bluuebunny/crossref_metadata_2025 huggingface dataset:
Silicon dioxide etching yield measurements with inductively coupled fluorocarbon plasmas
Authors: Chae Heeyeop , Vitale Steven A. , Sawin Herbert H.
Published: February 2003

Oxide etching yield has been measured directly with inductively coupled fluorocarbon plasmas. The yields measurement technique of this work can provide useful information for feature profile evolution modeling, which is essential to understand various issues in oxide etching such as reactive ion etching (RIE) lag, inverse RIE lag, etch stop, microtrenching, bowing, etc. Etching and deposition yields per ion were measured using quartz crystal microbalance (QCM) as a function of ion bombardment energy, ion-to-neutral flux ratio, and ion-impinging angle. C2HF5, C2F6, C2H4F2, and C4F8 were used for the oxide etching. Oxide etching mechanism with those gases is complex because etching and deposition are involved at the same time. In highly selective processes fluorocarbon deposition plays important role in determining etching characteristics. Two fluorocarbon deposition mechanisms are identified in this work: neutral deposition and ion-enhanced deposition. The low-energy ions are believed to enhance the deposition rates by creating active sites and fluorocarbon neutrals deposit on the active sites with higher sticking probability. A surface kinetic model is suggested to explain the ion-enhanced mechanism and shows good agreement with experimental data. Angular yield measurement shows that when fluorocarbon deposition is relatively severe, etching yield decreases significantly as the incident angle increases and deposit fluorocarbon at a high incident angle above 60°.
Some calculations for the thickness distribution of large-area high-temperature superconducting film deposited by inverted cylindrical sputtering
Authors: Tao B. W. , Liu X. Z. , Chen J. J. , Li Y. R. , Fromknecht R. , Geerk J.
Published: February 2003

The relative thickness distribution of large-area films deposited from an inverted cylindrical dc sputter gun with high gas pressure is calculated according to Feck’s diffusion law, based on a source-transformation method. The effects of the off-axis displacement rotation, tilted substrate rotation, and a biaxial rotation are compared. The calculated results show that homogeneous large-area films can be deposited with a small target-to-substrate distance by in-plane rotation with a 45° tilting angle or combined tilting together with an off-axis displacement. The biaxial rotation can be used to deposit also homogeneous large-area films. It is suitable for double-sided films. Some experiment data have been presented and show good consistence with the theoretical results. Both tilted in-plane rotation and biaxial rotation have the potential to deposit films with a high deposition rate and to increase the produce efficiency and the utilized ratio of the target. When deposited with these methods, the growth rate of the film would be higher than in the case of no tilting for the same requirement of the thickness homogeneity and meanwhile, the target life would be prolonged.
Etch characteristics of CeO2 thin film in Ar/CF4/Cl2 plasma
Authors: Kim Dong-Pyo , Chang Yun-Seong , Kim Chang-Il
Published: February 2003

The effect of Cl2 addition into CF4/Ar plasma on etching of CeO2 thin film was studied in terms of etch rate and selectivity. We obtained the maximum etch rate of 250 Å/min at 10% Cl2 addition into CF4/Ar gas mixing ratio of 20%. The maximum etch rate may be explained by the variation of volume density for Cl atoms and by the concurrence of two etching mechanisms such as physical sputtering and chemical reaction with formation of low-volatile products, which can be desorbed only by ion bombardment. In addition, the roles of ion bombardment include destruction of Ce–O bonds to facilitate the chemical interaction of Ce with chlorine and fluorine atoms. The variation of volume density for Cl, F, and Ar atoms are measured by optical emission spectroscopy. The chemical states of CeO2 thin films before and after etching are investigated with x-ray photoelectron spectroscopy.
Construction and performance of an ultrahigh vacuum-compatible high temperature vapor dosing system for low vapor pressure compounds
Authors: Thompson L. , Lee J.-G. , Maksymovych P. , Ahner J. , Yates J. T.
Published: February 2003

A gas dosing system for the quantitative deposition of low vapor pressure compounds onto surfaces in an ultrahigh vacuum system is reported. The dosing system is maintained at elevated temperature to achieve sufficiently high gas pressure for rapid transfer to the surface. Dosing is achieved through a heated calibrated leak valve which connects the high temperature source system to an internal tubular doser. The leak valve and the internal doser head are heated to a higher temperature than the source system to prevent condensation of the compound. The quantitative behavior of this doser is demonstrated for two low vapor pressure compounds.
Theoretical and experimental determination of the energy flux during magnetron sputter deposition onto an unbiased substrate
Authors: Ekpe Samuel D. , Dew Steven K.
Published: February 2003

The energy flux onto an unbiased substrate is determined theoretically and experimentally for aluminum and copper deposited using a 3 in. magnetron sputtering system. The energy per deposited atom is calculated. Energy per deposited atom trends towards being independent of power and pressure, especially at high magnetron powers. At low powers, the energy per deposited atom increases with pressure due to lower deposition rates. For the magnetron system used, plasma effects are shown to be important in determining the total energy flux to the substrate. Contributions of the electrons and thermal radiation from the target region are included in the model.
Prevention of injuries to children and adolescents
Authors: Rivara F P
Published: February 2003

Objective:To outline an approach and agenda for research to prevent injuries to children and adolescents.

Methods:Injuries to children and adolescents 18 years and younger in low, middle, and high income countries were investigated.

Results:A new paradigm for considering injury control research is presented. Research studies are suggested for the areas of etiologic research, intervention research, and outcomes research.

Conclusions:Injuries are an important cause of death and disability adjusted life years lost worldwide. Translation of existing research and rigorous randomized trials are needed to reduce the global burden of trauma.
The behaviour of purchasing smuggled cigarettes in Taiwan
Authors: Tsai Y-W , Sung H-Y , Yang C-L , Shih S-F
Published: February 2003

Objective:Since market liberalisation in 1987, the Taiwan Tobacco and Wine Monopoly Bureau (TTWMB) annual statistics indicate that both the demand for imported cigarettes as well as the number of seized smuggled packs have increased with an average revenue loss of NT$4942 million over the past 15 years. The NT$10 average increase in cigarette prices after Taiwan entered the World Trade Organization (WTO) and the implementation of the Tobacco and Alcohol Tax Law in 2002 are forcing policy makers to examine smuggling even more closely. This study evaluates factors that affect an individual smoker’s decision to purchase smuggled cigarettes, particularly when faced with higher prices.

Design:437 male smokers of imported cigarettes were drawn from a national interview survey on cigarette consumption, which the Division of Health Policy Research at the National Health Research Institutes conducted during the year 2000. Multiple logistic regression models were used to analyse the behaviour of purchasing smuggled cigarettes with respect to demographic factors, economic factors, smoking behaviour, and other variables.

Results:Cigarette price was the driving factor most closely linked to the purchase of smuggled cigarettes—a 1% increase in cigarette price raised the likelihood of purchasing smuggled cigarettes at least 2.60 times (95% confidence interval (CI) 1.08 to 6.26). Smokers who spent more than NT$1000/month on cigarettes were twice as likely to purchase smuggled cigarettes as those who spent less than NT$1000 (odds ratio (OR) 2.34, 95% CI 1.48 to 3.70). Betel nut chewers were more likely to purchase smuggled cigarettes (OR 1.80, 95% CI 1.09 to 2.90). Smokers who opposed cigarette taxation policy were 1.69 times more likely to buy smuggled cigarettes. Personal income was not significantly associated with smuggled cigarettes purchases.

Conclusions:This study evaluates what causes smokers to purchase smuggled cigarettes. We have determined that cigarette price is the most important factor and that betel nut vendors are the main suppliers. Our study provides policy makers with information that can help them develop effective strategies to curb cigarette smuggling after Taiwan’s recent cigarette tax reform, which has increased cigarette prices.
Increase in common cold symptoms and mouth ulcers following smoking cessation: Table 1
Authors: Ussher M , West R , Steptoe A , McEwen A
Published: February 2003

Objective:To examine changes in reports of common cold symptoms and mouth ulcers following smoking cessation. It was hypothesised that reports of these symptoms would increase on stopping smoking.

Design:Smokers were assessed one week before stopping smoking (baseline), then after one, two, and six weeks of smoking abstinence.

Participants:174 smokers attending a seven week smoking cessation programme combining behavioural support with nicotine patches.

Main outcome measures:Self reports of cold symptoms, mouth ulcers, and smoking abstinence (validated using expired carbon monoxide) were recorded on each measurement occasion.

Results:Following one, two, and six weeks of smoking abstinence 73.0% (127/174), 57.5% (100/174), and 44.8% (78/174) of the participants, respectively, maintained continuous abstinence and provided reports of cold symptoms and mouth ulcers. For those abstinent from smoking for six weeks, relative to baseline, a significant increase in reports of the number of cold symptoms was observed following one and two weeks of smoking abstinence (p = 0.009 and p = 0.038, respectively) and an increase in reports of mouth ulcers after one and two weeks of abstinence (p = 0.004 and p = 0.008, respectively). Following one week of abstinence significant increases in reports of sore throat, coughing, deafness, and sneezing were observed (p = 0.049, p < 0.001, p< 0.039, and p < 0.003, respectively).

Conclusions:This is the first study to systematically document significant increases in cold symptoms and mouth ulcers following smoking cessation. Smokers should be informed that they have an increased chance of experiencing these symptoms on stopping smoking. Being psychologically prepared for these effects may reduce their impact on the attempt to stop smoking.
Zebras in Russia! Where next?: Figure 1
Authors: Pollay R
Published: February 2003

The zebra may seem an odd choice as a brand image for a new cigarette in Russia, but subtle tobacco marketing forces are, as always, at work
Malawi: addicted to the leaf
Authors: Davies P
Published: February 2003

The east African country of Malawi, one of the poorest in the world, derives most of its economic income from tobacco production. The challenges facing Malawi if it is to decrease its dependence on the leaf are discussed here
fs3.1:a major fruit shape QTL conserved inCapsicum
Authors: Chaim Arnon Ben , Borovsky Yelena , Rao G U , Tanyolac Bahattin , Paran Ilan
Published: February 2003

fs3.1 is a major fruit shape (defined as the ratio of fruit length to fruit width) quantitative trait locus (QTL) originally detected in an intraspecific cross of Capsicum annuum between the blocky and elongated-fruited inbreds 'Maor' and 'Perennial', respectively. In addition to increasing fruit shape index, the 'Perennial' allele at fs3.1 increased fruit elongation and decreased fruit width and pericarp thickness. We verified the effect of fs3.1 in backcross inbred lines (BILs) derived from crossing 'Perennial' with 'Maor' and with a second blocky-type inbred line of C. annuum. To determine the effect of the fs3.1 region in additional Capsicum species, we constructed an advanced backcross population from the cross of 'Maor' and the oval-fruited Capsicum frutescens BG 2816 and an F2of the introgression line IL 152 that contains an introgression of the fs3.1 region from Capsicum chinense PI 152225. QTLs for fruit shape, fruit width, and pericarp thickness, but not for fruit length, were detected in both crosses, indicating the conservation of the fs3.1 region as a QTL affecting fruit shape in pepper. We also tested tomato (Lycopersicon spp.) introgression lines containing the corresponding fs3.1 region from L. pennellii and L. hirsutum, but we did not detect a significant fruit shape QTL in these lines. The effect of fs3.1 on the growth of fruit dimensions varied with the genetic background. By measuring the length and width of ovaries and fruits of near-isogenic C. annuum lines that differ in fs3.1 during fruit development, we determined that fs3.1 controls shape predominantly by increasing the growth rate of the longitudinal axis in the first 2 weeks after pollination. However, in the crosses of C. annuum with C. frutescens and C. chinense, fs3.1 predominantly exerted its effect on the width dimension.Key words: fruit shape, QTL, pepper, comparative mapping.
The new RENT family of repetitive elements in Nicotiana species harbors gene regulatory elements related to the tCUP cryptic promoter
Authors: Foster E , Hattori J , Zhang P , Labbé H , Martin-Heller T , Li-Pook-Than J , Ouellet T , Malik K , Miki B
Published: February 2003

The tCUP cryptic constitutive promoter was discovered in the tobacco genome by T-DNA (transfer DNA) tagging with a promoterless GUSnos gene. Here, we show that the portion of the tCUP sequence containing a variety of cryptic gene regulatory elements is related to a new family of moderately repetitive sequences (102 copies), the RENT (repetitive element from Nicotiana tabacum) family. The RENT family is found only in certain Nicotiana species. Five RENT elements were cloned and sequenced. The RENT elements are a minimum of 5 kb in length and share 8090% sequence similarity throughout their length. The 5' termini are the same in the isolated RENT family members and are characterized by a conserved border sequence (TGTTGA(T or C)ACCCAATTTT(T or C)). The 3' ends of RENT sequence similarity vary in location and sequence. The tCUP cryptic promoter originated from a unique truncated RENT element that interrupts a phytochelatin synthase-like gene that may have undergone rearrangements prior to or resulting from T-DNA insertion. No evidence was found for expressed coding regions within the RENT elements; however, like the cryptic gene regulatory elements within the tCUP sequence, the isolated RENT elements possess promoter activity and translational enhancer activity.Key words: cryptic promoter, Nicotiana, T-DNA, translational enhancer, repetitive element.
Uniparental loss of ribosomal DNA in the allotetraploid grassZingeria trichopoda(2n= 8)
Authors: Kotseruba Violetta , Gernand Dorota , Meister Armin , Houben Andreas
Published: February 2003

Analysis of the grass Zingeria trichopoda (2n = 8, 2C = 5.3 pg) revealed a dynamic evolution with the following characteristics. (i) Genomic in situ hybridization (GISH) demonstrates that Z. trichopoda evolved from an interspecific hybrid involving a species like contemporary Zingeria biebersteiniana (2n = 4) and a second species with a similar low number of chromosomes. The nucleus of Z. trichopoda is spatially organized at the genome level and the two parental genomes occupy distinct and separate domains of lateral arrangements. (ii) The copy number of the Z. biebersteiniana specific pericentromeric tandem repeat family Zbcen1 is drastically reduced in Z. trichopoda. (iii) GISH in combination with labeled rDNA sequences simultaneously discriminated the two parental genomes and the corresponding 5S and 45S rDNA sites. Hence, following allopolyploidization of Z. trichopoda the Z. biebersteiniana like parental chromosomes probably underwent drastic loss of 45S rDNA. This could have arisen either through the loss ofZ. biebersteiniana derived 45S rDNA or through Z. trichopoda genome-wide homogenization of Z. biebersteiniana type 45S rDNA and subsequent elimination of 45S rDNA loci from Z. biebersteiniana derived chromosomes. Finally, 5S rDNA loci are present in both subgenomes of Z. trichopoda and the chromosomal position of these loci is similar for both Z. biebersteiniana and the Z. biebersteiniana like parental genome of Z. trichopoda.Key words: genome evolution, polyploidy, ribosomal DNA, Poaceae.
Isolation and identification of Triticeae chromosome 1 receptor-like kinase genes (Lrk10) from diploid, tetraploid, and hexaploid species of the genusAvena
Authors: Cheng D W , Armstrong K C , Drouin G , McElroy A , Fedak G , Molnar S D
Published: February 2003

The DNA sequence of an extracellular (EXC) domain of an oat (Avena sativa L.) receptor-like kinase (ALrk10) gene was amplified from 23 accessions of 15 Avena species (6 diploid, 6 tetraploid, and 3 hexaploid). Primers were designed from one partial oat ALrk10 clone that had been used to map the gene in hexaploid oat to linkage groups syntenic to Triticeae chromosome 1 and 3. Cluster (phylogenetic) analyses showed that all of the oat DNA sequences amplified with these primers are orthologous to the wheat and barley sequences that are located on chromosome 1 of the Triticeae species. Triticeae chromosome 3 Lrk10 sequences were not amplified using these primers. Cluster analyses provided evidence for multiple copies at a locus. The analysis divided the ALrk EXC sequences into two groups, one of which included AA and AABB genome species and the other CC, AACC, and CCCC genome species. Both groups of sequences were found in hexaploid AACCDD genome species, but not in all accessions. The C genome group was divided into 3 subgroups: (i) the CC diploids and the perennial autotetraploid, Avena macrostachya (this supports other evidence for the presence of the C in this autotetraploid species); (ii) a sequence from Avena maroccana andAvena murphyi and several sequences from different accessions of A.sativa; and (iii) A. murphyi and sequences from A. sativa andAvena sterilis. This suggests a possible polyphyletic origin for A. sativa from the AACC progenitor tetraploids or an origin from a progenitor of the AACC tetraploids. The sequences of the A genome group were not as clearly divided into subgroups. Although a group of sequences from the accession 'SunII' and a sequence from line Pg3, are clearly different from the others, the A genome diploid sequences were interspersed with tetraploid and hexaploid sequences.Key words: phylogeny, genome evolution, speciation, oat.
Molecular phylogeny of tephritid fruit flies in the Bactrocera tau complex using the mitochondrial COI sequences
Authors: Jamnongluk Wanwisa , Baimai Visut , Kittayapong Pattamaporn
Published: February 2003

We compared sequences of the mitochondrial cytochrome oxidase I gene of eight species of the Bactrocera tau complex using Bactrocera dorsalis,Bactrocera pyrifoliae,Ceratitis capitata, Anopheles gambiae, and Locusta migratoria as outgroups. A 639-bp variable region was sequenced. The sequence divergence between species in the B. tau complex ranged from 0.06 to 28%, and up to 29% between the complex and its tephritid outgroups, B. dorsalis and C. capitata. According to the phylogenetic relationships, these members of the B. tau complex could be classified into four clades. Thus, species A and D form clades 1 and 3, respectively, while species C and I belong to clade 4. However, species B, E, and F form a distinct group, clade 2, and infested the fruits of non-cucurbit hosts. Host-plant shifts resulting in adaptive radiation and premating isolation among species might play an important role in species differentiation of the B. tau complex.Key words: Bactrocera, cytochrome oxidase I, species complex, mitochondrial DNA, phylogeny.
The genome composition of hexaploidPsammopyrum athericumand octoploidPsammopyrum pungens(Poaceae: Triticeae)
Authors: Ellneskog-Staam Pernilla , Salomon Björn , Bothmer Roland von , Anamthawat-Jónsson Kesara
Published: February 2003

The genomic constitution of two species in the genus Psammopyrum, i.e., Ps. athericum (2n = 6x = 42) and Ps. pungens (2n = 8x = 56), was studied by genomic in situ hybridization (GISH). In Ps. athericum, one diploid chromosome set hybridized to a genomic probe from Pseudoroegneria ferganensis (St genome), one diploid set to a probe from Agropyron cristatum (P genome), and one diploid set to a probe from Thinopyrum junceiforme (EbEegenomes) or Th. bessarabicum (Ebgenome). Substituting the St-genome probe with an L-genome probe from Festucopsis serpentinii resulted in exactly the same hybridization pattern, suggesting a genomic constitution of EStP or ELP for Ps. athericum. The same probes used on Ps. pungens showed two diploid sets of chromosomes hybridizing to the St-genome probe, one diploid set hybridizing to the P-genome probe, and one diploid set hybridizing to the EbEe-genome probe. The L-genome probe hybridized to approximately 14 of the chromosomes that were labeled by the St-genome probe. Hence the genomic constitution for Ps. pungens is proposed to be EStStP or EStLP.Key Words: Psammopyrum athericum, Psammopyrum pungens, in situ hybridization, Elytrigia pycnantha, Elytrigia pungens, genome analysis.
Genetic identification of a female partial-sterile mutant in soybean
Authors: Kato K K , Palmer R G
Published: February 2003

We report here the genetic identification of a female partial-sterile mutant derived from soybean mutant L67-3483. L67-3483, which originated from the cultivar Clark after X-ray irradiation, is male and female fertile. All F1plants in reciprocal pollinations of L67-3483 with 'Clark', 'Minsoy', or 'BSR 101' were female partial sterile. Partial sterility is expressed in the heterozygous condition at a single locus and upon self-pollination this locus exhibits a 1:1 segregation pattern. This locus is located on the terminus of the soybean molecular linkage group D1b+W, between simple sequence repeat (SSR) markers Satt157 and Satt266, and is linked to each by 5.3 and 1.2 cM, respectively. This gene is transmitted through both female and male gametes and there was no segregation distortion of SSR markers linked to this gene. We concluded that this female partial-sterile gene is a new mutation class, and differs from the previously reported mutation classes in soybean, i.e., sporophytic mutation, gametophytic female-specific mutation, and general gametophytic mutation. Restriction of recombination around the mutant gene suggested that this gene is located near or within (a) small inversion(s) or adjacent to (a) chromosomal deletion(s).Key words: Glycine max, simple sequence repeat marker, recombination restriction.
The effect of microorganisms on pulp mill effluent induced flocculation in receiving waters
Authors: Joyce Stephanie , Smith Daniel W
Published: February 2003

Recent studies have shown that organic matter discharged from a pulp mill flocculates and accumulates on the river bottom more rapidly than predicted by previous transport models, a phenomenon termed pulp mill effluent induced coagulation and flocculation (PMEICF). Pulp mill effluent induced coagulation and flocculation can cause accumulation of material on the river bottom that may induce anoxic or toxic conditions, subsequently harming benthic organisms and the entire food chain. Pulp mill effluent and river water were mixed in a standard jar test apparatus. Heterotrophic plate counts revealed that a variety of microorganisms was present in the floc material and the liquid portion. Individual colonies were isolated, identified, and tested for their role in flocculation. Seven isolates were found capable of enhanced flocculation: Comamonas testosteroni, species belonging to the Pseudomonas, Enterobacter, and Aeromonas genuses and an unidentified isolate. These isolates did induce flocculation, though not consistently. Results varied with the environment available for the microorganisms. Further tests are required that consider the changing effluent and river water characteristics. Key words: pulp mill effluent, coagulation, flocculation, bacteria, identification, sediment transport model.
Occurrence and removal of plant sterols in pulp and paper mill effluents
Authors: Mahmood-Khan Z , Hall E R
Published: February 2003

Pulp and paper mill effluents (PPMEs) are believed to contain some naturally occurring endocrine disrupting chemicals (EDCs) such as phytosterols or plant sterols, which may be related to a variety of physiological and morphological abnormalities in fish inhabiting receiving waters. Analyses of effluent streams from two Canadian pulp mills confirmed the presence of five different phytosterols in PPMEs. Sterol contents of biologically treated as well as untreated effluents are presented. ββ-Sitosterol, ββ-sitostanol (or stigmastanol), and campesterol formed the major fraction of plant sterols in PPMEs, accounting for 70 % or more of the total phytosterol content measured. Sterols entering the activated sludge treatment systems were generally removed from the effluents with average removal efficiencies of 72 and 66% for the two mills surveyed. Sorption and biodegradation may be responsible for the observed removal of plant sterols across the biological wastewater treatment systems. Key words: ββ-sitosterol, stigmastanol, campesterol, removal and mass flow of phytosterols or plant sterols, hormone disruptors, pulp mill effluents, activated sludge, industrial wastewater treatment.
Utilisation et regénération des écailles de cacao pour la récupération du plomb dans les solutions acides
Authors: Meunier Nathalie , Haberman Michael , Blais Jean-Francois , Tyagi Rajeshwar Dayal
Published: February 2003

Cocoa shells, a by-product of the food industry, is a promising adsorbent for the treatment of acid metal loaded wastewaters, particularly for lead removal. Elution tests carried out using different concentrations of hydrochloric acid have shown that a good portion can be eluted using a short contact time (approximately 10 min) and a diluted acid solution (0.51.0 M). The use of a more concentrated acid solution causes significant mineralization of the adsorbent and does not allow to improve the elution yield. Repeated adsorptionelution cycles have shown that cocoa shells can be reused for many times. However, their lead adsorption capacity progressively decreases from 19.3 mg Pb/g during the 1st cycle to 4.8 mg Pb/g during the 10th cycle. Finally, the use of successive adsorptionelution cycles is only interesting, from an economical point of view, in the case where the acid solution is used for many elution steps. Key words: adsorption, elution, lead, cocoa shells, effluent, acid.
Tannic acid induces transcription of laccase genecglcc1in the white-rot fungusCoriolopsis gallica
Authors: Carbajo José M , Junca Howard , Terrón María C , González Tania , Yagüe Susana , Zapico Ernesto , González Aldo E
Published: February 2003

Laccase, a phenoloxidase enzyme secreted by white-rot fungi, has a significant role in the degradation of lignin and environmental pollutants. Coriolopsis gallica is a ligninolytic basidiomycete that produces high levels of this extracellular enzyme. A laccase gene cglcc1 from this fungus has been cloned and sequenced. The capacity of C. gallica to efficiently degrade polyphenols has been successfully applied in our laboratory to the biotreatment and decolorization of several industrial wastewaters. This study focused on the effect of tannic acid, a natural compound widely distributed in plants, on the production of laccase activity by C. gallica. Our results showed an evident increase of extracellular laccase levels when C. gallica was grown in the presence of tannic acid. Concentrations of 50 and 100 μM of this compound increased laccase activity when compared with control samples grown without tannic acid. In addition, we found an increase in laccase transcript levels in C. gallica grown in culture media supplemented with tannic acid. The role of tannic acid was shown to be an inductor of laccase activity in this fungus, due to the enhancement of expression of the laccase gene at the transcriptional level.Key words: laccase, tannic acid, Coriolopsis gallica, induction, gene transcription.
Quantification and diversity of the archaeal community in a landfill site
Authors: Mori Koji , Sparling Richard , Hatsu Masahiro , Takamizawa Kazuhiro
Published: February 2003

At a sea-based, solid waste disposal site, methanogenic organisms were quantified by molecular approaches. The samples collected for analysis were from anaerobic leachate of the landfill site. When the DNA extracted from the leachate was examined by a quantitative PCR method using domain-specific 16S rDNA primers, archaeal DNA represented 23% of the total extracted DNA. On the basis of cloning and sequence comparison of the archaeal PCR products, more than half of the sequences belonged to Euryarchaeota, particularly relatives of the genus Methanosaeta. The cloning analysis suggested that the majority of methane emitted from the landfill site originated from the acetate-utilizing Methanosaeta.Key words: landfill, methanogen, archaea, 16S rDNA.
Peripheral chemoreceptor contributions to sympathetic and cardiovascular responses during hypercapnia
Authors: Shoemaker J K , Vovk A , Cunningham D A
Published: February 2003

We tested the hypothesis that integrated sympathetic and cardiovascular reflexes are modulated by systemic CO2 differently in hypoxia than in hyperoxia (n = 7). Subjects performed a CO2 rebreathe protocol that equilibrates CO2 partial pressures between arterial and venous blood and that elevates end tidal CO2 (PETCO2) from ~40 to ~58 mmHg. This test was repeated under conditions where end tidal oxygen levels were clamped at 50 (hypoxia) or 200 (hyperoxia) mmHg. Heart rate (HR; EKG), stroke volume (SV; Doppler ultrasound), blood pressure (MAP; finger plethysmograph), and muscle sympathetic nerve activity (MSNA) were measured continuously during the two protocols. MAP at 40 mmHg PETCO2 (i.e., the first minute of the rebreathe) was greater during hypoxia versus hyperoxia (P < 0.05). However, the increase in MAP during the rebreathe (P < 0.05) was similar in hypoxia (16±3 mmHg) and hyperoxia (17 ± 2 mmHg PETCO2). The increase in cardiac output (Q) at 55 mmHg PETCO2 was greater in hypoxia (2.61 ± 0.7 L/min) versus hyperoxia (1.09 ± 0.44 L/min) (P < 0.05). In both conditions the increase in Q was due to elevations in both HR and SV (P < 0.05). Systemic vascular conductance (SVC) increased to similar absolute levels in both conditions but rose earlier during hypoxia (>50 mmHg PETCO2) than hyperoxia (>55 mmHg). MSNA increased earlier during hypoxic hypercapnia (>45 mmHg) compared with hyperoxic hypercapnia (>55 mmHg). Thus, in these conscious humans, the doseresponse effect of PETCO2 on the integrated cardiovascular responses was shifted to the left during hypoxic hypercapnia. The combined data indicate that peripheral chemoreceptors exert important influence over cardiovascular reflex responses to hypercapnia. Key words: blood pressure, cardiac output, muscle sympathetic nerve activity, sympathetic nervous system, end tidal CO2, hypoxia.
Inhibitory effect of a novel bradykinin B1 receptor antagonist, R-954, on enhanced vascular permeability in type 1 diabetic mice
Authors: Simard Bryan , Gabra Bichoy H , Sirois Pierre
Published: February 2003

The morbidity and mortality associated with type 1 diabetes are essentially related to the micro- and macro-vascular complications that develop over time and lead to several diabetic complications, including hypertension, atherosclerosis, and retinopathy, as well as coronary and renal failure. Normally absent in physiological conditions, the bradykinin B1 receptor (BKB1-R) was recently found to be overexpressed in pathological conditions, including type 1 diabetes. In the present study, we evaluated the effect of the new BKB1-R antagonist, R-954 (Ac-Orn-[Oic2, α-MePhe5, D-βNal7, Ile8]desArg9-bradykinin, on the increase in vascular permeability in streptozotocin (STZ) - diabetic mice. The capillary permeability to albumin was measured by quantifying the extravasation of albumin-bound Evans blue dye in selected target tissues (liver, pancreas, duodenum, ileum, spleen, heart, kidney, stomach, skin, muscle, and thyroid gland). Acute single administration of R-954 (300 μg/kg, i.v.) to type 1 diabetic mice 4 weeks after STZ significantly inhibited the enhanced vascular permeability in most tissues. These data provide further experimental evidence for the implication of BKB1-R in the enhanced vascular permeability associated with type 1 diabetes.Key words:vascular permeability, type 1 diabetes, bradykinin B1 receptor.
Pregnancy influence on the vascular interactions between nitric oxide and other endothelium-derived mediators in rat kidney
Authors: Bobadilla Rosa A , Anguiano Liliana , Pérez-Alvarez Victor , Sanchez Pedro López
Published: February 2003

Peripheral vascular resistance and sensitivity to circulating pressor and vasoconstrictor agents are blunted during pregnancy. This has been mainly attributed to an increased production of endothelium-derived mediators. The objective of this work was to evaluate if pregnancy changes the relative participation of nitric oxide (NO) and prostaglandins (PG) in respect to the modulation of the increases in renal perfusion pressure induced by phenylephrine (Phe). Doseresponse curves were made with gradually increasing doses of Phe using an isolated kidney preparation in the presence of a NO synthase (NOS) inhibitor (L-NAME, 1 μM), a PG-synthesis inhibitor (indomethacin, 1 μM), both, or neither. Also, renal cyclooxygenase (COX-1 and COX-2) and endothelial NOS (eNOS) expression was determined using PCR. The experiments were done in kidneys from nonpregnant and pregnant rats. Our results showed that the relative participation of renal vasoactive mediators seems to change during pregnancy. We found the presence of a COX-1-dependent vasoconstrictor in the middle of pregnancy that was not found in nonpregnant rats. Our results also suggest that there is increased participation of another renal vasodilator substance, the effect of which is observed when NO or PG synthesis is inhibited during late pregnancy. In addition, an apparent interaction between renal eNOS and COX-1 expression was observed: eNOS expression was diminished, while COX-1 was increased during the 2nd week of pregnancy. In contrast, in kidneys from the 3rd week of pregnancy, the expression of these two enzymes was similar.Key words: pregnancy, nitric oxide, prostaglandins, EDHF, kidney.
Changes in muscle proteins and spermidine content in response to unloading and clenbuterol treatment
Authors: Deutsch Daniel A. von , Abukhalaf Imad K , Wineski Lawrence E , Silvestrov Natalia A , Bayorh Mohamed A , Potter David E
Published: February 2003

Anabolic agents such clenbuterol (Cb) are useful tools for probing the mechanisms by which muscles respond to disuse. Cb was examined under different loading conditions with respect to its effects on muscle mass, protein (myofibrillar and cytosolic), and spermidine content in mature male rats. Compared with control treatment, Cb significantly increased loaded and unloaded soleus, plantaris, and extensor digitorum longus (EDL) mass. Likewise, Cb significantly increased loaded and unloaded soleus (24.8 and 21.6%, respectively), plantaris (12.1 and 22.9%, respectively), and EDL (22.4 and 13.3%, respectively) myofibrillar protein content. After unloading, cytosolic proteins significantly increased in the EDL but decreased in the soleus and plantaris. Cb significantly increased cytosolic protein levels in all loaded muscles, while only causing increases in unloaded soleus. When compared with controls, unloading caused significant reductions in spermidine levels in the soleus (40.4%) and plantaris (35.9%) but caused increases in the EDL (54.8%). In contrast, Cb increased spermidine levels in unloaded soleus (42.9%), plantaris (102.8%), and EDL (287%). In loaded muscles, Cb increased spermidine levels in all three muscles, but to a lesser degree than under unloading conditions. Nonlinear regression analyses indicated that the plantaris behaves like a slow-twitch muscle under unloading conditions and like a fast-twitch muscle when loaded. This suggests that the responses of these muscles to unloading and (or) Cb treatment might be influenced by factors beyond fiber type alone.Key words: microgravity, skeletal muscle atrophy, nonlinear regression, clenbuterol, polyamines.
Lifetime patterns in adult female mass, reproduction, and offspring mass in semidomestic reindeer (Rangifer tarandus tarandus)
Authors: Rönnegård Lars , Forslund Pär , Danell Öje
Published: February 2003

The objective of our investigation was to examine relationships between lifetime patterns of female mass, calving incidence, and offspring mass in semidomestic reindeer (Rangifer tarandus tarandus). The analyses were made on data recorded from 1986 to 1997 on semidomestic reindeer in the herding district of Ruvhten Sijte in Sweden. A female rearing a calf was shown to weigh 3.1 ± 0.3 kg (mean ± SE) less in winter than a female not rearing a calf. The difference in calving incidence between females rearing a calf in the previous year and those not rearing a calf in the previous year was small, but there was a tendency for old females to have a decreased calving incidence if they had reared a calf in the previous year. The average calving percentage for adult females was 73%. Calf masses were affected by both the mother's mass and her age. The regression coefficient of calf autumn mass on female mass the previous winter was 0.26 ± 0.02. Mothers aged 24 years had calves that weighed less than calves of older mothers. The average difference in autumn mass between male and female calves was 2.9 ± 0.2 kg, but the difference was less for calves with mothers aged 24 years. We obtained lifetime patterns of female mass, calving incidence, and offspring mass. We also gave an organized structure of relationships between these traits.
Ethogram of Aspidisca sedigita
Authors: Banchetti R , Erra F , Ricci N , Dini F
Published: February 2003

The analysis of behaviour of Aspidisca sedigita has been undertaken to describe the main features of its biology. In drawing the standard ethogram of A. sedigita, several peculiarities have been discovered: (i) the cirri of Aspidisca are thicker and tufted versus the slim and pointed cirri of other hypotrichs; (ii) the side-stepping reaction is performed without its typical backward motion; (iii) a typical clockwise rotation of 90°, followed by a similar but anticlockwise one, is performed frequently and results in a shift of the creeping Aspidisca into a new trajectory, close and parallel to the previous one; (iv) the very rare swimming motion of the species occurs along a regular helicoid, with the ciliary organelles facing in the opposite direction of the centre of the helicoid; (v) the creeping and swimming of conjugating pairs are similar to those of single organisms. The analysis of behaviour of A. sedigita is suggested to contribute to our knowledge of the adaptive strategies of this species.
Digging energetics in the South American rodent Ctenomys talarum (Rodentia, Ctenomyidae)
Authors: Luna Facundo , Antinuchi C Daniel , Busch Cristina
Published: February 2003

Ctenomys is the most speciose among subterranean rodents. There are few studies on energetics of Ctenomys, and none of them have focused on the energetics of digging. The present study aims to quantify the energetic cost of burrowing in Ctenomys talarum in natural soil conditions and to compare the energetics data with those reported for other subterranean rodents. Digging metabolic rate (DMR) in gravelly sand for C. talarum was 337.4 ± 65.9 mL O2·h1 (mean ± SD). No differences in DMR were detected between sexes. Moreover, DMR was 295.9% of resting metabolic rate. In terms of a cost of burrowing model, the mass of soil removed per distance burrowed (Msoil) in gravelly sand was 44.5 ± 6.7 g·cm1. Coefficients of the equation that related the energy cost of constructing a burrow segment of length S and Msoil(Eseg/Msoil) were Ks = 0.33 ± 0.32 J·g1, which is the energy cost of shearing 1 g of soil, and Kp = 0.0055 ± 0.0042 J·g1·cm1, which is the energy cost of pushing 1 g of soil 100 cm. Regarding the cost of burrowing model, our data showed that C. talarum has the lowest DMR in gravelly sand among unrelated subterranean rodents analyzed. Moreover, despite C. talarum feeding aboveground, the foraging economics was similar that of to other rodents.
Photorefractoriness and seasonal changes in the brain in response to changes in day length in American goldfinches (Carduelis tristis)
Authors: Marsh Regan H , MacDougall-Shackleton Scott A , Hahn Thomas P
Published: February 2003

We examined neural and gonadal responses to photoperiod in a late-summer-breeding finch, the American goldfinch (Carduelis tristis). First we measured seasonal changes in the gonads of free-living goldfinches. Next we determined whether the gonads of goldfinches held on constant long days would eventually regress spontaneously. Finally, we compared the hypothalamic gonadotropin-releasing hormone (GnRH) system and song-control system of breeding and postbreeding birds. The results confirm that the gonads of wild goldfinches regress in late summer and show that the gonads of goldfinches held on constant long days regress spontaneously. Thus, according to at least one criterion, goldfinches become photorefractory, like other seasonally breeding songbirds. As well, goldfinches exhibited similar seasonal changes in the brain to spring-breeding birds. There was a decrease in GnRH immunoreactivity in autumn and a strong trend towards a reduction in the size of song-control regions (although this was statistically significant for only one area). Thus, although goldfinches breed late in summer as day length declines, some of their physiological responses to changes in photoperiod are similar to those that occur in spring-breeding songbirds.
Short visits reveal consistent patterns of interyear and intercolony variation in seabird nestling diet and performance
Authors: Bertram D F , Golumbia T , Davoren G K , Harfenist A , Brown J
Published: February 2003

To investigate the utility of short visits to seabird colonies to gauge nestling growth performance and diet, in 4 consecutive years (19951998) we measured nestling development and diet of Rhinoceros Auklets (Cerorhinca monocerata) at three colonies in British Columbia: Seabird Rocks, Triangle Island, and SGaang Gwaii (Anthony Island). In all years, nestlings of a given wing length on Triangle Island were significantly smaller than those on Seabird Rocks or SGaang Gwaii. Meals were also significantly lighter on Triangle Island than on Seabird Rocks or SGaang Gwaii; meals on the latter two islands were indistinguishable in mass. Retarded nestling development and small meal size on Triangle Island likely reflect the large contribution of rockfish (Sebastes spp.) to nestling diet on that colony alone. The intercolony differences in nestling performance appear to reflect the strong influence of local fish prey populations. Nonetheless, a united decline in performance in 1996 and subsequent increase on all colonies suggest the influence of large-scale ocean climate phenomena on our entire study region and beyond. We did not, however, observe noticeable effects of the 19971998 El Niño Southern Oscillation event on nestling growth performance or diet. We discuss the utility of our short-visit techniques for seabird-monitoring programs.
Pinniped diets inferred from scats: analysis of biases in prey occurrence
Authors: Arim Matías , Naya Daniel E
Published: February 2003

The diets of pinnipeds have often been used to study their ecology and resource dynamics and in ecosystem monitoring. Scat analysis is now the most widely used method of inferring the diets of pinnipeds. Using a mathematical model the present study explores the expected biases in prey occurrence that are related to prey mass, proportion of loss of remains, predator assimilation efficiency, size of the scats collected, and meal size. With the exception of meal size, variation in parameters implied variation in the probability of biases in prey occurrence. Biases were asymmetric among prey sizes, but in contrast with previous ideas, the results indicate that small prey have smaller biases than large ones do. Furthermore, the number of scats required to detect a large prey was notably larger than that needed to detect a small prey with the same occurrence. The present study is not limited to a particular pinniped or prey species, so it has the potential to represent a general framework for interpreting the results of scat analysis in pinnipeds. The model complements empirical studies, advancing our comprehension of biases associated with prey occurrence in dietary studies of pinnipeds.
Genetic homogeneity of Canadian mainland marten populations underscores the distinctiveness of Newfoundland pine martens (Martes americana atrata)
Authors: Kyle C J , Strobeck C
Published: February 2003

American pine martens (Martes americana) are mid-sized mustelids found in the boreal and taiga zones of North America that prefer late-successional coniferous forests. Studies have shown that tracts of treeless land and roads may impede marten dispersal and that fewer martens are captured or observed in clear-cut areas. If marten habitat is indeed fragmented by roads and treeless land, this may result in decreased gene flow between regions and therefore in increased levels of genetic structure and decreased genetic variation in regions where these potential barriers are present. In this study, we evaluate the genetic variation and connectivity of marten populations across Canada. Thirty-five regions from the Canadian provinces and territories were sampled, including 1262 individuals, genotyped at 11 microsatellite loci. As expected, and in agreement with previous studies, little genetic structure was observed in northern regions, where few barriers to marten dispersal are thought to exist. However, contrary to our expectations, no strong breaks in gene flow were observed between any of the 35 sampled regions with the exception of the insular Newfoundland population. The lack of genetic structure observed may suggest that, at a larger scale, marten dispersal is not as limited by some landscape features as was previously thought.
Characteristics of current and historical kit fox (Vulpes macrotis) dens in the Great Basin Desert
Authors: Arjo Wendy M , Bennett Tim J , Kozlowski Adam J
Published: February 2003

We examined the ecological and physical characteristics of den sites for 13 adult kit fox (Vulpes macrotis) in western Utah from December 1998 to February 2001. We also compared current and historical den distribution among habitat types. The number of den sites used was not influenced by home-range size (P = 0.11) or season (P = 0.40), but was influenced by geographical area. Home-range size was smallest (P = 0.007) and the number of dens used was greatest (P = 0.009) in mountainous areas. Ecological and physical characteristics of single-use dens (n = 30) were compared with those of multiple-use (n = 53) and natal dens (n = 8). Characteristics that differed between den types included number of entrances (P = 0.0001), diameter of entrances (P = 0.003), and height of vegetation along transects (P = 0.0001). Natal den entrance azimuths were weighted towards a northwesterly aspect (P = 0.0022); however, single- and multiple-use den exits appeared to be randomly distributed. Historical changes in kit fox den site selection have occurred since 1959 (P < 0.0001). We characterized more dens in invasive grasslands and fewer in greasewood (Sarcobatus vermiculatus) habitats than previously described. The conversion of native habitat to grassland and the increase in coyote population may have altered kit fox distribution to include mountainous areas not previously described.