bluuebunny/crossref_metadata_2025 huggingface dataset:
Jasmonic acid is involved in the water‐stress‐induced betaine accumulation in pear leaves
Authors: GAO X.‐P. , WANG X.‐F. , LU Y.‐F. , ZHANG L.‐Y. , SHEN Y.‐Y. , LIANG Z. , ZHANG D.‐P.
Published: December 2004

Jasmonic acid (JA) is known to be involved in the response of plants to environmental stresses such as drought, and betaine (glycinebetaine) is an osmopretectant accumulated in plants under environmental stresses including drought. However, it remains currently unclear whether JA is involved in the water‐stress‐induced betaine accumulation in plant leaves. The present experiment, performed with the whole pear plant (Pyrus bretschneideri Redh. cv. Suli), revealed that the exogenously applied JA induced a significant increase of the betaine level in the pear leaves when the plants were not yet stressed by drought, and when the plants were subjected to water stress, the ‘JA plus drought’ treatment induced a significant higher betaine level than did the drought treatment alone. Meanwhile, the ‘JA plus drought’ treatment induced higher levels of betaine aldehyde dehydrogenase (BADH, E C 1.2.1.8) and activities in the leaves than did the drought treatment alone. These results obtained in the whole plant experiments were supported by the results of detached leaf experiments. In detached leaves JA induced significant increases in betaine levels, BADH activities and BADH protein amounts in a time‐ and concentration‐dependent manner. These data demonstrate that JA is involved in the drought‐induced betaine accumulation in pear leaves.
Tolerance of septoria leaf blotch in winter wheat
Authors: Parker S. R. , Welham S. , Paveley N. D. , Foulkes J. , Scott R. K.
Published: December 2004

For individual varieties, tolerance of septoria leaf blotch was quantified by the slope of the relationship between disease and yield. Variation in disease severity and the associated yield responses were provided across two sites and three seasons of field experiments. Slopes were fitted by residual maximum likelihood for two contrasting models: (i) a fixed‐effects model, where no prior assumptions were made about the form of the variety slopes; and (ii) a random‐effects model, where deviations in individual variety slopes away from the mean variety slope formed a normal random population with unknown variance. The analyses gave broadly similar results, but with some significant differences. The random model was considered more reliable for predicting variety performance. The effects of disease were quantified as symptom area and green canopy duration. Models of the relationship between symptom area and yield were site‐specific. When site effects were not taken into account, these models had poor predictive precision. Models based on the canopy green area gave robust predictions of yield and were not site‐specific. Differences in disease tolerance were detected in a comparison of 25 commercial winter wheat varieties. Tolerance was not detected directly through symptom measurements, but instead through measurements of canopy green area, which provides a measurement of the effects of disease that accounts for differences in canopy size across sites and seasons. The varieties showing greatest tolerance tended to have lower attainable yield than the intolerant varieties. Presence of the 1BL/1RS chromosome translocation, which has been reported to increase radiation use efficiency, appeared to be associated with intolerance.
The Determinants of Bank Credit in Industrialized Countries: Do Property Prices Matter?
Authors: Hofmann Boris
Published: December 2004

In this study, we analyse the determinants of bank credit to the private non‐financial sector in 16 industrialized countries based on a cointegrating VAR. Cointegration analysis suggests that property prices are an important determinant of the long‐run borrowing capacity of the private sector, which needs to be taken into account to explain the long‐run movements of bank lending. Impulse response analysis reveals that innovations to property prices also have a highly significant and persistent positive dynamic effect on bank lending. This result suggests that innovations to property prices may give rise to significant and persistent cycles in bank lending and are thus a potential explanation for the persistent financial cycles observed in the past.
Evolution of a complex coevolved trait: active pollination in a genus of fig wasps
Authors: Cook J. M. , Bean D. , Power S. A. , Dixon D. J.
Published: December 2004

Only three insect lineages have evolved complex active pollination behaviour and only fig wasps (Agaonidae) have also reverted from active to passive pollination. Previously, it was assumed that there was a single origin of active pollination in fig wasps, followed by one independent loss in each of five genera. We show here that there have been three to six changes in pollination behaviour within just one genus (Pleistodontes). The results suggest multiple gains of active pollination in fig wasps, but are sensitive to assumptions about the relative costs of gaining and losing this complex behaviour. In addition, previous comparative studies at higher taxonomic levels have reported correlated evolution between active pollination in wasps and low anther/ovule ratios in figs. We report that changes in pollination behaviour between congeneric species correlate perfectly with changes in anther/ovule ratios in the host figs, showing no phylogenetic inertia in coadaptation at the species level.
Parasite-induced surfacing in the cockle Austrovenus stuchburyi: adaptation or not?
Authors: Tompkins D. M. , Mouritsen K. N. , Poulin R.
Published: December 2004

Parasite manipulation of host behaviour is a compelling example of the extended phenotype. However, in many cases, such manipulation may be incorrectly assumed. Previous work has demonstrated that Austrovenus stuchburyi cockles stranded on mud-flat surfaces due to an inability to re-burrow both contain significantly more metacercariae of the trematode Curtuteria australis and are predated by the definitive host of this parasite at a faster rate than burrowed cockles. These results have been interpreted as strong evidence for a manipulation of cockle behaviour by the trematode to facilitate transmission to the definitive host. The model presented here, however, indicates that the selective advantage to the parasite of the altered host behaviour is currently of a negligible level at our study site that is highly unlikely to have been realized as an adaptation over evolutionary time. Hence, there are no grounds on which the more parsimonious explanation, that the altered host behaviour observed is simply an incidental side-effect of infection, can be rejected. We thus maintain that for any change in the behaviour of infected hosts to be confirmed as potentially a parasite trait that has evolved in response to selection, the adaptive benefit taking into account the entire parasite life cycle may need to be considered.
Validation of ‘personal strain’ and ‘role strain’: Subscales of the short version of the Japanese version of the Zarit Burden Interview (J‐ZBI_8)
Authors: KUMAMOTO KEIGO , ARAI YUMIKO
Published: December 2004

Abstract  The eight‐item short version of the Japanese version of the Zarit Burden Interview (J‐ZBI_8) has been confirmed for reliability and validity, and its two subscales (personal strain and role strain) are based on the factor structure of the ZBI. It has been demonstrated that these subscales have good reliability. The aim of the present study was to confirm their construct validity. A total of 51 impaired elderly who had been receiving regular nurses’ visits in Kyoto Prefecture, Japan and their family primary caregivers, participated in the present study. Each caregiver was asked to complete a questionnaire which included the J‐ZBI_8, the hours spent in caregiving, and the physical and cognitive disability of the impaired elderly. A principal component analysis identified the following two principal components of these variables: ‘Activities of Daily Living deficits’ and ‘behavioral disturbances’. Consequently, Barthel Index (BI) and Troublesome Behavior Scale (TBS) were selected as the representative variable, respectively, for each component. We subsequently calculated the Spearman's rank correlations among the subscales of J‐ZBI_8, BI and TBS. Personal strain was found to be correlated with TBS (rho = 0.48, P < 0.01), while role strain was correlated with the BI (rho = −0.29, P = 0.04). The correlation between personal strain and BI was not significant, nor was the correlation between role strain and TBS. These findings indicate that the personal strain and role strain measured by J‐ZBI_8 correspond to the personal strain and role strain of the ZBI originally described by Whitlatch et al. Therefore, the construct validity of the J‐ZBI_8 subscales is confirmed.
Generating a learning curve for penile block in neonates, infants and children: an empirical evaluation of technical skills in novice and experienced anaesthetists
Authors: Schuepfer Guido , Jöhr Martin
Published: December 2004

Background : Literature concerning learning curves for anaesthesiological procedures in paediatric anaesthesia is rare. The aim of this study was to assess the number of penile blocks needed to guarantee a high success rate in children.

Methods : At a teaching hospital, the technical skills of 29 residents in anaesthesiology who performed penile blocks under the supervision of two staff anaesthesiologists were evaluated during a 12‐month period using a standardized self‐evaluation questionnaire. At the start of the study period, the residents had no prior experience in paediatric anaesthesia or in performing penile block. All residents entered the paediatric rotation after a minimum of 1‐year training in adult general and regional anaesthesia. The blocks were rated using a binary score. For comparison, the success rates of the two supervising staff anaesthesiologists were collected during the same period using the same self‐evaluation questionnaire. Statistical analyses were performed by generating individual and institutional learning curves by using the pooled data. The learning curves were calculated with the aid of a least square fit model. A 95% CI were estimated by a Monte Carlo procedure with a bootstrap technique.

Results : In a total number of 392 blocks performed, the overall success rate was 92.1%. There was no statistical difference between the success rate of the two staff members (success rate: 96.3%) and the overall success rate of the 29 residents performing a total of 339 blocks. The total success rate for this group was 91.5%. The failure rate for the first 10 blocks performed by the residents was 8.82% (95% CI: 5.0–14.14%), it was 4.12% (95% CI: 1.13–10.22%) for the next 10 blocks and from blocks 21 to 40 it was 6.5% (95% CI: 2.65–12.9%). For blocks 41–60, the failure rate was 4.4% (95% CI 0.54–15.15%).

Conclusions : Penile block in children is easily learned by residents. A steep learning curve was found. The success rate was over 93.5% after more than 40 blocks.
A case of severe diazoxide toxicity
Authors: Silvani Paolo , Camporesi Anna , Mandelli Anna , Wolfler Andrea , Salvo Ida
Published: December 2004

Hyperinsulism is a rare cause of persistent hypoglycemia in the neonatal period. Therapy can be accomplished either surgically or pharmacologically. Diazoxide treatment remains the mainstay of medical therapy. Tolerance of diazoxide is usually excellent, but several adverse effects of this drug have been described. A case of severe diazoxide intoxication with fluid retention, congestive heart failure, and respiratory failure is reported. The patient was a 43‐day‐old infant, affected by persistent and severe hypoglycemia. After the diagnosis, hyperinsulinism was established he was treated with diazoxide (17 mg·kg−1 daily) and octreotide (12 μg·kg−1 daily). A few days later he presented with hepatomegaly, severe fluid retention, diffuse edema, congestive heart failure, and respiratory failure requiring mechanical ventilation. After introduction of ACE inhibitors he developed acute renal failure. The clinical condition worsened and he developed pulmonary hypertension requiring high‐frequency oscillatory ventilation. Diazoxide was stopped on the 12th day in spite of poor control of blood sugar. During the next 5 days his hemodynamic status dramatically improved and he was weaned from catecholamines: he lost weight, had a negative fluid balance, and the edema disappeared, a normal diuresis resumed and renal function improved. Improvement of respiratory patterns and gas exchange made it possible to switch back to conventional ventilation and then to extubate the patient. Echocardiography demonstrated reduction of the PA pressure to normal and resolution of atrial enlargement. The patient was scheduled for elective subtotal pancreatectomy. Diagnosis and management of diazoxide intoxication are discussed.
Evaluation and costs of different haemoglobin methods for use in district hospitals in Malawi
Authors: Medina Lara A , Mundy C , Kandulu J , Chisuwo L , Bates I
Published: December 2004

Aims:To evaluate the characteristics of manual haemoglobin methods in use in Malawi and provide evidence for the Ministry of Health in Malawi to enable them to choose a suitable method for district hospitals.

Methods:Criteria on accuracy, clinical usefulness, user friendliness, speed, training time, and economic costs were determined by local health professionals and used to compare six different manual haemoglobin methods. These were introduced sequentially into use in a district hospital in Malawi alongside the reference method.

Results:HemoCue was the optimal method based on most of the outcome measures but was also the most expensive (US$0.75/test). DHT meter and Jenway colorimeter were the second choice because they were cheaper (US$0.20–0.35/test), but they were not as accurate or user friendly as HemoCue.

Conclusions:The process for choosing appropriate laboratory methods is complex and very little guidance is available for health managers in poorer countries. This paper describes the development and testing of a practical model for gathering evidence about test efficiency that could be adapted for use in other resource poor settings.
Association of specific genotype and haplotype of p53 gene with cervical cancer in India
Authors: Mitra S , Misra C , Singh R K , Panda C K , Roychoudhury S
Published: December 2004

Background:The predictive value of codon 72 arginine homozygosity at the p53 gene for human papilloma virus associated cervical cancer risk remains inconclusive. It has also been proposed that the inheritance of specific germline haplotypes based on three biallelic polymorphisms of p53 (intron 3 16 bp duplication, codon 72 Bst UI (Arg/Pro), and intron 6 Nci I restriction fragment length polymorphism at nucleotide 13494) is a better predictor of various cancer risks.

Aims:To determine the genotype and haplotype frequency of these three p53 polymorphisms in 61 patients with cervical squamous cell carcinoma and 94 ethnically matched controls from the eastern region of India and estimate the risk, if any, of specific genotypes and haplotypes.

Methods:Samples were genotyped by polymerase chain reaction followed by variant specific restriction enzyme digestion. Haplotypes were estimated by the maximum likelihood method using the expectation maximisation algorithm.

Results:Genotype distributions of the three polymorphisms in patients and controls showed a good fit to the Hardy-Weinberg equilibrium. The p53 codon 72 arginine homozygous genotype was significantly over represented in patients compared with controls. Those with the homozygous arginine genotype exhibited a 2.59 fold higher risk of developing squamous cell carcinoma of the uterine cervix. A significant risk was also seen with a combination of two haplotypes, 1–2–1 and 1–2–2.

Conclusion:p53 codon 72 arginine homozygotes appear to be at greater risk of developing squamous cell carcinoma of the uterine cervix. The high risk haplotypes 1–2–1 and 1–2–2 also contain the arginine allele, further strengthening this conclusion.
AN APPROACH TO MEMBRANE COMPUTING UNDER INEXACTITUDE
Authors: CASASNOVAS JAUME , MIRÓ JOE , MOYÀ MANUEL , ROSSELLÓ FRANCESC
Published: December 2004

In this paper we introduce a fuzzy version of symport/antiport membrane systems. Our fuzzy membrane systems handle possibly inexact copies of reactives and their rules are endowed with threshold functions that determine whether a rule can be applied or not to a given set of objects, depending of the degree of accuracy of these objects to the reactives specified in the rule. We prove that these fuzzy membrane systems generate exactly the recursively enumerable finite-valued fuzzy subsets of ℕ.
ARAUCARIA: SOFTWARE FOR ARGUMENT ANALYSIS, DIAGRAMMING AND REPRESENTATION
Authors: REED CHRIS , ROWE GLENN
Published: December 2004

Argumentation theory involves the analysis of naturally occurring argument, and one key tool employed to this end both in the academic community and in teaching critical thinking skills to undergraduates is argument diagramming. By identifying the structure of an argument in terms of its constituents and the relationships between them, it becomes easier to critically evaluate each part of an argument in turn. The task of analysis and diagramming, however, is labor intensive and often idiosyncratic, which can make academic exchange difficult. The Araucaria system provides an interface which supports the diagramming process, and then saves the result using AML, an open standard, designed in XML, for describing argument structure. Araucaria aims to be of use not only in pedagogical situations, but also in support of research activity. As a result, it has been designed from the outset to handle more advanced argumentation theoretic concepts such as schemes, which capture stereotypical patterns of reasoning. The software is also designed to be compatible with a number of applications under development, including dialogic interaction and online corpus provision. Together, these features, combined with its platform independence and ease of use, have the potential to make Araucaria a valuable resource for the academic community.
A Tychonoff theorem in intuitionistic fuzzy topological spaces
Authors: Çoker Doğan , Haydar Eş A. , Turanli Necla
Published: December 2004

The purpose of this paper is to prove a Tychonoff theorem in the
so‐called “intuitionistic fuzzy topological spaces.” After
giving the fundamental definitions, such as the definitions of
intuitionistic fuzzy set, intuitionistic fuzzy topology,
intuitionistic fuzzy topological space, fuzzy continuity, fuzzy
compactness, and fuzzy dicompactness, we obtain several
preservation properties and some characterizations concerning
fuzzy compactness. Lastly we give a Tychonoff‐like theorem.
Multiplicity and structures for traveling wave solutions of the Kuramoto‐Sivashinsky equation
Authors: Feng Bao-Feng
Published: December 2004

The Kuramoto‐Sivashinsky (KS) equation
is known as a popular prototype to represent a system in which
the transport of energy through nonlinear mode coupling produces a
balance between long wavelength instability and short
wavelength dissipation. Existing numerical results indicate that
the KS equation admits three classes (namely,
regular shock, oscillatory shock, and solitary wave) of
nonperiodic traveling wave solutions and families of multiple
solutions in each class. However, the details of multiple
solutions are still unclear because of numerical accuracy. In
this work, a rational spectral approach is used to compute these
multiple traveling wave solutions. Owing to the high accuracy of
the employed method, the new families of regular shock waves are
found and the fine structure of each family is recognized.
Materials science and engineering in Britain
Authors: Humphreys Colin
Published: December 2004

The funding of the materials science research effort in British universities and polytechnics has recently been reorganized with the founding the Materials Science and' Engineering Commission of the SERC. The chairman of the committee assesses Britain's performance in materials science and outlines the aims and objectives of the funding bodies in the UK. The recent increase in the importance of advanced materials has resulted in a surge research activity but have the funding levels kept pace?
Silicon molecular beam epitaxy
Authors: Gravesteijn Dirk J. , van De Walle Gerjan F. A. , van Gorkum Aart A.
Published: December 2004

Recent results in the field of silicon molecular beam epitaxy (SiMBE) are reviewed. Emphasis is put on the possibility of doping‐profile engineering, as in delta‐doped layers. Heteroepitaxy of Si1 −xGex on Si is discussed in detail. Due to the band‐gap narrowing in the Si1 −xGex several improved devices can be designed, such as heterojunction bipolar transistors and modulation‐doped structures which show potential for improved field‐effect transistors. An exciting area of research involves superlattices consisting of repetitions of layers of Si and Ge, each with a thickness of only a few atomic layers.
Reactions of hydridotrihalostannato complexes of platinum {trans‐[PtH(SnX3)(PR3)2]} with alkenes
Authors: Permin A B , Petrosyan V S
Published: December 2004

An interaction of trans‐[PtH(SnX3)L2] (I, L = PPh3, PMePh2, PEt3; PBu3; X = Cl, Br) with ethylene, propene and 2‐methylpropene has been studied by means of 31P and 1H NMR spectroscopy. The reactions of platinum hydrides I with ethylene are rapid and reversible at −90°C, giving cis‐[PtR(SnX3)L2] (II, R = C2H5). The reaction of propene with I (L = PPh3, PMePh2) gives II, R = C3H7. 13C and 1H NMR spectra prove the n‐propyl structure for II, L = PMePh2, X = Cl. Complexes II irreversibly isomerize into trans‐[PtR(SnX3)L2] between −50° and 0°C. The equilibrium constants and rates are estimated for the reactions of I with alkenes. They decrease as a function of L (PMePh2 > PPh3 > PBu3 > PEt3) and X (Br > Cl). The reactivities of alkenes decrease with increase of steric hindrances at the double bond.
Adsorption and desorption method for cacodylic acid with inorganic ion exchangers
Authors: Tanaka Yasuo , Tsuji Masamichi , Abe Mitsuo
Published: December 2004

Synthetic inorganic ion exchangers were studied regarding adsorption and desorption features of cacodylic acid [(CH3)2A3O(OH)] with a view to finding a selective adsorbent in aqueos solution. Hydrous oxides of titanium [Ti(IV)], Zirconium [Zr(IV)], manganese [Mn(IV)] and ion [Fe(III)] among synthetic inorganic ion exchangers showed a high selectivity towards cacodylic acid over a wide pH range lower than 12. A large capacity for cacodylic acid (1.0 mmol g−1) was observed for amorphous hydrous titanium dioxide (Am‐HTDO) at pH < 5.5 in a solution of ionic strength of 0.1 made with (NaCl + HCl) or (NaCl + NaOH). The uptake by the column method (0.9 mmol g−1) was in good agreement with the batch method. The acid could be quantitatively eluted by 1 mol dm−3 NaOH.
Arsenic compounds in the edible red alga, Porphyra tenera, and in nori and yakinori, food items produced from red algae
Authors: Shibata Yasuyuki , Jin Kazuo , Morita Masatoshi
Published: December 2004

Arsenic compounds were extracted with methanol/water (1:1, v/v) from freeze‐dried samples of the edible red alga, Porphyra tenera (asakusanori in Japanese), and also from nori and yakinori, food items produced from red algae. The extracts were analyzed by high‐performance liquid chromatography (HPLC) with an inductively coupled plasma mass spectrometer (ICPMS) serving as an arsenic‐specific detector. Two arsenic‐containing ribofuranosides were identified in all samples tigated, and they accounted for almost all the extractable arsenic (8.7–21 mg As Kg−1 dry sample) in each sample. A compound bearing a glycer‐ophosphoryl glycerol moiety was dominant in every sample. Arsenite, arsenate, methylarsonate, and dimethylarsinate were quantified by hydride generation and atomic absorption spectrometry. Arsenate and dimethylarsinate were detected in all samples at low levels (around 0.15 and 0.05 mg As Kg−1 dry sample, respectively). Arsenite was detected only in the unprocessed Porphyra tenera at 0.005 mg As Kg−1 dry sample. Methylarsonate was not found in any of the samples.
Determination of arsenic and other elemental abundances in marine macro‐algae by photon activation analysis
Authors: Suzuki Nobuo , Iwata Yoshihiro
Published: December 2004

A non‐destructive photon activation analysis technique with 30‐MeV bremsstrahlung followed by high‐resolution γ‐spectrometry is applied to multielement analysis of two brown algae, Laminaria religiosa and Sargassum horneri, and one red alga, Heterosiphoia japonica. This method is quite simple and gives good, reproducible results. Elemental abundances of nine elements including arsenic were determined. Arsenic content in the above algae are 50.8, 92.1, and 8.3 mg kg−1 (dry weight base), respectively. Arsenic contents in algae indifferent seasons and different locations do not show a large scatter. The concentration ranges of arsenic together with other essential main components (e.g. sodium, magnesium, phosphorus and chlorine) in a number of samples are summarized. The mean concentrations for these five elements are compared with the elemental abundance of these elements in seawater, and the high enrichment of arsenic and phosphorus is clearly observed.
Determination of arsenate and phosphate in rainwater: Preconcentration bt membrane filtration
Authors: Matsubara Chiyo , Yoshihara Kazuhiro , Ejima Hirofumi , Takamura Kiyoko
Published: December 2004

A simple and rapid method for the determining arsenate and phosphate in rainwater is proposed. These compounds form molybdoarsenate– and molybdophosphate–Malachite Green aggregates with MoMG reagent (MoMG = a mixture of ammouium molybdate and Malachite Green). The aggregates were first collected on a nitrocellulose membrane filter (pore size 3μm) and then dissolved with the filter in a small amount of 2‐methoxyethanol. Absorbance (627 nm), denoted as A(As + P), was found to be proportional to the sum of the arsenate and phosphate concentrations with a molar absorptivity of 2.8 × 105 (mol dm−3)−1 cm−1. Following the addition of thiosulphate, an agent which reduces arsenate, the absorbance A(P) was measured as described above. A(P) corresponded to the concentration of phosphate alone and A(As + P)–A(P), to arsenate concentration only. This method is shown to be a rapid and highly accurate means for determining arsenate and phosphate levels within the 1–150 nmol dm−3 concentration range.
Alkene isomerization catalysed with platinum hydride complexes
Authors: Permin A B , Petrosyan V S
Published: December 2004

The mechanism of but‐1‐ene, pent‐1‐ene and 3‐methylbut‐1‐ene isomerization catalysed with trans‐[PtH(SnX3)L2] (I, L = PPh3, PMePh2, PEt3, PPr3; X = Cl, Br) have been studied. Stoichiometric reactions of I with the alkenes proceed even at −90°C giving cis‐[Pt(alkyI‐1) (SnX3) L2] (II). The equilibrium amounts of II are dependent on the nature of the phosphines, halogens and alkenes. The isomerization rates, determined at +20°C, change in parallel with the relative stabilities of II as a function of phosphine (PMePh2 > PPh3 > PAlk3) and halogen (Br > Cl), and decrease with methyl substitution at γ‐ and δ‐ carbons of the alkenes. 2‐Substituted alk‐1‐enes undergo no isomerization in the reactions under investigation. When L is PPh3 or PMePh2, the main platinum‐containing species in the course of the isomerization are trans‐[Pt(alkyl‐1) (SnX3)L2], appearing as a result of cis‐trans isomerization of II. The conversion of I, L = PAlk3 into related trans‐alkyl complexes, and oxidation of I, proceed more slowly than the isomerization of alkenes. The ratio of cis‐ to trans‐alk‐2‐enes is dependent on the size of L and is a maximum for L = PPh3.
Detection of environmental polyorganosiloxanes (silicones) by silicon‐29 NMR spectroscopy
Authors: Bellama Jon M , Meyer Stephen R , Pellenbarg Robert E
Published: December 2004

The utility of 29Si NMR spectroscopy has been demonstrated on sediment‐like materials in the quantitative and qualitative determination of polyorganosiloxanes (silicones) in selected environmental samples. This technique is highly selective for polydimethylsiloxanes (PDMS) and is non‐destructive to the sample. Also, specific identification of polyorganosiloxanes in sediment is possible, in contrast to previous methods which provided only quantitative information while consuming the sample. The detection limit for a 9 h experiment is approximately 45 ppm.
Refractory arsenic species in estuarine waters
Authors: De Bettencourt A M M , Andreae M O
Published: December 2004

Total digestion of estuarine water samples by dry ashing shows that a significant fraction of dissolved arsenic does not form hydrides with sodium tetrahydroborane (NaBH4) and is therefore not detected by the normal hydride generation‐atomic absorption analytical technique. It is also refractory to alkaline digestion with sodium hydroxide. Sequential ultrafiltration suggests a molecular weight below 210 for this new arsenic fraction. The magnitude and molecular weight of this fraction may open new perspectives on the biogeochemical cycling of arsenic. Ecological reasons can explain the discrepancy between these findings and previous research.
Tolerance of aggressive and non‐aggressive isolates of Ceratocystis ulmi to organotin fungicides
Authors: Eng George , Acholonu Alexander D W
Published: December 2004

The effect of triorganotin compounds, R3SnX, on the growth of three wild strains of Ceratocystis ulmi (C. ulmi) fungus, two aggressive and one non‐aggressive strains, was evaluated in shake culture. In all cases, the triphenyltins were the more effective organotins for the inhibition of C. ulmi in vitro. The anionic group, X, did not have a significant role in the inhibition, suggesting that the species involved in the inhibition is the triphenyltin moiety (Ph3Sn+) or the hydrated triphenyltin moiety (Ph3Sn(H2O)+2). It is further suggested that the triphenyltin species Ph3SnOH and Ph3SnOAc are the preferred compounds for the control of Dutch elm disease. The tolerance of aggressive isolates to fungitoxins appears to depend more on the nature of the fungicide than on the type of fungus.
Quadratic nonlinear optical properties of ruthenium (II)‐bipyridine complexes in crystalline powders
Authors: Sakaguchi Hiroshi , Nagamura Toshihiko , Matsuo Taku
Published: December 2004

Quadratic nonlinear optical properties for the crystalline powders of two types of ruthenium‐bipyridine [Ru(bipy)3] complexes were investigated. The nonlinear optical processes markedly depended on the molecular structures of the ruthenium complexes. Second harmonic generation (SHG) and very weak two‐photon emission were observed for the alkylated ruthenium‐bipyridine compexes with two long alkyl chains attached via amide bonds (RuCnB), whereas only two‐photon emission was observed for Ru(bipy)3. The existence of two amide bonds in one bipyridine ligand for RuCnB complexes most probably enhanced the molecular hyperpolarizability as compared with Ru(bipy)3. The SHG intensity from RuCnB complexes increased in the order RuC18B < RuC12B < RuC16B. The order of SHG intensity from RuCnB was ascribed to the difference in size of each crystalline powder estimated by X‐ray diffraction methods.
Photochemical formation of silver‐gold (AgAu) composite colloids in solutions containing sodium alginate
Authors: Sato Tomoo , Kuroda Shigeru , Takami Akinori , Yonezawa Yoshiro , Hada Hiroshi
Published: December 2004

Photochemical formation of colloidal silver, colloidal gold and silver‐gold (Ag‐Au) composite colloids under mild conditions has been studied. Irradiation of either aqueous AgCIO4 or HAuCI4 solution in the presence of sodium alginate (SA) with 253.7 nm light yielded colloidal silver or gold, whose particle diamter was 10‐30 nm or 40‐60 nm, respectively. The Ag‐Au composite colloids consisting of mixtures of silver and gold domains (particle diameter 30‐150 nm) have been prepared and their extinction spectra have been examined on the basis of a conventional Mie theory in combination with an effective medium theory to estimate the optical constants of these colloids. It has been shown that the extinction spectra of the Ag‐Au composite colloids are completely different from those of Ag‐Au alloy colloids, in that the former have two extinction maxima close to the colloidal extinction bands of pure silver and gold, in contrast to a single extinction maximum of the latter. The importance of natural, high‐molecular carboxylic acids such as alginic acid in the photochemical formation of metal colloids and thin films has been stressed.
Evaluation of extraction techniques for butyltin compounds in sediment
Authors: Zhang Shuzhen , Chau Y K , Li W C , Chau A S Y
Published: December 2004

There have been many methods available for the determination of butyltin compounds in sediment. The variations of these methods are not in the methods of determination but rather in the extraction of these compounds from the complex matrices. All of these methods have not been critically compared or evaluated, mainly because of the lack of a suitable reference sediment for butyltin compounds.

Recently, the National Research Council of Canada has introduced a reference sediment (PACS‐1) which contains certified values of butyltin compounds. The present study compares the recoveries of ten extraction techniques for butyltin species using ethylation derivatization and GC AA as the method of determination. Of these ten methods, only four were found satisfactory for extraction of the dibutyltin and tributyltin species. None of the methods evaluated, however, could quantitatively extract monobutyltin from sediment.
Crystal and molecular structures of tris (p‐methoxyphenyl)‐ and tris(2,4, 6‐trimethylphenyl)tin(IV) acetates
Authors: Wharf I , Simard M G
Published: December 2004

The crystal and molecular structures of tris(p‐anisyl)tin acetate (1) (p‐anisyl = p‐methoxyphenyl) and trimesityltin acetate (2) (mesityl = 2,4,6‐trimethylphenyl) have been determined. Both have monomeric structures with the acetate group acting as an asymmetric bidentate ligand. Bond valence analysis of (1) and (2) and other Ph3SnO2CR suggest however that the carboxylate ligand effectively occupies a single bonding position at tin. Thus in (1) and (2) the tin atom is in a chemical environment equivalent to that found in four‐coordinate R3Sn‐X systems based on tetrahedral geometry.
Dimerization of aldehydes to carboxylic esters catalyzed by K2[Fe(CO)4]–crown ether system
Authors: Yamashita Masakazu , Ohishi Takahiro
Published: December 2004

K2[Fe(CO)4] (1) with a crown ether was found to be an efficient catalyst for the dimerization of aldehydes to carboxylic esters. Several aromatic aldehydes including furfural gave the corresponding esters in good yields. This reaction also proceeded intramolecularly to give phthalide from phthalaldehyde. However, aliphatic aldehydes gave aldol‐condensation products instead of the corresponding esters. In the reactions of p‐substituted benzaldehydes with 1, the reactivity decreased with increase of the electron‐releasing ability of the substituents. On the basis of these results, the reaction mechanism including the nucleophilic attack of tetracarbonylferrate dianion to the carbonyl carbon is discussed.
The neuroglia in the spinal cord of the newt, Triturus viridescens
Authors: Schonbach Christiane
Published: December 2004

This study of the fine structure of the neuroglia in the spinal cord of the newt, Triturus viridescens, has permitted the identification of three types of glial elements. One type is the ependymal cell whose processes are rich in filaments and glycogen and end on the pia in the deeper portion of the fissures of the cord. The two other types of glial cells display some morphological similarities to typical mammalian neuroglia although they appear to be more primitive. These are the astrocytes and oligodendrocytes. The astrocytes contain glial filaments, glycogen, specialized mitochondria, few ribosomes, and probably send end feet to the surface of the cord and to the intramedullary vessels. The oligodendrocytes present some variation in morphology but always exhibit an abundance of ribosomes. They are located either near the neurons, the intramedullary vessels, the pia, or the myelin sheath.
Projections of the inferior colliculus in cat
Authors: Powell Ervin W. , Hatton James B.
Published: December 2004

Projections of the feline inferior colliculus were studied using the Nauta‐Laidlaw method to demonstrate degenerating axons. A subtentorial stereotaxic approach was used to avoid corticofugal degeneration. Direct connections from the inferior colliculus to the anterior midline cerebellar cortex were observed. There is a topographical relationship of fibers of the brachium of the inferior colliculus and parabrachial region to the superior colliculus. A definite projection to the superior colliculi including a pathway through its commissure was found from the parabrachial region. A projection exists from the inferior colliculus to the dorsolateral portion of the central gray as far as the pretectum. There is a projection along the medial portion of the superior colliculus to the pretectum. Projections to the midbrain reticular formation, central gray and superior colliculi were substantial. Thalamic projections include a distribution of fibers to the magnocellular and rostral portion of the principal divisions of the medial geniculate body and to the lateral posterior thalamic nucleus. The rostral connections of the inferior colliculus with areas other than the medial geniculate body indicate that it may function in roles in addition to that of a mass somatomotor reflex center. Possible roles of the inferior colliculus in attention, habituation, and integration of corticovisual and auditory impulses are suggested.
A study of neuronal types in clarke's column in the adult cat
Authors: Loewy Arthur D.
Published: December 2004

Three neuronal classes have been identified in Clarke's column in the adult cat. The smallest cells (class A) exhibit variable dendritic branching patterns. Medium‐sized neurons (class B) can be subdivided into multipolar and fusiform cells. The majority of the multipolar cells have elongated perikarya and their dendrites project in a radial fashion, while the fusiform neurons often have their long axis perpendicularly oriented. The large Clarke cells (class C) and their dendrites project in the cranio‐caudal direction. Their dendrites are generally smooth and often extend for over 1000 μ from the perikaryon, but three types of dendritic specializations have been noted: spines, branchlets and varicosities. These specializations are not strictly restricted to Clarke cells. Dendrites of all three cell types cross the nuclear boundaries. Some enter the dorsal columns via Rexed's lamina V and others enter laminae VI, VII and X.

Neurons whose cell bodies lie within laminae V, VI, VII and X occasionally send dendrites into Clarke's column.

Class A cells account for at least 60% of the total neuronal population of Clarke's column and outnumber the Clarke cells (class C) by approximately three to one. Class B neurons are the least common and form between 6 and 16% of the population.
Electron microscopic studies of wallerian degeneration in rat optic nerves. I. The multipotential glia
Authors: Vaughn James E. , Hinds Patricia Lowary , Skoff Robert P.
Published: December 2004

The development of phagocytes has been studied with the electron and light microscopes in rat optic nerves undergoing Wallerian degeneration. The postoperative survival times ranged from five hours to 250 days. This paper focuses on cells that have been designated either as multipotential glia or as a third neuroglial cell type. Such cells increase markedly in number during the first several weeks of nerve fiber degeneration while the populations of astrocytes and oligodendrocytes remain relatively stable. During this early stage of degeneration, multipotential glial cells develop very irregular shapes and have many processes and complex folds that intermingle with the degenerating nerve fibers. These cells engulf myelin fragments and nerve fibers which become enclosed within vacuoles that show acid phosphatase reaction product in specimens prepared for cytochemistry. The debris containing vacuoles can therefore be considered as phagolysosomes. In addition, the multipotential glial cells show an increase in the number of lipid inclusions over that of cells in normal material. Eventually some multipotential glial cells accumulate large quantities of lipid inclusion and come to resemble the “Gitter” cells described in classical neuropathological studies.

The numerical and cytological changes occurring within the multipotential glial population indicate that these cells are an important source of phagocytes in the type of lesion which we have studied. The breakdown of degenerating myelin by multipotential glial cells, the origin of these cells and their relationship to the microglial cells stained in light microscopic preparations are discussed in detail.
Timm's sulfide silver reaction for zinc during experimental anterograde degeneration of hippocampal mossy fibers
Authors: Haug F.‐M. Š. , Blackstad T. W. , Simonsen A. H. , Zimmer J.
Published: December 2004

The boutons of the hippocampal mossy fibers stain particularly well with Timm's sulfide silver reaction for zinc and other metals. In the present study anterograde degeneration was produced in the mossy fibers in the rat by placing lesions in the fascia dentata, after which the Timm reaction was checked at different postoperative intervals. No unequivocal changes were seen as early as five hours after operation. Barely discernible blanching of the affected parts of the mossy fiber layer was observed after seven hours, a significant reduction of stainability was present after ten hours, and a nearly complete loss after 24 hours. The latter situation persisted for the rest of the period studied, viz., up to eight days after operation.

Topographical coincidence of reduced Timm staining with areas of anterograde degeneration was verified by impregnating alternating sections of the sulfide treated tissue according to the reduced silver method of Fink and Heimer. These sections moreover confirmed that the affected boutons retain their structural identity for at least several days after the disappearance of the stainability with Timm's method.

These findings are compatible with the concept that the zinc may be associated with some rapidly metabolized substance directly or indirectly involved in synaptic transmission.
Enlargement of synaptic vesicles as an early sign of terminal degeneration in the rat caudate nucleus
Authors: Kawana Etsuro , Akert Konrad , Bruppacher Helene
Published: December 2004

The enlargement of synaptic vesicles in degenerating terminals which has recently been demonstrated in the pigeon retino‐tectal fibers as an early sign of secondary degeneration, is confirmed in the rat cortico‐caudate system. Enlarged synaptic vesicles appear already five hours postoperatively in endings which subsequently undergo the classical changes of Wallerian degeneration. Three categories of terminals, SS−, SL− and F‐terminals, are defined on the basis of shape and size of synaptic vesicles in the normal rat caudate nucleus. Only the first category is involved after cortical ablation, while the others remain unchanged.
Organization of subcortical projections of visual areas I and II in the rabbit. An experimental degeneration study
Authors: Giolli Roland A. , Guthrie Mary D.
Published: December 2004

Sections prepared by the Nauta and Nissl methods have been used to study the subcortical distribution of axon and cell degeneration in rabbits after lesions in visual areas I and II (V I and V II) of the cerebral cortex. Degeneration was limited to the side of the lesions. Following lesions of either V I or V II, two distinct groups of degenerating axons were traced caudally. (i) One of these groups projected through the optic tract and its subjacent nuclei. The terminal portions of its axons were found to form zones of pericellular fiber (or boutonal) degeneration in the thalamic reticular nucleus (TRN), the ventral and dorsal lateral geniculate nuclei (LGv, LGd), the pulvinar (Pul), the nuclei praetectalis anterior and posterior (dorsal and lateral parts respectively), the nucleus tractus opticus, and the superior colliculus (SC). In the TRN, LGd, Pul, and nuclei praetectalis anterior and posterior the zones of degeneration were disposed into distinct columns. After lesions involving V II the terminal portions of these axons were also seen to form zones of pericellular fiber degeneration in the nuclei praetectalis and posterior (ventral and medial parts respectively), the ventrolateral thalamic nucleus, and the zona incerta. (ii) The second group of degenerating axons traversed the cerebral peduncle and the terminal portions of its axons were shown to form zones of pericellular fiber degeneration in the basal pons.

Retinotopically organized projections from V I were recognized in the LGv, LGd, Pul, nuclei praetectalis anterior and posterior (dorsal and lateral parts respectively), and SC; and the evidence reveals the presence of similarly organized projections from V II. Other retinotopically organized projections from the visual areas could not be demonstrated.

The data support the view that the collateral branches of visual cortical axons serve as a principal source of input to some of the cellular components receiving innervation from the visual areas.

Cellular degeneration was confined to the LGd and then present only with lesions involving V I. With each such lesion, the cellular degeneration formed a distinct column within the LGd, and this column and the one consisting of pericellular fiber (or boutonal) degeneration were consistently found to overlap.
Ascending brain stem projections of the anteroventral cochlear nucleus in the rhesus monkey
Authors: Strominger Norman L. , Strominger Adele I.
Published: December 2004

In a series of seventeen rhesus monkeys attempts were made to produce discrete stereotaxic lesions in the anteroventral cochlear nucleus (Av). Anterograde degeneration was described in detail in four cases with lesions confined within the cochlear complex to Av. Fibers decussating at pontine levels coursed exclusively in the trapezoid body. Degenerated fibers projected: ipsi‐laterally to the lateral superior olivary nucleus; bilaterally to the preolivary nuclei; to the lateral side of the ipsilateral medial superior olive and the medial side of the contralateral medial superior olive; and to the contralateral medial trapezoid nucleus. A topographic projection upon the medial superior olive was demonstrated. Projections were bilateral but mainly crossed to the nuclei of the lateral lemniscus and central nucleus of the inferior colliculus; the posterior end of the ipsilateral ventral nucleus of the lateral lemniscus contained an island of profuse degeneration. A few fibers crossed in the commissure of the inferior colliculus. Few if any fibers from Av projected to the contralateral magnocellular medial geniculate.
An autoradiographic study of the time of final division of neurons in rat hypothalamic nuclei
Authors: Ifft Jchn D.
Published: December 2004

An autoradiographic study of the development of 26 nuclei in the rat hypothalamus was made by injecting pregnant rats on different days of pregnancy with tritiated thymidine. The offspring were killed postnatally and the day of gestation on which peak percentages of heavily labeled neurons occurred was considered to be the birthdate of that nucleus. Postnatal animals for the first nine days were injected and were also included in the study. Laterally placed nuclei were found to arise on the fourteenth day of gestation while medial nuclei, in general, arose on day 16. Final cell divisions occurred over a period of time but the majority took place on the days indicated. Apparently a lateromedial gradient exists in the hypothalamus, and possibly a dorsoventral gradient.