bluuebunny/crossref_metadata_2025 huggingface dataset:
Rattail Fescue (Vulpia Myuros) Control in Chemical-Fallow Cropping Systems
Authors: Jemmett Eric D. , Thill Donald C. , Rauch Traci A. , Ball Daniel A. , Frost Sandra M. , Bennett Larry H. , Yenish Joseph P. , Rood Rodney J.
Published: September 2008

Rattail fescue infestations are increasing in dryland conservation-tillage winter wheat cropping systems in the inland Pacific Northwest (PNW) region of Idaho, Oregon, and Washington. Rattail fescue typically is controlled with cultivation in conventional tillage farming systems. However, reduced soil disturbance has allowed infestations to increase significantly. The objectives of this research were to determine the effectiveness of glyphosate rates and application timings on control of rattail fescue during a chemical-fallow period in winter wheat cropping systems. Chemical-fallow field studies were conducted during two growing seasons at nine sites throughout the PNW. Glyphosate was applied early POST, late POST, or sequentially in early plus late POST timings. Additionally, paraquat + diuron was applied early and late POST alone or sequentially with glyphosate. Sequential application treatments (glyphosate followed by [fb] glyphosate, paraquat + diuron fb glyphosate, and glyphosate fb paraquat + diuron) controlled rattail fescue (∼ 94% in Idaho and Washington, ∼ 74% in Oregon) and reduced panicle number (∼ 85% in Idaho, ∼ 30% in Oregon and Washington) equivalent to or greater than one-time treatments. Rattail fescue control and panicle reduction generally increased with increasing rates of glyphosate within application timings. Paraquat + diuron usually provided similar control and reduced rattail fescue panicle number compared to glyphosate treatments applied at the same application timing. Although not completely effective, sequential applications of either glyphosate or paraquat + diuron, fb glyphosate will provide effective control during chemical fallow.
Rotational Crops Response to Soil Applied Trifloxysulfuron
Authors: Minton Bradford W. , Matocha Mark A. , Senseman Scott A.
Published: September 2008

Research was conducted along the Texas Gulf Coast in 1998 and 1999 to determine trifloxysulfuron soil persistence and potential injury to corn, grain sorghum, rice, and soybeans. Trifloxysulfuron was applied at 0, 7.5, and 60 g/ha to plots 0, 15, 30, 60, and 90 d prior to planting of crops. Corn and grain sorghum were more sensitive to trifloxysulfuron than rice and soybeans when planted 0 to 90 d after treatment (DAT). Trifloxysulfuron was more persistent at the San Patricio location than at Fort Bend, which had a lower soil pH. However, no phytotoxicity or plant-height reduction was observed at the four locations with corn, grain sorghum, rice, and soybeans planted 209 to 312 DAT. Greenhouse data showed that neither corn nor sunflower planted 209 to 312 DAT were adversely affected by either rate of trifloxysulfuron. Trifloxysulfuron applied to cotton up to 20 g/ha the previous year should not cause phytotoxicity to corn, grain sorghum, rice, or soybeans when grown in rotation under soil and weather conditions similar to those in these studies.
Control of Rhizome Johnsongrass (Sorghum Halepense) in Sugarcane with Trifloxysulfuron and Asulam
Authors: Dalley Caleb D. , Richard Edward P.
Published: September 2008

It has been suggested that trifloxysulfuron might increase the efficacy of asulam for control of johnsongrass. Container and field studies were conducted to determine the efficacy of POST applications of trifloxysulfuron and asulam for johnsongrass control in sugarcane. Asulam was applied at 460 and 920 g ai/ha to container-grown johnsongrass plants, with and without 8 g ai/ha of trifloxysulfuron. Combinations of asulam and trifloxysulfuron generally reduced johnsongrass height, rhizome length, and biomass more than when either was applied alone. Results suggested that combinations of asulam and trifloxysulfuron were synergistic in their control of johnsongrass biomass 8 wk after treatment. In a sugarcane field heavily infested with rhizome johnsongrass, asulam was applied at 1,800, 2,800, and 3,700 g/ha with and without trifloxysulfuron at 16 g/ha. Asulam plus trifloxysulfuron generally controlled johnsongrass more effectively than either herbicide alone. The control of johnsongrass with asulam at 1,800 g/ha resulted in an increase in sugar yield of more than twice that in the nontreated control. Sugar yield increased further when asulam was applied at 2,800 g/ha or combined with trifloxysulfuron, but application of trifloxysulfuron alone did not increase yield. Combinations of asulam and trifloxysulfuron might slow the spread of rhizome johnsongrass enough to allow an increased number of ratoon crops before sugarcane fields need to be replanted.
Annual Broadleaf Control With KIH-485 in Glyphosate-Resistant Furrow-Irrigated Corn
Authors: King Steven R. , Garcia Josefina O.
Published: September 2008

Weed management in furrow-irrigated corn is challenging because of weed emergence associated with each irrigation event. Residual herbicides that provide extended in-season control of a broad spectrum of weeds would be beneficial to producers in this system. Field experiments were conducted in 2005 and 2006 in Yellowstone County, Montana, to evaluate KIH-485 for the control of velvetleaf, kochia, and wild buckwheat in furrow-irrigated corn. KIH-485 was applied at three rates (166, 209, and 250 g ai/ha) and two timings (PRE and POST) and compared to standard rates of S-metolachlor, acetochlor, and pendimethalin. All PRE treatments were applied alone, whereas POST treatments were combined with 1,261 g ae/ha of glyphosate. All rates of KIH-485 applied PRE controlled velvetleaf and kochia 88% or greater at 4 mo after planting (MAP). Wild buckwheat was controlled 89% or greater with the high rate of KIH-485 applied PRE, which was superior to control achieved with any other PRE herbicide treatment. Velvetleaf, kochia, and wild buckwheat were controlled 91% or greater when any herbicide treatment was combined with glyphosate. Corn treated with KIH-485 applied at 209 g ai/ha PRE produced yield that was similar to that produced by the weed-free control in both years.
Weed Resistance Monitoring in the Canadian Prairies
Authors: Beckie Hugh J. , Leeson Julia Y. , Thomas A. Gordon , Brenzil Clark A. , Hall Linda M. , Holzgang Grant , Lozinski Chris , Shirriff Scott
Published: September 2008

Weed resistance monitoring has been routinely conducted in the Northern Great Plains of Canada (Prairies) since the mid-1990s. Most recently, random surveys were conducted in Alberta in 2001, Manitoba in 2002, and Saskatchewan in 2003 totaling nearly 800 fields. In addition, nearly 1,300 weed seed samples were submitted by growers across the Prairies between 1996 and 2006 for resistance testing. Collected or submitted samples were screened for group 1 [acetyl-CoA carboxylase (ACCase) inhibitor] and/or group 2 [acetolactate synthase (ALS) inhibitor] resistance. Twenty percent of 565 sampled fields had an herbicide-resistant (HR) wild oat biotype. Most populations exhibited broad cross-resistance across various classes of group 1 or group 2 herbicides. In Manitoba, 22% of 59 fields had group 1–HR green foxtail. Group 2–HR biotypes of kochia were documented in Saskatchewan, common chickweed and spiny sowthistle in Alberta, and green foxtail and redroot pigweed in Manitoba. Across the Prairies, HR weeds are estimated to occur in fields covering an area of nearly 5 million ha. Of 1,067 wild oat seed samples submitted by growers and industry for testing between 1996 and 2006, 725 were group 1 HR, 34 group 2 HR, and 55 groups 1 and 2 HR. Of 80 submitted green foxtail samples, 26 were confirmed group 1 HR; most populations originated from southern Manitoba where the weed is most abundant. Similar to the field surveys, various group 2–HR biotypes were confirmed among submitted samples: kochia, wild mustard, field pennycress,Galiumspp., common chickweed, and common hempnettle. Information from grower questionnaires indicates patterns of herbicide usage are related to location, changing with cropping system. Two herbicide modes of action most prone to select resistance, groups 1 and 2, continue to be widely and repeatedly used. There is little evidence that growers are aware of the level of resistance within their fields, but a majority have adopted herbicide rotations to proactively or reactively manage HR weeds.
Field Presence of Glyphosate-Resistant Horseweed (Conyza Canadensis), Common Lambsquarters (Chenopodium Album), and Giant Ragweed (Ambrosia Trifida) Biotypes with Elevated Tolerance to Glyphosate
Authors: Westhoven Andrew M. , Davis Vince M. , Gibson Kevin D. , Weller Stephen C. , Johnson William G.
Published: September 2008

Late-season field surveys conducted in Indiana from 2003 to 2005 showed that common lambsquarters and giant ragweed plants were present in 11 and 22%, respectively, of randomly sampled soybean fields that also contained glyphosate-resistant horseweed. In the fall of 2005 and 2006, seed from 13 common lambsquarters and 22 giant ragweed populations were collected from previously surveyed fields that had confirmed glyphosate-sensitive or -resistant horseweed. The objective of this study was to determine whether the presence of glyphosate-resistant horseweed was correlated with the presence of common lambsquarters and giant ragweed biotypes with elevated tolerance to glyphosate. Through a series of greenhouse screens, 57% of common lambsquarters and 31% of giant ragweed populations collected from fields that had glyphosate-resistant horseweed expressed elevated levels of glyphosate tolerance. However, elevated tolerance to glyphosate was expressed by 33% of giant ragweed and 100% of common lambsquarters populations collected in fields that had glyphosate-sensitive horseweed. Therefore, under the parameters of this experiment and through different types of analyses, we concluded there was not a strong correlation between the late-season presence of glyphosate-resistant horseweed and common lambsquarters and giant ragweed populations with elevated glyphosate tolerance in the same field. A number of the weed populations expressed significant stunting from exposure to glyphosate, but were able to resume growth. Thus, researchers should evaluate plant regrowth in addition to biomass suppression when making assessments of glyphosate resistance in weed populations through greenhouse and field screening.
Influence of Hexazinone on ‘Tifton 85’ Bermudagrass Growth and Forage Quality
Authors: Wilder B. , Ferrell J.A. , Sellers B.A. , MacDonald G.E.
Published: September 2008

Smutgrass is a clump-type grassy weed that is commonly found in grazed pastures throughout the Southeast. Currently, the only herbicide registered for control of smutgrass is hexazinone and it is unknown if hexazinone negatively impacts bermudagrass forage growth and quality. Experiments were conducted to determine the impact of hexazinone rate on bermudagrass yield and crude protein. All rates of hexazinone reduced bermudagrass yield at 4 wk after treatment (WAT). From 6 to 12 WAT, no bermudagrass yield reduction was observed except for the 2 kg/ha treatment. The yield reducing effects of hexazinone were transitory at the 0.5 and 1.0 kg/ha rates; cumulative yield for the season was reduced by 17 and 23%, respectively. Although yield was negatively influenced by hexazinone, crude protein generally increased in a linear fashion with increased hexazinone rate.
Integrating Flea Beetles (Aphthonaspp.) with Herbicide and Grasses for Leafy Spurge (Euphorbia Esula) Management
Authors: Joshi Ankush
Published: September 2008

Most management tactics used against leafy spurge are not economical, practical, or efficacious when used alone. Combinations of the biological control agent,Aphthonabeetles, the herbicide imazapic (105 g/ha), and interseeded native grass species were evaluated for leafy spurge management at two sites: Sheyenne National Grassland and Ekre Grassland Preserve in North Dakota during 2001 to 2005. At the Sheyenne site, over a 5-yr study period, leafy spurge was reestablishing its stem density after a single application of imazapic, but stand suppression was maintained to < 11 stems/m2when management combined imazapic withAphthonaor interseeding of native grasses.Aphthonabeetles established at the Sheyenne site, but declined as leafy spurge density decreased. However, the remainingAphthonapopulation continued to suppress leafy spurge density. Leafy spurge stem control was successfully maintained for 3 yr byAphthonaand grass competition without repetition of the imazapic treatment. Leafy spurge root dry weights were reduced by 66% (< 111g/m2) in the insect plots during this period. At the Ekre site, similar results were observed for the first 3 yr. However, in the fourth yr, a failure of biological control agents to establish resulted in the resurgence of leafy spurge. During this study, lowerAphthonaemergence was observed in imazapic-treated plots, possibly due to reduced leafy spurge density.
Effects of Row Pattern Configurations and Reduced (1/2×) and Full Rates (1×) of Imazapic and Diclosulam for Control of Yellow Nutsedge (Cyperus Esculentus) in Peanut
Authors: Besler Brent A. , Grichar W James , Senseman Scott A. , Lemon Robert G. , Baughman Todd A.
Published: September 2008

Field studies were conducted from 2000 to 2002 to evaluate yellow nutsedge control and peanut yield when diclosulam and imazapic were applied at the rate recommended by the manufacturer (1×) and reduced (1/2×) rates in single and twin-row planting patterns. In 2001, both diclosulam and imazapic applied to the twin-row pattern at the full and reduced rate provided better yellow nutsedge control than herbicide applications to the single-row spacing. Because of excessive rainfall in 2002, yellow nutsedge control was considerably reduced with all treatments. Imazapic at the full rate (71 g/ha) controlled yellow nutsedge 80 to 96% in the twin-row pattern, and 79 to 86% in single-row spacings. Yellow nutsedge control was less than 65% when diclosulam and imazapic were applied at the reduced rate. The twin-row configuration yielded higher than the single-row pattern when averaged across herbicides in 1 yr. All herbicide treatments enhanced yield relative to the nontreated control, except the reduced rate of imazapic in 2002. This study revealed that to fully maximize yellow nutsedge control, the full rate of either imazapic or diclosulam should be applied to peanuts planted in a single or twin-row spacing. However, these treatments may not necessarily increase peanut yields.
Mesosulfuron-Resistant Italian Ryegrass (Lolium Multiflorum) Biotype from Texas
Authors: Ellis Andrew T. , Morgan Gaylon D. , Mueller Thomas C.
Published: September 2008

Acetolactate synthase (ALS)–inhibiting herbicides are often used to control Italian ryegrass in winter wheat in Texas. An Italian ryegrass biotype near Waco, TX was evaluated for resistance to mesosulfuron in field and greenhouse experiments. Control of the biotype in the field was less than 10% with the label rate of mesosulfuron (15 g ai/ha). Greenhouse studies confirmed that the biotype was resistant to mesosulfuron; control of the biotype was less than 35% at 120 g ai/ha mesosulfuron. The herbicide dose required to reduce plant biomass of a susceptible and the Waco biotype by 50% (GR50) was 1.3 and 31 g ai/ha, respectively, indicating a resistance level of 24-fold in the Waco biotype. However, the Waco biotype was controlled with the acetyl-CoA carboxylase inhibitors diclofop and pinoxaden.
Chemical Management of Cut-Leaved Teasel (Dipsacus Laciniatus) in Missouri
Authors: Bentivegna Diego J. , Smeda Reid J.
Published: September 2008

Cut-leaved teasel is an invasive weed along highway corridors and is classified noxious in four states, including Missouri. Few herbicides have been examined for cut-leaved teasel control. Herbicides were evaluated for efficacy on established plants and residual activity for suppressing seedling emergence. Various growth regulator herbicides, amino acid inhibitors, and paraquat were applied on established teasel at two locations in central Missouri in fall 2003 and spring 2004, and two additional locations in fall 2004 and spring 2005. At 2 wk after treatment (WAT), paraquat resulted in the highest injury of teasel (85%), but injury declined over time. At 4 WAT, teasel control was most consistent with dicamba + diflufenzopyr applied in spring, ranging from 75 to 94% control. At 8 wk, glyphosate, dicamba + diflufenzopyr, metsulfuron-methyl, imazapyr, and combinations of growth regulator herbicides with 2,4-D were most effective, with teasel control from 86 to 100%. Control with 2,4-D alone was inconsistent; sulfosulfuron, sulfometuron-methyl, and paraquat were ineffective. Residual herbicides did not reduce teasel seedling emergence the following year. A number of herbicides were effective in managing emerged plants but reinfestations of treated sites is likely, even with the residual herbicides used in this research.
Quiescent Human Hematopoietic Stem Cells in the Bone Marrow Niches Organize the Hierarchical Structure of Hematopoiesis
Authors: Yahata Takashi , Muguruma Yukari , Yumino Shizu , Sheng Yin , Uno Tomoko , Matsuzawa Hideyuki , Ito Mamoru , Kato Shunichi , Hotta Tomomitsu , Ando Kiyoshi
Published: September 2008

Hematopoiesis is a dynamic and strictly regulated process orchestrated by self-renewing hematopoietic stem cells (HSCs) and the supporting microenvironment. However, the exact mechanisms by which individual human HSCs sustain hematopoietic homeostasis remain to be clarified. To understand how the long-term repopulating cell (LTRC) activity of individual human HSCs and the hematopoietic hierarchy are maintained in the bone marrow (BM) microenvironment, we traced the repopulating dynamics of individual human HSC clones using viral integration site analysis. Our study presents several lines of evidence regarding the in vivo dynamics of human hematopoiesis. First, human LTRCs existed in a rare population of CD34+CD38− cells that localized to the stem cell niches and maintained their stem cell activities while being in a quiescent state. Second, clonally distinct LTRCs controlled hematopoietic homeostasis and created a stem cell pool hierarchy by asymmetric self-renewal division that produced lineage-restricted short-term repopulating cells and long-lasting LTRCs. Third, we demonstrated that quiescent LTRC clones expanded remarkably to reconstitute the hematopoiesis of the secondary recipient. Finally, we further demonstrated that human mesenchymal stem cells differentiated into key components of the niche and maintained LTRC activity by closely interacting with quiescent human LTRCs, resulting in more LTRCs. Taken together, this study provides a novel insight into repopulation dynamics, turnover, hierarchical structure, and the cell cycle status of human HSCs in the recipient BM microenvironment.

Disclosure of potential conflicts of interest is found at the end of this article.
Differential impact of adipokines derived from primary adipocytes of wild-type versus streptozotocin-induced diabetic rats on glucose and fatty acid metabolism in cardiomyocytes
Authors: Palanivel Rengasamy , Vu Vivian , Park Min , Fang Xiangping , Sweeney Gary
Published: September 2008

The causal relationship between obesity and cardiovascular disease is extensively acknowledged; however, the exact mechanisms linking obesity and heart failure remain unclear. Here, we investigated the influence of adipokines derived from primary adipocytes on glucose and fatty acid uptake and metabolism in isolated primary cardiomyocytes. Either co-culture of these cell types or incubation with adipocyte-conditioned medium significantly increased glucose uptake in cardiomyocytes. When streptozotocin-induced diabetic rats were used as a source of adipocytes, there was a lower ability to elicit glucose uptake in cardiomyocytes which corresponded with lower Akt and AMPK phosphorylation. The profile of glucose metabolism also differed with oxidation being favored upon co-culture with wild-type adipocytes whereas lactate production was strongly induced by adipocytes from diabetic rats. Examination of fatty acid uptake revealed that stimulation only occurred in response to adipokines secreted by wild-type rat adipocytes. Importantly, oxidation of fatty acids by cardiomyocytes was decreased by adipokines derived from diabetic rat adipocytes. Analysis of adipokine profiles in diabetic rat adipocyte-conditioned medium demonstrated the most significant decreases in adiponectin and leptin with increased IL6 expression. Taken together, these data suggest that the profile of adipokines secreted by adipocytes from diabetic rats have a deleterious influence on cardiomyocyte metabolism which may be of relevance in the pathophysiology of heart failure.
Morphological adrenarche in rhesus macaques: development of the zona reticularis is concurrent with fetal zone regression in the early neonatal period
Authors: Nguyen Ann D , Mapes Samantha M , Corbin C Jo , Conley Alan J
Published: September 2008

Human adrenarche is associated with the establishment of a functional zona reticularis (ZR) and increasing secretion of dehydroepiandrosterone (DHEA) in sulfated form (DS). Like most non-human primates, rhesus macaques are not believed to undergo adrenarche, though they clearly establish a functional ZR after birth. However, the origins of the rhesus ZR are not well defined. Therefore, we investigated the zonal development, steroidogenic enzyme expression and morphology of rhesus adrenals from 1 day to 14 months of age. Immunohistochemistry was conducted to determine expression profiles of the steroidogenic enzymes 17α-hydroxylase/17,20-lyase cytochrome P450, family 17, subfamily A, polypeptide 1 (CYP17A1), cytochrome P450, family 21, subfamily A, polypeptide 2 (CYP21A2), hydroxy-Δ-5-steroid dehydrogenase, 3β- and steroid Δ-isomerase 2 (HSD3B2), the redox partner NADPH-cytochrome P450 oxidoreductase (CPR), as well as the accessory protein cytochrome b5 (b5), a marker of the primate ZR. The rhesus ZR is mature by 3 months of age based on differentiation of the innermost zone that lacks HSD3B2, but exhibits increased b5 expression during this period. Further, the ZR develops in neonates from a previously described dense band of cells which we show expresses b5, CYP17A1, CPR, and CYP21A2 throughout maturation. The fetal zone (FZ) is distinguished from the ZR by its lack of CYP21A2, and ZR development proceeded as the FZ regressed with two important implications: neither FZ regression nor ZR maturation can be monitored independently by circulating adrenal androgens, and these events must be induced by different factors in rhesus, and likely humans. Collectively these data demonstrate that ZR development begins before birth in the rhesus, proceeding concomitantly with FZ regression post-natally, suggesting that rhesus experiences morphological adrenarche during the first three months of life.
Application of the wheel reflective cracking test for assessing geosynthetics in anti-reflection pavement cracking systems
Authors: Prieto J. N. , Gallego J. , Pérez I.
Published: September 2008

The reflective cracking phenomenon occurs when joints and cracks in a pavement that is generally made of concrete or cement-treated layers propagate up through the asphalt overlay and appear on the pavement surface. These cracks allow water to enter and cause the pavement deterioration process to accelerate, thereby increasing maintenance costs. The wheel reflective cracking (WRC) test permits the crack reflection strength of asphalt overlays and anti-reflection systems incorporating an asphalt-impregnated geotextile to be assessed. The test apparatus simultaneously applies the tensile, flexural and shear stresses in the vicinity of the pavement crack. This article describes the WRC test, and reports on a statistical study of the results obtained using different asphalt overlays and anti-reflection crack systems with and without reinforcing geosynthetic products. Each anticrack solution is analysed according to two criteria: (1) time to failure; and (2) the configuration of the cracked area after specimen failure. This second criterion is of practical concern, because it is related to the expected rate of deterioration of the cracked area in a field pavement and the level of difficulty in remediating the cracking as part of road maintenance.
Behavioral, physiological, and cellular responses following trophic transfer of toxic monoaromatic hydrocarbons
Authors: Scarlett Alan , Dissanayake Awantha , Rowland Steven J. , Galloway Tamara S.
Published: September 2008

The trophic transfer of monoaromatic hydrocarbons to predatory organisms feeding upon contaminated marine animals is not well reported within the scientific literature. Branched alkylbenzenes (BABs) unresolved by gas chromatography have been reported to be principal toxic components of bioaccumulated hydrocarbons in the tissues of some wild mussel, Mytilus edulis, populations with poor health status. Mussels, M. edulis, contaminated with a commercial mixture of BABs were fed to shore crabs, Carcinus maenas, for 7 d, and effects upon the behavior, heart rate, hemolymph cellular viability, and immune response of the crabs were assessed. Accumulation of BABs in crab midgut gland tissue was quantified by gas chromatography–mass spectrometry, and the presence of BABs in crab urine was detected spectrophotometrically using ultraviolet fluorescence spectroscopy. Analysis of crab tissues and urine revealed a proportion of the BABs was transferred from the mussel tissues to the crabs, but the majority was not present 3 d after consumption of the mussels and may have been metabolized, excreted, or both. The results do not support the hypothesis that BABs are likely to be biomagnified, at least by crabs, in the marine environment. Alterations to measured cellular and physiological responses of crabs fed BAB-exposed mussels were not significant. Consumption of contaminated mussels was shown to cause highly significant abnormal behavior that, in the wild, may affect the feeding ability of crabs and make them more vulnerable to predation.
Ecological models in support of regulatory risk assessments of pesticides: developing a strategy for the future
Authors: Forbes Valery E , Hommen Udo , Thorbek Pernille , Heimbach Fred , Van den Brink Paul J , Wogram Jörn , Thulke Hans-Hermann , Grimm Volker
Published: September 2008

This brief communication reports on the main findings of the LEMTOX workshop, held from 9 to 12 September 2007, at the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany. The workshop brought together a diverse group of stakeholders from academia, regulatory authorities, contract research organizations, and industry, representing Europe, the United States, and Asia, to discuss the role of ecological modeling in risk assessments of pesticides, particularly under the European regulatory framework. The following questions were addressed: What are the potential benefits of using ecological models in pesticide registration and risk assessment? What obstacles prevent ecological modeling from being used routinely in regulatory submissions? What actions are needed to overcome the identified obstacles? What recommendations should be made to ensure good modeling practice in this context? The workshop focused exclusively on population models, and discussion was focused on those categories of population models that link effects on individuals (e.g., survival, growth, reproduction, behavior) to effects on population dynamics. The workshop participants concluded that the overall benefits of ecological modeling are that it could bring more ecology into ecological risk assessment, and it could provide an excellent tool for exploring the importance of, and interactions among, ecological complexities. However, there are a number of challenges that need to be overcome before such models will receive wide acceptance for pesticide risk assessment, despite having been used extensively in other contexts (e.g., conservation biology). The need for guidance on Good Modeling Practice (on model development, analysis, interpretation, evaluation, documentation, and communication), as well as the need for case studies that can be used to explore the added value of ecological models for risk assessment, were identified as top priorities. Assessing recovery potential of exposed nontarget species and clarifying the ecological relevance of standard laboratory test results are two areas for which ecological modeling may be able to provide considerable benefits.
Achieving Stability under Inaccessible Conversions Using CSTR Cascades
Authors: Mjalli Farouq S. , Subramanian Jayakumar Natesan
Published: September 2008

Multiple steady states in an isothermal CSTR for reaction rates of the form R=kC/(1+KC)2 exhibit concentration multiplicity for a certain parameter range of the Damkohler number, Da. The unstable steady state of the above reaction rate form is very difficult to be observed and maintained. In this work the graphical solution method as proposed by Chen and Crynes (1987) is modified to attain a cascade of CSTRs that are capable of achieving this inaccessible steady state. The modified numerical scheme is based on optimization search. This method was successful in achieving the inaccessible steady state by two CSTRs cascade. The comparison with the graphical method showed that the modified method is faster and more accurate in solving the CSTR problem. The CSTR cascade gives better stability and tolerance to a probable control system failure.
Role of Glass-Transition on Fluid Transport in Porous Food Materials
Authors: Takhar Pawan S
Published: September 2008

Many food materials such as pasta, potatoes, starch, corn, soybeans, food gels etc. exhibit glass transition in the range of industrial temperature and fluid content values during transport processes such as drying, sorption, cooking, frying etc. Glass transition plays a critical role in affecting the fluid distribution profiles inside the food and average rate of fluid uptake by the whole food matrix. Yet this phenomenon is not included in most modeling studies that are primarily based upon Fick's law of diffusion. The purpose of this communication is to elucidate that Fick's law is valid only when the food is in glassy or rubbery states. Near glass-transition, the relaxation time of polymers is of the order of diffusion time. Thus, time-dependent conformational changes in food biopolymers add an extra stress term to fluid flow. Keeping track of this stress term is also the key to predict quality changes (related to food texture, physical state and crust formation) in foods via modeling. Based upon the average moisture and temperature at a given instant, even if the entire food matrix exists in a specific mechanical state in an average sense, its different sub-regions may be glassy, rubbery or in glass transition state. For example, during sorption, as a fluid front penetrates through a glassy food matrix, regions ahead of the front will be glassy. Regions in the proximity of the moving front would be undergoing glass transition and the regions already saturated by the fluid would be in a rubbery state. In the proximity of the moving front, where glass-transition is taking place, the fluid flow behavior is non-Fickian. During drying of biopolymers these regions will be in reverse order with the outer surface in a glassy state, center in a rubbery state and the middle region in transition state. Here a continuum mechanics based modeling approach is presented that can be used to predict fluid profiles and normalized stress profiles in all three states (glassy, rubbery and transition).
Before and After: Gender Transitions, Human Capital, and Workplace Experiences
Authors: Schilt Kristen , Wiswall Matthew
Published: September 2008

We use the workplace experiences of transgender people  individuals who change their gender typically with hormone therapy and surgery  to provide new insights into the long-standing question of what role gender plays in shaping workplace outcomes. Using an original survey of male-to-female and female-to-male transgender people, we document the earnings and employment experiences of transgender people before and after their gender transitions. We find that while transgender people have the same human capital after their transitions, their workplace experiences often change radically. We estimate that average earnings for female-to-male transgender workers increase slightly following their gender transitions, while average earnings for male-to-female transgender workers fall by nearly 1/3. This finding is consistent with qualitative evidence that for many male-to-female workers, becoming a woman often brings a loss of authority, harassment, and termination, but that for many female-to-male workers, becoming a man often brings an increase in respect and authority. These findings challenge the omitted variables explanations for the gender pay gap and illustrate the often hidden and subtle processes that produce gender inequality in workplace outcomes.
Hepatic Mesenchymal Hamartoma: Cytogenetic Analysis of a Case and Review of the Literature
Authors: Baboiu Oana-Eugenia , Saal Howard , Collins Margaret
Published: September 2008

Hepatic mesenchymal hamartoma (HMH) is a rare benign liver tumor generally occurring in young children. Abnormalities of chromosome 19q13.4 and chromosomal aneuploidy detected by flow cytometry have been reported in HMH. We recently analyzed a HMH in a 14-month-old girl and identified additional novel chromosome abnormalities, including hypodiploidy with deletions of several chromosomes, without rearrangement of 19q13.4 on both routine chromosome analysis and fluorescent in-situ hybridization analysis using subtelomere probes for chromosome 19q. This case underscores the need for chromosome analysis of all HMH and the need to report these changes to better understand the pathophysiology and the entire spectrum of cytogenetics of this uncommon tumor.
Tissue Microarrays from Bone Marrow Aspirates for High-Throughput Assessment of Immunohistologic Markers in Pediatric Acute Leukemia
Authors: Hazard Florette K. , Zhao Shuchun , Schiffman Joshua D. , Lacayo Norman J. , Dahl Gary V. , Natkunam Yasodha
Published: September 2008

Gene expression profiling studies have been employed to investigate prognostic subgroups in pediatric acute leukemia. Tissue microarrays (TMAs) are useful for high-throughput analysis of protein expression of target genes in acute leukemia samples and for validation of gene microarray analysis. Using cryopreserved samples of pediatric acute leukemia bone marrow aspirates, we constructed TMA from as few as 1 million cells. Bone marrow core biopsies from the same patients were included on the same TMA for comparison. A panel of 15 immunohistochemical markers typically used for diagnosis as well as those targeting recently characterized, prognostically relevant molecules of interest in pediatric acute leukemia was used to evaluate protein expression. Staining results confirm that suspension cells from bone marrow aspirates can be effectively used to derive protein expression data from multiple cases simultaneously with comparable efficacy to that of biopsy tissue. This method allows for new markers of diagnostic, prognostic, or therapeutic importance to be screened on large numbers of study patients. Furthermore, this technique may facilitate the inclusion of small samples, aspirates, and body fluids in large-scale studies of protein expression in clinical trials and protocols in which tissue biopsies are often unavailable.
Multicystic Adenomatoid Hamartoma of the Pancreas: A Hitherto Undescribed Pancreatic Tumor Occurring in a 3-Year-Old Boy
Authors: Thrall Michael , Jessurun Jose , Stelow Edward B. , Adsay N. Volkan , Vickers Selwyn M. , Whitson Amy K. , Saltzman Daniel A. , Pambuccian Stefan E.
Published: September 2008

This report describes an unusual pancreatic tumor in a 3-year-old boy. He presented with abdominal pain secondary to pancreatitis and was found to have a complex, multicystic lesion within the head of the pancreas. He subsequently underwent a pancreatoduodenectomy. Grossly, the mass was 3 cm, multicystic, and well demarcated. Histologically, there were numerous variably sized, dilated ducts lined by tall columnar mucinous cells surrounded by a stroma that exhibited foci of cellular condensations resembling primitive pancreatic mesenchyme. Acinar and endocrine cells were often seen budding into the ducts forming “ductulo-insular bodies.” As a result of its superficial resemblance to Stocker type 2 cystic adenomatoid malformation of the lung, we are proposing the name “multicystic adenomatoid hamartoma” for this lesion.
Congenital Intracranial Mesenchymal Chondrosarcoma: Case Report and Review of the Literature in Pediatric Patients
Authors: De Cecio Rossella , Migliaccio Ilenia , Falleti Jessica , Del De Caro Marialaura Basso , Pettinato Guido
Published: September 2008

In this paper we report the 1st case of a congenital intracranial mesenchymal chondrosarcoma in a 2-month-old infant, apparently present at birth. A magnetic resonance image showed a large left parietal solid mass, while microscopy revealed a mixture of undifferentiated small cells and mature hyaline cartilage islands, positive for vimentin, S-100, and CD99. A surgical excision was performed but the patient died after a few weeks as a result of a rapid relapse of the tumor. We also review the pediatric cases (in patients less than 20 years old) of extraskeletal (intracranial) mesenchymal chondrosarcomas of the literature, with a focus on the most recent cytogenetic and immunohistochemical studies.
Beta-Catenin Mutations Do Not Contribute to Cardiac Fibroma Pathogenesis
Authors: Miller Dylan V. , Wang Huamin , Wang Hua , Fealey Michael E. , Tazelaar Henry D.
Published: September 2008

Cardiac fibromas are the 2nd most common benign cardiac tumor occurring in children and bear a striking morphologic resemblance to soft tissue or desmoid fibromatosis. Since activating mutations in beta-catenin are common in desmoid fibromatosis as well as other spindle cell proliferations, the aim of our study was to determine if such mutations could be identified in cardiac fibroma. Nine cardiac fibromas from patients with surgical resection were examined for beta-catenin mutations by immunoperoxidase staining for beta-catenin protein and DNA sequencing of a region in exon 3 of the beta-catenin gene, where relatively conserved mutations have been described in desmoid fibromatosis. The mean age of the patients was 7.6 years (range: 10 weeks to 27 years), and 6 of the patients were male. No nuclear staining for beta-catenin was seen in the fibroma cells by immunoperoxidase methods. The beta-catenin exon 3 sequence data showed no mutations in any of the 9 tumors. We conclude that despite their morphologic similarity, cardiac fibroma and desmoid fibromatosis do not share this common molecular pathway of neoplastic growth.
Variability of Acetylcholinesterase Hyperinnervation Patterns in Distal Rectal Suction Biopsy Specimens in Hirschsprung Disease
Authors: Pacheco M. Cristina , Bove Kevin E.
Published: September 2008

Variability in cholinergic innervation may contribute to false-negative and false-positive evaluations for Hirschsprung disease (HD). We compared intraspecimen variability of histochemical acetylcholinesterase (ACE) activity in 62 distal rectal mucosal biopsy specimens from 33 patients with short-segment HD (SSHD), 14 patients with short-segment HD/Down syndrome (SSHD/DS), 10 patients with total colonic aganglionosis (HDTC), and 45 ganglionated control specimens obtained because of clinical suspicion for HD. Specimens were evaluated in 1-mm linear segments for abnormal distribution and abnormal intensity of staining reaction in the lamina propria (LP), muscularis mucosae (MM), numerical excess of small submucosal nerves (SSN), and presence or absence of large submucosal nerves (LSN) defined as >35 microns in diameter. Patients with HD and controls were predominantly infant males. Aggregate length of specimens was 186 mm in HD and 136 mm in controls. We defined multiple patterns and relative frequencies of normal and abnormal ACE reactivity in the muscularis mucosae, submucosal nerves, and innervation in the lamina propria. We verified a hyperinnervation pattern more common in neonates within each subset of HD. Large submucosal nerves >35 microns in diameter are relatively less common in SSHD/DS and HDTC. Eleven of 57 patients with HD had at least 1 mm of normal muscularis mucosae accounting for 19/186 mm examined. Ten percent of control mm had at least 1 submucosal nerve >35 microns in diameter. Intraspecimen variability in ACE patterns, when extreme, can usually be resolved by findings elsewhere in an adequate specimen, minimizing the need for repeat procedures.
Expression of Insulin-Like Growth Factor Pathway Proteins in Rhabdomyosarcoma: IGF-2 Expression is Associated with Translocation-Negative Tumors
Authors: Makawita Shalini , Ho Michael , Durbin Adam D. , Thorner Paul S. , Malkin David , Somers Gino R.
Published: September 2008

Recent studies have shown a significant involvement of insulin-like growth factor (IGF) signaling components in the pathogenesis of rhabdomyosarcoma (RMS). Furthermore, there has been some evidence to indicate that differential expression of IGF pathway genes can distinguish RMS subtypes. The present study utilized immunohistochemistry to determine the expression patterns of IGF1, IGF2, IGF binding protein 2 (IGFBP2), IGF receptor 1 (IGF1R), and IGF receptor 2 (IGF2R) in 24 embryonal RMS (ERMS) and 8 alveolar RMS (ARMS). A majority of tumors were positive for IGF2, IGFBP2, IGF1R, and IGF2R and negative for IGF1 expression. However, only IGF2 showed a significant difference in expression between the ERMS and ARMS subtypes, with higher levels of expression in ERMS ( P = 0.0003). Within the ARMS subtype, IGF2 positivity was limited to PAX/FKHR translocation-negative tumors. The staining pattern for all 5 proteins was diffuse cytoplasmic in the majority of tumors. Analysis of RMS cell lines by real-time reverse transcriptase–polymerase chain reaction for IGF2 expression revealed significantly higher mean expression levels in ERMS and translocation-negative ARMS cell lines when compared to translocation-positive ARMS cell lines ( P = 0.0027). Stable introduction of PAX3/FKHR into an ERMS cell line also demonstrated a significant reduction in IGF2 expression. The results of this study show that expression of the IGF2 ligand is associated with translocation-negative tumors and may serve as a diagnostic aid in distinguishing RMS subtypes. Furthermore, the in vitro results are supportive of a role for the PAX3/FKHR fusion gene in the inhibition of IGF2 expression.
Atypical Hyperplasia of the Marginal Zone of B Follicles in a Polymorphic Epstein-Barr Virus–Associated Lymphoproliferative Disorder Occurring in an Adolescent with Human Immunodeficiency Virus Infection
Authors: Dargent Jean-Louis , Haller Annick , Durdurez Jean-Pierre , Gennotte Anne Françoise
Published: September 2008

Epstein-Barr virus (EBV)-associated lymphoid proliferations that are similar to post-transplantation lymphoproliferative disorders may occasionally occur in the setting of human immunodeficiency virus (HIV) infection. Herein, we describe such a lesion involving the adenoids in a HIV-seropositive adolescent who acquired immunity against EBV during childhood. On microscopic examination, the marginal zone of B follicles and the interfollicular area were enlarged due to the accumulation of small or intermediate-sized lymphocytes, immunoblasts, epithelioid histiocytes, and plasma cells. A few atypical immunoblasts resembling Reed-Sternberg cells were also present. Most of the cells seen in these expanded regions belonged to the B-cell lineage and displayed a phenotype consistent with that of postgerminal center B cells. No clonal rearrangement of the genes coding for the heavy chain of the immunoglobulin could be demonstrated by polymerase chain reaction analysis. In-situ hybridization studies revealed the presence of EBV early RNA in a significant number of these cells, which suggests the participation of this virus in the pathogenesis of such a B-cell proliferation. The clinical course was benign; no progression or recurrence could be seen more than 24 months after the diagnosis. This atypical lymphoproliferative disorder is probably related to polyclonal reactivation of a latent EBV infection due to a local or systemic immune imbalance induced by HIV replication. Recognition of this reactive condition is important to prevent overtreatment.
Bite and kick injuries in horses: Prevalence, risk factors and prevention
Authors: KNUBBEN J. M. , FÜRST A. , GYGAX L. , STAUFFACHER M.
Published: September 2008

Reasons for performing study: Studies on the prevalence and predisposing factors of bite and kick injuries in horses have not been reported in a population‐based data sample.

Objectives: To investigate the prevalence of bite and kick injuries in horses and associated risk factors in a representative sample of horses in Switzerland.

Methods: A questionnaire on the incidence of disease and injury, which included the frequency of bite and kick injuries and their association with breed, housing, use and feeding regime, was sent to 2559 horse owners randomly selected throughout Switzerland.

Results: The data of 2912 horses with 897 disorders diagnosed by a veterinarian were analysed. There were 231 injuries, 50 (21.6%) caused by a bite or kick from another horse; this number corresponded to 5.6% of all diseases and injuries and concerned only 1.7% of all the horses evaluated. Warmblood, Thoroughbred and Arabian horses had a 4.3 times higher risk of bite or kick injuries than horses of other breeds. Eighteen per cent of injuries were associated with a change in housing management and occurred regardless of whether horses were kept in groups permanently or sporadically.

Conclusions and potential relevance: A stable group hierarchy and a housing system that provides adequate space and is adapted to horse‐specific behaviour are important factors in prevention and kick and bite injuries.