Phylogeny as a proxy for ecology in seagrass amphipods: which traits are most conserved?

Increasingly, studies of community assembly and ecosystem function combine trait data and phylogenetic relationships to gain novel insight into the ecological and evolutionary constraints on community dynamics. However, the key to interpreting these two types of information is an understanding of the extent to which traits are phylogenetically conserved. In this study, we develop the necessary framework for community phylogenetics approaches in a system of marine crustacean herbivores that play an important role in the ecosystem functioning of seagrass systems worldwide. For 16 species of amphipods and isopods, we (1) reconstructed phylogenetic relationships using COI, 16S, and 18S sequences and Bayesian analyses, (2) measured traits that are potentially important for assembling species between and within habitats, and (3) compared the degree to which each of these traits are evolutionarily conserved. Despite poor phylogenetic resolution for the order Amphipoda as a whole, we resolved almost all of the topology for the species in our system, and used a sampling of ultrametric trees from the posterior distribution to account for remaining uncertainty in topology and branch lengths. We found that traits varied widely in their degree of phylogenetic signal. Body mass, fecundity, and tube building showed very strong phylogenetic signal, and temperature tolerance and feeding traits showed much less. As such, the degree of signal was not predictable based on whether the trait is related to environmental filtering or to resource partitioning. Further, we found that even with strong phylogenetic signal in body size, (which may have large impacts on ecosystem function), the predictive relationship between phylogenetic diversity and ecosystem function is not straightforward. We show that patterns of phylogenetic diversity in communities of seagrass mesograzers could lead to a variety of interpretations and predictions, and that detailed study of trait similarities and differences will be necessary to interpret these patterns

Investigation of length changes in prestressed concrete slabs with outside exposures

In general, pavements may be classed as being either rigid or flexible. The term “rigid pavement”, as commonly used in the United States, is applied only to wearing surfaces constructed of portland-cement concrete. All other types of pavements are classed as “flexible”. A pavement constructed of portland-cement concrete is assumed to possess considerable flexural strength which will permit it to act as a beam and allow it to bridge any minor irregularities which may occur in the base on which it rests, hence the term “rigid”…. In view of the experience and information gathered in over 50 years of road building, one might expect to find precise and standardized methods for the design of portland-cement concrete pavements. Instead, nearly every state has different design practices. Because of increased usage and heavier loadings, what was once considered good design practice is now to some extent inadequate. The results of the increased usage and loadings is evident in the fact that pavements that were designed for a life expectancy of 20 to 25 years are being completely destroyed in approximately half that time…. It is the purpose of this investigation to determine, by tests conducted on normal pavement concretes placed on prepared subgrades, the daily cycles of length changes with temperature variation, and also to determine the longtime changes in length of slabs on subgrades with moisture and evaporation variables approximating those of normal highway slabs. Each slab will be subjected to a known, relatively constant, average intensity of prestress. In accord with the above purpose, the primary objective of this project is to determine overall length changes for daily and seasonal cyclic changes of temperature and moisture on short sections of prestressed concrete slabs. The slabs will be placed in outside exposure on prepared highway subbases. A secondary objective of this project is to investigate changes in one-directional warping measurements along the length of these slabs. This will be done under the different intensities of average known prestress for daily and seasonal changes in slab temperature and moisture --Introduction, pages 1, 2, 5

Effects of ethephon on sex expression and yields of summer squash

The plant growth regulator 2-chloroethylphosphonic acid (ethephon) was applied to four summer squash cultivars to determine its effects on yield and flowering habits. Four ethephon rates, three application regimes, and two locations were used in field studies. Flowering patterns were examined for two cultivars under early fall greenhouse growth conditions. Four ethephon rates and four stages of plant growth for ethephon application were utilized in the greenhouse study. Ethephon levels of 150, 300, and 600 ppm were tested in field studies. The 150 ppm level resulted in the highest yields with the least amount of quality reduction as defined by percentage of fruit marketable. The 600 ppm level resulted in the highest percentage of unmarketable fruit, especially for Zucchini cultivars. Fruit quality was lowered by inadequate pollination, and supplemental pollen sources planted near ethephon treated plants helped alleviate the problem. Average fruit weight was lowered by ethephon for about two weeks after treatment. In field studies, ethephon at the 150 ppm rate applied at the three-leaf stage resulted in higher early yields than did the control in all cultivars. \u27Early Prolific\u27 (a yellow open-pollinated cultivar), \u27Dixie\u27 (a yellow hybrid cultivar), \u27Aristocrat\u27 and \u27Senator\u27 (Zucchini cultivars) exhibited early yield increases of 540, 58, 51, and 150 per cent respectively with the 150 ppm, three-leaf stage ethephon treatment. Only Senator exhibited a season total yield increase (32 percent) resultant from ethephon treatment. Ethephon treatment resulted in an increase in total fruit number but not total yield for Early Prolific. Split application of 150 or 300 ppm ethephon were no more successful in increasing yields than were single, three-leaf stage applications of these treatments. Plants treated with split applications tended to distribute yields throughout the season rather than concentrating them at the early part of the harvest period, thereby exhibiting a yield pattern similar to that of control plants. Ethephon levels of 75, 150, and 300 ppm resulted in about the same total numbers of pistillate flowers as did the control for either Early Prolific or Dixie plants grown under early fall greenhouse conditions. However, due to a shortage of staminate flowers, all ethephon treated plants had significantly fewer pollinated pistillate flowers than did control plants. Numbers of pistillate primordia which formed on plants but aborted prior to reaching the flowering stage were 307 to 382 percent higher for Early Prolific plants treated with 75 and 300 ppm ethephon respectively than for control plants. Plants treated with ethephon at the first flower stage had more fruit formed partheno-carpically than did control plants or those treated at the seed stage (seeds were soaked in ethephon for 30 minutes prior to planting) or first fruit stage

Sequential cropping of vegetables for market windows

With the decline in profitability of several Southern commodities, farmers in Tennessee and other surrounding areas have been forced to reevaluate the crops they are producing. This study provides information that is beneficial to these farmers on alternative crops they can use in their decision making processes. How good an alternative crop is at producing income on average can be determined by using simple statistical procedures and price data for different crops. Price risk, which is one of the most important risks to be considered when growing vegetables, can be observed by finding the standard deviation that goes with the average price. A coefficient of variation can be found using the average price and the standard deviation for a product. The coefficient of variation provides a relative risk rating for comparison of the vegetables in this study. Production risk can also be looked at using temperature data in the same manner as price data. Data needed for the study came from several different sources. The price data for the vegetables came from wholesale market reports at different locations in the region. The temperature data used came from the state of Tennessee. Other budgets and expenses came from different publications and businesses around the area. Vegetable production in Tennessee appears to be profitable under the conditions of this study. Depending on the actual size of his farm and his current financial condition, a farmer can produce for market windows by targeting his harvest dates and increase his income. Other farmers with fewer resources who prefer lower risk can sequence crops and make the most effective use of their land and other limiting resources

Costs and Benefits of Full Dual-Frame Telephone Survey Designs

Assesses the cost, sample composition, weighting, and substantive effect on survey results involved in interviewing respondents by cell phone, including those with landlines. Includes demographic profiles of cell phone-only, landline-only, and dual users

Statistical distribution models : goodness of fit tests

The purpose of a one-sample test of fit is to give an objective measure of how well a probability model agrees with observed data. Here we discuss the test of Karl Pearson and derivatives of it, tests based on the empirical distribution function and the construction of the Neyman-Barton smooth tests. In the final section, we then address some modern developments in smooth testing: diagnostics, Cholesky components, data-driven tests and model selection. Other tests of fit, such as correlation tests and Laplace transform tests, are not considered here

Recovery capital pathways : modelling the components of recovery wellbeing.

In recent years, there has been recognition that recovery is a journey that involves the growth of recovery capital. Thus, recovery capital has become a commonly used term in addiction treatment and research yet its operationalization and measurement has been limited. Due to these limitations, there is little understanding of long-term recovery pathways and their clinical application. We used the data of 546 participants from eight different recovery residences spread across Florida, USA. We calculated internal consistency for recovery capital and wellbeing, then assessed their factor structure via confirmatory factor analysis. The relationships between time, recovery barriers and strengths, wellbeing and recovery capital, as well as the moderating effect of gender, were estimated using structural equations modelling. The proposed model obtained an acceptable fit (χ(2) (141, N=546)=533.642, p<0.001; CMIN/DF=3.785; CFI=0.915; TLI=0.896; RMSEA=0.071). Findings indicate a pathway to recovery capital that involves greater time in residence ('retention'), linked to an increase in meaningful activities and a reduction in barriers to recovery and unmet needs that, in turn, promote recovery capital and positive wellbeing. Gender differences were observed. We tested the pathways to recovery for residents in the recovery housing population. Our results have implications not only for retention as a predictor of sustained recovery and wellbeing but also for the importance of meaningful activities in promoting recovery capital and wellbeing. [Abstract copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

When the Wheels Touch Earth and the Flight is Through, Pilots Find One Eye is Better Than Two?

This study investigated the impact of near to eye displays on both operational and visual performance by employing a human-in-the-loop simulation of straight-in ILS approaches while using a near to eye (NTE) display. The approaches were flown in simulated visual and instrument conditions while using either a biocular NTE or a monocular NTE display on either the dominant or non dominant eye. The pilot s flight performance, visual acuity, and ability to detect unsafe conditions on the runway were tested