bluuebunny/crossref_metadata_2025 huggingface dataset:
Taxonomic basis for variation in the colonization strategy of arbuscular mycorrhizal fungi
Authors: Hart Miranda M. , Reader Richard J.
Published: March 2003

Arbuscular mycorrhizal fungi (AMF) are important components of terrestrial communities but the basic ecology of individual AMF, including their colonization strategy, remains unclear. The colonizing behaviours of 21 AMF isolates from three families (Acaulosporaceae, Gigasporaceae and Glomaceae) were compared to test for a relationship between AMF taxonomy and colonization strategy.

 Both the rate and extent of colonization were considered by measuring percentage root colonization, root fungal biomass, soil hyphal length and soil fungal biomass over 12 wk.

 Most Glomaceae isolates colonized roots before Acaulosporaceae and Gigasporaceae isolates. The fastest colonizers were also often the most extensive. Taxonomic differences were apparent in the amount and proportion of fungal biomass found in roots vs in soil. Glomaceae isolates had high root colonization but low soil colonization, Gigasporaceae isolates showed the opposite trend whereas Acaulosporaceae isolates had low root and soil colonization. These results were similar for four different host plants.

 The results indicate that the colonizing strategies of AM fungi differ considerably and that this variation is taxonomically based at the family level. Arbuscular mycorrhizal fungal taxonomy therefore has a functional basis.
Mineral content of excreta from the spittlebug Philaenus spumarius closely matches that of xylem sap
Authors: Ponder K. L. , Watson R. J. , Malone M. , Pritchard J.
Published: March 2003

Analysis of xylem sap from intact transpiring plants is possible using excreta of xylem feeding insects. However, the extent to which the inorganic composition of ingested sap is altered by its passage through the insect has not been fully evaluated. The impact of the xylem feeding insect Philaenus spumarius (meadow spittlebug) on the inorganic composition of ingested sap from tomato (Lycopersicon esculentum) is reported here.

 Two nondestructive experimental approaches were used. Sap exuding due to root pressure from a cut tomato stem was compared with excreta from a caged insect feeding just below the cut surface. A second method involved pumping a solution of inorganic ions through a section of tomato stem upon which an adult insect was caged. The composition of insect excreta was compared with that of the input and output solutions.

 Overall, the concentrations of inorganic ions were similar in ingested fluid and excreta except for ammonium, which was generally elevated in excreta samples.

 It is demonstrated that excreta of P. spumarius can be used for continual monitoring of most inorganic ions in xylem sap of intact transpiring plants, and that stem perfusion is a useful tool for quantifying the effect of the insect on solutions of known composition.
Monoterpene emissions in relation to foliar photosynthetic and structural variables in Mediterranean evergreen Quercus species
Authors: Niinemets Ülo , Hauff Karin , Bertin Nadia , Tenhunen John D. , Steinbrecher Rainer , Seufert Günther
Published: March 2003

The relationships between foliar photosynthetic variables and monoterpene emission rates (E) are reported here for two sclerophylls, Quercus coccifera L. and Q. ilex L., which lack specialized foliar monoterpene‐storage structures.

 Photosynthesis rates and E were measured within a forest canopy, and in leaves of different exposure in a garrigue ecosystem. Leaf dry mass per unit area (LMA) was used as a proxy of long‐term leaf light availability.

 Maximum photosynthetic electron transport rate (Jmax), Rubisco carboxylase activity (Vcmax) and light‐saturated E (Emax) per unit area increased strongly with increasing LMA. The positive effect of LMA on area‐based Emax resulted from an accumulation of enzymes responsible for monoterpenoid synthesis per unit area. Positive relationships were observed between both area‐ and mass‐based Emax and Jmax, but not with photosynthesis rates, suggesting a possible control of terpene synthesis by foliar electron transport rates. Results suggested that monoterpene volatility limitations at low temperatures might also constrain E. Nonspecific storage may explain bursts of monoterpene emission on warm days following cold days, and monoterpene emission in low quantities during night.

 Although the correlations between Emax and Jmax do not necessarily give mechanistic insight into the physiology of monoterpene emission, they provide a basis for scaling up leaf emissions to a canopy level. However, both the leaf‐to‐leaf differences in monoterpene synthase activities, and monoterpene storage may perplex the relations between the electron transport rates and E.
Hepatitis B core antibodies in Danish blood donors: a surrogate marker of risk behaviour
Authors: Christensen P. B. , Titlestad I. L. , Homburg K. M. , Georgsen J. , Kristensen T.
Published: March 2003

Background and Objectives

The aim of this work was to determine the prevalence of antibodies to hepatitis B core antigen (anti‐HBc) among Danish blood donors and to correlate this with risk factors for blood‐borne and sexually transmitted diseases.

Materials and Methods

During a 5‐month period, 10 862 consecutive donors in the County of Funen were screened for anti‐HBc, and repeat‐reactive samples were confirmed by supplementary testing. Information on risk factors was assessed by questionnaire in 585 consecutive anti‐HBc‐negative blood donors and compared with information obtained from confirmed positive donors.

Results

The prevalence of confirmed positive anti‐HBc among donors was 0·70% (76/10 862, 95% confidence interval [CI]: 0·55–0·87). One donor was positive for anti‐HBc immunoglobulin M (IgM); none tested positive for hepatitis B virus (HBV) DNA. In a logistic regression analysis, age, female gender, tattoos and commercial sexual relations, were independent predictive factors for the presence of anti‐HBc.

Conclusion

Anti‐HBc is a surrogate marker for previous risk behaviour in the Danish blood donor population. We suggest that screening for anti‐HBc may be used among new donors to supplement interviews on risk behaviour.
Anti‐inflammatory responses and oxidative stress in Nippostrongylus brasiliensis‐induced pulmonary inflammation
Authors: McNeil Kathryn S. , Knox David P. , Proudfoot Lorna
Published: March 2003

summary

Migration of L3 larvae of Nippostrongylus brasiliensis through the lungs of the rat, during primary infection, was studied at 24 h, 72 h and 8 days. At 24 h p.i., there was evidence of damage to lung epithelial cells and microvasculature, with increased protein and γ‐glutamyl transpeptidase in the bronchoalveolar lavage (BAL) fluid. However, there was little evidence of inflammatory cell recruitment. At 24 h p.i., there was a significant reduction in the inflammatory cytokine tumour necrosis factor α. Superoxide (O2−·) production was also reduced, accompanied by an increase in superoxide dismutase activity. Lipid peroxidation was reduced at 24 h p.i. and L3 larvae were shown to possess high levels of glutathione compared to host lung tissue. Nitric oxide, detected as nitrite, was produced in BAL fluid, and inducible nitric oxide synthase protein was increased by 72 h p.i. There was evidence of peroxynitrite production throughout the infection period with specific protein bands nitrosylated at 75, 30 and 25 kDa. It appears that despite early evidence of lung damage, the inflammation was reduced in response to L3 larvae of N. brasiliensis.
Heterogeneity in the effect of different ixodid tick species on human natural killer cell activity
Authors: Kubeš M. , Kocáková P. , Slovák M. , Sláviková M. , Fuchsberger N. , Nuttall P. A.
Published: March 2003

summary

Tick saliva plays a vital role in blood‐feeding, including manipulation of the host response to tick infestation. Furthermore, a diverse number of tick‐borne pathogens are transmitted to vertebrate hosts via tick saliva, some of which exploit the immunomodulatory activities of their vector’s saliva. We report that salivary gland extracts (SGE) derived from Dermacentor reticulatus adult ticks induce a decrease in the natural killer (NK) activity of effector cells obtained from healthy human blood donors. The decrease was observed with SGE from both female and male D. reticulatus fed for either 3 or 5 days on mice, but no significant effect was observed with SGE from unfed ticks or ticks that had fed for 1 day. These results indicate that the tick anti‐NK factor(s) is only active after blood‐feeding has commenced. Microscopic examination revealed that the first step of NK activity, namely effector/target cell conjugate formation, was affected by SGE. The observed reduction in conjugate formation occurred when effector (but not target) cells were treated with SGE for 30 min, and the effect persisted after 12 h of treatment. Similar but less potent anti‐NK activity was detected for SGE from Amblyomma variegatum and Haemaphysalis inermis. By contrast, SGE derived from Ixodes ricinus and Rhipicephalus appendiculatus female ticks did not decrease NK activity. The apparent absence of such activity in these two important vectors of tick‐borne viruses suggests that control of NK cells does not play an important role in promoting virus transmission, at least for these particular species.
Human Trichuris‐specific antibody responses in vaccinated hu‐PBL‐SCID mice
Authors: Taylor Matthew D. , Else Kathryn J.
Published: March 2003

Trichuris trichiura is a highly prevalent intestinal helminth of humans with a well‐characterized animal model, Trichuris muris in the mouse. Relating the murine work back to the human infection has been difficult, however, as many of the questions addressed in the mouse cannot be asked in humans. The ability to reconstitute a mouse with a human immune system could help bridge this gap, allowing a human immune response to be studied under a controllable laboratory environment. In this study, we demonstrate that severe combined immunodeficient mice engrafted with naïve human peripheral blood lymphocytes are capable of mounting a Trichuris specific human antibody response after vaccination with T. muris antigens. The phenotype of the response depended on the vaccinating antigen with excretory/secretory antigens eliciting a human immunoglobulin (Ig)G2 response, and whole worm homogenate stimulating IgG1 and IgG2 responses. Vaccination with homogenate also enhanced a human IgG response against a 66‐kDa component of T. muris homogenate in a donor‐dependent manner. This work shows the potential of using the humanized mouse model for studying the immune responses of humans living in T. trichiura endemic areas.
Multistage reaction textures in xenolithic high‐MgAl granulites at Anakapalle, Eastern Ghats Belt, India: examples of contact polymetamorphism and infiltration‐driven metasomatism
Authors: Rickers K. , Raith M. , Dasgupta S.
Published: March 2003

High‐MgAl rocks occur as xenoliths (up to 2 m in diameter) in mafic granulites at a newly discovered locality near Anakapalle. Following an early phase of deformation, ultrahigh‐temperature (UHT) metamorphism and near‐isothermal decompression, the rocks were intruded in a lit‐par‐lit manner by felsic melts (charnockite), which caused local‐scale metasomatism. A subsequent deformation produced isoclinal folds and the distinct gneissic foliation of the charnockite still at granulite facies conditions.

The sequence of multiphase reaction textures in the high‐MgAl xenoliths reflects the changes of physico‐chemical conditions during the polyphase evolution of the terrane; UHT metamorphism (stage 1, > 1000°C,c. 10 kbar) is documented by relics of extremely coarse grained domains with the assemblage orthopyroxene (opx)1 + garnet (grt)1 + sapphirine (spr)1 + spinel (spl)1 + rutile (rt). A subsequent phase of near‐isothermal decompression in the order of 1–2 kbar (stage 2) resulted in extensive replacement of grt1and opx1megacrysts by lamellar (opx2 + spr2) symplectites. The intrusion of felsic melt (stage 3) led to the development of a narrow metasomatic black wall reaction zone (bt + sil + plg3 + opx2,3 + rt) at the immediate contact of the xenoliths and in melt infiltration zones to the partial replacement of (opx2 + spr2) symplectites by biotite and sillimanite and/or plg3, mainly at the expense of orthopyroxene, with concomitant coarsening of the intergrowth texture. The subsequent deformation (stage 4) further modified the symplectite textures through polygonization, recrystallization and grain‐size coarsening. The deformation was followed by a period of cooling and decompression (stage 5,c. 800°C, 4–7 kbar) as indicated by local growth of late garnet (grt5) at the expense of (opx + spr + plg) domains at static conditions.

Recently published isotope data suggest that the multistage evolution of the high‐MgAl granulites at Anakapalle followed a discontinuousP–Ttrajectory that may be related to heating of the crust through magmatic accretion culminating in deep‐crustal UHT metamorphism at 1.4 Ga (stage 1), fast uplift of the UHT granulites into mid‐crustal levels as a consequence of extensional tectonics (stage 2), emplacement of felsic magmas in the Grenvillian (atc. 1 Ga, stage 3) resulting in reheating of the crust to high–Tconditions followed by a phase of compressional tectonics (stage 4) and a period of cooling to the stable geotherm (stage 5) still in the Grenvillian.
The ASVIN Project: a study of electronic and printed veterinary science journals in the UK and Ireland
Authors: Davies Bryn
Published: March 2003

ASVIN was a Research Support for Libraries Programme (RSLP) Funded Project, whose principal aim was to develop better co‐operation between nine libraries in the veterinary and animal health field. The project examined a number of library‐related areas, such as journal archiving, collection development policies, development of a common Z39.50 catalogue interface, grey literature, and printed and electronic journals. This paper examines the latter, whilst also providing a detailed analysis of printed journals held in partner libraries. Comparisons of the nine partner library collections are undertaken with a range of secondary sources, and an ASVIN core list of veterinary journals was developed. It looks at some of the issues relating to e‐journals, expressing the benefits and concerns that many librarians are experiencing, such as licensing arrangements, archiving and general management issues.
Factors contributing to teachers' successful implementation of IT
Authors: Granger C.A. , Morbey M.L. , Lotherington H. , Owston R.D. , Wideman H.H.
Published: March 2003

Abstract It has become increasingly important for educators to examine successful ICT implementations with the aim of understanding precisely what makes them successful in teaching and learning. In this study, an analysis of data from qualitative case studies of four Canadian schools illuminates factors that facilitate successful ICT implementation. Findings suggest that informal ICT education, such as ‘just‐in‐time’ learning, is most influential. Furthermore, supportive and collaborative relationships among teachers, a commitment to pedagogically sound implementation of new technologies, and Principals who encourage teachers to engage in their own learning are viewed as highly useful factors.
Role of primary intrahepatic T‐cell activation in the ‘liver tolerance effect’
Authors: Bertolino Patrick , McCaughan Geoffrey W , Bowen David G
Published: March 2003

There is accumulating evidence suggesting that hepatic permeability to both naive and activated T lymphocytes may be unique among the solid organs. The possibility that the liver may act as a site of primary activation for CD8+ T lymphocytes is supported by experimental data and may contribute to some of the unique immunological properties of this organ, particularly its ability to induce antigen‐specific tolerance. This review discusses the nature of the liver APC inducing primary T‐cell activation within the liver: Kupffer cells, liver dendritic cells, liver sinusoidal endothelial cells and hepatocytes are favourably located to allow physical contact with circulating T lymphocytes. Here, we examine the capability of each cell type to act as APC for naive CD4+ or CD8+ T cells and to induce tolerance.
High prevalence of cfxAβ‐lactamase in aminopenicillin‐resistant Prevotella strains isolated from periodontal pockets
Authors: Fosse T. , Madinier I. , Hannoun L. , Giraud‐Morin C. , Hitzig C. , Charbit Y. , Ourang S.
Published: March 2003

This prospective study was designed to investigate amoxicillin‐resistant oral anaerobes, and to identify their β‐lactamase‐encoding genes. Three subgingival bacterial samples were collected from 12 patients suffering from periodontitis. One to seven β‐lactamase‐producing strains were obtained from each patient, mostly belonging to the Prevotella genus (Bacteroides eggerthii, 2/35 strains; Prevotella sp., 33/35 strains). PCR assays were used to detect cfxA and cepA/cblA, the genes encoding class A/group2e β‐lactamases previously described in the Bacteroides fragilis group. The present investigation confirmed the role of Prevotella species as β‐lactamase producers in periodontal pockets. Additionally, this PCR screening showed (1): the high prevalence of CfxA β‐lactamase production by aminopenicillin‐resistant Prevotella (32/33: 97.0% positive strains) vs. cepA/cblA (1/33: 3.0% positive strains), and (2) the presence of cfxA in the periodontal reservoir in the absence of antimicrobial therapy during the previous 6 months.
A comparison of adapalene gel 0.1% vs. tretinoin gel 0.025% in the treatment of acne vulgaris in China
Authors: Tu P , Li G‐Q , Zhu X‐J , Zheng J , Wong W‐Z
Published: March 2003

Aim To compare the efficacy, safety and tolerability of adapalene gel 0.1% vs. tretinoin gel 0.025% in a Chinese patient population.

Background Although acne vulgaris is a common problem among Asians and Asian‐Americans, little has been published on the specific manifestations, sequelae, and treatment‐responsiveness of this disorder in Asian skin types. Since Asian skin types tend to be more highly pigmented than those of white people of European descent, many Asians share the predisposition toward postinflammatory hyperpigmentation seen in Africans, African‐Americans and other dark‐skinned peoples. It is generally assumed that the efficacy and safety of topical retinoids is the same in Asians as in white people. Tretinoin has been available in China for decades; adapalene became available in 1998.

Methods A total of 150 patients with grade II–III acne vulgaris seen at three dermatology clinics were randomized to 8 weeks of daily treatment with either adapalene gel 0.1% or tretinoin gel 0.025%. Counts of total lesions, inflammatory lesions and non‐inflammatory lesions were made at baseline and again at treatment weeks 2, 4, 6 and 8. Global assessment ratings, based on percent lesion reduction from baseline were also made. Erythema, burning, pruritus, scaling and dryness were rated on a 0–3 severity scale.

Results A total of 139 patients completed the efficacy evaluation, and 144 patients completed the safety evaluation. Both adapalene and tretinoin produce dramatic reductions in total, inflammatory and non‐inflammatory lesion counts, in the range of 69–74% on average. More than 70% of patients in both groups had complete clearance or marked improvement. In general, irritation was mild, but was both more common and more severe in the tretinoin group vs. the adapalene group. No systemic side effects were seen.

Conclusions Adapalene offers comparable efficacy to tretinoin, but is less irritating. It represents a good alternative for the treatment of mild to moderate acne vulgaris in Chinese patients.
Effects of rumen‐protected methionine in a low protein ration on metabolic traits and performance of early lactating cows as opposed to rations with elevated crude protein content
Authors: Kröber T. F. , Kreuzer M. , Senn M. , Langhans W. , Sutter F.
Published: March 2003

A 5‐week experiment with 24 multiparous early lactating Brown Swiss cows was conducted to investigate the effects of supplementary rumen‐protected methionine in conjunction with dietary protein reduction on metabolism and performance after 1 week of control measurement. Three rations containing 175, 150 and 125 g of crude protein/kg feed dry matter were supplemented with methionine. The fourth ration, also only containing 125 g of crude protein/kg dry matter, remained unsupplemented. The four treatment groups had a similar metabolic supply of other essential amino acids, protein and energy, as calculated by various approaches. The two low protein rations were, however, slightly deficient in ruminally degraded protein. Treatment effects remained low on feed intake, forage meal pattern, milk yield and fat as well as lactose content. In contrast, the content and yield of milk protein significantly declined only in the unsupplemented low protein ration relative to the initial value. Compared with this ration, the decline in milk protein yield was clearly delayed in the supplemented low protein ration. Blood plasma methionine tended to be reduced without supplementation and to be increased with additional methionine. Supplementation of methionine reduced other plasma amino acids. Plasma insulin, glucose, lactate, ketone bodies and aspartate amino transferase activity indicated a certain liver stress and a somewhat elevated energy requirement with high and particularly with low protein content (when unsupplemented). Methionine improved metabolic protein utilization, followed by the lowest plasma, urine and milk urea levels in the supplemented low protein diet. In conclusion, no major adverse effects were assessed under the conditions tested. Supplementation of methionine may nevertheless be useful in rations with particularly low protein content fed to early lactating cows in order to prevent negative long‐term effects which were only visible here as trends.
The release of genetically modified crops into the environment
Authors: Conner Anthony J. , Glare Travis R. , Nap Jan‐Peter
Published: March 2003

Despite numerous future promises, there is a multitude of concerns about the impact of GM crops on the environment. Key issues in the environmental assessment of GM crops are putative invasiveness, vertical or horizontal gene flow, other ecological impacts, effects on biodiversity and the impact of presence of GM material in other products. These are all highly interdisciplinary and complex issues. A crucial component for a proper assessment is defining the appropriate baseline for comparison and decision. For GM crops, the best and most appropriately defined reference point is the impact of plants developed by traditional breeding. The latter is an integral and accepted part of agriculture. In many instances, the putative impacts identified for GM crops are very similar to the impacts of new cultivars derived from traditional breeding. When assessing GM crops relative to existing cultivars, the increased knowledge base underpinning the development of GM crops will provide greater confidence in the assurances plant science can give on the risks of releasing such crops.
The K domain mediates heterodimerization of theArabidopsisfloral organ identity proteins, APETALA3 and PISTILLATA
Authors: Yang Yingzhen , Fanning Laura , Jack Thomas
Published: March 2003

MADSgenes in plants encode key developmental regulators of vegetative and reproductive development. The majority of well‐characterized plant MADS proteins contain two conserved domains, the DNA‐binding MADS domain and the K domain. The K domain is predicted to form three amphipathic α‐helices referred to as K1, K2, and K3. In this report, we define amino acids and subdomains important for heterodimerization between the twoArabidopsisfloral organ identity MADS proteins APETALA3 (AP3) and PISTILLATA (PI). Analysis of mutants defective in dimerization demonstrates that K1, K2 and the region between K1 and K2 are critical for the strength of AP3/PI dimerization. The majority of the critical amino acids are hydrophobic indicating that the K domain mediates AP3/PI interaction primarily through hydrophobic interactions. Specially, K1 of AP3 and PI resembles a leucine zipper motif. Most mutants defective in AP3/PI heterodimerization in yeast exhibit partial floral organ identity function in transgenicArabidopsis. Our results also indicate that the motif containing Asn‐98 and specific charged residues in K1 (Glu‐97 in PI and Arg‐102 in AP3) are important for both the strength and specificity of AP3/PI heterodimer formation.
Reproducibility and repeatability of transabdominal uterine artery Doppler velocimetry between 10 and 14 weeks of gestation
Authors: Hollis B. , Mavrides E. , Campbell S. , Tekay A. , Thilaganathan B.
Published: March 2003

Objective

To assess the intraobserver repeatability and interobserver reproducibility of Doppler flow velocity measurements of the uterine arteries in pregnant women between 10 and 14 weeks of gestation.

Methods

In this prospective study, Doppler velocimetric indices (maximum peak systolic velocity, end‐diastolic velocity, peak systolic velocity/end‐diastolic velocity ratio, pulsatility index and resistance index) were measured twice by the same trained observer in each uterine artery of 63 women. In 47 of these women, a second trained observer then repeated the measurements. In addition, both observers classified qualitatively the blood flow with regard to the presence or absence of an early diastolic notch. The coefficient of variation, intraclass correlation coefficients, within observer and between observers repeatability coefficient and Cohen's kappa coefficient were calculated.

Results

The best parameter in terms of repeatability and reproducibility in both uterine arteries was the resistance index with a low coefficient of variation and high intraclass correlation coefficient. The other parameters (pulsatility index, peak systolic velocity/end‐diastolic velocity ratio, peak systolic velocity and end‐diastolic velocity) performed poorly with high coefficients of variation on both sides. Agreement between the repeated observations (inter‐ and intraobserver) with regard to the presence or absence of an early diastolic notch was good.

Conclusion

Doppler velocimetry of uterine artery blood flow is technically feasible between 10 and 14 weeks of gestation. This study demonstrates that this technique is prone to measurement errors. Quantitatively, the resistance index appears to be the most repeatable and reproducible measurement at this gestational age. Qualitative assessment of the waveform morphology also shows high levels of intra‐ and interobserver agreement.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
The genome of the Queensland fruit flyBactrocera tryonicontains multiple representatives of themarinerfamily of transposable elements
Authors: Green C. L. , Frommer M.
Published: March 2003

Representatives of five distinct types of transposable elements of themarinerfamily were detected in the genomes of the Queensland fruit flyBactrocera tryoniand its sibling speciesBactrocera neohumeralisby phylogenetic analysis of transposase gene fragments. Threemarinertypes were also found in an additional tephritid,Bactrocera jarvisi. Using genomic library screening and inverse PCR, full‐length elements representing the mellifera subfamily (B. tryoni.mar1) and the irritans subfamily (B. tryoni.mar2) were isolated from theB. tryonigenome. Nucleotide consensus sequences for each type were derived from multiple defective copies. Predicted transposase sequences share ≈ 23% amino acid identity.B. tryoni.mar1elements have an estimated copy number of about 900 in theB. tryonigenome, whereasB. tryoni.mar2element types appear to be present in low copy number.
Phylogeography of the intertidal copepod Tigriopus californicus reveals substantially reduced population differentiation at northern latitudes
Authors: Edmands S.
Published: March 2003

Previous studies of the intertidal copepod Tigriopus californicus revealed one of the highest levels of mitochondrial DNA differentiation ever reported among conspecific populations. The present study extends the geographical sampling northward, adding populations from northern California to south‐east Alaska. The mitochondrial phylogeny for the entire species range, based on cytochrome oxidase I sequences for a total of 49 individuals from 27 populations, again shows extreme differentiation among populations (up to 23%). However, populations from Oregon northwards appear to be derived and have interpopulation divergences five times lower than those between southern populations. Furthermore, although few individuals were sequenced from each locality, populations from Puget Sound northward had significantly reduced levels of within‐population variation. These patterns are hypothesized to result from the contraction and expansion of populations driven by recent ice ages.
Phylogeography of the Vosges mountains populations of Gonioctena pallida (Coleoptera: Chrysomelidae): a nested clade analysis of mitochondrial DNA haplotypes
Authors: Mardulyn P.
Published: March 2003

The pattern of genetic variation in the leaf beetle Gonioctena pallida was investigated inside the Vosges mountains using a highly variable 363 bp DNA fragment of the mitochondrial control region. Sequencing of 242 individuals, sampled in a geographical area of 100 × 40 km, identified 61 haplotypes whose genealogy was inferred. The resulting haplotype network exhibits four star‐like phylogenies, two of which may be indicative of a population having recently expanded in size from a small number of founders. Nested clade analysis suggested multiple past expansion events, but also isolation by distance and possibly past fragmentation events, as the causes of the detected geographical associations of haplotypes. These results indicate the existence of effective barriers to gene flow inside the investigated area. Because the oldest demographic events inferred in the nested clade analysis were identified as expansion events, we hypothesize that a small population of founders have expanded not only in size, but also in geographical range from the south towards the north and east of the Vosges.
A molecular phylogenetic analysis of diversification in AmazonianAnolislizards
Authors: Glor R. E. , Vitt L. J. , Larson A.
Published: March 2003

We present a mitochondrial DNA (mtDNA) haplotype phylogeny for AmazonianAnolislizards, including geographical sampling within four species distributed across the Amazon basin (A. fuscoauratus,A. nitens,A. ortoniiandA. punctatus). Approximately 1500 bp of mtDNA encoding ND2, COI and four transfer RNAs (tRNAs) are reported for 39 specimens representing four to five populations of each widespread species, plus eight outgroups. These new sequences are aligned with eight previously published sequences, yielding 914 variable characters and 780 parsimony‐informative characters. Phylogenetic analyses using maximum parsimony and maximum likelihood reject the hypothesis that Amazonian anoles form a monophyletic group excluding Central American and Caribbean anoles, and suggest multiple faunal exchanges among these regions. Haplotype divergence among geographical populations ofA. nitens, whose variation was influential in formulating the Pleistocene refuge hypothesis of Amazonian speciation, is very large (13–22% sequence difference), suggesting that these populations separated well before the Pleistocene. Haplotype divergences among geographical populations ofA. fuscoauratus(3–4%),A. punctatus(4–9%) andA. ortonii(6–8%) also indicate pre‐Pleistocene differentiation within each species, but temporally incongruent patterns among species.
Differential patterns of spatial divergence in microsatellite and allozyme alleles: further evidence for locus‐specific selection in the acorn barnacle,Semibalanus balanoides?
Authors: Dufresne F , Bourget E , Bernatchez L
Published: March 2003

We compared patterns of genetic structure at potentially selected (two allozyme loci) and neutral molecular markers (six microsatellite loci) in the acorn barnacle,Semibalanus balanoidesfrom the Gulf of St. Lawrence. Our results confirmed the presence of a geographical shift in allelesMPIandGPInear the Miramichi River. In contrast, no significant patterns of population differentiation among samples located north and south of the river mouth were detected for four of six microsatellite loci. However, analysis of molecular variance (amova) at individual loci revealed that a significant proportion of the total variance in allele frequencies was partitioned among samples located north and south of the river for both the allozyme and the other two microsatellite loci. The two most common alleles at these microsatellites showed frequencies that were highly correlated (r = 0.65–0.74,P < 0.05) with those of theMPI*2 allele, perhaps because of either physical linkage or epistasis. The two allozyme loci were significantly correlated in barnacles located north of the Miramichi River (r = 0.86,P < 0.05). Overall, our results supported the hypothesis that the broad scale pattern of allozyme allelic shifts is maintained by selection. They also indicated that microsatellites may not always behave in a neutral way and must be used cautiously, especially when evidence for genetic structuring relies on only a few assayed loci.
Male reproductive competition in spawning aggregations of cod (Gadus morhua, L.)
Authors: Bekkevold D , Hansen M. M , Loeschcke V
Published: March 2003

Reproductive competition may lead to a large skew in reproductive success among individuals. Very few studies have analysed the paternity contribution of individual males in spawning aggregations of fish species with huge census population sizes. We quantified the variance in male reproductive success in spawning aggregations of cod under experimental conditions over an entire spawning season. Male reproductive success was estimated by microsatellite‐based parentage analysis of offspring produced in six separate groups of spawning cod. In total, 1340 offspring and 102 spawnings distributed across a spawning season were analysed. Our results show that multiple males contributed sperm to most spawnings but that paternity frequencies were highly skewed among males, with larger males on average siring higher proportions of offspring. It was further indicated that male reproductive success was dependent on the magnitude of the size difference between a female and a male. We discuss our results in relation to the cod mating system. Finally, we suggest that the highly skewed distribution of paternity success observed in cod may be a factor contributing to the low effective population size/census population size ratios observed in many marine organisms.
The estimation of population differentiation with microsatellite markers
Authors: Balloux François , Lugon‐Moulin Nicolas
Published: March 2003

Microsatellite markers are routinely used to investigate the genetic structuring of natural populations. The knowledge of how genetic variation is partitioned among populations may have important implications not only in evolutionary biology and ecology, but also in conservation biology. Hence, reliable estimates of population differentiation are crucial to understand the connectivity among populations and represent important tools to develop conservation strategies. The estimation of differentiation is c from Wright’s FST and/or Slatkin’s RST, an FST‐analogue assuming a stepwise mutation model. Both these statistics have their drawbacks. Furthermore, there is no clear consensus over their relative accuracy. In this review, we first discuss the consequences of different temporal and spatial sampling strategies on differentiation estimation. Then, we move to statistical problems directly associated with the estimation of population structuring itself, with particular emphasis on the effects of high mutation rates and mutation patterns of microsatellite loci. Finally, we discuss the biological interpretation of population structuring estimates.
Amplified fragment length polymorphism analysis identifies hybrids between two subspecies of warblers
Authors: Bensch Staffan , Helbig Andreas J. , Salomon Marc , Seibold Ingrid
Published: March 2003

In the western Pyrenees (Southwest France and Northwest Spain), a narrow hybrid zone exists between the common chiffchaffPhylloscopus (collybita) collybitaand the Iberian chiffchaffPhylloscopus (c.) brehmii. In this zone, which is approximately 20 km wide, mixed matings and individuals singing the songs of both taxa occur at substantial frequencies (24 and 8.6%, respectively), suggesting frequent hybridization. Previous studies have shown very weak mitochondrial gene flow (Nm = 0.065), whereas four microsatellites suggested much higher nuclear gene flow (Nm = 4.9). In this study we used the amplified fragment length polymorphism (AFLP) method in order to identify hybrids and early backcrosses. We typed 91 birds from both allopatric and sympatric areas for 12 informative AFLP markers (of > 141 polymorphic fragments), obtained by screening 13 AFLP primer combinations. These individuals were previously typed for song (brehmii, collybitaor mixed singers), mitochondrial DNA (mtDNA) haplotype and allelic genotypes at four microsatellite loci. Assignment tests demonstrated that in the zone of sympatry, a substantial number of intermediate genotypes existed among the birds previously believed to be purecollybitaandbrehmii, based on song and mtDNA haplotype. The majority of the mixed singers had intermediate genotypes. Our data suggest that the fraction of the adult population having a hybrid origin (hybrids or backcrosses) is in the order of 10%. With such a frequency of genetic hybrids, there would have been much more mtDNA introgression than observed, had female hybrids been perfectly fertile/viable. This result is consistent with male‐biased gene flow and Haldane’s rule.
Effects of life history variation on size and growth in stream‐dwelling Atlantic salmon
Authors: Letcher B. H. , Gries G.
Published: March 2003

A large size variation amongst life histories for stream‐dwelling Atlantic salmon Salmo salar was found and the relative effect of life histories on size varied over time. As early as December (age 0+ years), fish that later smolted at age 2+ years were significantly larger than fish that did not smolt at age 2+ years. In contrast, there were no mass differences at age 0+ years between fish that would mature or not at age 1+ years (October). The mass differences between smolts and non‐smolts persisted until smolting, and differences between mature and immature fish first appeared in May (age 1+ years). Following September (age 1+ years), there was also a significant interaction between smolting and maturity. Previously mature and immature age 2+ year smolts were not significantly different in size, but immature age 2+ year non‐smolts were much lighter than mature age 2+ year non‐smolts. Based on mass differences, the apparent ‘decision’ to smolt occurred c. 5 months before (winter, age 0+ years) the decision to mature (late spring, age 1+ years). In addition to strong seasonal growth variation, sizes of freshwater Atlantic salmon were largely structured by the complex interaction between smolt‐age and maturity.
Sonographic features of trisomy 18 at midpregnancy
Authors: Tongsong Theera , Sirichotiyakul Supatra , Wanapirak Chanane , Chanprapaph Pharuhas
Published: March 2003

Objective:
 To evaluate the sonographic characteristics of the fetuses with trisomy 18 at 16–22 weeks of gestation.

Methods:
 The subjects were recruited from pregnant women undergoing prenatal sonographic examinations at 16–22 weeks of gestation and subsequently proven to be trisomy 18. The results of ultrasound findings were retrospectively reviewed in 25 cases with chromosomes which were confirmed as trisomy 18.

Results:
 All cases had at least one abnormal sonographic finding. There was only one case that had no structural abnormality, but fetal growth restriction was documented. The common sonographic findings included fetal growth restriction, choroid plexus cysts, cardiac anomalies, clenched hand, omphalocele and cleft lip. Fetal growth restriction was the most common finding demonstrated in nearly half of all cases. Other less common findings were diaphragmatic hernia, abnormal head shape, polyhydramnios, single umbilical artery.

Conclusion:
 Nearly all fetuses with trisomy 18 had characteristic sonographic patterns of abnormalities demonstrated at midpregnancy. Detailed ultrasound at midpregnancy could effectively screen fetuses with trisomy 18 for further genetic testing.
Immature brain injury via peroxynitrite production induced by inducible nitric oxide synthase after hypoxia‐ischemia in rats
Authors: Ikeno Shinji , Nagata Naoki , Yoshida Souichi , Takahashi Hiroyuki , Kigawa Junzo , Terakawa Naoki
Published: March 2003

Objective:
 To determine whether, and if so, how, iNOS expresses and affects brain injury induced by hypoxia‐ischemia in an immature brain.

Material and Methods:
 Seven‐day‐old Wistar rat pups were exposed to right common carotid artery ligation followed by 1.5 hours of hypoxia. The time course of iNOS mRNA expression, enzymatic activity, and protein production in the cerebral cortex were determined. The extent of the infarct area in the cerebral cortex and the production of 3‐nitrotyrosine (a biomarker of peroxynitrite) were compared between the control pups and pups treated with S‐methyl‐isothiourea (a selective iNOS inhibitor).

Results:
 In the cortex ipsilateral to carotid ligation, iNOS mRNA appeared from 6 hours to 24 hours after hypoxia‐ischemia and disappeared at 48 hours. The iNOS protein and its activity also increased at 12 hours and reached a maximum level at 48 hours after the insult. The percentage of damage in the cerebral cortex was significantly higher in the control pups than in treated pups (31.9 vs 10.6%). Tri‐nitrotyrosine following iNOS expression‐positive cells were located predominantly at the infarct and peri‐infarct regions.

Conclusion:
 iNOS expression might be an important determinant of ischemic immature brain injury.
Defective sexuality and female circumcision: The cause and the possible management
Authors: Thabet Saeed Mohamad Ahmad , Thabet Ahmed S.M.A.
Published: March 2003

Aim:  To verify the effect of circumcision on female sexuality and to define the need for clitorolabioplasty in these cases.

Methods:  Thirty uncircumcised controls, 30 minorly circumcised, 30 minorly circumcised mutilated, and 57 circumcised cases having clitoral cysts were selected on random bases at Kasr El Aini School of Medicine. Sexuality was assessed by a special questionnaire sheet prepared by the authors to fit the circumcised cases. Clitorolabioplasty and clitoral cyst excision were also done in cases of sexual defects.

Results:  Sexuality was not affected in minorly circumcised cases. However, sexuality was markedly affected in the mutilated cases. The scores for sex desire and arousal and for orgasm were especially affected in such cases. These defects were not detected in cases having clitoral cysts until late, when cysts enlarged. The role of clitorolabioplasty in restoration of sexuality was confirmed.

The loss of certain clitoral and labial bulk, necessary for orienting the woman towards her genitalia and initiating her interest in their function, was responsible for the occurrence of such defects; this was able to be restored by surgery.

Conclusion:  Counseling parents about these sexual defects and asserting the need for correcting the mutilation, which resulted from these circumcisions, are effective steps in banning such procedures.
Gasless laparoscopic hysterectomy: A comparative study with total abdominal hysterectomy
Authors: Tintara Hatern , Choobun Thanapan , Geater Alan
Published: March 2003

Aim:  To evaluate the short‐term results of gasless laparoscopic hysterectomy (GLH) compared to total abdominal hysterectomy.

Methods:  A comparative study of GLH using an abdominal wall‐lifting device (n = 31) and total abdominal hysterectomy (TAH) (n = 31) was carried out between July 1999 and July 2001.

Results:  One patient (3.2%) in the GLH group required conversion to TAH. The operative time was 168 ± 38 min and 112 ± 29 min (P < 0.001) for the GLH and TAH groups, respectively. Gasless laparoscopic hysterectomy cases had a shorter hospital stay and convalescent period (2.6 ± 0.9 days vs 5.0 ± 1.3 days, P < 0.001 and 8.0 ± 3.0 days vs 15.8 ± 2.4 days, P < 0.001, respectively). Postoperative meperidine use and estimated blood loss were lower for GLH (P < 0.001). Complications were comparable in the two groups. Hospital charges were 8.5% higher for GLH (P = 0.02).

Conclusions:  Gasless laparoscopic hysterectomy may be an alternative technique for hysterectomy which provides laparoscopic benefit with minimal increase in hospital charges.
Primary nursing: staff perception of changes in ward atmosphere and role
Authors: Rigby A. , Leach C. , Greasley P.
Published: March 2003

The value of a primary nursing care delivery structure remains undecided. This study was carried out on an acute psychiatric admissions unit as it changed its care delivery system to that of primary nursing. A review of the literature highlights the inconclusive nature of previous investigations. The principle of evidence‐based practice raises the need for further research to put this issue to rest. The staff perception of this change on both the atmosphere of the ward and on the role of the nurses themselves was analysed. A general reduction in satisfaction with role was discovered, as was a reduction in eight out of 10 subscales of the Ward Atmosphere Scale (Moos 1989). As primary nursing generally receives favourable reviews by nurses, and was in fact positively received by the staff in this study at the time of initiation, this negative result is surprising. It is conjectured that primary nursing may be an ideal philosophy of nursing that is difficult to realize due to constraints surrounding contemporary nursing practice.
p53 Expression, growth, and spontaneous metastasis of the human GI 101 breast carcinoma in athymic nude mice
Authors: Daoud Sayed S. , Leathers Charles W. , Hurst Josephine M.
Published: March 2003

The human GI 101 breast carcinoma cell lines produces spontaneous metastasis to the lungs when xenografted subcutaneously in female athymic nude mice. To establish the time‐course of tumor growth and distant metastasis to the lungs and axillary lymph nodes, 5 mm 3 of tumor tissue was implanted in the subaxial region of female athymic nude mice. Micrometastases in the lung were first detected 3 weeks after tumor implantation. The incidence of lung metastasis and the number of tumor emboli were correlated with the volume of the primary tumors. Ipsilateral axillary lymph node metastasis was observed within 17 weeks, indicating that metastasis to the lymph node is a later event. Unlike pulmonary micrometastases which were in the form of clusters of four to six tumor cells, metastasis to the lymph nodes were in nodules of poorly differentiated and larger tumor cells. Immunohistochemistry evaluation of p53 oncoprotein in the primary and metastatic tumor cells showed different patterns of subcellular accumulation. Cytoplasmic staining was mainly detected in the primary and secondary tumor cells disseminated to the lungs. In contrast, nuclear staining was only detected in tumor cells infiltrated to the axillary lymph nodes. There was no gain of loss of positivity of p53 accumulation (i.e., qualitative measurements) as the tumor grew in size. The data indicate that the GI 101 tumor cells could be used as a useful model for studying the malignant progression of hormone‐independent breast cancer, antimetastatic drugs, and early events in tumor metastasis.