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1 Negative feedback may exist between plant species and their biotic soil communities. Two co-occurring native tallgrass species (Andropogon gerardii, a perennial grass, and Chamaecrista fasciculata, an annual legume) were reciprocally transplanted into pots containing soil from areas dominated by one of the species. Half of the soil derived from each area was microwaved to reduce soil fungi, resulting in four different 'soil types'. 2 Chamaecrista fasciculata plants were smaller when grown in their native soil vs. that from under A. gerardii, but were unaffected by microwaving (i.e. fungal reduction). Andropogon gerardii plants were shorter with fewer inflorescences in non-microwaved soil, with the poorest growth occurring in non-microwaved C. fasciculata soil. 3 Fungi were isolated from roots of A. gerardii growing in the different soil types. We tested whether the fungi found differed between the four soil types and whether any species characteristic of C. fasciculata soil were responsible for the poor growth of A. gerardii in this medium. 4 Fungi unique to the non-microwaved C. fasciculata soil type reduced tillering and caused an early reduction in growth of A. gerardii. These effects were partially ameliorated when potentially mycoparasitic fungi associated with A. gerardii were also included. By the end of the experiment, both fungal treatments increased above-ground biomass but greatly reduced below-ground biomass of A. gerardii compared with controls, suggesting that the exposure to potential fungal pathogens from C. fasciculata soil altered biomass allocation within plants. 5 There was no evidence of negative feedback between the prairie species and their own soils. However, fungi associated with Chamaecrista fasciculata were detrimental to A. gerardii, one of the dominant perennials in the surrounding area, and may facilitate the annual's long-term persistence. Arbuscular mycorrhizae did not ameliorate the pathogenic effects of these fungi as there was little colonization of A. gerardii roots in C. fasciculata soil. Keywords: arbuscular mycorrhizae (AM), biotic soil communities, negative feedback, soil pathogenic fungi

Summary 1. Metapopulation and metacommunity theories occupy a central role in ecology, but can be difficult to apply to plants. Challenges include whether seed dispersal is sufficient for population connectivity, the role of seed banks and problems with studying colonization and extinction in long-lived and clonal plants. Further, populations often do not occupy discrete habitat patches. Despite these difficulties, we present case studies to illustrate explicit integration of spatial and temporal data in plant ecology. 2. First, on the population level, we focused on two early successional species that lack discrete habitat patches. Multi-year data sets taken with a grid approach and simple models permit the analysis of landscape dynamics that reflect regional as well as local processes. Using Silene latifolia, we examined colonization. We found evidence for seed dispersal and connectivity among populations across a large landscape. With Helianthus annuus, a species with seed banks, we determined the degree to which landscape-level patterns of abundance were predicted by local processes (previous year recruitment at a site plus seed banks) vs. seed dispersal. Local processes dominated dynamics. 3. Second, at the community level, we utilized a landscape-level experiment to examine the influence of environmental gradients and spatial processes (dispersal limitation) on community composition during 18 years of succession. Throughout succession, environmental and spatial factors both contributed significantly to spatial variation in species composition (beta diversity). When connectivity was disrupted, space was the dominant factor underlying beta diversity, and this did not change over time. Across more connected communities, spatial effects diminished over succession as the importance of environmental factors increased, consistent with species-sorting metacommunity models. 4. Synthesis. Metapopulation/metacommunity concepts emphasize the interaction between space and time in ecological processes. Spatial processes, such as long-distance dispersal, play a crucial role in creating new populations. Temporal processes, including seed banks, may dominate dynamics at both local and regional scales. The relative importance of spatial vs. temporal processes changes as populations persist and communities assemble over time; these patterns may only emerge after many years. Integrating long-term data with spatial data is thus essential for understanding spatio-temporal patterns inherent in metapopulation and metacommunity theories. [ABSTRACT FROM AUTHOR]

Previously, we found that myometrial tumor necrosis factor-α (TNF-α) messenger RNA (mRNA) expression did not increase with preterm or term labor. To further investigate the role of TNF-α in human labor, we studied TNF-α receptor (TNFR1A and B) expression, regulation, and associated intracellular signaling pathways in human myometrial samples obtained both before and after the onset of labor and in primary cultures of uterine smooth muscle cells (USMCs). We found that the mRNA expression of both receptors increased with advancing gestation and labor and protein levels of TNFR1B were significantly higher in term laboring myometrial samples than in nonlabor controls. Tumor necrosis factor-ᾳ treatment of USMCs activated all mitogen-activated protein kinase (MAPK) subtypes and nuclear factor κ-B (NF-κB). The TNF-α induced increases in the expression of TNFR1B and prostaglandin H synthase type 2 were reduced by inhibitors of NF-κB and MAPKs, respectively. The TNF-α induced increase in interleukin 8 (IL-8) appeared to be independent of MAPK and NF-κB pathway. These data suggest that the uterus may become more sensitive to the action of TNF-α with advancing gestation and labor and that TNF-α acts via MAPK and NF-κB to promote labor-associated gene expression. [ABSTRACT FROM PUBLISHER]

Summary 1. The success of locally applied treatments for exotic weed control depends on the effectiveness of the method used and workers' abilities to find plants within infested sites. Detectability of exotic plants, however, depends on aspects of a plant's spatial distribution such as the number and size of patches. We lack an explicit examination of how incomplete detection affects the spread of exotic weeds under a range of realistic field conditions. 2. We developed a model of spatial spread of the exotic plant, Lespedeza cuneata, based on 3 years of data in a Kansas, USA, grassland. We then expanded and generalized the model to study how treatment intensity, spatial distribution of stems and detectability influenced control efforts. 3. When left untreated, occupancy and abundance were higher with randomly distributed infestations than with patchy distributions. Control treatments slowed spread, but only the most intense treatments reduced occupancy and abundance. 4. The greatest spread occurred when low detectability was accompanied with low treatment intensity because many small patches were not treated; this phenomenon was particularly common with random spatial distributions that initially lacked large, easily detectable patches. In contrast, high treatment intensity led to similarly slow spread for both spatial patterns and a range of detectability functions. 5. Synthesis and applications. We developed a model to simultaneously manipulate the spatial distribution of the invading plant, the intensity of control methods used to manage the population and the detectability of occupied areas at a site; different combinations of these three factors led to very different rates of exotic spread. Managers will reasonably try to implement intensive weed control. However, poor timing of treatments, for example, could lead to variation in treatment effectiveness. To maximize success, managers should explicitly consider detectability, especially where small patches are scattered throughout a site. To quantify the probability of detection, managers could perform multiple observer surveys; such information could help to determine the effort needed for effective control. Creating weed maps may increase the detection of existing patches from year to year, but workers would still need to search the entire site for new or previously undetected patches. [ABSTRACT FROM AUTHOR]

The ability of species to establish and persist in multiple habitats is of increasing importance given ecotone shifts following climate change. We examined a sedge (Carex blanda) that primarily occurs in woodlands in Kansas but is reported at low frequency in grasslands. At a Kansas, USA site, we found C. blanda occurred at similar densities across woodland, edge and grassland habitats. Plants differed in morphology: grassland plants were often broader and shorter than woodland plants. We transplanted cloned woodland plants into woodland, edge and grassland habitats. Transplanted plants developed similar height to naturally occurring plants, showing a plastic response. Further, seed number per plant was highest tot woodland plants transplanted to grasslands. Both naturally occurring and transplanted plants growing in the grassland also had low disease incidence, suggesting that pathogen presence is affected more by habitat than plant origin. Since light differed greatly among the habitats, we grew cloned plants from each habitat in low and high light in a growth chamber. Regardless of origin, high light plants were broader and shorter than plants growing at low light, again illustrating plasticity. Finally, we examined herbarium records. Ninety percent of Kansas specimens occurred in woodland or edge habitat. Although collection biases are possible, these results suggest a primarily woodland habitat of this species in Kansas. Our results showing "woodland" plants thriving in grasslands illustrates the broad adaptability of this species and raises cautions on simplistic interpretations of habitat distributions. [ABSTRACT FROM AUTHOR]

• Premise: Variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. To explore the adaptive significance of seedling emergence timing, it should be studied under realistic conditions and in the context of other traits that influence fitness. • Methods: In a common garden, we monitored maternal families from seed to flowering (including over winter) with intra- and interspecific competition. We assessed the effects of emergence timing and plant size on survival to anthesis in different genetic backgrounds and under varying competition. • Key Results: We found genetic variation for emergence (probability and timing), size, and survival to anthesis. We also found negative selection, both phenotypic and genetic, on emergence time, such that early emergers (day 8) had almost twice as great a predicted probability of surviving as later emergers (day 28). Size had strong positive effects on survival and, furthermore, the beneficial effects of early emergence may be mediated through size. Maternal family and competitive environment can also affect selection on emergence timing. • Conclusions: Our results indicate that early emergence is related to greater survival in wild sunflower, although there may be little direct selection on this trait; rather, its importance may be mediated by its effects on highly adaptive traits associated with size. Also, the effects of early emergence may vary across genetic backgrounds and competitive conditions, facilitating the maintenance of variation for this trait across a diverse landscape. [ABSTRACT FROM AUTHOR]

Overexpression of cyclin D1 is commonly observed in human cancers. The best-known association is with mantle cell lymphoma in which there is a t(11:14) translocation. We describe an unusual case of high-grade T cell lymphoma, presenting as rapidly enlarging, painless lymphadenopathy in an 80-year-old female. She died 13 months after presentation, having relapsed after chemotherapy. The lymph node showed diffuse effacement by blastic lymphoid cells, positive for T cell markers and cyclin D1. Molecular genetics investigations found t(11:14) translocation. There was definite T cell clonality demonstrating clonal rearrangement of both T cell receptor gamma and beta genes but no convincing evidence of B cell clonality. These data represent the first documented case where deregulation of the cyclin D1 expression has been implicated in human T cell lymphoreticular malignancy. [ABSTRACT FROM AUTHOR]

Abstract: Endometrial hyperplasia is considered present when the ratio of glandular to stromal tissue of the endometrium is greater than 1:1. Further differentiation is made into simple or complex hyperplasia with or without the presence of cytological atypia. Such changes are caused by excess or unopposed oestrogenic stimulation. Clinically endometrial hyperplasia is often asymptomatic but can present as abnormal uterine bleeding. Many cases are detected incidentally or following abnormal vaginal bleeding by an increase in the normal endometrial thickness on transvaginal ultrasonography (TVS). An endometrial biopsy can be obtained using a pipelle or at hysteroscopy, and examination of this allows a histological diagnosis. Cytological atypia mandates active intervention as its presence correlates with both a significant risk of progression to endometrial cancer as well as an increased rate of occult endometrial cancer. Hysterectomy is therefore the treatment of choice. The absence of cytological atypia confers a lower risk of malignant change. Thus management is more conservative. Progestogens are used to oppose the oestrogenic stimuli, coupled with ongoing surveillance. [Copyright &y& Elsevier]

1. Most population dynamics studies are geographically restricted, yet species ranges are large. We performed multiyear roadside surveys of the sunflower, Helianthus annuus, at two locations that differ in precipitation (eastern Kansas, KS; western Nebraska, NE). Our goals were to (i) document if there was geographic variation in dynamics and evaluate the role of habitat variables and the landscape matrix; (ii) determine the likely amount of occupiable habitat and (iii) explore the role of seed banks in dynamics. 2. Geographical variation: Occupancy and mean numbers of plants per occupied roadside unit were generally higher in NE than KS. Sunflower abundance was linearly related to spring precipitation in NE but not in KS. Soil disturbance was associated with increased occupancy and apparent colonization, and reduced apparent extinction. Variation in the landscape adjacent to roads had a larger effect on occupancy in KS than in NE. In KS, smaller populations were more prone to apparent extinction; NE results were more variable. Note that we refer to ‘apparent’ colonization or extinction because seed banks may persist even when above-ground plants are absent. 3. Occupiable habitat: 25% of the roadside was never occupied by sunflowers in KS, despite surveying for 6 years. An asymptotic limit to occupancy in NE was not apparent, but fewer years were surveyed. 4. Seed banks: Seed banks appear prevalent. The strongest evidence comes from a year following a spring drought in NE, when 100s to 1000s of plants were found in units that lacked plants the year before. 5. Synthesis. We found both geographical similarities (role of soil disturbance, seed banks) and differences (response to rainfall variation, importance of landscape matrix) in sunflower dynamics. Our work suggests that for appropriate species (including many weedy and invasive plants), replicate roadside surveys are an efficient way to evaluate geographic variation in dynamics, the landscape matrix and habitat characteristics across a broad geographic area. Such data help bridge the gap between broad-scale distributional studies and small experimental plot studies, and provide insights on the population dynamics that underlie species ranges. [ABSTRACT FROM AUTHOR]

1. Analysis of population trajectories is central to assessing risk in populations of conservation concern. In animal studies, researchers realize that probabilities of detection of individuals are often less than one. Plants can also escape detection due to dormancy, herbivory, or observer error, but such information is rarely incorporated into population studies. 2. We monitored a population of Asclepias meadii, a rare long-lived prairie perennial. Despite standardized methods, numbers of observed plants fluctuated greatly from 1992 to 2006. Individual plants often had periods of 1–5 years between initial and final sighting when no stems were found. To determine the actual population trajectories, we estimated rates of survival and population growth using mark-recapture models. We also estimated initial and resighting probabilities of detection. In 2007, we repeated surveys to identify reasons for low detection probabilities. 3. We estimated 95% annual survival and a population growth rate of 1.023. Probabilities of initial detection were low (typically from 0.120 to 0.311 depending on prairie burn treatment), whereas average probability of detection for marked plants was 0.728. 4. Comparisons of survival estimates from 15- and 8-year data sets revealed that survival estimates decline in the final years of a multi-year period, probably due to heterogeneity in encounter histories. 5. By conducting three different surveys in 2007, we found that both herbivory over a multiple-week period and observer error contributed substantially to gaps in detection. 6. Synthesis. Probabilities of detection that are less than one complicate interpretation of population dynamics, whether of mobile animals or inconspicuous plants. Our work illustrates three general points that could apply to many plant population studies: (i) mark-recapture models may provide insights on vital rates and population trajectories despite the extreme variability in count data that can arise because of low detectability, (ii) probabilities of initial detection can be quantified and can be considerably less than probabilities of resighting, and (iii) repeated surveys can help researchers determine the degree to which dormancy, herbivory, or observer error contribute to low probabilities of detection. Consideration of these points can improve the design and analysis of monitoring programs. [ABSTRACT FROM AUTHOR]

The demand for methods to translate information between spatial scales (i.e. size of observational units and the total area of study) has intensified given increased recognition that empirical data collection and practical applications occur at scales ranging from individual organisms to landscapes. For example, there has been considerable interest in “scaling-down” methods that have been successful at predicting fine-scale species’ distributions from coarse-scale distributional maps. Here, we describe the application of scaling-down methods to the estimation of colonization and extinction rates in metapopulations using long-term, large-scale data sets of two roadside plant species, Helianthus annuus and Silene latifolia. Fine-scale data collected from roadside populations were aggregated to generate data at several increasingly coarse scales. The relationships between occupancy, colonization, or extinction and the scale of measurement (scale-curves) were determined using the standard “fully-nested” method and the “stratified random sampling” method. Both methods were successful at predicting not only occupancy, but also the dynamic metapopulation processes of extinction and colonization (R2 values, averaged across species and methods, were 88.5, 69.3, and 88.8%, respectively, for occupancy, extinction, and colonization). Scaling-down generated more accurate predictions in Helianthus (average R2=88.4) compared to Silene (average R2=63.4), and in both species, scaling-down generated more accurate predictions for occupancy and colonizations compared to extinctions. This is one of the first demonstrations that dynamic processes are scalable, and provides a useful methodology for dealing with the logistical challenges of collecting fine-scale data over large geographic areas when studying metapopulation processes or range limits. [ABSTRACT FROM AUTHOR]

Dietary flaxseed has been shown to have potent antiatherogenic effects in rabbits. The purpose of the present study was to investigate the antiatherogenic capacity of flaxseed in an animal model that more closely represents the human atherosclerotic condition, the LDL receptor-deficient mouse (LDLrKO), and to identify the cellular mechanisms for these effects. LDLrKO mice were administered a regular diet (RG), a 10% flaxseed-supplemented diet (FX), or an atherogenic diet containing 2% cholesterol alone (CH) or supplemented with 10% flaxseed (CF), 5% flaxseed (CF5), 1% flaxseed (CF1), or 5%, coconut oil (CS) for 24 wk. LDLrKO mice fed a cholesterol-supplemented diet exhibited a rise in plasma cholesterol without a change in triglycerides and an increase in atherosclerotic plaque formation. The CS mice exhibited elevated levels of plasma cholesterol, triglycerides, and saturated fatty acids and an increase in plaque development. Supplementation of the cholesterol-enriched diet with 10% (wt/wt) ground flaxseed lowered plasma cholesterol and saturated fatty acids, increased plasma ALA, and inhibited plaque formation in the aorta and aortic sinus compared with mice fed a diet supplemented with only dietary cholesterol. The expression of proliferating cell nuclear antigen (PCNA) and the inflammatory markers IL-6, mac-3, and VCAM-1 was increased in aortic tissue from CH and CS mice. This expression was significantly reduced or normalized when flaxseed was included in the diet. Our results demonstrate that dietary flaxseed can inhibit atherosclerosis in the LDLrKO mouse through a reduction of circulating cholesterol levels and, at a cellular level, via antiproliferative and anti-inflammatory actions. [ABSTRACT FROM AUTHOR]

1 Seed banks are important to many plant populations, yet we lack clear understanding of how environmental factors promote seed bank formation. We experimentally varied seed density, and soil disturbance size and timing, to examine the formation of seed banks and the resulting population dynamics in wild annual sunflowers ( Helianthus annuus). Seed density treatments reflected the expected increase in seed production of individual wild sunflowers due to hybridization with Bt-transgenic crop sunflowers. Soil disturbances of two sizes (large and small) were applied either before or after seed dispersal. We followed the experimental plots for 21/2 years measuring seedling emergence, seeds in the soil, and reproduction, while preventing additional seed input. We assessed seed bank formation by the numbers of emergent seedlings and seeds in the soil. 2 Soil disturbances, regardless of timing, were required for successful germination and reproduction of wild sunflowers. Large disturbances resulted in greater seedling emergence and reproduction than small disturbances. Reproduction on small disturbance plots was low, due to low seedling survival. Higher seed density resulted in more seedlings only in large-disturbance plots. 3 Post-dispersal disturbances led to significant seed bank formation. This effect was greater for large, post-dispersal disturbances. Higher seed density increased seed bank size only in the presence of large, post-dispersal disturbances. 4 Negative density-dependence in seedling mortality and reproduction meant that there was no effect of the high seed density treatment on reproduction. Thus the positive effects of increased seed bank size on population growth were tempered by density-dependence. To assess fully the impact of seed banks on population growth, studies should continue beyond the seedling stage. 5 Our results suggest increased seed production of individual sunflowers resulting from crop transgenes would be unlikely to increase population growth on the scale of small patches. Increased seed production could result in dispersal of seeds across larger areas, and thus could lead to larger seed banks in disturbed environments and an increased prevalence of sunflowers across the landscape. These results are relevant to other annual species, especially those with transgenic crop relatives. [ABSTRACT FROM AUTHOR]

Abstract: Endometrial hyperplasia is defined as an increase in the glandular to stromal tissue ratio to more than 1. Further classification derives from architectural and cytological features. It typically results from excess or unopposed oestrogenic stimulation. Although it is often asymptomatic, endometrial hyperplasia can present with abnormal uterine bleeding. Transvaginal ultrasonography (to measure endometrial thickness), endometrial sampling and hysteroscopy are common investigations used to diagnose this condition. Management depends on cellular atypia, the presence of which confers a high risk of concurrent or subsequent endometrial cancer. Such cases should usually therefore be treated with hysterectomy. The absence of atypia allows a conservative approach, usually with progestogen therapy combined with ongoing surveillance. [Copyright &y& Elsevier]

“On-demand” regulation of gene expression is a powerful tool to elucidate the functions of proteins and biologically-active RNAs. We describe here three different approaches to the regulation of expression or activity of genes or proteins. Promoter-based regulation of gene expression was among the most rapidly developing techniques in the 1980s and 1990s. Here we provide basic information and also some characteristics of the metallothionein-promoter-based system, the tet-off system, Muristerone-A-regulated expression through the ecdysone response element, RheoSwitch®, coumermycin/novobiocin-regulated gene expression, chemical dimerizer-based promoter activation systems, the “Dual Drug Control” system, “constitutive androstane receptor” based regulation of gene expression, and RU486/mifepristone-driven regulation of promoter activity. A large part of the review concentrates on the principles and usage of various RNA interference techniques (RNAi: siRNA, shRNA, and miRNA-based methods). Finally, the last part of the review deals with historically the oldest, but still widely used, methods of temperature-dependent regulation of enzymatic activity or protein stability (temperature-sensitive mutants). Due to space limitations we do not describe in detail but just mention the tet-regulated systems and also fusion-protein-based regulation of protein activity, such as estrogen-receptor fusion proteins. The information provided below is aimed to assist researchers in choosing the most appropriate method for the planned development of experimental systems with regulated expression or activity of studied proteins. [ABSTRACT FROM AUTHOR]

1 Small, isolated populations at species’ borders have been postulated to be less likely to have specialist pathogens and predators. Field and herbarium surveys were thus used to determine if two pathogens (a smut and a rust) and a pre-dispersal seed predator were less common at the western range limit of the forest sedge Carex blanda in Kansas, USA . 2 Host plant size, reproduction and density did not decline at the western border of the range. In fact, plants at two western sites had unusually large size and seed production. 3 Host populations at the edge of the range were more likely to be disease-free or lack the pre-dispersal seed predator. Where the smut, seed predator and rust were found, the proportion of infected or infested plants was not related to longitude, latitude or percentage forest cover. 4 More of the peripheral populations lacked the smut than the rust, as expected given the more localized nature of smut spore dispersal and the limited period when smut infection can occur. 5 In the adjacent, more highly forested state of Missouri, there were no geographical patterns in the incidence of the smut or seed predator in herbarium data. 6 The smut and rust increased in frequency over the 129-year span of herbarium collections. 7 Although field and herbarium distributional data were not identical (for example, smut infection was found much farther west in the field than in the herbarium data), the qualitative agreement between the two data sets suggests herbarium data can be used more broadly for studies of natural enemy distributions. 8 Limited dispersal by pathogens and seed predators is probably the reason why small, isolated western populations were less likely to have natural enemies. Peripheral host populations may thus have different ecological and evolutionary trajectories compared with more central populations. This conclusion, as well as the considerable variation among peripheral populations, is relevant to geographical studies of co-evolution and to research on climatic effects on plants inhabiting ecotonal regions. [ABSTRACT FROM AUTHOR]

Low levels of fruit production are thought to threaten the persistence of Asclepias meadii (Mead's milkweed) populations. We evaluated four hypotheses explaining the low fruit production in one population (herbivory, pollen limitation, resource shortages and rainfall) by collecting within-year data on stem size, levels of fruit initiation and mature fruit production and by considering among-year data on total fruit production and annual rainfall. In 2002, severe herbivory resulted in the death of about 63% of the population's flowering stems. Managers could increase fruit production by protecting stems from mammal herbivory. A path analysis revealed that leaf width and the number of fruits initiated were the most important predictors of mature fruit production. In 1991-2002 the previous year's total annual precipitation significantly affected the total number of fruits produced only in years of burning. Increasing the persistence of these long-lived plants to years of greater rainfall could have the most dramatic effects on fruit production and on survival of the species. [ABSTRACT FROM AUTHOR]

Journal of Ecology (2003) 91, 987–998 [ABSTRACT FROM AUTHOR]

hagen s., bugge c. & alexander h. (2003) Journal of Advanced Nursing 44(5), 461–468 Psychometric properties of the SF-36 in the early post-stroke phase Patients who have had a stroke are a large group in whom long-term disability is common and therefore impaired general health is likely. The Short Form 36 (SF-36) is a popular measure of general health that has been used with this patient group, but not all aspects of its psychometric properties have been established for use in this context, and its use in the early post-stroke phase has been neglected. To examine the reliability, validity and sensitivity to change of the SF-36 (UK version I) in patients in the early post-stroke period. A prospective, observational study of stroke outcomes was carried out. From May 1996 to April 1997, patients who had had a stroke were identified by 24 general practices in Scotland and were recruited within 1 month of their stroke, whether in hospital or at home. Outcome measures including the SF-36 were administered at one, 3 and 6 months after onset. The internal consistency of the eight subscales at all three time-points was good except for 1 month Vitality ( α = 0·6824) and 3 month General Health ( α = 0·6650), which were borderline in comparison with the criterion value of 0·7. Construct validity was adequate overall, although correlations between Role Physical and General Health and the Barthel Index and Canadian Neurological Scale were lower than hypothesized. Most SF-36 subscales were sensitive to change between 1 and 3 months post-stroke, but none detected change between 3 and 6 months. There were some practical problems in using the SF-36 in an acutely unwell stroke population. However, analysis of psychometric properties suggested that most of the subscales were adequately reliable and valid. Sensitivity to change was poorer in the later stages of the study. [ABSTRACT FROM AUTHOR]

Statistical similarities exist between estimating numbers of cryptic animals and of inconspicuous plants. Without flowers, Mead's milkweed (Asclepias meadii) is an unobtrusive prairie plant, and most plants flower irregularly. We used maximum likelihood to estimate probabilities of survival and detection for milkweeds in annual censuses during 1992-1999. Initially, we assumed no recruitment and fit models to all data and to flowering plants only. Because plants were marked when located, probabilities of resighting exceeded those of initial discovery. Plants were most likely to flower and be detected in years when the prairie was burned. We marked 177 plants in eight years but estimated the 1992 population to be 337 or 191 plants with 166 or 121 surviving to 1999, depending on the data set. Thus, estimated population size exceeded number of plants seen. Estimated annual survival probability was generally ≥ 0.95, but aggregate survival over eight years predicted rapid extinction without recruitment. When we included recruitment, estimates of survival changed little, and estimated population size varied between 118 and 147 individuals. Discovery of new plants in two additional years (2000 and 2001) appeared to be consistent with required recruitment, but simple counts of these plants did not track population trends. [ABSTRACT FROM AUTHOR]

The article presents a study that aims to measure changes in frequencies the crop-specific genetic markers in wild sunflower in eastern Kansas. It offers details of the method of the study that observes three allozyme markers in three artificial populations. It outlines the result which suggests that ecological data can be useful for estimating the frequencies of crop genes after crop-wild hybridization in sunflowers.

Assessing the effects of seed density on the population dynamics of wild plant species with crop relatives will be vital in determining the potential effects of introducing traits into wild populations as a result of crop-to-wild gene flow. We examined experimental sunflower (Helianthus annuus) patches in eastern Kansas to determine the effects of seed density and predation on seedling recruitment and seed production in the next generation. High seed density treatment plots had significantly more seedlings and adult plants than did low seed density treatment plots. Overwinter vertebrate seed predator exclusion treatments resulted in increases in plant density compared to plots in which vertebrates were not excluded. Control patches (no seeds added) contained virtually no plants. Head production and estimated total seed production for a patch were not statistically different among treatments (excluding control plots). Although initial seed density and vertebrate post-dispersal seed predation do appear to have effects on seedling recruitment, neither appear to be limiting seed production of competing adult plants. Therefore, variation in seed densities (over the range examined) may have limited effects on local population dynamics. It is important to note that the choice of seed densities may affect the results obtained: the seed densities used in this study may, in retrospect, be higher than in the small roadside populations typical in eastern Kansas, yet other natural sites have much larger densities. Further, the effects of increased seed density at a local site may have other important effects such as altering metapopulation dynamics through increased long-distance dispersal or increased local seed bank size. [ABSTRACT FROM AUTHOR]

Focuses on a study which examined seed size variations and its relationship to predation with common sunflower, Helianthus annuus. Materials and methods; Results; Discussion.

Focuses on a study which examined the survivorship and flowering of Mead's milkweed, known as Asclepias meadii. Difficulties in the detection of the prairie perennial; Factors affecting the population; Methodology of the study; Results and discussion.

The effect of seed and seedling mortality on plant population dynamics depends on the degree to which the growth and reproduction of surviving individuals can compensate for the deaths that occur. To explore this issue, we sowed seeds of the annual Kummerowia stipulacea at three densities in sunken pots in the field, which contained either field soil, microwaved field soil, or microwaved field soil augmented with oospores of three Pythium species. High sowing density reduced seedling establishment and seedling size, but these effects were independent of the soil treatment. In the oospore-augmented soil, seed and seedling survival was low. The surviving plants were initially smaller but, at maturity, average plant size was greatest in the oospore-augmented soil, compared to the other treatments. Total population seed production was unaffected by soil treatment, suggesting that the effect of disease was limited to the seedling stage, with surviving plants released from intraspecific competition. To test the hypothesis that the surviving plants in the oospore-augmented soil were more disease-resistant, seeds from each of the sowing density-soil type treatments were sown in a growth chamber inoculation study. No evidence for selection for resistance was found. A second inoculation experiment revealed that oospore inoculum reduced plant numbers and mass regardless of whether field or microwaved soil was used, suggesting that results from the field experiment were not dependent on the use of microwaved soil. The findings of this study indicate that the ecological effects of disease on individual plants and on plant populations are not necessarily equivalent. [ABSTRACT FROM AUTHOR]

Examines the dynamics of the plant-fungus interaction in a population of the dioecious host plant Silene alba in Virginia. Details on how the anther-smut fungus Ustilago violacea sterilizes S. alba; Relationship of the number of spores deposited on male flowers to the number and proportion of diseased flowers close by; Effects of plant recruitment and disease-spread on the fate of infected populations.

Examines pollination limitation in a population of Silene alba infected by the anther-smut fungus Ustilago violacea. Higher number of flowers maturing fruit and number of seeds per fruit in hand-pollinated female Silene compared to controls; Sterile spore-producing flowers caused by Ustilago infection.

Disease severity and crop yield were compared in monocultures and mixtures of two wheat cultivars, one susceptible and one resistant to Puccinia graminis f. sp. tritici. Part of each plot was inoculated and part treated with fungicide. Rust severity was inversely related to the proportion of resistant plants present. Weight of grain in 100 heads of the susceptible cultivar increased as the amount of rust decreased. The susceptible cultivar yielded less than the resistant cultivar in monoculture, but was a stronger competitor in mixtures. Competitive abilities of the cultivars were independent of severity of rust in the mixtures studied. [ABSTRACT FROM AUTHOR]

Naturally established individuals of Plantago lanceolata with the inflorescence disease caused by Fusarium moniliforme var. subglutinans had more inflorescences and were more likely to be male-sterile than healthy plants. Half-sib families planted in the field varied in the percentage of diseased plants, the number of inflorescences per plant, the incidence of male-sterility, and the pattern of inflorescence phenology. The rankings of families with respect to disease incidence was, however, not simply related to their reproductive phenotypes. Plants derived from field genotypes with a history of disease were slightly more likely to become diseased than plants derived from healthy genotypes. Inflorescence infection was more severe on plants derived from genotypes with a known history of disease. Since the fungus reduces seed production in the plants it infects, differential incidence of disease based on plant phenotype and genotype may have ecological and evolutionary consequences for the host population. [ABSTRACT FROM AUTHOR]

Disese induced by Albugo candida or Peronospora parasitica was found to have significant effects on the survival and reproductive output of affected individuals of Capsella bursa-pastoris. The time of infection by either pathogen was of considerable importance in determining the ultimate effect of disease. Systemic (primary) infection of seedling plants led to a high degree of mortality (88%) prior to reproductive maturity, however, localized or systemic secondary infection did not affect survival. Fruit production of surviving infected plants was negatively correlated with disease severity. [ABSTRACT FROM AUTHOR]