structure of rainforest species respond to cyclonic disturbances. However, there have been few such studies on palms although they are important components of rainforests. Therefore, these study aimed to investigate how the population structure of Arenga australasica (H. Wendl. & Drude) S. T. Blake ex H. E. Moore, Calamus australis Mart., C. moti F. M. Bailey, Hydriastele wendlandiana (F. Muell.) H. Wendl. & Drude and Licuala ramsayi var. ramsayi (F. Muell.) H. Wendl. & Drude responded to a cyclone, as shown by size class reflecting mass recruitment after a periodic major disturbance (case study: Cyclone Larry). The field research was carried out in three study sites: Tam OShanter/Djiru National Park, Clump Mountain National Park and Kurrimine Beach Conservation Park located near Mission Beach and Kurrimine Beach, in north Queensland. Observations were made of life stage distribution, height and dbh distribution and wind resistance. We found that responses of the population structures of these rainforest palms varied following cyclonic disturbance by demonstrating higher densities of seedlings and juveniles, suggesting populations would be retained. More seedlings of C. australis and C. moti were found in gaps with higher canopy openness; oppositely, less seedlings of L. ramsayi were encountered under sites with lower sunlight