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Western sandpiper (Calidris mauri) chicks are precocial and leave the nest shortly after hatch to forage independently. Chicks require thermoregulatory assistance from parents (brooding) for 5--7 days posthatch, and parents facilitate chick survival for 2--3 weeks posthatch by leading and defending chicks. Parental vocal signals are likely involved in protecting chicks from predators, preventing them from wandering away and becoming lost and leading them to good foraging locations. Using observational and experimental methods in the field, we describe and demonstrate the form and function of parent--chick communication in the western sandpiper. We document 4 distinct calls produced by parents that are apparently directed toward their chicks (brood, gather, alarm, and freeze calls). Through experimental playback of parental and non--parental vocalizations to chicks in a small arena, we demonstrated the following: 1) chicks respond to the alarm call by vocalizing relatively less often and moving away from the signal source, 2) chicks respond to the gather call by vocalizing relatively more often and moving toward the signal source, and 3) chicks respond to the freeze call by vocalizing relatively less often and crouching motionless on the substrate for extended periods of time. Chicks exhibited consistent directional movement and space use to parental and non--parental signals. Although fewer vocalizations were given in response to non--parental signals, which may indicate a weaker response to unfamiliar individuals, the relative number of chick calls given to each type of call signal was consistent between parental and non--parental signals. We also discovered 2 distinct chick vocalizations (chick-contact and chick-alarm calls) during arena playback experiments. Results indicate that sandpiper parents are able to elicit antipredatory chick behaviors and direct chick movement and vocalizations through vocal signals. Future study of parent--offspring communication should determine whether shorebird chicks exhibit parental recognition though vocalizations and the role of chick vocalizations in parental behavior. Copyright 2008, Oxford University Press.

Indicators of soil fertility are needed for the effective management of organic farming systems. Sustainable management hinges upon our gaining an improved understanding of C and N dynamics. The influence of cropping systems and amendments applied in the Lakeland Wisconsin Integrated Cropping Systems Trial on total hydrolyzable organic N (THN) fractions and particulate organic matter (POM) was investigated after a decade in a conventional cash grain system (Conv) of continuous maize amended with inorganic fertilizer, an organic cash-grain system (Org-CG) that relied on legume N, and an organic animal-based system (Org-AN) that included alfalfa and manure additions. Maize yields had consistently ranked Org-CG Org-CG > Conv. Amino sugar-N (AS-N) contents, which reflect microbially derived N, did not differ among systems and concentrations were quite high (346.5 mg AS-N/kg soil in the 0–50 cm depth). This, and soil variability were attributed to the sites’ history of manure application. The amount (1.3 g POM-C/kg soil) and proportion (≈7.5% of total SOC) of POM-C were quite low and did not differ among systems. Failure to accumulate SOC or POM in these soils, even under organic management, is attributed to rapid C decay and/or limited root growth. An N rate study was added the fall before samples were taken and N addition did increase yield in the Conv and Org-CG systems despite evidence of soil N surplus. This suggests that either amino N is unavailable to plants or that root N acquisition is limited by other constraints. Low POM-C contents accompanied by high AS-N and AA-N levels reveal an imbalance in these soils which are likely to be C limited. Based on this, we conclude excess N has prevented use of organic practices from enhancing soil quality at this site.

We tested the hypothesis that partial volume effects due to poor in-plane resolution and/or low temporal resolution used in clinical dynamic contrast-enhanced magnetic resonance imaging results in erroneous diagnostic information based on inaccurate estimates of tumor contrast agent extravasation and tested whether reduced encoding techniques can correct for dynamic data volume averaging. Image spatial resolution was reduced from 469 x 469 microm2 to those reported below by selecting a subset of k-space data. We then compared the top five K(trans)/V(T) "hot spots" obtained from the original data set, 469 x 469-microm in-plane spatial resolution and an 18-s temporal resolution processed by fast Fourier transform (FFT), with values obtained from data sets having in-plane spatial resolutions of 938 x 938, 1875 x 1875 and 2500 x 2500 microm2 and a temporal resolution of 18 s, or data sets with temporal resolutions of 36, 54 and 72 and a spatial resolution of 469 x 469 microm2, and found them to statistically differ from the parent data sets. We then tested four different post processing methods for improving the spatial resolution without sacrificing temporal resolution: zero-filled FFT, keyhole, reduced-encoding imaging by generalized-series reconstruction (RIGR) and two-reference RIGR (TRIGR). The top five values of K(trans)/V(T) obtained from data sets, the in-plane spatial resolutions of which were improved to 469 x 469 microm2 by zero-filling FFT, Keyhole and RIGR, statistically differed from those obtained from the original 469 x 469 microm2 FFT parent image data set. Only the 938 x 938 and 1875 x 1875 microm2 data sets reconstructed to 469 x 469 microm2 with TRIGR reconstruction method yielded values of the top five K(trans)/V(T) hot spots statistically the same as the original parent data set, 469 x 469 microm2 in-plane spatial and 18-s temporal-resolution FFT. That is, partial volume effects from data sets of different in-plane spatial resolution resulted in statistically different values of the top five K(trans)/V(T) hot spots relative to a high spatial and temporal resolution data set, and TRIGR reconstruction of these low resolution data sets to high resolution images provided statistically similar values with a savings in temporal resolution of 2 to 4 times.

Actuellement plusieurs pays prescrivent une reglementation des tests sur cigarettes, exigeant des conditions de fumage plus intense que celles definies dans les conditions normalisees de la Federal Trade Commission (FTC) et l'Organisation internationale de normalisation (ISO), combinees a l'obstruction intentionnelle des orifices de ventilation des cigarettes au cours des tests. Recemment une recommandation initiale a ete lancee sous les auspices de la Convention-cadre sur le controle du tabac, exigeant a l'echelle internationale des tests sur cigarettes sous des conditions normalisee de 55 cc/20 s/2 s apres l'obstruction des orifices a 100%. Les modifications des rendements de la fumee en fonction des parametres de fumage par machine sont parfaitement connues, cependant les connaissances sur les changements potentiels de la composition de la fumee sont plus restreintes. Dans la presente etude, l'influence des conditions de fumage sur le devenir de la nicotine dans une cigarette en combustion a ete etudiee par chromatographie en phase gazeuse avec detection par emission atomique (GC-AED) en utilisant de la nicotine-d 4 injectee a coeur. Quatre conditions differentes de fumage et deux conditions differentes d'obstruction des orifices ont ete examinees. La GC avec detection par spectrometrie de masse a ete utilise pour identifier les composants marques au deuterium, produisant une reaction AED accrue. Une comparaison de la distribution dans la fumee du courant principal des composants marques au deuterium, le courant secondaire et les reliquats (megots et cendres) d'une cigarette plein arome fumee sous les quatre conditions de fumage etudiees, indique qu'un pourcentage plus important de la nicotine marquee reste intact au cours du fumage en fonction d'une intensification du regime de fumage. L'intensification du regime de fumage mene a une diminution des produits de pyrolyse et d'oxydation de la nicotine dans la fumee du courant secondaire. Cependant une augmentation marginale de ces composants est observee dans la fumee du courant principal et dans le megot. Le rapport entre courant secondaire et courant principal pour la nicotine diminue significativement en fonction d'une intensification du regime de fumage. Des petites quantites de nicotine intacte ont ete observees dans la phase gazeuse du courant secondaire, mais la nicotine n'a pas ete trouvee dans les echantillons de la phase gazeuse du courant principal.

Rising CO2 is predicted to increase forest productivity, although the duration of the response and how it might be altered by variation in rainfall, temperature and other environmental variables are not well understood. We measured the basal area of rapidly growing Pinus taeda trees exposed to free-air CO2 enrichment for 8 years and used these measurements to estimate monthly and annual growth. We used these measurements in a statistical model to estimate the start and end of growth in each year. Elevated CO2 increased the basal area increment (BAI) of trees by 13–27%. In most years, exposure to elevated CO2 increased the growth rate but not the duration of the active growth period. With the exception of 1 year following an extreme drought and a severe ice storm, BAI was positively correlated with the amount of rainfall during the active growth period. The interannual variation in the relative enhancement of BAI caused by elevated CO2 was strongly related to temperature and rainfall, and was greatest in years with high vapor pressure deficit. There was no evidence of a systematic reduction in the stimulation of growth during the first 8 years of this experiment, suggesting that the hypothesized limitation of the CO2 response caused by nitrogen availability has yet to occur.

In developing management strategies for hemipteran pests in cotton (Gossypium hirsutum L.), it is important to understand the potential of plants to compensate for loss of the fruiting structures. Because of its northern latitude, Virginia has fewer available heat units relative to other cotton-producing states. Therefore, there may be limited opportunity for compensation relative to more southerly production areas. Previous work in Virginia demonstrated that cotton can sustain relatively high levels of first position square loss with no yield loss. This study evaluated the impact of a single event loss of 10–14-d-old bolls via mechanical removal on cotton lint yields with the premise that boll loss would have greater impact than square loss as less time and fewer heat units are available for compensation. Field experiments examining four levels of boll removal (0, 5,15 and 20%) were conducted in 2001,2002 and 2003. Each boll removal level was imposed at three different dates, beginning 2 wks after first flower and at 3- to 5-d intervals thereafter. Yields ranged from 1103–1422 in 2001, 909–1124 in 2002, and 843–1015 kg lint per ha in 2003. There were no significant differences in lint yields among the boll removal dates or removal levels. The results of our study showed that cotton in Virginia, which approaches the northernmost latitude for cotton production, is capable of sustaining losses as high as 20% of 10–14-d-old bolls at a single removal event without affecting lint yield. Results were consistent despite the wide variation in rainfall and temperatures during the 3 study years.

Earthworms affect soil structure and the movement of agrochemicals. Yet, there have been few field-scale studies that quantify the effect of earthworms on dissolved nitrogen fluxes in agroecosystems. We investigated the influence of semi-annual earthworm additions on leachate production and quality in different row crop agroecosystems. Chisel-till corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (CT) and ridge-till corn-soybean-wheat (Triticum aestivum L.) rotation (RT) plots were arranged in a complete randomized block design (n = 3) with earthworm treatments (addition and ambient) as subplots where zero-tension lysimeters were placed 45 cm below ground. We assessed earthworm populations semi-annually and collected leachate biweekly over a three-year period and determined leachate volume and concentrations of total inorganic nitrogen (TIN) and dissolved organic nitrogen (DON). Abundance of deep-burrowing earthworms was increased in addition treatments over ambient and for both agroecosystems. Leachate loss was similar among agroecosystems, but earthworm additions increased leachate production in the range of 4.5 to 45.2% above ambient in CT cropping. Although leachate TIN and DON concentrations were generally similar between agroecosystems or earthworm treatments, transport of TIN was significantly increased in addition treatments over ambient in CT cropping due to increased leachate volume. Losses of total nitrogen in leachate loadings were up to approximately 10% of agroecosystem N inputs. The coincidence of (i) soluble N production and availability and (ii) preferential leaching pathways formed by deep-burrowing earthworms thereby increased N losses from the CT agroecosystem at the 45-cm depth. Processing of N compounds and transport in soil water from RT cropping were more affected by management phase and largely independent of earthworm activity.

Sound pavement design is important for improving pavement performance, but construction is equally critical. Because of variations in pavement construction, the as-constructed pavement layer thickness varies spatially within a pavement section, and the mean constructed pavement layer thickness often deviates from the designed values. The as-constructed pavement layer thicknesses are compared to their design values by using data from the newly constructed flexible pavement sections in the Long-Term Pavement Performance program. First, the distribution type of the mean layer thickness deviation was investigated, and a combined statistical test for skewness and kurtosis showed that the mean thickness deviations may be assumed to be normally distributed for a given layer type and target thickness. Typical thickness deviation summary statistics values were derived to estimate the extent of deviations from the design thicknesses. Second, the analysis showed that elevation thickness data differ from the core examination data. Furthermore, as-constructed layer thickness values were compared to their design values by looking into the percentage of the individual measurements falling into specified ranges from the design values and by using two-sided and one-sided t-tests to compare the mean constructed thicknesses and the design values. The analyses showed that the mean constructed layer thicknesses tend to be above the design value for the thinner layers and below the design value for the thicker layers for the same layer and material type. Results from the study will be useful as inputs for reliability-based design procedures.

Estimating the variability of key pavement design inputs is essential to reliability-based pavement design. The thickness of most pavement layers has a great impact on the outcome of practically all analyses of pavement performance. The within-section layer thickness variability is investigated here, as is the extent of the mean layer thickness deviation from its design thickness. Pavement layer thickness data (elevation and core measurements) from a large number of newly constructed flexible and rigid pavement sections in the Long-Term Pavement Performance (LTPP) program were examined. To determine the distribution type of the thickness data, a combined statistical test for skewness and kurtosis showed that ( a) thickness variations within a layer indicate a normal distribution for 86% of 1,034 layers and ( b) the mean thickness deviations from the design values may be assumed to be normally distributed for a layer having a given type and design thickness. The estimated thickness-within-layer variability values and the estimated typical thickness deviations derived from LTPP data may serve as benchmarks for use in pavement design reliability, construction quality assurance specifications, and other research studies. In addition, statistical comparisons of layer thickness variability indicators were made between the elevation and core layer thickness data to determine whether there are systematic differences between these two measuring methods. These results will be very useful to both researchers and practitioners who develop or use reliability-based pavement design procedures.

DNA arrays were used to investigate the functional role of Rox1 in mediating acclimatization to anaerobic conditions in Saccharomyces cerevisiae . Multiple growth conditions for wild-type and rox1 null strains were used to identify open reading frames with a statistically robust response to this repressor. These results were compared to those obtained for a wild-type strain in response to oxygen availability. Transcripts of nearly one-sixth of the genome were differentially expressed ( P < 0.05) with respect to oxygen availability, the majority (>65%) being down-regulated under anoxia. Of the anaerobically induced genes, about one-third (106) contain putative Rox1-binding sites in their promoters and were significantly ( P < 0.05) up-regulated in the rox1 null strains under aerobiosis. Additional promoter searches revealed that nearly one-third of the anaerobically induced genes contain an AR1 site(s) for the Upc2 transcription factor, suggesting that Upc2 and Rox1 regulate the majority of anaerobically induced genes in S. cerevisiae . Functional analyses indicate that a large fraction of the anaerobically induced genes are involved in cell stress (∼1/3), cell wall maintenance (∼1/8), carbohydrate metabolism (∼1/10), and lipid metabolism (∼1/12), with both Rox1 and Upc2 predominating in the regulation of this latter group and Upc2 predominating in cell wall maintenance. Mapping the changes in expression of functional regulons onto metabolic pathways has provided novel insight into the role of Rox1 and other trans -acting factors in mediating the physiological response of S. cerevisiae to anaerobic conditions.

Region, soil type, and tillage are important factors in severity of crop pest infestation. This study was conducted to determine the relative importance of these factors on severity of crop pest infestation as perceived by farmers. Correlations between pests were also studied. In a 1992 survey, farmers in 12 U.S. Corn Belt states were asked to rate the severity of crop pest infestation in their fields. The categories of pests included perennial and annual weeds in row crops, insects and diseases of corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench], and insects and diseases of soybean [Glycine max (L.) Merr.]. Means ranked from highest to lowest in the following order: annual weeds, perennial weeds, corn and sorghum insects, corn and sorghum diseases, soybean diseases, and soybean insects. Correlation coefficients ranged between 0.47 to 0.69 among corn and sorghum diseases, among soybean insects, and among soybean diseases, and between 0.04 and 0.41 among perennial weeds. Correlation coeffidents among annual weeds and among corn and/or sorghum insects spanned both of these ranges. Effects of either region and/or tillage were very highly significant (0.001), while soil type was not as significant an effect. In farmers' perceptions, weeds were the most serious pests and soybean pests the least serious pests; there was less relationship among perennial weeds than among pests in any other category; the drier western region was generally less severely infested; higher amount of conventional tillage practices produced less infestation; and differences in soil type were due to more severe infestation in loams, followed by infestation in clays, and then infestation in sands.

The purpose of this study was to compare histologically determined cellularity and extracellular space to dynamic contrast-enhanced magnetic resonance imaging (DCE MRI)-based maps of a two-compartment model's parameters describing tumor contrast agent extravasation, specifically tumor extravascular extracellular space (EES) volume fraction (ve), tumor plasma volume fraction (vp) and volume-normalized contrast agent transfer rate between tumor plasma and interstitium (KTRANS/VT).Obtained ve, vp and KTRANS/VT maps were estimated from gadolinium diethylenetriamine penta-acetic acid DCE T1-weighted gradient-echo images at resolutions of 469, 938 and 2500 microm. These parameter maps were compared at each resolution to histologically determined tumor type, and the high-resolution 469-microm maps were compared with automated cell counting using Otsu's method and a color-thresholding method for estimated intracellular (Vintracellular) and extracellular (Vextracellular) space fractions.The top five KTRANS/VT values obtained from each tumor at 469 and 938 microm resolutions are significantly different from those obtained at 2500 microm (P.0001) and from one another (P=.0014). Using these top five KTRANS/VT values and the corresponding tumor EES volume fractions ve, we can statistically differentiate invasive ductal carcinomas from noninvasive papillary carcinomas for the 469- and 938-microm resolutions (P=.0017 and P=.0047, respectively), but not for the 2500-microm resolution (P=.9008). The color-thresholding method demonstrated that ve measured by DCE MRI is statistically similar to histologically determined EES. The Vextracellular obtained from the color-thresholding method was statistically similar to the ve measured with DCE MRI for the top 10 KTRANS/VT values (P.05). DCE MRI-based KTRANS/VT estimates are not statistically correlated with histologically determined cellularity.DCE MRI estimates of tumor physiology are a limited representation of tumor histological features. Extracellular spaces measured by both DCE MRI and microscopic analysis are statistically similar. Tumor typing by DCE MRI is spatial resolution dependent, as lower resolutions average out contributions to voxel-based estimates of KTRANS/VT. Thus, an appropriate resolution window is essential for DCE MRI tumor diagnosis. Within this resolution window, the top KTRANS/VT values with corresponding ve are diagnostic for the tumor types analyzed in this study.

Objective—To test the effects of computed tomography (CT) image plane and window settings on diagnostic certainty for CT characteristics associated with dysplastic elbow joints (elbow joint dysplasia) in dogs and to provide optimal display guidelines for these CT characteristics. Sample Population—CT images of 50 dysplastic elbow joints from 49 lame dogs and 10 elbow joints from 5 sound dogs. Procedures—CT image data were obtained in transverse, sagittal, and dorsal planes. Each plane was examined by use of 3 Hounsfield unit (HU) window settings. Two veterinary radiologists independently evaluated sets of CT images for evidence of 7 CT characteristics. Effect of elbow joint status, image plane, and window settings on diagnostic certainty for these CT characteristics was tested by use of a visual analogue scale. Results—Diagnostic certainty for abnormalities of the medial coronoid process (MCP) and radial incisure was highest in the transverse plane, subchondral defects or sclerosis of the trochlea humeri was highest in the dorsal plane, and joint incongruity was highest in the sagittal plane. Certainty for hypoattenuating subchondral defects or fissures was highest at 2,500 or 3,500 HUs, whereas certainty for subchondral sclerosis was highest at 1,500 HUs and lowest at 3,500 HUs. Conclusions and Clinical Relevance—Diagnostic certainty for CT characteristics of elbow joint dysplasia in dogs was affected by image display variables. Diagnostic certainty for altered subchondral bone density was primarily influenced by window settings, whereas structural MCP abnormalities and joint incongruity were influenced most by image plane.

Publisher Summary The chapter describes the history of the Morrow Plots and the effects of their experimental treatments on corn yield and soil variables. Statistical analyses of the complete yield and soil organic matter (SOM) record are presented. The chapter considers the trends in response to rotation and fertility treatments applied during the main phases of the Morrow Plots' history. Yield responses simultaneously reflect changing soil productivity levels and the immediate effects of improved technology and weather. By analyzing soil variables, soil organic C, total N, pH, P, and K throughout the trial's history, the chapter explores the long-term effects of treatments on the system's productive potential. Changes in the Morrow Plots' treatments have provided an empirical basis upon which one can evaluate the several phases in agricultural history. Findings have shown that production is greater where soil condition is maintained, and that use of mineral fertilizers has offset to large extent losses in soil productivity.

This paper makes explicit some of the assumptions underlying the view that infanticide is one of two (or more) alternative reproductive strategies utilized by adult male langur monkeys (genus Presbytis ). A mathematical model has been developed from these assumptions, and formulae derived which give the equilibrium proportion of infanticidal males expected in langur populations under any given set of reproductive and demographic conditions. Together with estimates of adult male reproductive success obtained from a previous analysis of langur infanticide, these formulae were then used to calculate the precise proportion of infanticidal males expected in natural populations of langurs characterized by specific average male tenures. Further, the number of generations required for such populations to reach their predicted equilibrium was estimated using a simple computer model of langur population dynamics. The present work has thus produced several quantitative predictions which are directly falsifiable with observational data obtainable from wild populations of langur monkeys. With only slight modification, the present model may also be applied to the numerous other primate and non-primate species whose mating systems include many of the same general features as that of langurs.

It is difficult to evaluate effectively the low-temperature stiffness of bituminous hot-poured crack sealants with existing test methods. The standard bending beam rheometer (BBR) was found to be inappropriate for testing soft bituminous-based hot-poured crack sealant, even at a temperature of -40°C. To address this issue, the moment of inertia of the tested beam was increased by doubling its thickness (from 6.35 mm to 12.7 mm). For the new beam dimensions, only 4% of the beam center deflection is due to shear, a value deemed acceptable for sealant evaluation and comparison. On this basis, the BBR stiffness of hot-poured sealants was obtained at several discrete temperatures between -10°C and -40°C to assess the repeatability of the method for the evaluation of the low-temperature stiffness of bituminous sealants. Ten different sealants were tested at -40°C; three of these 10 were further tested at -35°C, -30°C, -28°C, -25°C, and -20°C; and the three "hard" sealants were tested at -10°C. A minimum of three replicates were used. The coefficient of variation on the measured stiffness after 60 s of loading was always lower than 18%, with almost 75% of the measurements having a coefficient of variation less than 10%. A pairwise comparison showed that the modified BBR could be used to classify sealant products according to their measured stiffness. As to the effect of temperature, it was found that the stiffness varies exponentially with temperature in the range of -40°C to -20°C. A statistical analysis of the results indicated that the modified BBR method could be used to classify sealants based on low-temperature stiffness., Also published in "Transportation Research Board 84th Annual Meeting: Compendium of Papers CD-ROM.(2005)", Transportation Research Board 84th Annual Meeting, January 9-13, 2005, Washington, D.C., USA, Series: Journal of the Transportation Research Board; no. 1933