bluuebunny/crossref_metadata_2025 huggingface dataset:
Yield and Economic Responses to Phosphorus Fertilizer Placement in Dual‐Use and Grain‐Only Wheat Production Systems
Authors: Sij J. W. , Pinchak W. E. , Malinowski D. P. , Robinson D. L. , Bevers S. J. , Baughman T. A. , Gill R. J.
Published: May 2007

Wheat (Triticum aestivum L.) production in the southern Great Plains is a unique enterprise that provides both high‐quality forage and a grain crop within the same growing season. However, information on fertility management programs to maximize forage and beef production in a dual‐use wheat production system is lacking. A 3‐yr, field‐scale production study was initiated on a Tillman clay loam near Vernon, TX, in 1999 to (i) determine the influence of P fertilizer and P fertilizer placement on forage, beef, and grain production from dual‐use wheat, and (ii) compare economic costs and returns of dual‐use and grain‐only wheat production systems. Varying numbers of stocker cattle (Bos spp.) were placed in each pasture based on forage availability. Beef‐to‐forage allowance among pastures was kept relatively constant by adjusting cattle numbers monthly. Applying 20 kg P ha−1 yr−1 increased soil test P in the upper 15 cm two‐ to threefold, forage production 18 to 54%, and animal gains ha−1 27 to 29% compared with no P. With respect to forage and subsequent beef production, surface‐applied P was generally equal to or better than injected P. Average return between the graze‐plus‐grain and graze‐out systems was significant (P < 0.0001) but not among fertilizer treatments (P = 0.26), although surface‐applied P resulted in numerically higher returns each year. There was no significant system × fertilizer treatment interaction. However, during the study period, the graze‐plus‐grain system was clearly superior to the graze‐out system in generating higher net returns ($94 vs. $29 ha−1).
Tillage and Crop Sequence Effects on Heterodera glycines and Soybean Yields
Authors: Chen Senyu
Published: May 2007

Conservation tillage has been increasingly used in the midwestern USA. Long‐term effects of tillage practices on the soybean [Glycine max (L.) Merr.] cyst nematode (SCN), Heterodera glycines, and soybean yields in corn–soybean rotation were studied in two fields in Minnesota (USA). The experiments were arranged in a split‐plot design with tillage treatments as main plots and crop sequences as subplots. Tillage treatments were no‐tillage (NT) and conventional tillage (CT). The crop sequences were six (Waseca) or nine (New Richland) combinations of SCN‐susceptible ‘Sturdy’, SCN‐resistant ‘Freeborn’ (‘PI 88788’ resistance source) and ‘Pioneer brand 9234’ (‘Peking’ resistance source) soybean rotated annually with corn. Tillage did not affect SCN population density at New Richland and had only minimal and inconsistent effects on SCN at Waseca. However, CT resulted in up to 370 kg ha−1 greater soybean yield than NT at Waseca. Growing SCN‐resistant cultivars was effective in the corn–soybean rotation for managing SCN and minimizing yield loss to SCN. Resistant soybean not only reduced SCN population density and increased soybean yield in the year when it was grown, but also resulted in a smaller inoculum population density and increased yield of susceptible and resistant soybean in the following soybean years. Pioneer brand 9234 was more effective than Freeborn in reducing SCN population density and increasing soybean yield in the following years. This study confirmed that use of resistant cultivars is an effective tactic for SCN management, but tillage is not an option solely for managing SCN population in the northern climate and soil conditions.
Nitrogen Response of Grain Sorghum in Rotation with Soybean
Authors: Wortmann Charles S. , Mamo Martha , Dobermann Achim
Published: May 2007

The grain sorghum [Sorghum bicolor (L.) Moench] and soybean [Glycine max (L.) Merr.] rotation is the major sorghum production system in Nebraska. Fertilizer N needs for rotations are commonly determined by adjusting the N rate for continuous sorghum by a fertilizer nitrogen replacement value (FRV). The FRV due to rotation with soybean varies widely and, given the importance of the soybean–sorghum rotation, a basis for direct determination of N rates for grain sorghum following soybean is needed that includes the cost of fertilizer N. Thirty‐nine N rate trials for grain sorghum following soybean were conducted in southern Nebraska on medium to fine texture soils. The treatment structures varied but generally included five or more N rates in increments of 35 kg ha−1 or less. Grain sorghum yield response to applied N and the economically optimum nitrogen rate (EONR) increased as yield level increased. The agronomic efficiency of applied N increased with increased yield level and, within each yield category, decreased with increased N rate. Agronomic N efficiencies were <6 kg grain kg N−1 applied at sites with maximum yields of <6 Mg ha−1, indicating presence of severe constraints other than N. The EONR decreased and the range of profitable N rates decreased as the N price–grain price (PN:PG) ratio increased. Expected sorghum yield, as well as PN:PG, was therefore important for the determination of EONRs. Soil organic matter (SOM; 17–37 g kg−1 in the 0‐ to 20‐cm depth) and soil nitrate concentration (1.3–6.7 mg kg−1 in the 0‐ to 120‐cm depth) were positively correlated with grain yield without N application, but showed no correlation with the yield response to applied N. Within the ranges represented by these trials, soil information was less essential for determining the EONR for grain sorghum following soybean than setting a realistic yield goal (YG).
Production and Nutritive Value of Grazed Simple and Complex Forage Mixtures
Authors: Deak A. , Hall M. H. , Sanderson M. A. , Archibald D. D.
Published: May 2007

Sustainability of forage production in the Northeast USA is affected by environmental and climatic variability. Complex forage mixtures may be better adapted than simple mixtures to variable environments and produce greater dry matter (DM) yield more evenly throughout the growing season, thereby increasing sustainability of forage production. A grazing trial was set up to evaluate forage production, nutritive value, and botanical composition dynamics of well‐adapted and commonly sown forage species. The forage treatments consisted of simple mixtures (two and three species) and complex mixtures (six and nine species). The experiment was mob‐grazed with cow–calf (Bos taurus L.) pairs five times each year. Dry matter distribution during the growing season was independent of mixture complexity; it was, instead, influenced mainly by the weather. When averaged across all 3 yr, mixtures containing six species produced greater (P < 0.001) forage yield (9900 kg DM ha−1) compared with two‐species (8700 kg DM ha−1) or three‐species mixtures (8400 kg DM ha−1). However, forage production varied within species richness groups. In general, regardless of the initial botanical composition, the predominant species in most mixtures by the end of the experiment were orchardgrass (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and white clover (Trifolium repens L.). Variation in nutritive value among mixtures was explained mainly by variation in the proportions of grasses and legumes. We conclude that when it comes to large yields and top nutritive value, the most important consideration is the individual species, not the complexity of the mixtures.
Impacts of Variable‐Rate Phosphorus Fertilization Based on Dense Grid Soil Sampling on Soil‐Test Phosphorus and Grain Yield of Corn and Soybean
Authors: Bermudez Manuel , Mallarino Antonio P.
Published: May 2007

Most agricultural fields have high soil‐test phosphorus (STP) variability. Variable‐rate (VR) technology facilitates application of different P rates over a field and could improve nutrient application and crop yield. Replicated strip trials (6–12 ha) were established at six Iowa fields and were evaluated during 4 yr to compare VR and fixed‐rate (FR) P fertilization for corn (Zea mays L.)–soybean (Glycine max L. Merr.) rotations. Fields had median Mehlich‐3 STP ≤ 20 mg P kg−1, although minimum and maximum values within each field were 4 to 18 and 22 to 62 mg P kg−1, respectively. Treatments replicated at least three times were a control, VR based on STP from grid sampling (0.06‐ to 0.08‐ha grids), and FR based on median STP. Treatments were applied with commercial spreaders and grain was harvested with combines equipped with yield monitors and global positioning systems (GPS). Phosphorus increased yield in 13 site‐years and application methods differed in 1 site‐year, when FR increased yield further. On average, VR applied 12.4% less P and reduced STP variability in five fields compared with FR. Semivariograms and SD showed that fertilization, especially VR, often reduced yield variability and seldom increased it. High STP variability at a small scale and P recommendations to maximize yield and buildup STP in low‐testing soils might explain a lack of yield differences between application methods. Although VR did not increase yield compared with FR, it managed P better and showed potential for reducing excess P loss from fields through reduced P application to high‐testing field areas.
Relationship between P and N Concentrations in Corn
Authors: Ziadi Noura , Bélanger Gilles , Cambouris Athyna N. , Tremblay Nicolas , Nolin Michel C. , Claessens Annie
Published: May 2007

Tools to diagnose P crop status are becoming increasingly important to minimize the risk of surface and groundwater contamination from excessive fertilization while still applying sufficient P to optimize crop yield. The objectives of this study were to establish the relationship between P and N concentrations of corn (Zea mays L.) during the growing season and, in particular, to determine the critical P concentration required to diagnose P deficiency. Shoot biomass and P and N concentrations were determined weekly in an experiment with four to six N rates conducted over 2 yr (2004 and 2005) at three sites with adequate soil P for growth. The P and N concentrations decreased with time and increasing shoot biomass at all sites. The P concentration in relation to N under nonlimiting N conditions is described by a linear relationship (P = 1.00 + 0.094N, R2 = 0.76, P < 0.001, n = 71) in which the concentrations are expressed in g kg−1 dry matter (DM). Under limiting N conditions, the relationship was different with greater P concentrations for a given N concentration. The present study establishes a predictive model for critical P concentration in corn shoots, as a function of the N concentration in the shoot biomass and the degree of N deficiency. This critical P concentration can then be used to quantify the degree of P deficiency during the current growing season.
Predicting Soil pH and Buffer pH In Situ with a Real‐Time Sensor
Authors: Staggenborg S. A. , Carignano M. , Haag L.
Published: May 2007

Measuring soil pH is an important step in assessing the chemical status of a soil and in remediating high and low soil pH situations. Soil pH measurements on a spatial scale are limited by labor and lab analysis costs. A pH sensor mounted on a mobile sensing platform may be able to reduce these costs while providing a high‐resolution soil pH map. The objective of this research was to evaluate a pH sensor mounted on a mobile platform on two fields in Kansas, one with a uniform soil and one with six different soil complexes. Real‐time measurements were taken at a density of 17 points ha−1and compared with soil samples collected at depths of 0 to 7.5 and 7.5 to 15 cm. The real‐time sensors predicted soil pH most accurately at the 0‐ to 7.5‐cm depth (R2from 0.75 to 0.83) and less accurately for the other depth and combined depth (R2from 0.53 to 0.79). The inclusion of soil electrical conductivity (EC) improved pH predictions in the field with six different soil types, but not the uniform field. Buffer pH predictions were less accurate than pH predictions (R2from 0.04 to 0.43) across locations and depths. However, if a relationship between lab pH to buffer pH was developed and used to predict buffer pH from real‐time pH, the accuracy improved (R2from 0.75 to 0.95), suggesting that real‐time pH measurements may be capable of predicting buffer pH and lime requirements in real time. These results suggest that real‐time pH sensors on a mobile platform can be used to measure spatial pH and buffer pH and provide subsequent variable‐rate lime recommendations.
Mid‐Continent Fall Temperatures at the 10‐cm Soil Depth
Authors: Forcella Frank , Weyers Sharon Lachnicht
Published: May 2007

Recommendations for applying nitrogen (N) fertilizer in autumn involve delaying applications until daily soil temperature at 10‐cm depth is ≤10°C. Daily soil temperature data during autumn were examined from 26 sites along a transect from 36° to 49° N latitude in mid‐continent USA. After soils first cooled to ≤10°C (First10), temperatures usually rebounded for varying amounts of time before the final date, at which they decreased to ≤10°C (Last10) for the remainder of the winter. Because N may be lost during warm episodes between First10 and Last10, understanding the extent, duration, and timing of these warm periods is important. Soils at sites between 41° and 44° N latitude in mid‐continent USA accumulated more degree‐days (base 10°C) between First10 and Last10 than soils north or south of this region. Thus, if N fertilizer is applied too early, soils in Iowa, South Dakota, and southern Minnesota are more susceptible to N losses compared with soils in Missouri or North Dakota and northern Minnesota. Progressively more conservative guidelines for applying N fertilizer in autumn may be to wait until the dates of (i) average Last10, (ii) Last10 plus one SD, or (iii) Last10 plus two SD units. All of these alternative dates can be estimated reliably through simple polynomial equations for latitudes between 35° and 50°.
Acute coronary syndromes and diabetes mellitus
Authors: Trichon Benjamin H , Roe Matthew T
Published: May 2007

Patients with diabetes mellitus who present with acute ST-segment elevation myocardial infarction or non-ST-segment elevation acute coronary syndromes have a higher risk of adverse outcomes than patients without diabetes, and appear to derive greater benefit from evidence-based therapies. However, patients with diabetes mellitus are less commonly treated with proven therapies, so renewed efforts are needed to improve the quality of care and outcomes for patients with diabetes mellitus who present with acute coronary syndromes.
Common polymorphisms in the glyoxalase-1 gene and their association with pro-thrombotic factors
Authors: Gale Christopher P , Futers T. Simon , Summers Lucinda KM
Published: May 2007

Advanced glycation endproducts (AGEs) form at an accelerated rate in diabetes and contribute to the development of macrovascular disease. Their precursors are detoxified by the glyoxalase system. Perturbations of the glyoxalase-1 gene may alter AGEs' interactions and affect pro-thrombotic factors.

We screened the glyoxalase-1 gene for mutations and measured pro-thrombotic markers in 537 subjects from 89 healthy probands. Common single nucleotide polymorphisms (SNPs) were identified at positions-7 (C to T) and 20203 (C to A) from the translation start site. These SNPs were in Hardy-Weinberg equilibrium (CC=105, CA=266, AA=148; p>0.05; CC=126, CT=279, TT=114; p>0.05, respectively) and in linkage disequilibrium (D=27%, p<0.01), with mutant allele frequencies of 48% and 52% respectively.

A significant association was found between SNPs at position 20203 and PAI-1 antigen concentrations and-7 and factor XIII A2B2 complex (p=0.001 and p=0.042). After Bonferroni correction a significant association remained between the SNP at 20203 and PAI-1 concentrations (p=0.005), and after adjustment for pedigree the association accounted for 1.3% of its heritability (p=0.04). No significant associations were found for SNP-7 T to C and factor VII activity, tPa concentrations, fibrinogen concentrations or factor XIII concentrations and SNP 20203 C to A and factor VII concentrations, PAI-1 concentrations, tPa concentrations or fibrinogen concentrations.

Common variants in the glyoxalase-1 gene are associated with some pro-thrombotic factors, account for part of their heritability in healthy pedigrees and may alter susceptibility to macrovascular complications.
Pathobiology and cell interactions of platelets in diabetes
Authors: Stratmann Bernd , Tschoepe Diethelm
Published: May 2007

Diabetes is a well-recognised risk factor for atherosclerotic cardiovascular disease and in fact most diabetic patients die from vascular complications. The Diabetes Control and Complications Trial (DCCT) and the UK Prospective Diabetes Study (UKPDS) indicate a consistent relationship between hyperglycaemia and the incidence of chronic vascular complications in patients with diabetes. Platelets are essential for haemostasis, and abnormalities of platelet function may cause vascular disease in diabetes. Diabetic patients have hyperreactive platelets with exaggerated adhesion, aggregation and thrombin generation. In summary, the entire coagulation cascade is dysfunctional in diabetes.

This review provides a comprehensive overview of the physiological role of platelets in maintaining haemostasis and of the pathophysiological processes that contribute to platelet dysfunction in diabetes and associated cardiovascular diseases, with special emphasis on proteomic approaches and leukocyte-platelet cross-talk.
Protein kinase C β inhibition: a novel therapeutic strategy for diabetic microangiopathy
Authors: Idris Iskandar , Donnelly Richard
Published: May 2007

Biochemical mechanisms involved in hyperglycaemia-induced vascular damage include alterations in cellular signalling by activation of protein kinase C (PKC). Twelve isoforms of PKC have been characterised according to their structure and co-factor requirements. Activation of PKC is mediated primarily through increased release of diacylglycerol (DAG). Adverse effects of PKC and DAG on vascular function include increased permeability, endothelial cell activation, altered blood flow, leukocyte adhesion and abnormal growth factor signalling.

A highly selective and orally active PKC-β isoform-selective inhibitor, ruboxistaurin, has been developed. Initial studies suggest that this agent decreased the development of sight-threatening macular oedema and the occurrence of visual loss. It did not, however, prevent the progression of diabetic retinopathy.
The insulin resistance syndrome: physiological considerations
Authors: Kashyap Sangeeta R , Defronzo Ralph A
Published: May 2007

The insulin resistance syndrome, also referred to as the ‘metabolic syndrome’ or ‘syndrome X’, is associated with a primary cellular defect in insulin action (insulin resistance) and a compensatory increase in insulin secretion. The combination of insulin resistance and subsequent hyperinsulinaemia causes a number of metabolic and cardiovascular changes that result in a syndrome typically characterised by type 2 diabetes, obesity, dyslipidaemia, coronary artery disease and hypertension. Moreover, disturbances in sleep (sleep apnoea) and ovarian dysfunction are also characterised by insulin resistance. The pathophysiological basis for these disturbances reflects the impact of variable genetic and environmental influences. At a molecular level, insulin resistance involves defects of insulin signalling such as reduced insulin receptor tyrosine kinase activity and reduced post-receptor phosphorylation steps that impinge on metabolic and vascular effects of insulin.
Metabolic syndrome, or What you will: definitions and epidemiology
Authors: Day Caroline
Published: May 2007

The ‘metabolic syndrome’ is a clustering of risk factors which predispose an individual to cardiovascular morbidity and mortality. There is general consensus regarding the main components of the syndrome (glucose intolerance, obesity, raised blood pressure and dyslipidaemia [elevated triglycerides, low levels of high-density lipoprotein cholesterol]) but different definitions require different cut points and have different mandatory inclusion criteria. Although insulin resistance is considered a major pathological influence, only the World Health Organization (WHO) and European Group for the study of Insulin Resistance (EGIR) definitions include it amongst the diagnostic criteria and only the International Diabetes Federation (IDF) definition has waist circumference as a mandatory component.

The prevalence of metabolic syndrome within individual cohorts varies with the definition used. Within each definition, the prevalence of metabolic syndrome increases with age and varies with gender and ethnicity. There is a lack of diagnostic concordance between different definitions. Only about 30% of people could be given the diagnosis of metabolic syndrome using most definitions, and about 35-40% of people diagnosed with metabolic syndrome are only classified as such using one definition. There is currently debate regarding the validity of the term metabolic syndrome, but the presence of one cardiovascular risk factor should raise suspicion that additional risk factors may also be present and encourage investigation. Individual risk factors should be treated.
Two-week treatment with pravastatin improves ventriculo-vascular haemodynamic interactions in young men with type 1 diabetes
Authors: Casey Rowan G , Joyce Myles , Moore Kevin , Thompson Chris , Fitzgerald Patricia , Bouchier-Hayes David J
Published: May 2007

Young patients with diabetes but without established vascular disease have altered conduit and resistance artery reactivity. Early endothelial dysfunction is an initial step in atherogenesis: reductions in nitric oxide (NO) production in these vascular beds are implicated.

The study aim was two-fold: first, to detect baseline abnormalities in cardiac function, conduit vessels and the microcirculation using applanation tonometry, brachial artery ultrasound and laser Doppler fluximetry, respectively; and second, to investigate any modification in these parameters with the use of pravastatin.

Nine young men with diabetes and normoalbuminuria were randomised in a double-blind cross-over fashion to placebo or pravastatin (40 mg) treatment for two weeks. They underwent scans on three separate occasions. Control patients (n=12) underwent a baseline scan but were not given any drug treatment.

It was found that patients with diabetes had significantly higher systolic and diastolic blood pressures, heart rate and Buckberg index (propensity to myocardial ischaemia). Brachial artery reactivity and microcirculatory dilation were both reduced. Levels of von Willebrand Factor, a marker of endothelial damage, were also elevated. Pravastatin treatment restored these sub-clinical abnormalities towards normal levels.

In conclusion, pravastatin improves vascular abnormalities in young male patients with diabetes through alterations in microcirculation and conduit vessel function, with secondary myocardial effects. This may be of benefit in preventing end-organ injury.
Intracoronary ultrasound examinations reveal significantly more advanced coronary atherosclerosis in people with type 1 diabetes than in age- and sex-matched non-diabetic controls
Authors: Larsen Jakob R , Tsunoda Taro , Tuzcu E Murat , Schoenhagen Paul , Brekke Magne , Arnesen Harald , Hanssen Kristian F , Nissen Steven E , Dahl-Jorgensen Knut
Published: May 2007

Aims/hypothesis: The extent of coronary atherosclerosis is significantly more advanced in symptomatic type 1 diabetes patients than in symptomatic non-diabetic patients. Whether this difference exists between asymptomatic individuals with diabetes and controls is not documented. In vivo imaging techniques allow quantification of the difference at a preclinical stage.

Methods: The degree of coronary atherosclerosis in early onset type 1 diabetes patients without symptoms of cardiovascular disease was compared with that of age- and sex-matched controls. Intracoronary ultrasound (IVUS) examinations were performed to determine the degree of atherosclerosis. The mean age of the patients was 43 years (35–58), they had a mean duration of disease of 30 (23–39) years and the diagnosis of type 1 diabetes was made at a mean age of 12.5 years. The controls were people with transplanted hearts; donors were sex- and age-matched and had a mean age of 43 (35–58) years.

Results: The degree of subclinical coronary atherosclerosis was significantly more severe in type 1 diabetes patients than in controls. This was the case for all parameters measured. The mean plaque area was ≥ 40% in 71% (54/76) of diabetic arteries as opposed to 33% (25/76) of arteries from controls (p<0.0001). The mean plaque thickness was 0.59±0.38 mm vs. 0.44±0.30mm in controls (p<0.0001). The mean lumen area was 8.6±3.8mm2 in type 1 diabetes and 12.1±4.3 mm2 in controls (p<0.0001).

Conclusions/interpretation: Asymptomatic individuals with type 1 diabetes have significantly more advanced sub-clinical coronary atherosclerosis than controls. Coronary atherosclerosis in type 1 diabetes develops at an early age.
Microwave Tubes
Authors: Granatstein Victor L. , Parker Robert K.
Published: May 2007

The sections in this article are

Principles of Operation

Types of Microwave Tubes

Future Directions
Energy Dispersive X‐Ray Diffraction Potentiality in the Field of Cultural Heritage: Simultaneous Structural and Elemental Analysis of Various Artefacts
Authors: Caponetti Eugenio , Caminiti Ruggero , Chillura Martino Delia , Saladino Maria Luisa
Published: May 2007

The applicability of an Energy Dispersive X‐ray Diffractometer to some technical questions in the field of Cultural Heritage is presented. This diffractometer, equipped with a white source, has been utilized for the structural and elemental analysis of some items having different nature. Given its design, the instrument allows to collect data from samples as big as a book or a little more. Samples, without collection of any portion and without any preliminary preparation, have been placed in the instrument and spectra have been collected in a wide energy range that contains X‐ray fluorescence and diffraction features. In all cases, data acquired in air and in a non destructive way were reliable and their collection was fast. Fluorescence and X‐ray diffraction information, when possible, have been compared with those obtained by XRF micro‐analysis and by an Angle Dispersive X‐ray Diffractometer equipped with a Cu X‐ray source. By using the last two techniques, data have been collected from small areas of the samples.
The Simultaneous Analysis of Proteins, Lipids, and Diterpenoid Resins Found in Cultural Objects.
Authors: Singer Brian , McGuigan Ross
Published: May 2007

We report a GC‐MS method for the simultaneous analysis of proteins oil, and diterpenoid resins found in cultural objects. The method was initially designed for protein analysis of protenaceous paints and adhesives and involves acid hydrolysis as the first step. The amino acids in the protein hydrolysates, thus obtained, are treated with propan‐1‐ol/ hydrogen chloride and then pentafluoropropionic anhydride. The procedure was found also to yield the propyl esters of fatty acids derived from lipids and diterpenoid acids derived from natural resins, and thus allows the choice of a single method for the analysis of artists media which contain either oil s or proteins or mixtures of both proteins and oils or even resins. Thus natural mixtures such as egg yolk and also mixtures made by the artist such as animal glue / seed oil emulsions can be analysed. Coupled with FTIR analysis of paints and the staining of cross sections, to indicate layer structure the method can help to elucidate the paints and adhesives used by artists.
The geometry of separation boundaries. II. Mathematical formalism
Authors: Lucia Angelo , Taylor Ross
Published: May 2007

This article is concerned with the mathematical proof that distillation boundaries correspond to locally longest residue curves. Perturbation theory and the implicit function theorem are used to provide an analytical relationship between neighboring trajectories while local congruence and a variety of limiting arguments are used to establish the relative distances between neighboring residue curves. The mathematical conditions on which this analysis is based include (1) The assumptions that trajectories are twice continuously differentiable and do not cross. (2) The comparison of neighboring trajectories that converge to the same stable node. (3) The existence and placement of a proper focal point. (4) Local congruence. While all of these assumptions and conditions are important, it is the existence and proper placement of a focal point and local congruence that are the keys to establishing relative distances between neighboring residue curves and, in turn, the main result that distillation boundaries are defined by locally longest trajectories from any unstable node to all reachable stable nodes. Wherever possible, geometric illustrations are used to clarify key concepts. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Variations in worker compensation claims by company—the potential for achieving a significant reduction in claims
Authors: Rosenman Kenneth D. , Kalush Alice , Reilly Mary Jo
Published: May 2007

Background

The objective of our study was to examine the potential reduction in paid worker compensation claims if the rate of claims were as low as the rates of the top companies in that industry category.

Methods

Using Michigan data for the years 1999–2001, we first excluded companies who had no paid worker compensation claims for wage replacement and then calculated the top 10th, 25th, and 50th percentile rates of paid worker compensation claims for wage replacement of all the remaining companies combined and by 2 digit SIC. The percent reduction was calculated separately for small (<20 employees) and large companies based on the differences in observed minus expected if all companies did as well as the top companies in their industry grouping.

Results

Fifty‐nine percent of large companies and 90% of small companies had no paid worker compensation claims for wage replacement over the 3‐year period. Controlling for industry type there would have been 91,504 fewer paid workers' compensation claims if all companies with at least one claim did as well as the 10th percentile or better as the companies in their industry grouping. Reductions were found across all industries and for both small and large companies.

Conclusion

Variations in worker compensation claims between states are highlighted when legislators consider “reforms” to reduce workers' compensation costs. These reforms overlook the larger variation between companies within the same type of industry in the same state. Possible reasons for this variation between companies and its implication on reducing morbidity and health care costs are discussed. Am. J. Ind. Med. 50:415–420, 2007. © 2007 Wiley‐Liss, Inc.
Family‐based association study of neuregulin‐1 gene and psychosis in a Spanish sample
Authors: Rosa Araceli , Gardner M. , Cuesta M.J. , Peralta V. , Fatjó‐Vilas M. , Miret S. , Navarro M.E. , Comas D. , Fañanás L.
Published: May 2007

Neuregulin 1 (NRG1) is one of the most exciting candidate genes for schizophrenia since its first association with the disorder in an Icelandic population. Since then, many studies have analyzed allele and haplotype frequencies in European and Asian populations in cases and controls yielding varying results. We investigated the association of NRG1 with psychosis in a total sample set of 575 individuals from 151 Spanish nuclear families. We tested eight SNPs across 1.2 Mb along NRG1 including regions previously associated to schizophrenia in association studies. After correction for multiple testing, the TDT analysis for each marker did not show a significant over‐transmission of alleles from the parents to the affected offspring for any of the markers (P > 0.05). The haplotypic analysis with TRANSMIT and PDT did not show preferential transmission for any of the haplotypes analyzed in our sample. These results do not seem to suggest that the investigated NRG1 markers play a role in schizophrenia in the Spanish population, although the finding of a trend for association with one SNP in the 3′of the gene warrants further investigation. © 2007 Wiley‐Liss, Inc.
Porcine maternal infanticide as a model for puerperal psychosis
Authors: Quilter Claire R. , Blott Sarah C. , Wilson Anna E. , Bagga Meenakshi R. , Sargent Carole A. , Oliver Gina L. , Southwood Olwen I. , Gilbert Colin L. , Mileham Alan , Affara Nabeel A.
Published: May 2007

Childbirth is a period of substantial rapid biological and psychological change and a wide range of psychotic disorders can occur ranging from mild ‘baby blues’ to severe episodes of psychotic illnesses. Puerperal psychosis is the most extreme form of postnatal psychosis, occurring in 1 in 1,000 births. In this study, we have used the pig as an animal model for human postnatal psychiatric illness. Our aim was to identify quantitative trait loci (QTL) associated with maternal (infanticide) sow aggression. This is defined by sows attacking and killing their own newborn offspring, within 24 hr of birth. An affected sib pair whole genome linkage analysis was carried out with 80 microsatellite markers covering the 18 porcine autosomes and the X chromosome, with the aim of identifying chromosomal regions responsible for this abnormal behavior. Analysis was carried out using the non‐parametric linkage test of Whittemore and Halpern, as implemented in the Merlin software. The results identified 4 QTL mapping on Sus scrofa chromosomes 2 (SSC2), 10 (SSC10), and X (SSCX). The peak regions of these QTL are syntenic to HSA 5q14.3‐15, 1q32, Xpter‐Xp2.1, and Xq2.4‐Xqter, respectively. Several potential candidate genes lie in these regions in addition to relevant abnormal behavioral QTL, found in humans and rodents. © 2007 Wiley‐Liss, Inc.
Cytogenetic and molecular characterization of A2BP1/FOX1 as a candidate gene for autism
Authors: Martin Christa Lese , Duvall Jacqueline A. , Ilkin Yesim , Simon Jason S. , Arreaza M. Gladys , Wilkes Kristin , Alvarez‐Retuerto Ana , Whichello Amy , Powell Cynthia M. , Rao Kathleen , Cook Edwin , Geschwind Daniel H.
Published: May 2007

Cytogenetic imbalances are increasingly being realized as causes of autism. Here, we report a de novo translocation between the short arms of chromosomes 15 and 16 in a female with autism, epilepsy, and global developmental delay. FISH analysis identified a cryptic deletion of approximately 160 kb at the boundary of the first exon and first intron of the 1.7 Mb ataxin‐2 binding protein‐1 (A2BP1) gene, also called FOX1. Quantitative real time PCR (Q‐PCR) analysis verified a deletion of exon 1 in the 5′ promoter region of the A2BP1 gene. Reverse transcription PCR (qRT‐PCR) showed reduced mRNA expression in the individual's lymphocytes, demonstrating the functional consequence of the deletion. A2BP1 codes for a brain‐expressed RNA binding or splicing factor. Because of emerging evidence in the role of RNA processing and gene regulation in pervasive developmental disorders, we performed further screening of A2BP1 in additional individuals with autism from the Autism Genetics Resource Exchange (AGRE) collection. Twenty‐seven SNPs were genotyped across A2BP1 in 206 parent‐child trios and two regions showed association at P ≤ 0.008 level. No additional deletions or clear mutations were identified in 88 probands by re‐sequencing of all exons and surrounding intronic regions or quantitative PCR (Q‐PCR) of exon 1. Although only nominal association was observed, and no obvious causal mutations were identified, these results suggest that A2BP1 may affect susceptibility or cause autism in a subset of patients. Further investigations in a larger sample may provide additional information regarding the involvement of this gene in the autistic phenotype. © 2007 Wiley‐Liss, Inc.
No evidence for a preferential transmission of the methylenetetrahydrofolate reductase 677T allele in families with schizophrenia offspring
Authors: Muntjewerff Jan‐Willem , Hoogendoorn Mechteld L.C. , Aukes Maartje F. , Kahn René S. , Sinke Richard J. , Blom Henk J. , Heijer Martin den
Published: May 2007

The methylenetetrahydrofolate reductase (MTHFR) 677C > T polymorphism has been associated with an increased risk of schizophrenia in various case‐control studies. However, case‐control studies are sensitive to population stratification, which is not an issue in family‐based studies. We conducted a family‐based study comprising 120 families with a schizophrenic family member to explore the association between the parental MTHFR 677C > T polymorphism and schizophrenia risk in offspring. In addition, a meta‐analysis was performed using the available studies with data on this subject. Transmission Disequilibrium Test (TDT) analysis showed no preferential transmission of the 677T allele from parents heterozygous for the MTHFR 677C > T polymorphism to schizophrenia offspring (P = 0.27). The genotype relative risks were 1.43 (95% CI: 0.83–2.47) for the 677TT and 1.42 (95% CI: 0.54–3.78) for the 677CT genotype, relative to the 677CC genotype. A meta‐analysis using data from family‐based studies comprising a total of 416 parent‐child triads yielded no evidence implicating the 677T allele in schizophrenia risk (P = 0.58). By applying a log‐linear model, we found no asymmetry within parental mating type. Our data provided no evidence that transmission of the MTHFR 677T allele is associated with schizophrenia risk. In addition, we found no evidence that the maternal genotype influences the risk of having schizophrenia offspring substantially. © 2007 Wiley‐Liss, Inc.
Technical note: Compatibility of microtomographic imaging systems for dental measurements
Authors: Olejniczak Anthony J. , Tafforeau Paul , Smith Tanya M. , Temming Heiko , Hublin Jean‐Jacques
Published: May 2007

Modern micro‐computed tomography techniques allow the accurate visualization of internal dental structures, and are becoming widely used within (paleo‐) anthropological dental studies. There exist several types and name brands of microtomographic systems, however, which have been demonstrated to produce images that vary in resolution and signal‐to‐noise ratio. As a growing body of dental research using disparate microtomographic techniques is likely to continue accumulating, it is imperative that different systems are compared to ensure that results are comparable and not machine‐dependent. In the present study, we compare volume, surface area, and linear measurements recorded on a sample of modern and fossil teeth using four microtomographic systems (three laboratory scanners, and the ID19 beamline of the European Synchrotron Radiation Facility). Results indicate that measurements are comparable between systems (within 3%), but that synchrotron radiation is superior to the other systems because its monochromatic X‐rays prevent beam hardening and its parallel beam prevents geometric artifacts in the resultant images, making it easier to record measurements and see fine details at the enamel cervix or dentine horn tips. Although the synchrotron produces higher resolution images with less artifacts, results indicate that for gross morphological measurements (e.g., enamel cap volume, intercuspal distances), each of the scanners produces approximately the same measurements. Combining measurements of teeth from multiple microCT systems presupposes that measurements from each system are comparable; the research presented here indicates that this is the case when teeth are not severely diagenetically remineralized. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
The problem of assessing landmark error in geometric morphometrics: Theory, methods, and modifications
Authors: von Cramon‐Taubadel Noreen , Frazier Brenda C. , Lahr Marta Mirazón
Published: May 2007

Geometric morphometric methods rely on the accurate identification and quantification of landmarks on biological specimens. As in any empirical analysis, the assessment of inter‐ and intra‐observer error is desirable. A review of methods currently being employed to assess measurement error in geometric morphometrics was conducted and three general approaches to the problem were identified. One such approach employs Generalized Procrustes Analysis to superimpose repeatedly digitized landmark configurations, thereby establishing whether repeat measures fall within an acceptable range of variation. The potential problem of this error assessment method (the “Pinocchio effect”) is demonstrated and its effect on error studies discussed. An alternative approach involves employing Euclidean distances between the configuration centroid and repeat measures of a landmark to assess the relative repeatability of individual landmarks. This method is also potentially problematic as the inherent geometric properties of the specimen can result in misleading estimates of measurement error. A third approach involved the repeated digitization of landmarks with the specimen held in a constant orientation to assess individual landmark precision. This latter approach is an ideal method for assessing individual landmark precision, but is restrictive in that it does not allow for the incorporation of instrumentally defined or Type III landmarks. Hence, a revised method for assessing landmark error is proposed and described with the aid of worked empirical examples. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Robusticity and sexual dimorphism in the postcranium of modern hunter‐gatherers from Australia
Authors: Carlson Kristian J. , Grine Frederick E. , Pearson Osbjorn M.
Published: May 2007

Throughout much of prehistory, humans practiced a hunting and gathering subsistence strategy. Elevated postcranial robusticity and sexually dimorphic mobility patterns are presumed consequences of this strategy, in which males are attributed greater robusticity and mobility than females. Much of the basis for these trends originates from populations where skeletal correlates of activity patterns are known (e.g., cross‐sectional geometric properties of long bones), but in which activity patterns are inferred using evidence such as archaeological records (e.g., Pleistocene Europe). Australian hunter‐gatherers provide an opportunity to critically assess these ideas since ethnographic documentation of their activity patterns is available. We address the following questions: do skeletal indicators of Australian hunter‐gatherers express elevated postcranial robusticity and sexually dimorphic mobility relative to populations from similar latitudes, and do ethnographic accounts support these findings. Using computed tomography, cross‐sectional images were obtained from 149 skeletal elements including humeri, radii, ulnae, femora, and tibiae. Cross‐sectional geometric properties were calculated from image data and standardized for body size. Australian hunter‐gatherers often have reduced robusticity at femoral and humeral midshafts relative to forager (Khoi‐San), agricultural/industrialized (Zulu), and industrialized (African American) groups. Australian hunter‐gatherers display more sexual dimorphism in upper limb robusticity than lower limb robusticity. Attributing specific behavioral causes to upper limb sexual dimorphism is premature, although ethnographic accounts support sex‐specific differences in tool use. Virtually absent sexual dimorphism in lower limb robusticity is consistent with ethnographic accounts of equivalently high mobility among females and males. Thus, elevated postcranial robusticity and sexually dimorphic mobility do not always characterize hunter‐gatherers. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Fas small interfering RNA reduces motoneuron death in amyotrophic lateral sclerosis mice
Authors: Locatelli Federica , Corti Stefania , Papadimitriou Dimitra , Fortunato Francesco , Del Bo Roberto , Donadoni Chiara , Nizzardo Monica , Nardini Martina , Salani Sabrina , Ghezzi Serena , Strazzer Sandra , Bresolin Nereo , Comi Giacomo Pietro
Published: May 2007

Objective

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease characterized by selective motoneuron death. Understanding of the molecular mechanisms that trigger and regulate motoneuron degeneration could be relevant to ALS and other motoneuron disorders. This study investigates the role of Fas‐linked motoneuron death in the pathogenesis of ALS.

Methods

We performed in vitro and in vivo small interfering RNA–mediated interference, by silencing the Fas receptor on motoneurons that carry the superoxide dismutase‐1 (SOD1)‐G93A mutation.

Results

We observed a significant reduction in Fas expression at messenger RNA (p < 0.001) and protein levels. Treated motoneurons demonstrated an increase in survival and a reduction in cytochrome c release from mitochondria. In vivo, continuous intrathecal administration of Fas small interfering RNA by an osmotic minipump improved motor function and survival in SOD1‐G93A mice (mean increase, 18 days; p < 0.0001). Treated mice showed a significant reduction in Fas and Fas mediators p38 mitogen‐activated protein kinase, neuronal nitric oxide synthase, and caspase‐8.

Interpretation

Fas silencing interferes with motoneuron‐specific downstream death pathways and results in increased motoneuron survival and amelioration of the SOD1‐G93A phenotype, suggesting new possible strategies for molecular therapy of ALS. Ann Neurol 2007
Synthesis and characterization of amphiphilic polymer networks based on acrylated poly(ϵ‐caprolactone) and N‐vinylpyrrolidone
Authors: Liao Liqiong , Zhang Chao , Gong Shaoqin
Published: May 2007

New amphiphilic polymer networks were synthesized by the free‐radical copolymerization of α,ω‐diacryl polycaprolactone (DAPCL) and N‐vinylpyrrolidone (NVP), which was initiated by 0.5% azobisisobutyronitrile at 70°C. The chemical structures of the networks were characterized by proton nuclear magnetic resonance spectrometry. The NVP/DAPCL feed ratio played an important role in the crosslinking process. The synthesized amphiphilic polymer networks exhibited controlled swelling properties in water and organic solvents (ethanol, acetones, and toluene). A porous structure was observed for the amphiphilic polymer networks under a scanning electron microscope. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007