bluuebunny/crossref_metadata_2025 huggingface dataset:
Feline Leukemia Virus-associated Myelopathy in Cats
Authors: Carmichael K. P. , Bienzle D. , Mcdonnell J. J.
Published: April 2003

Feline leukemia virus (FeLV) infection is associated with distinct neoplastic, hematologic, and immunosuppressive diseases. Here we report on a novel neurologic syndrome in 16 cats infected with FeLV for more than 2 years. Clinical signs consisted of abnormal vocalization, hyperesthesia, and paresis progressing to paralysis. The clinical course of affected cats involved gradually progressive neurologic dysfunction invariably resulting in euthanasia. Microscopically, white-matter degeneration with dilation of myelin sheaths and swollen axons was identified in the spinal cord and brain stem of affected animals. Neither neoplastic nor hematologic diseases commonly associated with FeLV infection were present. Fungal and protozoal infection in one animal was suggestive of impaired immune competence. Immunohistochemical staining of affected tissues revealed consistent expression of FeLV p27 antigens in neurons, endothelial cells, and glial cells. Furthermore, proviral DNA was amplified from multiple sections of spinal cord as well as intestine, spleen, and lymph nodes. These findings suggest that in a proportion of chronically FeLV-infected cats, a virus evolved with cytopathic potential for cells in the central nervous system.
Equine Epitheliogenesis Imperfecta in Two American Saddlebred Foals Is a Lamina Lucida Defect
Authors: Lieto L. D. , Swerczek T. W. , Cothran E. G.
Published: April 2003

Necropsy of two American Saddlebred fillies diagnosed with epitheliogenesis imperfecta (EI) revealed missing patches of epithelium of the skin and oral mucosa as well as dental abnormalities. Examination of the digestive tract did not reveal signs of pyloric atresia in either foal. Histopathologic examination revealed separation of the epidermis from the dermis. In both foals a division within the lamina lucida of the basal lamina was observed by transmission electron microscopy. In comparison with an age-specific control, the ultrastructure of intact skin from the EI-affected foals showed abnormal hemidesmosomes, which lacked a subbasal plate. The morphological and ultrastructural defects observed in the EI-affected American Saddlebred foals were similar to those observed in Herlitz junctional epidermolysis bullosa-affected human newborns, which is caused by a defect in one of the subunits of laminin-5. The close similarity of lesions of the human and equine diseases suggests that EI may be caused by a laminin-5 defect.
Correlation of Vascular Endothelial Growth Factor Expression to Overall Survival in Feline Invasive Mammary Carcinomas
Authors: Millanta F. , Lazzeri G. , Vannozzi I. , Viacava P. , Poli A.
Published: April 2003

Samples from feline invasive mammary carcinomas (FMCs) were used to determine the prognostic significance of the immunohistochemical expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD). Forty-eight queens bearing FMCs were included in a 2-year follow-up study. Mammary tumors were classified according to the World Health Organization system and graded on the basis of histologic criteria. Tumor sections were immunostained using anti-VEGF and anti-von Willebrand factor (vWf) antibodies. VEGF expression was quantified on the basis of the percentage of positive cells. MVD of vWf-positive microvessels was determined by both mean microvessel counts and highest microvessel counts. Normal mammary gland tissues showed an inconspicuous VEGF staining. In FMCs the proportion of VEGF-positive cells was significantly higher in papillary and solid carcinomas than in tubular and papillary cystic tumors. An increased number of cells expressing VEGF was also observed in poorly differentiated FMCS. Sixteen (33.3%) of the queens bearing invasive carcinomas were still alive at the end of the 2-year follow-up period, and 32 (66.7%) had died. The VEGF expression was significantly correlated with the clinical outcome, but no correlation was observed with the invasion of lymphatic vessels. A correlation between the higher percentage of VEGF-positive cells and the unfavorable prognosis was demonstrated by the estimation of curves for overall survival ( P = 0.03). Univariate analysis showed that MVD did not correlate with the overall survival. The results of our study demonstrated that VEGF expression, although not associated with increased angiogenesis, is a prognostic indicator in feline mammary tumors. In contrast, there is no support for a role of neovascularization as an indicator of survivability.
Cerebellar Abiotrophy in a Family of Border Collie Dogs
Authors: Sandy J. R. , Slocombe R. F. , Mitten R. W. , Jedwab D.
Published: April 2003

Cerebellar abiotrophies have a nonsex-linked, autosomal, recessively inherited basis in a number of species, and lesions typically reflect profound and progressive loss of Purkinje cells. In this report, an unusual form of abiotrophy is described for two sibling Border Collies. Extensive loss of the cerebellar granular cell layer was present with relative sparing of Purkinje cells of two female pups. The biochemical basis for this form of cerebellar abiotrophy is unknown, but the lack of disease in other siblings supports an autosomal recessive mode of inheritance.
Pilocytic Astrocytoma in a Cat
Authors: Sant'Ana F. J. F. , Serakides R. , Graça D. L.
Published: April 2003

A 12-year-old crossbred female cat was presented for necropsy with a history of anorexia, ataxia, convulsions, and blindness. Grossly, a whitish, firm, and well-circumscribed nodule with an irregular surface of approximately 1.5 cm in diameter was observed in the right dorsal, parietal, and occipital lobes of the brain. Histologically, the tumor was composed of neoplastic astrocytes forming irregular interweaving sheets and bundles. These cells were elongated, spindle-shaped, and bipolar, and some had clear cytoplasm and a dense nuclear chromatin pattern. Extensive areas of cartilaginous and osseous metaplasia were observed. By immunohistochemistry, the neoplastic cells were found to be markedly positive for S-100 protein and glial fibrillary acidic protein. On the basis of morphologic and immunohistochemical features, the diagnosis of pilocytic astrocytoma was made.
Telomerase: A Potential Diagnostic and Therapeutic Tool in Canine Oncology
Authors: Argyle D. J. , Nasir L.
Published: April 2003

In recent years there has been considerable interest in telomerase as a target for therapeutic intervention in oncology. This largely stems from the vast number of studies that have demonstrated expression and activity of the enzyme telomerase in the majority of human cancer tissues with little or no activity detectable in normal somatic tissues. These studies have led to an interest in the role of telomerase in cancers associated with domesticated species, in particular tumors that affect dogs. This article reviews the biology of telomerase and the biological significance of telomerase activity in canine tumors and discusses the clinical implications of telomerase expression in canine cancers with regard to therapeutics and diagnostics.
Camelid Mucoutaneous Fibropapillomas: Clinicopathologic Findings and Association with Papillomavirus
Authors: Schulman F. Y. , Krafft A. E. , Janczewski T. , Reupert R. , Jackson K. , Garner M. M.
Published: April 2003

Five camelid mucocutaneous fibropapillomas with histologic features similar to equine sarcoids were diagnosed. They were characterized by a dermal fibroblastic proliferation and overlying, often ulcerated hyperplastic epidermis with thin rete pegs extending down into the dermis. Two of the tumors came from llamas and three from alpacas. Four of the animals were 6-year-old females. The fifth was a 6-year-old castrated male. The fibropapillomas were located on the nose, lip, and cheeks. One of the llama tumors waxed and waned before surgery and recurred and spread after surgery. None of the other tumors recurred. All five tumors were positive for papillomavirus (PV) DNA by polymerase chain reaction testing. Nucleotide sequence analysis of the PCR product from one of the llama fibropapillomas confirmed a unique PV. This report provides the microscopic and clinical features of fibropapillomas in camelids as well as evidence for a PV etiology.
Diagnosis of Canine Lymphoid Neoplasia Using Clonal Rearrangements of Antigen Receptor Genes
Authors: Burnett R. C. , Vernau W. , Modiano J. F. , Olver C. S. , Moore P. F. , Avery A. C.
Published: April 2003

Although the diagnosis of canine leukemia and lymphoma in advanced stages is usually uncomplicated, some presentations of the disease can be a diagnostic challenge. In certain situations, lymphoma and leukemia can be difficult to distinguish from a benign reactive proliferation of lymphocytes. Because clonality is the hallmark of malignancy, we have developed an assay that uses the polymerase chain reaction to amplify the variable regions of immunoglobulin genes and T-cell receptor genes to detect the presence of a clonal lymphocyte population. The assay detected clonally rearranged antigen receptor genes in 91% of the 77 dogs with lymphoid malignancy. Of the 24 dogs tested, that were either healthy or had clearly defined conditions not related to lymphoid malignancy, a clonally rearranged antigen receptor gene was found in one (a dog with Ehrlichia canis infection). Gene rearrangement was appropriate for the immunophenotype (immunoglobulin gene rearrangement in B-cell leukemias and T-cell receptor gene rearrangement in T-cell leukemias). Dilution analysis showed that the clonal rearrangement could be detected when 0.1–10% of the DNA was derived from neoplastic cells, depending on the source tissue. Potential applications of this assay include the diagnosis of lymphoma or leukemia in biopsy samples, cavity fluids, fine needle aspirates, bone marrow and peripheral blood; the determination of lineage (B or T cell); staging of lymphoma; and detection of residual disease after chemotherapy.
Pancreatic Injury in Equine Acute Abdomen Evaluated by Plasma Trypsin Activity and Histopathology of Pancreatic Tissue
Authors: Grulke S. , Deby-Dupont G. , Cassart D. , Gangly M. , Caudron I. , Lamy M. , Serteyn D.
Published: April 2003

In cases of equine acute abdominal disease, where pancreatic damage is suspected, pancreatic damage can be assessed by measuring increased trypsin activity in the plasma of horses suffering intestinal obstruction and severe shock. The pancreas is particularly vulnerable to splanchnic hypoperfusion because it is a highly active tissue. In this study, 10 horses undergoing abdominal surgery for intestinal obstruction were assayed for trypsin activity on admission and, because of extensive intestinal lesions that were not amenable to surgery, euthanasia was selected; the pancreas was removed before euthanasia. Trypsin activity in the plasma of these horses was significantly higher than in healthy horses (196 ng/ml ± 128.2 versus 28.5 ng/ml ± 19.2; P = 0.0026). Light and transmission electron microscopy revealed slight to severe lesions of vacuolar degeneration, a few zymogen granules, dilation of the endoplasmic reticulum, and swelling of mitochondria in the exocrine pancreas. The activation of an inflammatory cascade occurring during strangulating intestinal obstruction could increase pancreatic anoxic lesions caused by severe shock and hypoperfusion in the horse. Further studies will show the significance of pancreatic lesions and the ensuing damage in equine acute intestinal obstruction and shock.
Detection Rates of Porcine Reproductive and Respiratory Syndrome Virus, Porcine Circovirus Type 2, and Swine Influenza Virus in Porcine Proliferative and Necrotizing Pneumonia
Authors: Drolet R. , Larochelle R. , Morin M. , Delisle B. , Magar R.
Published: April 2003

A retrospective study on pig lung tissues from 60 cases of proliferative and necrotizing pneumonia (PNP) was performed to determine the presence of porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), and porcine circovirus type 2 (PCV2) in these lesions. Cases selected included 30 cases diagnosed between 1988 and 1992 and 30 cases diagnosed between 1997 and 2001. In each group of 30 cases, 10 were from suckling piglets, whereas the other 20 were from postweaned animals representing either nursery or grower-finisher pigs. Immunohistochemistry using a monoclonal antibody to influenza virus type A was used to determine the presence of SIV, and in situ hybridization was used for the detection of PRRSV and PCV2 nucleic acids. PRRSV was detected in 55 of the 60 cases examined (92%), PCV2 in 25 cases (42%), and SIV in only 1 case (2%). In 30 cases (50%), PRRSV was the only virus detected, whereas in 25 other cases (42%), a combination of PRRSV and PCV2 could be detected in the lungs with PNP lesions. PCV2 could not be detected in the lungs of suckling pigs with PNP. All PCV2-positive cases were found in postweaned pigs and were always in combination with PRRSV. In this latter age group, PCV2 was detected in 63% of the cases (25/40). Data from our study indicate that SIV is rarely identified in PNP and that PCV2 infection is not essential for the development of PNP lesions. The results of the present study demonstrate that PRRSV is consistently and predominantly associated with PNP and should be considered the key etiologic agent for the condition.
Parathyroid Gland Carcinoma in a Wistar Rat
Authors: Pace V. , Scarsella S. , Perentes E.
Published: April 2003

An anaplastic carcinoma was found in one of the two parathyroids of a 2-year-old male Wistar rat, which was sacrificed at the end of a carcinogenicity study. Morphologically, it was characterized by the presence of nodular areas of pleomorphic and dense cells with numerous atypical mitoses and large regions of smaller and dark monomorphic cells devoid of mitoses and forming small cystic spaces. Local invasion of the capsule and pronounced compression of the parenchyma of the thyroid gland were observed. Immunohistochemically, the tumor was markedly positive for the parathyroid hormone and negative for the thyroid transcription factor. The proliferative activity was assessed by immunostaining the endogenous cell proliferation associated-antigen Ki-67, and the proliferating cell nuclear antigen. The diagnosis of carcinoma of the parathyroid was made on the basis of microscopic and immunohistochemical findings.
A Simple Tool for Designing with Ceramics
Authors: Rentzsch W.H.
Published: April 2003

A safety factor as a handy criterion for estimating maximum tensile strength has been developed on the basis of analyses of retrieved alumina‐ceramic body implants. The factor, which depends mainly on the given failure probability of a part, and on the statistically‐derived Weibull modulus allows inexpensive estimations for the designing of ceramic implants.
Influence of Deformation on Recrystallization of an Yttrium Oxide Dispersion‐Strengthened Iron Alloy (PM2000)
Authors: Capdevila Montes C. , Bhadeshia H.K.D.H.
Published: April 2003

A two‐fold effect of non‐uniform deformation of the yttria‐strengthened Fe alloy PM2000 has been revealed by analysis of the microstructure: Firstly, recrystallization temperature decreases, in accordance with the hypothesis that anything that makes the original microstructure more heterogeneous will encourage recrystallization; and secondly, the increase in number and density of recrystallization nuclei leads to fine grain structures which are more 3D isotropic.
Layered Organic–Inorganic Materials: A Way towards Controllable Magnetism
Authors: Rabu P. , Drillon M.
Published: April 2003

The search for new materials for tailor‐made applications and new devices involves not only solid‐state chemists, physicists or materials engineers, but also the area molecular and organo‐metallic chemistry, and even biochemistry. This is especially clear in the field of organic–inorganic multifunctional materials, whose design necessitates to investigate new concepts and principles developed in these different disciplines. Here, the authors review the structure‐magnetic property relationships in layered structures, made of organic and inorganic subunits.
Die Entwicklung der Sozialgeschichte der modernen Mathematik und Naturwissenschaft und die Frage nach dem sozialen Raum zwischen Disziplin und Wissenschaftler
Authors: Schirrmacher Arne
Published: April 2003

The use of the concept of social history of science is sketched in the Anglo‐American and the German discussions from the mid 1970s up to recent work. By presenting a ‘social map’ of a selected scientific community it is argued that between the categories of discipline and single scientist there exists a wide ‘social space’ of groups within which science is pursued. In adopting a milieu theoretic approach an ecology of science is proposed as a suitable extension of the social history of science.
Zwischen Naturphilosophie und Wissenschaftspolitik: Zum Profil der Isis oder Encyklopädischen Zeitschrift von Oken als naturwissenschaftliches Publikationsorgan in den Jahren 1817 bis 1822
Authors: Stiefel Katrin
Published: April 2003

Isis oder Encyklopädische Zeitung, edited by the German natural philosopher Lorenz Oken (1779‐1851), is supposed to be one of the most significant journals of natural sciences in the early 19th century. The following study, based on a quantitative analyses of all articles (1817‐1822), investigates the profile of the natural sciences in this journal. The results are interpreted according to Oken's concept of the journal as well as his editorial notes. It is shown that the encyclopedically broadly designed journal focuses on the natural sciences as major part of it's content, presenting the descriptive history of natural sciences (Naturgeschichte) as main subject. The journal's research perspective follows the encyclopedical spread of issues and scientific subjects; a clear research profile of scientific disciplines can not be discerned. Although scientific subjects, issues and authors are heterogeneous, Oken preserves an inner coherence by a common perspective founded in natural philosophy: his strategy was therefore to interfere with the content of the articles by comments and footnotes. Finally it is shown that Oken's idea of encyclopedism and it's realisation in Isis comprises sciences as well as politics as two sides of the same coin: based on the philosophical understanding of the unity of nature Oken tries to educate the consciousness of his readers towards a socially and politically homogeneous nation.
Advertised reference prices in an Internet environment: Effects on consumer price perceptions and channel search intentions
Authors: Jensen Thomas , Kees Jeremy , Burton Scot , Turnipseed Fernanda Lucarelli
Published: April 2003

This research examines the effects of inclusion of a reference price in an Internet advertisement on consumer price perceptions and price-search intentions both (1) on the Internet and (2) in brick-and-mortar retail channels. Proposed differences between Internet sites and brick-and-mortar channels are examined across three studies using different methodologies: (1) a survey administered in a classroom setting, (2) an Internet survey, and (3) a mail panel survey. Findings show that both price perceptions and price-search intentions differ for the Internet and brick-and-mortar retail channels. There is mixed evidence for the prediction that the reference price impact on price perceptions for the brick-and-mortar retailer is attenuated for the Internet channel. Finally, respondents with Internet access had different price perceptions and price-search intentions than those without access.
Correction to Withdrawn Article[3,4] Cyclization Products of δ‐Oxo‐α,β‐unsaturated Ketoxime During Reaction with Hydrochloric Acid in Anhydrous Diethyl Ether
Authors: Uncuta Cornelia , Tudose Adriana , Caproiu Miron T. , Udrea Silvia , Roussel Christian
Published: April 2003

We have studied the cyclization of (4Z)‐2,2,5,8,8‐pentamethyl‐4‐nonene‐3,7‐dione (3E)‐oxime (2). We have previously claimed the formation of a stable 3,5,5‐trisubstituted 3‐isoxazolidinol and of a bridged bicycle 4,5‐dihydro‐2,5‐methano‐1,4,3‐dioxazepine in the reaction of 2 with hydrochloric acid in anhydrous diethyl ether. We report in this article that the above compounds are actually 3,3‐dimethyl‐1‐(5′‐tert‐butyl‐5′‐hydroxy‐3′‐methylisoxazolidin‐3′‐yl)butan‐2‐one (5) and 1,3‐di‐tert‐butyl‐5‐methyl‐2,7‐dioxa‐6‐azabicyclo[3.2.1]oct‐3‐ene (6). The formation of these products involves the splitting of hydroxylamine in 2 and its re‐addition as an O‐nucleophile under acidic reaction conditions. Surprisingly, 5 provided the 2‐isoxazoline derivative 3 on heating or on standing in CDCl3/TFA solution at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Evaluation of thermotolerant coliforms and salinity in the four available water sources of an irrigated region of southern Sri Lanka
Authors: Shortt Rebecca , Boelee Eline , Matsuno Yutaka , Faubert Gaetan , Madramootoo Chandra , van der Hoek Wim
Published: April 2003

In many developing countries a close linkage exists between drinking and irrigation water; however, the effects of irrigation management on drinking water availability and quality, and what drinking water supplies are best suited to irrigated areas, have been little studied. Bacterial contamination and salinity of drinking water sources in a community within the Uda Walawe irrigation system of southern Sri Lanka were monitored from August to December 2000. Water with the lowest combination of faecal contamination and salt content (highest quality) was found in shallow wells, recharged with seepage water from the irrigation system. Of these wells, those surrounded by a protective wall had the lowest levels of thermotolerant coliforms (median of 244 ThCU 100 ml−1) as compared to shallow wells without protective walls (549 ThCU 100 ml−1). Furthermore, tube well waters were highly saline (average of 0.67 mS cm−1), while canal and reservoir waters had high thermotolerant coliform levels (3940 and 950 ThCU 100 ml−1). Interseasonal canal closures eliminate the canals as a water source, lowering water levels in shallow wells, and thus reducing regional water availability. Concrete lining of canals may exacerbate the drying up of shallow wells during canal closure, therefore eliminating the primary source of water in the region that can be used for drinking after only simple treatment. Copyright © 2002 John Wiley & Sons, Ltd.
Ab initio studies for the photodissociation mechanism of hydroxyacetone
Authors: Wu Yong , Xie Daiqian , Xue Ying
Published: April 2003

The reaction pathways for CH3COCH2OH (hydroxyacetone) photodissociation on the low‐lying electronic states have been studied with use of the CASSCF energy gradient techniques. The S0/S1 and S1/T1 intersection points were determined by the state‐average CASSCF method. Two main reaction pathways, which are possible to the photodissociation, have been studied. It has been found that the mechanism is stepwise, and belongs to Norrish type‐I reaction. The n → π* excitation leads to the first excited singlet state, followed by the intersystem crossing from S1 to T1. On the T1 potential energy surface, the system can dissociate adiabatically to CH3(x̃) +COCH2OH( x̃) and CH3CO(x̃)+CH2OH(x̃). The COCH2OH(x̃) and CH3CO(x̃) radicals can further dissociate into CO, OH, and other fragments. Our calculated results are in good agreement with recent experimental results. © 2003 Wiley Periodicals, Inc. J Comput Chem 8: 931–938, 2003
Rapid hyperpolarized 3He diffusion MRI of healthy and emphysematous human lungs using an optimized interleaved‐spiral pulse sequence
Authors: Salerno Michael , Altes Talissa A. , Brookeman James R. , de Lange Eduard E. , Mugler John P.
Published: April 2003

Purpose

To develop and validate an interleaved‐spiral diffusion pulse sequence capable of hyperpolarized 3He MR imaging of the whole lung in less than 10 seconds.

Materials and Methods

Hyperpolarized 3He diffusion measurements were performed in seven healthy volunteers and five patients with emphysema using an interleaved‐spiral pulse sequence that provided 11 contiguous 15‐mm thick coronal ADC maps, with an in‐plane resolution of 3.9 mm, covering the whole lung in 5.5 seconds. The resulting means and SDs of ADC values were compared statistically to those from a gradient‐echo pulse sequence with identical resolution and diffusion‐weighting gradients that acquired five ADC maps in 10.5 seconds.

Results

High‐quality diffusion‐weighted interleaved‐spiral images covering the whole lung were obtained, and showed no significant susceptibility‐induced image degradation compared to corresponding gradient‐echo images. On a subject‐by‐subject basis, the means and SDs of ADC values for the interleaved‐spiral technique were not statistically different from those for the gradient‐echo technique. The mean ADC values from the two techniques were highly correlated on a section‐by‐section basis (R = 0.99).

Conclusion

The interleaved‐spiral diffusion pulse sequence permits rapid acquisition of contiguous ADC maps covering the whole lung during a short breath‐hold period, and provides ADC values that are statistically equivalent to those from standard gradient‐echo techniques. J. Magn. Reson. Imaging 2003;17:581–588. © 2003 Wiley‐Liss, Inc.
Changes in amount of organic and inorganic fractions of nitrogen in an Eutrochrept soil after long‐term cropping with different fertilizer and organic manure inputs
Authors: Sammi Reddy Kotha , Singh Muneshwar , Tripathi Awadesh Kumar , Singh Mahavir , Saha Manbendra Nath
Published: April 2003

The influence of 30 years of cropping with different fertilizer and farmyard manure (FYM) inputs on the contents and depth distribution of organic C, total N (Nt), soil mineralizable N, and organic and inorganic N fractions was investigated in an Eutrochrept. Continuous application of 100 %NPK(+S), 150 %NPK(+S), and 100 %NPK(+S)+FYM led to a marked increase in organic C, total N, hydrolyzable N (viz., amino acid N, hydrolyzable NH4‐N, hexose amine N, and unidentified hydrolyzable N), and nonhydrolyzable N as compared to an adjacent fallow. The contents of the various organic N fractions were largest in surface soil and thereafter decreased with the depth. However, at 30 – 45 cm depth the content of organic C was not affected by the different treatments except 100 %NPK(+S)+FYM. On the other hand, continuous cropping without fertilization resulted in a depletion of total hydrolyzable N in control over fallow by 27.2 % (0–15 cm), 19.6 % (15–30 cm), and 4.7 % (30–45 cm). The incorporation of FYM with 100 %NPK(+S) resulted in greater contents of soil mineralizable N as compared to 100 %NPK(+S) (0–15, 15–30 cm). The proportion of hydrolyzable N (57–76 % of Nt) decreased and that of nonhydrolyzable N (22–40 % of Nt) increased with depth. The proportion of amino acid N (19–26 % of Nt), hexose amine N (2.1–3.5 % of Nt) and unidentified hydrolyzable N (17–27 % of Nt) decreased with depth. All organic soil N fractions including even nonhydrolyzable N in surface and subsurface soils were highly significantly correlated with soil mineralizable N derived from incubations under waterlogged and aerobic conditions. The best correlation to mineralizable N was found for amino acid N and the least significant correlation for nonhydrolyzable N.
Growth and phosphorus uptake of maize cultivated alone, in mixed culture with other crops or after incorporation of their residues
Authors: El Dessougi Hanadi , zu Dreele Alexander , Claassen Norbert
Published: April 2003

Intercropping or rotating of P‐efficient crop species which mobilize sparingly soluble P by their root exudates can have beneficial effects on growth and P uptake of P‐inefficient species. We aimed at studying the effect of intercropping or incorporating of crop residues of P‐efficient crops on the components of maize P‐uptake, i.e. the root‐system size and P influx (P‐uptake rate per unit root length). This was studied in 3 pot experiments in a low‐P sandy soil. In the first experiment, maize was intercropped with white lupine, sugar beet or oilseed rape, and with groundnut in the second experiment. In the third experiment, maize was grown after incorporating the crop residues of white lupine, sugar beet or oilseed rape. Maize growth and yield was strongly inhibited when intercropped with white lupine, sugar beet or oilseed rape, probably because of competition for nutrients. But with groundnut as the accompanying species, maize yield was increased by a factor of 3, mainly because of an enhanced P influx. Crop residues of oilseed rape and sugar beet increased the yield of maize by factors 2 and 1.6, respectively, because of a 3 and 2 times higher P uptake as compared to maize grown after maize without incorporation of crop residue. The reason for the higher maize P‐uptake after oilseed rape was an 11 times higher P influx as compared to maize without crop residues, and after sugar beet residues because of an enhanced root growth and a 4 times higher P influx. Lupine residues did not improve maize growth, mainly because of a low P influx, which was even less than that of maize grown without crop residues. The soil solution P concentration and calcium acetate lactate‐extractable P (CAL P) measured in this study did not reflect the P availability as indicated by the plants (P uptake, P influx). This indicates that other mechanisms such as P mobilization in the rhizosphere by root exudates or cell‐wall components were responsible for the increased P availability. These mechanisms need further investigation.
On the Crystal Structure of cis‐1,4‐Poly(2,3‐dimethyl‐1,3‐butadiene)
Authors: Pirozzi Beniamino , Napolitano Roberto , Petraccone Vittorio , Esposito Simona
Published: April 2003

Models for the crystal structure of cis‐1,4‐poly(2,3‐dimethyl‐1,3‐butadiene) are elucidated by the joint use of molecular mechanics and WAXS. The chain conformation can be predicted by using different sets of potential functions. A model of crystal structure calculated by molecular mechanics has been refined in order to find the best accordance with the experimental X‐ray powder spectra. Another model is proposed to explain a few minor discrepancies between the calculated and the experimental WAXS powder spectra.

Portion of the chain of cis‐PDMBD, containing two monomer units with indications of the symmetry elements of the tci line repetition group, and of the bond and torsion angles of the backbone, which are independent variables.

magnified image

Portion of the chain of cis‐PDMBD, containing two monomer units with indications of the symmetry elements of the tci line repetition group, and of the bond and torsion angles of the backbone, which are independent variables.
Variation in cyclooxygenase expression levels within the colorectum
Authors: Wiese Frederick W. , Thompson Patricia A. , Warneke James , Einspahr Janine , Alberts David S. , Kadlubar Fred F.
Published: April 2003

The positive association of decreased risk of colorectal cancer with nonsteroidal antiinflammatory drug (NSAID) use, combined with the observation that cyclooxygenase(COX)‐2 is present in a majority of colorectal tumors, has led to the proposed use of isozyme‐specific COX inhibitors as preventive agents in polyp and tumor formation in the colon. However, the exact biochemical mechanisms and disease stage at which reduced risk is mediated remain somewhat controversial, in part because of the complex biochemical changes that occur during the progression from aberrant crypt to polyp to tumor. In this study, COX‐1 and COX‐2 protein expression levels were determined in sets of tumor and normal colon tissue. Changes were characterized in COX‐1 and COX‐2 expression within individuals, in relation to such factors as sex, tumor grade, and location in the colorectum. COX‐1 expression levels were found to be significantly reduced in tumors compared to matched normal tissues (Dunn's method, P < 0.05). Additionally, COX‐1 expression was decreased in stage T3 tumors as compared to stage T2 tumors (Student's t‐test, P = 0.009). Similar to previous reports, COX‐2 protein expression was present in 73% of the tumors studied and appeared to be independent of tumor grade and sex. Interestingly, decreased COX‐2 expression correlated with tumor occurrence in rectal mucosa (Wilcoxon two‐sample test, P < 0.05). These results warrant further investigation, especially the identification of determinants that would predict which populations would be most responsive to COX‐2 inhibition as a means of colorectal cancer chemoprevention. Published 2003 Wiley‐Liss, Inc.
Characterisation of catalytic nucleic acids targeting the survival of motor neuron messenger RNA
Authors: Trülzsch Barbara , Davies Kay , Wood Matthew
Published: April 2003

Catalytic nucleic acids have been used in a reverse genetics approach to study gene function. We are interested in applying this technology to study the autosomal recessive disease Spinal Muscular Atrophy (SMA) which is caused by loss of survival motor neuron gene (SMN) product leading to progressive motor neuron loss and muscular atrophy. Although the SMN gene is ubiquitously expressed, the cause for selective motor neuron loss is unknown. Embryonal lethality in mice has made it extremely difficult to generate animal models of SMA. We describe a procedure for selecting effective DNAzymes (DZ) and ribozymes (RZ) based on their ability to cleave the full length Smn mRNA at low magnesium concentrations, after a short time period, and at a low catalytic nucleic acid to target ratio. Using these criteria three effective RZ and DZ were generated. These results indicate that catalytic nucleic acids can effectively cleave Smn target RNA in an environment closely resembling that present in the cell and thus have potential for interference with Smn gene expression in cells and in vivo.
Cutting and Machining Energetic Materials with a Femtosecond Laser
Authors: Roeske Frank , Benterou Jerry , Lee Ronald , Roos Edward
Published: April 2003

A femtosecond (fs) laser has been used as a tool for solving many problems involving access, machining, disassembly, inspection and avoidance of undesirable hazardous waste streams in systems containing energetic materials. Because of the unique properties of the interaction of ultrashort laser pulses with matter, the femtosecond laser can be used to safely cut these energetic materials in a precise manner without creating an unacceptable waste stream. Many types of secondary high explosives (HE) and propellants have been cut with the laser for a variety of applications ranging from disassembly of aging conventional weapons (demilitarization), inspection of energetic components of aging systems to creating unique shapes of HE for purposes of initiation and detonation physics studies. Hundreds of samples of energetic materials have been cut with the fs laser without ignition and, in most cases, without changing the surface morphology of the cut surfaces. The laser has also been useful in cutting nonenergetic components in close proximity to energetic materials.
Study of the Reaction of Model Reactive Armour to Jet Attack
Authors: Trzciński Waldemar Andrzej , Trębiński Radosław , Cudziło Stanisław
Published: April 2003

The reaction of a model reactive armour to a jet attack was studied as well experimentally as theoretically. An analysis of the process of driving metal plates of the armour by the gaseous products of the detonation initiated in a confined layer of an explosive by the jet at various incidence angles was performed. The X‐ray impulse photography was applied to record the motion of plates at two perpendicular directions. The theoretical analysis was performed by using a simple model, in which the plate deformation and finite time of its acceleration were taken into account. The time‐space characteristics of the motion of model reactive armour elements obtained from experiments and numerical modelling can be applied for designing cumulative heads destined for destroying armours protected by reactive armour.
Design of high‐strength concrete members: state‐of‐the‐art
Authors: Mendis Priyan
Published: April 2003

The advancement of material technology and production has led to higher grades of concrete strengths. In recent years a marked increase in the use of high‐strength concrete (compressive strength, f′c>50 MPa) has been evident in construction projects around the world. High‐strength concrete (HSC) offers significantly better structural engineering properties, such as higher compressive and tensile strengths, higher stiffness, better durability, compared with conventional normal‐strength concrete (NSC). Many structures built now have at least some components constructed with HSC. However, to a large extent, practice has preceded theory with constitutive equations simply being extrapolated to higher strengths. The main concern regarding the use of HS Concrete is the reduction in ductility with the increase in compressive strength observed under uniaxial compression. Past research has shown that members made of HSC exhibit, in some instances, different failure mechanisms, and simply extrapolating models and equations meant for NSC to HSC may lead to unsafe designs. Major codes of practice around the world are still based on experimental and theoretical results derived from investigations on NSC. Individual design rules codified in any of the national and international design codes need to be experimentally verified and categorized with a view to taking further action. In some instances structural designers are unable to take full advantage of the material because of insufficient information.

Recent developments in design and performance of HSC members, especially the papers published within the last two or three years are presented in this paper. The paper covers the topics of engineering properties, fire design, flexural members, shear and torsion, bond and anchorage, HSC columns, transmission of HSC column loads through weaker slabs, walls, impact resistance and seismic design of HSC structures. Copyright © 2003 John Wiley & Sons, Ltd.
Bloch waves of small high‐Tc bipolarons
Authors: Alexandrov A. S.
Published: April 2003

Over the last decade several competing models of high‐temperature superconductivity were proposed, most of them with short‐range interactions. We review a more realistic model with strong on‐site repulsive correlations, the Coulomb and strong finite‐range electron–phonon interactions. Bipolarons in the model exist in the itinerant Bloch states at temperatures below about half of the characteristic phonon frequency. Depending on the ratio of the inter‐site Coulomb repulsion and the polaron level shift, the ground state of the model is a polaronic Fermi (or Luttinger) liquid, bipolaronic high‐Tc superconductor, or charge‐segregated insulator for the strong, intermediate, and weak Coulomb repulsion, respectively. Two particular lattices are analysed in detail: a chain with the finite range electron–phonon interaction and a zig‐zag ladder. Charge carriers in the ladder are superlight mobile intersite bipolarons. They propagate coherently without emission or absorption of phonons with about the same mass as single polarons. The model describes key features of the cuprates, in particular their Tc values, different isotope effects, normal state pseudogaps, and spectral functions measured in tunnelling and photoemission.
Recent progress in path integrals
Authors: Kleinert H.
Published: April 2003

A survey is given over important recent advances made with the help of path integrals in four different fields: (i) strong‐coupling theory and critical phenomena, (ii) perturbative path integrals, (iii) theory of distributions, (iv) option pricing for non‐Gaussian fluctuations.
Propagator and Slater sum in one‐body potential theory
Authors: March N. H. , Howard I. A.
Published: April 2003

For a one‐body potential V(r) generating eigenfunctions ψi(r) and corresponding eigenvalues ϵi, the Feynman propagator K(r, r′, t) is simply related to the canonical density matrix C(r, r}′, β) by β → it. The diagonal element S(r, r},β) of C is the so‐called Slater sum of statistical mechanics. Differential equations for the Slater sum are first briefly reviewed, a quite general equation being available for a one‐dimensional potential V(x). This equation can be solved for a sech2 potential, and some physical properties of interest such as the local density of states are derived by way of illustration. Then, the Coulomb potential –Ze2/r is next considered, and it is shown that what is essentially the inverse Laplace transform of S(r, β)/β can be calculated for an arbitrary number of closed shells. Blinder has earlier determined the Feynman propagator in terms of Whittaker functions and contact is here established with his work. The currently topical case of Fermion vapours which are harmonically confined is then treated, for both two and three dimensions. Finally, in an Appendix, a perturbation series for the Slater sum is briefly summarized, to all orders in the one‐body potential V(r). The corresponding kinetic energy is thereby accessible.
Moore's law: new playground for quantum physics
Authors: Van Rossum M. , Schoenmaker W. , Magnus W. , De Meyer K. , Croitoru M. D. , Gladilin V. N. , Fomin V. M. , Devreese J. T.
Published: April 2003

CMOS technology has been proven as one of the most important achievements in modern engineering history. In less than 30 years, it has become the primary engine driving the world economy. Device scaling makes this possible. For decades, progress in device scaling has followed an exponential curve: this has come to be known as Moore's law. Downscaling such devices like MOSFETs to their limiting sizes is a key challenge of the semiconductor industry now. Therefore device simulation requires new theory and modeling techniques, what helps to improve the understanding of device physics and design, for structures at the sub‐100 nm scale, and complements experimental work in addressing this challenge. We present a new approach, which allows us to make predictions about performance of future MOSFETs. The quantum‐mechanical features of the electron transport are extracted from the numerical solution of the quantum Liouville equation in the Wigner function representation.
Investigation of EDTA anticoagulant in plasma to improve the throughput of liquid chromatography/tandem mass spectrometric assays
Authors: Sadagopan Nalini P. , Li Wenlin , Cook Jack A. , Galvan Betsy , Weller David L. , Fountain Scott T. , Cohen Lucinda H.
Published: April 2003

In this study, EDTA and heparin are compared as anticoagulants with respect to their efficiency in preventing clot formation in plasma samples that were subsequently analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). A pilot in vivo pharmacokinetic study for the drug chlorpheniramine was conducted in which both EDTA and heparin plasma samples were collected simultaneously. All conditions except the anticoagulant were held constant during the pharmacokinetic study. Bioanalytical results were compared from samples transferred by manual pipette and by an automated liquid handler workstation. The concentration of chlorpheniramine in samples was determined by LC/MS/MS. Results from the analysis of variances (ANOVA) of log‐transformed plasma chlorpheniramine concentrations were used to calculate 90% confidence intervals for the ratio least‐squares mean values for anticoagulants and for transfer methods. Analytical concentrations of the drug chlorpheniramine were equivalent in heparin‐ and EDTA‐containing plasma. Results suggest that the failure rate for transfer of EDTA plasma (50 μL by automated workstation or manually) is less than that for heparinized plasma. As a consequence of these results, the vast majority of plasma samples in our laboratories are now collected in EDTA, which allows for use of automated sample transfer resulting in a three‐fold timesaving over manual transfer using a single‐channel pipette. The ability to use automation has resulted in improved efficiency and cost savings. Copyright © 2003 John Wiley & Sons, Ltd.
Optimization of in‐gel protein digestion system in combination with thin‐gel separation and negative staining in 96‐well plate format
Authors: Katayama Hiroyuki , Satoh Keiko , Takeuchi Masakazu , Deguchi‐Tawarada Maki , Oda Yoshiya , Nagasu Takeshi
Published: April 2003

Improvement of in‐gel digestion efficiency is highly desirable for one‐ or two‐dimensional gel electrophoretic separation and mass spectrometric (MS) analysis in proteomics, because the resultant increases in sequence coverage and MS signal intensity lead to higher confidence in protein identification. Here an optimized in‐gel digestion system, in combination with thin‐gel separation and negative staining in a high‐throughput format using 96‐well plates, is described. The combination of negative staining and protein separation on a 0.9 mm thick gel showed a clear improvement in in‐gel digestion efficiency in comparison with the more typical protocols such as the combination of silver staining and a 1.0 mm gel. In addition, the use of 96‐well plates to increase throughput did not decrease the efficiency of this strategy when the stirring of the gel pieces in processes such as destaining, washing, gel‐shrinking and peptide extraction was performed by sonication instead of shaking the plates. This procedure was optimized and applied to identify proteins of the postsynaptic density fraction; 105 proteins were identified after SDS‐PAGE separation. Copyright © 2003 John Wiley & Sons, Ltd.
Organization of the endoplasmic reticulum in dividing cells of the gymnosperms Pinus brutia and Pinus nigra, and of the pterophyte Asplenium nidus
Authors: Zachariadis M , Quader H , Galatis B , Apostolakos P
Published: April 2003

Endoplasmic reticulum (ER) organization in the dividing cells of the pterophyte Asplenium nidus and of the gymnosperms Pinus brutia and Pinus nigra has been studied by immunolocalization techniques using the monoclonal antibody 2E7, which recognizes luminar ER resident proteins containing C‐terminal HDEL sequences. In the pterophyte, the ER reorganization during cell cycle is similar to that in angiosperms. Among others, prominent ER gatherings were found at the mitotic spindle poles and in the phragmoplast during cytokinesis. However, in the gymnosperms examined, the ER displays a unique pattern of reorganization not described so far. In both the Pinus species, well‐defined ER patterns are successively formed during cell cycle. They are the preprophase ER‐band, the prophase‐ metaphase‐ and anaphase ER‐spindle, the interzonal ER‐system, the ER‐phragmoplast and an ER‐system lining the daughter cell wall. The ER patterns are closely similar to that of the correspondent microtubule (MT) arrangements with which they are co‐organized.

Observations made on P. nigra root‐cells affected by oryzalin, colchicine and cytochalasin D favour the conclusion that the pattern of ER organization is controlled during mitosis and cytokinesis by the MT cytoskeleton.
On Dispensing with Q?: Goodacre on the Relation of Luke to Matthew
Authors: KLOPPENBORG JOHN S.
Published: April 2003

The case against Q depends logically on the plausibility of Luke's direct use of Matthew. Goodacre's carefully argued book contends (a) that none of the objections to the Mark-without-Q hypothesis is valid; (b) that given certain assumptions about Luke's aesthetic preferences, it is plausible that he systematically reordered the ‘Q’ material from Matthew; (c) that Luke's rearrangement of Matthew shows as much intelligence and purposefulness as Matthew's; and (d) that certain features of the ‘Q’ in Luke 3–7 betray the influence of Matthean redaction. Careful scrutiny of these arguments shows that (a) is only partially true; that Goodacre's assumptions about Lukan aesthetics (b) are open to serious objection; and that while (c) is true, Goodacre's argument in (d) ultimately cuts against his case against Q.