bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological activities as patchiness driving forces in wetlands of northern Belize
Authors: Macek Petr , Rejmánková Eliška , Fuchs Roman
Published: August 2009

Patchiness in wetlands is a common and well documented phenomenon. Oligotrophic wetlands of northern Belize display noticeable vegetation heterogeneity at both large and small scales. In this paper, we document the small scale patches in herbaceous wetlands, describe differences between patches and surrounding wetland habitats and explain patch formation and sustenance.

We conducted a survey of patches and confirmed their occurrence by spatial analysis. Patches were distinguished from a surrounding wetland by denser and taller vegetation, higher amount of empty snail shells and elevated soil phosphorus (P). Plants in patches had higher tissue nitrogen (N) and P content and there was also higher total N and P per m2 incorporated in plant biomass. In terms of stable isotopes, plants in patches were enriched in 15N; patch soils were depleted in 13C.

Observations of focal individuals of Aramus guarauna, limpkin, a wading bird feeding almost exclusively on snails, revealed the origin of the snail shell piles frequently found in patches. An adult limpkin captured on average 18 snails daily, of these 80% were handled in patches and birds often repeatedly used the same patch.

Experimental patch creation by adding chicken manure or P to 1 m2 plots resulted in higher and denser vegetation with values increasing in order: control, P, manure plots. The effect was significant at both experimental locations six months after the treatment and at one location even 40 months after the treatment.

We present a simple mechanistic explanation for nutrient redistribution in wetlands and their eventual accumulation in patches. Both nutrient and isotopic differences result from animal input into patches, e.g. bird droppings or prey remnants. Foraging activity of Aramus guarauna is most likely responsible for patch formation. A positive feedback (repeated use of a suitable patch) is apparently the mechanism sustaining patches in these marsh environments.
Nutrients and disturbance history in twoPlantagospecies: maternal effects as a clue for observed dichotomy between resprouting and seeding strategies
Authors: Latzel Vít , Hájek Tomáš , Klimešová Jitka , Gómez Sara
Published: August 2009

We assessed the role of nutrients and disturbance experienced by mothers (maternal effects) in the growth of progeny in a pot experiment using twoPlantagospecies. Photosynthetic capacity, biomass allocation and fecundity were measured. Offspring of plants grown in nutrient poor conditions produced more leaves, spikes and longer leaves and in case ofP. lanceolata, they had also higher photosynthetic capacity. The progeny ofP. mediamothers that had resprouted after disturbance was favored in nutrient poor conditions whereas the progeny of undisturbed plants was favored in nutrient rich conditions.

This study demonstrates that maternal effects may play a role in the success of either a seeding or a resprouting strategy in environments with different nutrient availability. Moreover, we showed that alteration of photosynthetic capacity, even during adult stages, is a mechanism through which maternal plants may impact their progeny.
Role of the epidermal barrier in atopic dermatitis
Authors: Proksch Ehrhardt , Fölster‐Holst Regina , Bräutigam Matthias , Sepehrmanesh Marjan , Pfeiffer Stephan , Jensen Jens‐Michael
Published: August 2009

The skin's permeability barrier protects against extensive water loss and prevents the entry into the skin of harmful substances like irritants, allergens and microorganisms. The permeability barrier is mainly located in the stratum corneum and consists of corneocytes and a lipid‐enriched intercellular domain. The barrier is formed during epidermal differentiation. In atopic dermatitis the skin barrier is disturbed already in non‐lesional skin. The disturbed skin barrier allows the entry of environmental allergens from house dust mites, animal dander and grass pollen into the skin. In predisposed individuals these allergens may trigger via immunologic pathways the inflammation of atopy. The causes for the disturbed epidermal skin barrier are changes in skin lipids and in epidermal differentiation, in particular filaggrin mutations. Filaggrin mutations lead to a disturbed skin barrier and dry skin which are hallmarks in atopic dermatitis. Therapeutic agents influence the skin barrier differently; topical therapy with potent corticosteroids does not lead to the repair of the barrier in atopic dermatitis, whereas therapy with the calcineurin inhibitors and lipid‐containing emulsions support barrier repair.
Variations in resistance to canopy disturbances and their interactions with the spatial structure of major species in a cool‐temperate forest
Authors: Torimaru Takeshi , Nishimura Naoyuki , Matsui Kiyoshi , Hara Toshihiko , Yamamoto Shin‐Ichi
Published: August 2009

Question:How does typhoon‐related disturbance (more specifically, disturbance in the understorey due to tree‐fall and branch‐fall) affect different species mortality rates in a vertically well‐structured forest community?

Location:Cool‐temperate, old‐growth forest in the Daisen Forest Reserve, Japan.

Methods:We investigated the canopy dynamics and mortality rate trends of trees ≥5 cm diameter at breast height in a 4‐ha study plot, and analysed the effects of tree diameter and spatial structure on the mortality risks for major tree species in the understorey.

Results:Significant differences were found in the mortality rates and proportions of injured dead stems between census periods, which were more pronounced in the understorey than in the canopy.Acer micranthum, which showed increased mortality during typhoon disturbance periods, had a clumped distribution. In contrast,Acer japonicumandViburnum furcatum, which showed similar mortality rates between census periods, had a loosely clumped spatial distribution and a negative association with canopy trees, respectively. In the understorey stems ofAcanthopanax sciadophylloidesandFagus crenata, whose spatial distribution patterns depended on canopy gaps, significant increases in mortality rates were observed only during severe typhoon‐related disturbance periods.

Conclusions:The sensitivity of trees to typhoon‐related canopy disturbance is more pronounced in the lower layers of vertically structured forest communities. Differences in mortality patterns generated through the combined effects of spatial variation in disturbance regime and species‐specific spatial distribution patterns (spatial aggregation, association with canopy trees, and canopy gap dependency) contribute to the co‐existence of understorey species in forest communities that are subject to typhoon‐related disturbance.
Causes of plant community divergence in the early stages of volcanic succession
Authors: Tsuyuzaki Shiro
Published: August 2009

Question: How do temporal changes in plant communities occur after volcanic eruptions? What characteristics determine successional divergence or convergence?

Location: The summit area of Mount Usu, northern Japan, completely destroyed by 1‐3 m of thick ash and pumice during the 1977‐1978 eruptions. Habitats were classified into three types: gullies where the pre‐eruption topsoil was exposed due to the erosion of tephra (EG), gullies covered with tephra (CG), and outside of gullies covered with thick tephra (OG).

Methods: Plant community structure was monitored for 15 years from 1983 to 1997 in 14 2 m × 5 m permanent plots. The data were summarized by species diversity, life form, and the detrended correspondence analysis.

Results: The common species were perennial herbaceous plants, but habitat preferences differed between species. Seed bank species, including a nitrogen fixer Trifolium repens, were dominant in EG, and excluded the establishment of the later colonists. Pioneer trees slowly increased in cover. The detrended correspondence analysis indicated that species composition in the earlier stages did not differ greatly between plots. Thereafter, three patterns of temporal community changes were observed: seed bank species persisted in EG, and in OG and CG forest development proceeded or community structure did not change greatly.

Conclusion: Pre‐eruption topsoil contributed to revegetation by the supply of seed bank and nutrients in the earliest stages, but resulted in the delay of forest development due to the persistence of seed bank species. Plant community divergence was driven by the persistence of earlier colonists.
A 5‐year follow‐up of older adults residing in long‐term care facilities: utilisation of a comprehensive dental programme
Authors: Wyatt Chris C. L.
Published: August 2009

Objective:  This study will compare the clinical outcomes of 139 elders residing in long‐term care (LTC) who received dental treatment with those who did not receive care under a comprehensive dental programme over 5 years.

Background:  Numerous studies have documented very poor oral health and limited access to dental care among frail older adults residing in LTC facilities. The University of British Columbia and Providence Healthcare developed a comprehensive dental programme to serve elderly LTC residents within seven Vancouver hospitals. Since 2002, the Geriatric Dentistry Programme has provided annual oral health assessments and access to comprehensive dental care.

Material and methods:  A comprehensive oral health assessment was provided using CODE (an index of Clinical Oral Disorders in Elders). A change in oral health status (improvement or worsening) was evaluated by measuring CODE scores including caries and periodontal condition, and other aspects of the dentition.

Results:  Eighty‐three residents received dental treatment of some form over the 5 years, while 56 did not receive any treatment beyond an annual examination. The percentage of residents initially recommended for treatment in 2002 was 97%, which declined to 70–73% after the 3rd year. The percentage of residents treated increased after the first year and remained at 56–72% thereafter. The comparison between CODE scores from baseline and 5 years later showed an improvement for those receiving care (p = 0.02, χ2 = 7.9, df = 2).

Conclusion:  Within the limitations of this study, residents who did consent and receive care showed an improvement in their oral health status after 5 years.
Submillimetre surveys: the prospects for Herschel
Authors: Pearson Chris , Khan Sophia A.
Published: August 2009

Using the observed submillimetre source counts, from 250 to 1200μm[including the most recent 250, 350 and 500μm counts from Balloon-borne Large-Aperture Submillimetre Telescope (BLAST)], we present a model capable of reproducing these results, which is used as a basis to make predictions for upcoming surveys with the Spectral and Photometric Imaging Receive (SPIRE) instrument aboard the Herschel Space Observatory. The model successfully fits both the integral and differential source counts of submillimetre galaxies in all wavebands, predicting that while ultra-luminous infrared (IR) galaxies dominate at the brightest flux densities, the bulk of the IR background is due to the less luminous IR galaxy population. The model also predicts confusion limits and contributions to the cosmic IR background that are consistent with the BLAST results. Applying this to SPIRE gives predicted source confusion limits of 19.4, 20.5 and 16.1mJy in the 250, 350 and 500μm bands, respectively. This means the SPIRE surveys should achieve sensitivities 1.5 times deeper than the BLAST, revealing a fainter population of IR-luminous galaxies and detecting approximately 2600, 1300 and 700 sources per deg2 in the SPIRE bands (with one in three sources expected to be a high-redshift ultra-luminous source at 500μm). The model number redshift distributions predict a bimodal distribution of local quiescent galaxies and a high-redshift peak corresponding to strongly evolving star-forming galaxies. It suggests the very deepest surveys with Herschel–SPIRE ought to sample the source population responsible for the bulk of the IR background.
Results for Rarely Determined Elements in MPI‐DING, USGS and NIST SRM Glasses Using Laser Ablation ICP‐MS
Authors: Hu Zhaochu , Liu Yongsheng , Li Ming , Gao Shan , Zhao Laishi
Published: August 2009

New analytical results are reported for rarely determined elements Be, B, Ge, As, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, W, Re, Ir, Pt, Au, Tl and Bi in MPI‐DING and USGS (BCR‐2G, BHVO‐2G, BIR‐1G) silicate glasses and the NIST SRM 610‐614 synthetic soda‐lime glasses using 193 nm ArF excimer laser ablation and quadrupole ICP‐MS. The method used involved external calibration against GOR132‐G for Ir and NIST SRM 610 for other elements, internal standardisation using Ca, and ablation with a crater diameter of 160 μm and a pulsed laser repetition rate of 10 Hz. Small amounts of nitrogen (5 ml min−1) were added to the central channel gas of the plasma to improve the limits of detection for most of these elements by a factor of 1.2–2.5 and to reduce the oxide interference level to 0.02% (ThO+/Th+). Under these conditions, the LODs for most of these rarely determined elements were within the range 0.1 to 10 ng g−1. The operating conditions that were required to minimise ICP‐induced fractionation (U+/Th+≈ 1) in the mode without nitrogen were accompanied by a 50–60% reduction in sensitivity for elements such as Ca, Au and Pt. In contrast, ICP‐induced fractionation could be minimised (U+/Th+≈ 1) with no loss of analyte sensitivity in the nitrogen mode. Interferences of CuAr+, ZnAr+, Cd+, Pb2+ and Sn+ on Pd+, Rh+, Cd+ and In+ were corrected. Oxide interferences were not considered due to their lower production rate. Analytical precision, as given by one relative standard deviation (% RSD) was less than 15% for most of the elements present at concentrations greater than 0.1 μg g−1. A significant negative correlation was found between logarithmic concentration and logarithmic RSD, with a correlation coefficient of −0.76. This trend indicates that possible chemical heterogeneities for most of these elements are smaller than the analytical uncertainty. Our results for Be, B, Ge, Sb and W are generally in good agreement with their reference values. In contrast, other elements in many of the reference glasses have only information values, upper limits or even no values, which restrict any detailed evaluation of the accuracy of the determined values. However, concentrations from multiple isotopes of one element analysed in this study showed excellent agreement, which guarantee the quality of our data to a certain extent.
OLFinder—a program which disentangles DNA sequences containing heterozygous indels
Authors: DIXON C. J.
Published: August 2009

The presence of heterozygous indels in a DNA sequence usually results in the sequence being discarded. If the sequence trace is of high enough quality, however, it will contain enough information to reconstruct the two constituent sequences with very little ambiguity. Solutions already exist using comparisons with a known reference sequence, but this is often unavailable for nonmodel organisms or novel DNA regions. I present a program which determines the sizes and positions of heterozygous indels in a DNA sequence and reconstructs the two constituent haploid sequences. No external data such as a reference sequence or other prior knowledge are required. Simulation suggests an accuracy of >99% from a single read, with errors being eliminable by the inclusion of a second sequencing read, such as one using a reverse primer. Diploid sequences can be fully reconstructed across any number of heterozygous indels, with two overlapping sequencing reads almost always sufficient to infer the entire DNA sequence. This eliminates the need for costly and laborious cloning, and allows data to be used which would otherwise be discarded. With no more laboratory work than is needed to produce two normal sequencing reads, two aligned haploid sequences can be produced quickly and accurately and with extensive phasing information.
The effect of ginkgo biloba on the rat retinal ganglion cell survival in the optic nerve crush model
Authors: Ma Ke , Xu Liang , Zhang Haijuan , Zhang Shixian , Pu Mingliang , Jonas Jost B.
Published: August 2009

Purpose:  To investigate the effect of ginkgo biloba on the retinal ganglion cell survival in a rat optic nerve crush model.

Methods:  Twenty‐four Sprague–Dawley rats were divided randomly into a study group of 12 animals receiving intraperitoneal injections of ginkgo biloba and a control group of 12 animals receiving intraperitoneal saline injections. All injections were performed 1 hr before the optic nerve crush and daily afterwards. For each animal, the right optic nerve was crushed closely behind the globe for 60 seconds using a microclip with 40 g power. The left optic nerve was kept intact. At 23 days after the optic nerve crush, the retinal ganglion cells were labelled retrogradely by injecting 3% fluorogold into both sides of the superior colliculus of the brain. At 4 weeks after the optic nerve crush, the animals were killed. Photographs taken from retinal flat mounts were assessed for the number and density of the retinal ganglion cells.

Results:  The survival rate, defined as the ratio of the retinal ganglion cell density in the right eye with the optic nerve crush divided by the retinal ganglion cell density in left eye without an optic nerve trauma, was significantly (p = 0.035) higher in the study group with ginkgo biloba than in the control group (60.0 ± 6.0% versus 53.5 ± 8.0%).

Conclusion:  The results suggest that intraperitoneal injections of a ginkgo biloba extract given prior to and daily after an experimental and standardized optic nerve crush in rats were associated with a higher survival rate of retinal ganglion cells.
The North Jutland County Diabetic Retinopathy Study (NCDRS)
Authors: Knudsen Lars Loumann , Lervang Hans‐Henrik , Lundbye‐Christensen Søren , Gorst‐Rasmussen Anders
Published: August 2009

Purpose:  This study set out to map the associations between retinal lesions, visual acuity (VA) and the presence of clinically significant macular oedema (CSMO) in diabetes subjects.

Methods:  This cross‐sectional study comprised 656 type 1 and 328 type 2 diabetes subjects undergoing retinopathy screening in the County of North Jutland, Denmark. Numbers of specific retinal lesions were quantified from retinal photographic recordings. Associations between CSMO, number of specific retinal lesions and VA were established. The percentages of eyes with CSMO ascribed to retinal lesions were calculated.

Results:  The presence of CSMO, number of specific retinal lesions and VA were all significantly associated. The parameter with the highest statistical association with CSMO measured by Spearman’s correlation coefficient was hard exudates (type 1: 0.524; type 2: 0.715), followed by microaneurysms (type 1: 0.298; type 2: 0.508), retinal haemorrhages (type 1: 0.227; type 2: 0.595), cottonwool spots (type 1: 0.207; type 2: 0.259) and VA (type 1: − 0.137; type 2: − 0,175).

Conclusions:  All retinal lesions are significantly associated with CSMO and together can predict for up to 42.3% (in type 1 diabetes) and 64.3% (in type 2 diabetes) of CSMO cases.
Liposomes as an ocular delivery system of fluconazole: in‐vitro studies
Authors: Habib Fawzia S. , Fouad Ehub A. , Abdel‐Rhaman Mohamed S. , Fathalla Dina
Published: August 2009

Acta Ophthalmol. 2010: 88: 901–904

Purpose:  To study the clinical effect of topical controlled‐release ophthalmic fluconazole liposomal formulation and to compare its effect with fluconazole solution in a reproducible model of Candida keratitis in rabbits.

Methods:  Forty adult rabbits were included in this study. Right eyes were inoculated with freshly prepared Caindida albicans strain no. 4925 and showed signs of infected keratitis. The rabbits were divided randomly into two groups: in the first group (18 rabbits) the right eyes received fluconazole solution, while in the second group (22 rabbits) the right eyes received fluconazole‐loaded liposomes. The rabbits’ eyes were examined daily over a 21‐day period and results were recorded.

Results:  Rabbits infected with C. albicans responded better and showed more improvement in terms of size of ulcer and hypopyon using fluconazole‐loaded liposomal formulae than using fluconazole solution. In the first group (solution), nine rabbits’ cornea showed complete healing (50%) at the end of third week while in group 2 (liposome), 19 rabbits’ cornea showed complete healing (86.4%) at equal duration. These results were statistically significant.

Conclusion:  Therapy with topical liposomal fluconazole (2 mg/ml) was successful in eliminating experimental C. albicans infection of the rabbit cornea and was superior to fluconazole solution.
Use of the retinal vessel analyzer in ocular blood flow research
Authors: Garhofer Gerhard , Bek Toke , Boehm Andreas G. , Gherghel Doina , Grunwald Juan , Jeppesen Peter , Kergoat Hélène , Kotliar Konstantin , Lanzl Ines , Lovasik John V. , Nagel Edgar , Vilser Walthard , Orgul Selim , Schmetterer Leopold
Published: August 2009

Acta Ophthalmol. 2010: 88: 717–722

The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.
Prevalence of anti cyclic citrullinated peptide antibodies in Malaysian rheumatoid arthritis patients and its correlation with disease activity
Authors: SOCKALINGAM Sargunan , KHUAN Chow Sook , STHANESHWAR Pavai
Published: August 2009

Aim:  The objectives of this study are to provide data regarding the prevalence of anti‐cyclic citrullinated peptide (CCP) antibodies in Malaysian rheumatoid arthritis (RA) patients and to correlate the levels of anti‐CCP antibody with the Disease Activity Score (DAS).

Method:  We studied the prevalence of anti‐CCP antibodies in 51 RA patients attending our clinic and 29 controls. We also looked for correlation between anti‐CCP antibody levels with the DAS and parameters such as duration of disease, rheumatoid factor (RF) and disease‐modifying anti rheumatic drug (DMARD) usage.

Results:  None of the controls demonstrated anti‐CCP antibodies. Forty‐one out of 51 patients (80.4%) were positive for anti‐CCP antibodies. Sensitivity and specificity were 80.4% and 100% respectively in this study. Anti‐CCP levels correlated significantly with rheumatoid factor, but no correlation was observed with the other parameters.

Conclusions:  Anti‐CCP antibody is prevalent in Malaysian RA patients at 80.4% and more sensitive than RF in our cohort of established RA patients. Even though the anti‐CCP levels correlated with RF, it did not show correlation with DAS.
Survey of vitamin D levels among post‐menopausal Filipino women with osteoporosis
Authors: RASO Anne‐Annette P. , NAVARRA Sandra V. , LI‐YU Julie , TORRALBA Tito P.
Published: August 2009

Objective:  To determine the prevalence of vitamin D inadequacy in a group of Filipino post‐menopausal women with osteoporosis.

Methods:  Seventy otherwise healthy post‐menopausal Filipino women seen at the University of Santo Tomas Hospital, Section of Rheumatology, were diagnosed with osteoporosis by central dual‐energy X‐ray absorptiometry (DXA) technique. Levels of serum 25‐hydroxyvitamin D were measured using enzyme‐linked immunosorbent assay.

Results:  The mean age of this population was 70 ± 8 years, with an average of 22 ± 10 years since menopause, and mean body mass index (BMI) of 22 ± 1 kg/m2. Only 30% (21/70) were on calcium plus vitamin D supplementation. Overall serum 25‐hydroxyvitamin D levels ranged from 48–128 nmol/L, with a mean of 87 ± 20.48 nmol/L. Serum 25‐hydroxyvitamin D levels were divided as follows: 80–140 nmol/L (adequate), 25–79 nmol/L (inadequate/insufficient), and < 25 nmol/L (deficient). Sixty‐four percent (45/70) of subjects had adequate levels while 36% (25/70) had inadequate levels of 25‐hydroxyvitamin D. There were no subjects with deficient levels of 25‐hydroxyvitamin D. Fischer’s exact test did not show a significant association between BMD and 25‐hydroxyvitamin D (P = 0.4804).

Conclusion:  Among this group of women with post‐menopausal osteoporosis, only 36% had insufficient levels of 25‐hydroxyvitamin D, with none of the subjects having deficient 25‐hydroxyvitamin D levels. The majority (64%) had normal serum 25‐hydroxyvitamin D levels – comparatively higher than that reported in the literature. These results suggest the possible contribution of factors other than vitamin D deficiency in post‐menopausal Filipino women with osteoporosis.
Successful use of infliximab in a patient with neuro‐Behçet’s disease
Authors: ABALOS‐MEDINA Gracia Maria , SÁNCHEZ‐CANO Daniel , RUIZ‐VILLAVERDE Gonzalo , RUIZ‐VILLAVERDE Ricardo , QUIROSA FLORES Susana , RAYA ÁLVAREZ Enrique
Published: August 2009

Behçet′s disease (BD) is a systemic vasculitic disorder of unknown aetiology characterised by recurrent oral and often genital ulcers, which may be associated with ocular, cutaneous, articular, neurological or vascular involvement. We report a 52‐year‐old woman diagnosed of neuro‐BD who was treated with infliximab with a dramatic response to this treatment.
Recurrent fractures in an elderly patient with systemic lupus erythematosus
Authors: CHIA Faith Li‐Ann , THONG Bernard Yu‐Hor , LAU Tang‐Ching , FENG Pao‐Hsii
Published: August 2009

Glucocorticoid‐induced osteoporosis (GIO) is an important problem that remains undertreated, even by rheumatologists. We present a case of an elderly patient with systemic lupus erythematosus diagnosed more than 40 years ago, who suffered from recurrent fractures and attendant complications despite a bone mineral density (BMD) score in the osteopenic range and treatment with bisphosphonates. With improved treatment and outcome of lupus, an increasing number of elderly patients who are susceptible to osteoporotic fractures are expected. This case serves to highlight that rheumatic disease patients on steroids should be screened for GIO, as effective treatment and preventive measures are available. Teriparatide is a promising treatment for patients who have failed bisphosphonate treatment or who are at high risk for fracture. We should also bear in mind that BMD scores alone are not indicative of fracture risk, and other tools such as the WHO‐FRAX (Fracture risk assessment tool), serum vitamin D3 levels and bone turnover markers should be used where appropriate. Other measures including attention to factors that contribute to falls should also be considered, necessitating a multi‐disciplinary approach.
The Molecular Basis of Nacre Formation
Authors: Kröger Nils
Published: August 2009

A protein complex guides the process of nacre formation in mollusk shells.
Formation of ArF from LPdAr(F): Catalytic Conversion of Aryl Triflates to Aryl Fluorides
Authors: Watson Donald A. , Su Mingjuan , Teverovskiy Georgiy , Zhang Yong , García-Fortanet Jorge , Kinzel Tom , Buchwald Stephen L.
Published: August 2009

Facile Fluorination

Fluorine atoms have become a useful substituent in pharmaceuticals. However, they remain challenging to introduce synthetically because present methods for carbon-fluorine bond formation require either corrosive conditions or somewhat exotic, and thus expensive, reagents. A sticking point has been the failure of traditional palladium catalysts to couple aryl groups with coordinated fluoride.

Watson
et al.

(p.
1661
, published online 13 August; see the Perspective by

Gouverneur

) show that pairing palladium with a well-designed phosphine ligand produces a versatile catalyst for aryl fluorination using simple fluoride salts. The method tolerates a range of functional groups and should facilitate efficient syntheses of multiple fluoroaromatic targets.
Teleoanticipation in all-out short-duration cycling
Authors: Wittekind A L , Micklewright D , Beneke R
Published: August 2009

Objective

To investigate the effect of all-out cycling test duration on indices of power, anaerobic lactic energy metabolism, perceived exertion and mood.

Methods

Nine physically active men undertook four all-out cycling tests of 5, 15, 30 or 45 s from seated stationary start on an ergometer fit with power cranks. The participants completed a Profile of Mood States questionnaire before each test and indicated perceived exertion immediately post-test (Borg 6–20 scale). Indices of anaerobic lactic metabolism were determined from blood lactate concentrations.

Results

Pacing strategy was apparent in the 45-s tests with lower peak (p<0.01) and mean power in the initial 10 s compared to the 5- and 15-s tests (p<0.05). The first 15 s of the 30- and 45-s tests revealed lower fatigue indices compared to the 15-s tests (p<0.05) indicating some pacing in the 30-s tests. Perceived exertion increased with duration, with no difference between the 15- and 30-s tests (p>0.05). Extravascal lactate generation (reflecting exercising muscle lactate production) explained 59% of the variance in perceived exertion. There was no effect of knowledge of test duration on mood states or total mood disturbance (p>0.05).

Conclusions

An all-out pacing strategy was apparent for at least up to 15 s, with indicators of dampened power in both 30 and 45 s sprints. Reduced power at the start of all-out long-duration sprints support a central control of at least initial pacing strategy.
Complex patterns of chromosomal variation along a latitudinal cline in the grasshopper Caledia captiva
Authors: Shaw David D. , Coates David J. , Arnold Michael L.
Published: August 2009

An analysis of chromosomal variation along a 1500-km latitudinal cline in the Moreton subspecies of Caledia captiva has revealed the existence of complex and systemic changes to genome structure. These changes involved variation in the position of the centromere on every chromosome, from medial locations in northern populations to more distal or terminal locations in the southern populations. At the ends of this genomic cline, two contrasting chromosomal patterns were evident. In the north, the genome was fixed for metacentric chromosomes whereas at the southern limit, the genome was homozygous for acrocentric and telocentric chromosomes. Intermediate populations showed highly complex patterns of chromosomal polymorphisms. All populations along the cline were homogeneous for mitochondrial DNA restriction fragment length polymorphisms, highly repeated DNA sequences, and allozyme variation, with no evidence of genetic differentiation or inhibition of gene flow. It is argued that these complex patterns of genomic change reveal evidence of an adaptive role for both fixed and polymorphic chromosomal rearrangements within the same taxon.Key words: chromosome variation, natural selection, Caledia, grasshopper.
Nuclear gene induced plastid alterations in Pennisetum americanum
Authors: Reddy M. K. , Subrahmanyam N. C.
Published: August 2009

A nonlethal stripe mutant (700430) of Pennisetum americanum was crossed reciprocally with other normal inbred lines to establish its inheritance pattern. A recessive nuclear gene, when homozygous, led to defective plastid development with variable penetrance and expressivity. Intraplant and interspikelet crosses revealed maternal plastid transmission. When stripe plants were crossed with pollen from normal inbreds, green and yellow progeny were obtained; selfing stripe plants or crossing with its green sib produced yellow, stripe, and green progeny. These results suggest that in egg cells with exclusively defective plastids, the plastids do not revert back inspite of acquiring a dominant allele from the pollen parent, while in egg cells with a mixture of green and yellow plastids, the yellow plastids could develop into functional plastids under the influence of a dominant allele.Key words: altered plastids, variable penetrance, plastid transmission, plastid reversion.
Stomatal guard cell length as an indictor of ploidy in microspore-derived plants of barley
Authors: Borrino E. M. , Powell W.
Published: August 2009

A cytological examination of 96 microspore-derived barley genotypes indicated that haploid and diploid progeny were produced in approximately equal proportions. In order to discriminate between haploid and nonhaploid derivatives, indirect ploidy evaluation techniques were examined. Stomatal guard cell length provided a convenient and reliable method for classifying microspore-derived plants into haploid, diploid, and tetraploid groups.Key words: haploid, microspore, ploidy level, guard cell, stomata, Hordeum vulgare L.
Assessment of chromosome associations in haploids and their parental accessions in Hordeum
Authors: Bothmer R. von , Subrahmanyam N. C.
Published: August 2009

Meiotic pairing was studied in the following species and their haploid derivatives: Hordeum cordobense 2x, H. marinum 2x and 4x, H. secalinum 4x, H. capense 4x, H. jubatum 4x, H. brachyantherum 4x and 6x, H. lechleri 6x, and H. procerum 6x. The study revealed (i) homologous pairing in diploid species and very little nonhomologous associations in their mono-haploids; (ii) the alloploid nature of the polyploid taxa; (iii) a certain degree of homoeologous pairing in polyhaploids despite the diploid-like meiotic behaviour of the polyploids; (iv) genetic variation in the suppression of homoeologous chromosome pairing in different Hordeum species.Key words: Hordeum, meiotic pairing, haploids.
The interspecific and evolutionary relationships of Triticum ovatum
Authors: Kimber Gordon , Sallee P. J. , Feiner M. M.
Published: August 2009

Meiotic analysis of 13 hybrids, 3 of which are new combinations, shows that the M genome of Triticum ovatum has undergone substantial modification. The pivotal U genome is much closer to its diploid progenitor, Triticum umbellulatum. However, the possibility exists that it too has been somewhat modified. If this is substantiated, then some reconsideration of the pivotal–differential theory of evolution in the wheat group may be required.Key words: genome analysis, meiosis, Aegilops, wheat.
Langdon durum disomic substitution lines and aneuploid analysis in tetraploid wheat
Authors: Joppa L. R. , Williams N. D.
Published: August 2009

A complete set of disomic substitution lines have been developed in the tetraploid wheat cultivar Langdon (Triticum turgidum L. var. durum). These aneuploid lines each have a pair of durum wheat homoeologues replaced by a pair of D-genome chromosomes transferred from 'Chinese Spring' hexaploid wheat. They can be used to determine the chromosomal location of genes, to transfer chromosomes from one cultivar or line of tetraploid wheat to another, to study the cytogenetics of tetraploid wheat, to determine gene linkages, and to identify chromosomes involved in translocations. Their phenotypic characteristics, their cytogenetic behavior, and suggested methods for their use are described.Key words: cytogenetics, monosomic, chromosome transmission, telosomic, chromosome substitution.
The inheritance and chromosomal location of a gene for chocolate chaff in durum wheat
Authors: Konzak C. F. , Joppa L. R.
Published: August 2009

The durum wheat (Triticum turgidum L. var. durum) cultivar 'Vic' was treated with the chemical mutagen N-methyl-N′-nitrosourea and among the M2 progeny a mutant with "chocolate chaff" (designated cc) was identified. Genetic analyses indicated that chocolate chaff is due to a single recessive gene mutation. The penetrance of the gene for chocolate chaff was environmentally influenced and varied from dark blotches on the glumes to complete coloration of culms as well as spikes. To determine the chromosomal location of the gene, the mutant was crossed with a set of 'Langdon' durum disomic substitution lines in which each of the 14 A- and B-genome chromosomes of durum wheat were replaced by their respective D-genome homoeologues. The segregation of cc was normal in all of the crosses except for those with the 7D(7A) and 7D(7B) lines. Cytogenetic analysis indicated that the gene was located on chromosome 7B, and that chromosome 7D has a gene that prevents the expression of cc when present in one or more copies. It was shown that the 'Langdon' D-genome disomic substitution lines can be used to determine the chromosomal location of genes in tetraploid wheat.Key words: Triticum turgidum, aneuploid, chromosome substitution, monosomic, cytogenetics.
Cytoplasmic male sterility in rapeseed (Brassica napus L.): female fertility of restored rapeseed with "Ogura" and cybrids cytoplasms
Authors: Pellan-Delourme R. , Renard M.
Published: August 2009

The study of Brassica napus L. plants carrying restorer genes introgressed from radish (Raphanus sativus L.) showed that these genes ensured restoration of male fertility in rapeseed for all the male sterility-inducing cytoplasm studied, i.e., "Ogura"-type cytoplasm and that of four cybrids obtained by protoplast fusion. Plants with high levels of restored male fertility were obtained. However, the introduction of restorer genes was accompanied by a large decrease in seed set. Observations of embryo sacs inside the ovules and correlation between number of seeds per pod and percentage of octonucleate embryo sacs indicated that low seed set could be attributed to a high rate of embryo sac abortion, mainly at the uninucleate stage. Introduction of too much radish genetic information was assumed to be the cause of this low female fertility. Female fertility must be improved before the restored material can be used for F1 hybrid rapeseed production.Key words: Brassica napus, Raphanus sativus, cytoplasmic male sterility, restorer, cybrid, female fertility, embryo sac.
Intergeneric hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x)
Authors: Comeau A. , Fedak G. , St-Pierre C. A. , Cazeault R.
Published: August 2009

Twelve embryos of interspecific hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x) cv. Fukuho were produced out of 280 pollinated florets. Embryos were minute and globular and only one of them was successfully grown in vitro. Plant morphology of the hybrid was intermediate between the two parents and hybrid vigor was observed. Several traits of the hybrid were characteristic of the Hordeum parent such as brittle rachis, long awn, outerglume characteristics, and foliage waxiness being the most prominent. Average meiotic chromosome pairing in the hybrid was 28.6 univalents + 3.2 bivalents + 0.007 trivalents, which is not above what would be expected in a common wheat haploid.Key words: intergeneric hybrids, Critesion, Hordeum, Triticum, meiosis.
Dependence on genie balance for synaptonemal complex formation in Drosophila melanogaster
Authors: Grishayeva T. M. , Bogdanov Y. F.
Published: August 2009

Electron microscopic examination of gonads of Drosophila melanogaster with different genotypes, including a metafemale 3X;2A and an intersex XXY;3A, have revealed that the formation of synaptonemal complexes is controlled by the genie balance, i.e., the ratio of X chromosomes to autosomes. The Y chromosome is not involved in the genetic control of the formation of precursors of the central element of synaptonemal complexes in males, nor does it disturb their formation in [Formula: see text] females. Hyperploidy for sections 1 – 3A and 18A – 20 of the X chromosome does not lead to the appearance of synaptonemal complexes in males and does not interfere with their formation in females. Females hyperploid for extensive regions of the X chromosome (sections 1 – 11A, 11A – 20, and 8C – 20) are fertile and show apparently normal formation of synaptonemal complexes. Hyperploidy for sections 8C – 11A of the X results in a sharp decrease in the viability of females, in abnormal differentiation of ovary cells, and in the lack of synaptonemal complexes. These data suggest a possible important role for the sections 8C – 11A in the genic balance controlling the formation of synaptonemal complexes in D. melanogaster. The lack of synaptonemal complexes in hypoploid females may be the result of abnormal cell differentiation in gonads.Key words: Drosophila melanogaster, synaptonemal complex, sex chromosomes, genic balance.
Extrinsic afferent nerve sensitivity and enteric neurotransmission in murine jejunum in vitro
Authors: Mueller Mario H. , Xue Bing , Glatzle Joerg , Hahn Jutta , Grundy David , Kreis Martin E.
Published: August 2009

Enteric and extrinsic sensory neurons respond to similar stimuli. Thus they may be activated in series or in parallel. Because signal transmission via synapses or mediator release would depend on calcium, we investigated its role for extrinsic afferent sensitivity to chemical and mechanical stimulation. Extracellular multiunit afferent recordings were made in vitro from paravascular nerve bundles supplying the mouse jejunum. Intraluminal pressure and afferent nerve responses were recorded under control conditions and under four conditions designed to interfere with enteric neurotransmission. We found that phasic intestinal contractions ceased after switching perfusion to Ca2+-free buffer with or without a purinergic P2 receptor antagonist, pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid) (PPADS) or cadmium (blocking all Ca2+-channels) but not following ω-conotoxin GVIA (N-type Ca2+-channel blocker). Luminal HCl (pH 2) and 5-HT (500 μM) evoked peak firing of 17 ± 4 impulses per second (imp/s) ( n = 10) and 21 ± 4 imp/s ( n = 13) under control conditions. These responses were reduced to 4 ± 2 imp/s and 5 ± 2 imp/s by cadmium ( n = 7, P < 0.05), to 7 ± 2 imp/s and 6 ± 1 imp/s by Ca2+-free perfusion ( n = 6, P < 0.05), and to 3 ± 1 imp/s and 4 ± 1 imp/s by Ca2+-free perfusion with PPADS ( n = 6, P < 0.05). Responses were unchanged by ω-conotoxin GVIA. Mechanical ramp distension of the intestinal segment to 60 cmH2O was not altered by any of the experimental conditions. We concluded that HCl and 5-HT activate extrinsic afferents via a calcium-dependent mechanism, which is unlikely to involve enteric neurons carrying N-type calcium channels. Extrinsic mechanosensitivity is independent of enteric neurotransmission. It appears that cross talk from the enteric to the extrinsic nervous system does not mediate extrinsic afferent sensitivity.
Endocytic trafficking from the small intestinal brush border probed with FM dye
Authors: Hansen Gert H. , Rasmussen Karina , Niels-Christiansen Lise-Lotte , Danielsen E. Michael
Published: August 2009

The small intestinal brush border functions as the body's main portal for uptake of dietary nutrients and simultaneously acts as the largest permeability barrier against pathogens. To enable this, the digestive enzymes of the brush border are organized in lipid raft microdomains stabilized by cross-linking galectins and intelectin, but little is known about the dynamic properties of this highly specialized membrane. Here, we probed the endocytic membrane trafficking from the brush border of organ-cultured pig intestinal mucosal explants by use of a fixable, lipophilic FM dye. The fluorescent dye readily incorporated into the brush border, and by 15 min faint but distinct punctae were detectable ∼1 μm beneath the brush border, indicative of a constitutive endocytosis. The punctae represented a subpopulation of early endosomes confined to the actomyosin-rich terminal web region, and their number and intensity increased by 1 h, but trafficking further into the enterocyte was not observed except in immature epithelial cells of the crypts. A powerful ligand for receptor-mediated endocytosis, cholera toxin B subunit, increased apical endocytosis and caused membrane trafficking to proceed to compartments localized deeper into the cytoplasm of the enterocytes. Two major raft-associated brush border enzymes, alkaline phosphatase and aminopeptidase N, were excluded from endocytosis. We propose that the terminal web cytoskeleton, by inhibiting traffic from apical early endosomes further into the cell, contributes to the overall permeability barrier of the gut.
Alternative splicing of the Menkes copper Atpase (Atp7a) transcript in the rat intestinal epithelium
Authors: Collins James F. , Hua Ping , Lu Yan , Ranganathan P. N.
Published: August 2009

The intestinal Menkes copper Atpase ( Atp7a) gene is strongly induced by iron deficiency in the rat intestine. We sought to develop an in vitro model to understand the mechanism of this induction by performing molecular studies in native rat intestine and in intestinal epithelial (IEC-6) cells. IEC-6 cells express Atp7a, and induction was noted with iron deprivation. 5′ Rapid amplification of cDNA ends and PCR experiments revealed three splice variants in rat intestine and IEC-6 cells; all variants were strongly induced during iron deprivation (five- to sevenfold). The splice variants presumably encode proteins that would either contain the extreme NH2 terminus of the protein (containing copper binding domain 1) or not. We thus hypothesized that more than one version of Atp7a protein exists. Antibodies against this NH2-terminal region of the protein were developed (named N-term) and used along with previously reported antibodies (against more COOH-terminal regions, termed 54–10) to perform immunoblotting and immunolocalization studies. Results with the 54–10 antiserum revealed an Atp7a protein variant of ∼190 kDa that localized to the trans-Golgi network of IEC-6 cells and trafficked to the plasma membrane with copper loading. Using the N-term antiserum, however, we noted protein of ∼97 and 64 kDa. The 97-kDa protein was cytosolic and nuclear, whereas the 64-kDa protein was nuclear specific. Immunolocalization analyses with the N-term antiserum showed strong staining of nuclei in IEC-6 and Caco-2 cells and in rat intestine. We conclude that novel Atp7a protein variants may exist in rat and human intestinal epithelial cells, with different intracellular locations and potentially distinct physiological functions.