bluuebunny/crossref_metadata_2025 huggingface dataset:
On the biogeography of seed mass in Germany – distribution patterns and environmental correlates
Authors: Tautenhahn Susanne , Heilmeier Hermann , Götzenberger Lars , Klotz Stefan , Wirth Christian , Kühn Ingolf
Published: May 2008

With environmental factors being spatially structured, plant traits that are related to these factors should exhibit a corresponding spatial pattern. We analyzed the distribution pattern of seed mass in Germany. We calculated the median seed mass for 10′ longitude by 6′ latitude grid cells across Germany using the trait databases BIOLFLOR and the plant distribution database FLORKART. To explain these distribution patterns of median seed mass, we applied multiple regression analyses on twelve selected environmental variables, accounting for spatial autocorrelation. To deal with collinearities of the predictors, we used hierarchical partitioning to analyze the independent and joint explanatory power of the environmental variables. To test whether statistical relationships are due to hidden correlations between seed mass and plant growth form, we conducted seperate analyses for annual, perennial herbs, shrubs and trees. Low median seed mass was found in the lowlands and river valleys whereas high median seed mass was typical for the rich loess regions and the calcareous mountain ranges. Seed mass exhibited a strong positive correlation with soil pH (62% of variance explained) and a negative correlation with soil moisture (25%). Light was less important as a predictor of seed mass. Within the growth forms we observed similar distribution and correlation patterns pointing to a direct link between seed mass and the environmental variables soil pH and moisture. We argue that this striking relationship with soil pH is caused by the high stress from competition on fertile calcareous sites. The negative moisture effect may be due to drought stress. Both relationships are particulary interesting for the prediction of ecosystem responses to climate and land use changes.
Modelling species distributions without using species distributions: the cane toad in Australia under current and future climates
Authors: Kearney Michael , Phillips Ben L. , Tracy Christopher R. , Christian Keith A. , Betts Gregory , Porter Warren P.
Published: May 2008

Accurate predictions of the potential distribution of range‐shifting species are required for effective management of invasive species, and for assessments of the impact of climate change on native species. Range‐shifting species pose a challenge for traditional correlative approaches to range prediction, often requiring the extrapolation of complex statistical associations into novel environmental space. Here we take an alternative approach that does not use species occurrence data, but instead captures the fundamental niche of a species by mechanistically linking key organismal traits with spatial data using biophysical models. We demonstrate this approach with a major invasive species, the cane toadBufo marinusin Australia, assessing the direct climatic constraints on its ability to move, survive, and reproduce. We show that the current range can be explained by thermal constraints on the locomotor potential of the adult stage together with limitations on the availability of water for the larval stage. Our analysis provides a framework for biologically grounded predictions of the potential for cane toads to expand their range under current and future climate scenarios. More generally, by quantifying spatial variation in physiological constraints on an organism, trait‐based approaches can be used to investigate the range‐limits of any species. Assessments of spatial variation in the physiological constraints on an organism may also provide a mechanistic basis for forecasting the rate of range expansion and for understanding a species’ potential to evolve at range‐edges. Mechanistic approaches thus have broad application to process‐based ecological and evolutionary models of range‐shift.
100 Myr record of sequences, sedimentary facies and sea level change from Ocean Drilling Program onshore coreholes, US Mid‐Atlantic coastal plain
Authors: Browning James V. , Miller Kenneth G. , Sugarman Peter J. , Kominz Michelle A. , McLaughlin Peter P. , Kulpecz Andrew A. , Feigenson Mark D.
Published: May 2008

We analyzed the latest Early Cretaceous to Miocene sections (∼110–7 Ma) in 11 New Jersey and Delaware onshore coreholes (Ocean Drilling Program Legs 150X and 174AX). Fifteen to seventeen Late Cretaceous and 39–40 Cenozoic sequence boundaries were identified on the basis of physical and temporal breaks. Within‐sequence changes follow predictable patterns with thin transgressive and thick regressive highstand systems tracts. The few lowstands encountered provide critical constraints on the range of sea‐level fall. We estimated paleowater depths by integrating lithofacies and biofacies analyses and determined ages using integrated biostratigraphy and strontium isotopic stratigraphy. These datasets were backstripped to provide a sea‐level estimate for the past ∼100 Myr. Large river systems affected New Jersey during the Cretaceous and latest Oligocene–Miocene. Facies evolved through eight depositional phases controlled by changes in accommodation, long‐term sea level, and sediment supply: (1) the Barremian–earliest Cenomanian consisted of anastomosing riverine environments associated with warm climates, high sediment supply, and high accommodation; (2) the Cenomanian–early Turonian was dominated by marine sediments with minor deltaic influence associated with long‐term (107year) sea‐level rise; (3) the late Turonian through Coniacian was dominated by alluvial and delta plain systems associated with long‐term sea‐level fall; (4) the Santonian–Campanian consisted of marine deposition under the influence of a wave‐dominated delta associated with a long‐term sea‐level rise and increased sediment supply; (5) Maastrichtian–Eocene deposition consisted primarily of starved siliciclastic, carbonate ramp shelf environments associated with very high long‐term sea level and low sediment supply; (6) the late Eocene–Oligocene was a starved siliciclastic shelf associated with moderately high sea‐level and low sediment supply; (7) late early–middle Miocene consisted of a prograding shelf under a strong wave‐dominated deltaic influence associated with major increase in sediment supply and accommodation due to local sediment loading; and (8) over the past 10 Myr, low accommodation and eroded coastal systems were associated with low long‐term sea level and low rates of sediment supply due to bypassing.
Carbonate seismic stratigraphy of the Gulf of Papua mixed depositional system: Neogene stratigraphic signature and eustatic control
Authors: Tcherepanov Evgueni N. , Droxler André W. , Lapointe Philippe , Mohn Kenneth
Published: May 2008

The Eocene–Miocene carbonate deposition in the Gulf of Papua (GoP) corresponds to the carbonate evolution phase of this continental margin mixed depositional system. Global sea‐level (eustatic) fluctuations appear to have been the most important factor influencing the mixed depositional system development during its carbonate phase. Development of the major carbonate system in the Gulf was initiated during the Eocene. Subsequent to an early Oligocene hiatus, the carbonate system expanded its surface area, vertically aggraded, then systematically backstepped, and finally partially drowned during the late Oligocene–early part of the early Miocene. During the late early Miocene–early middle Miocene, the carbonate system continued its vertical growth in most platform areas, where it was able to keep up with sea‐level rise. At the early middle/late middle Miocene (Langhian/Serravallian) boundary, carbonate deposition shifted downward during a long‐term sea‐level regression, exposing most of the early middle Miocene platform tops. Following this downward shift, active carbonate production became restricted during the late middle Miocene to only the northeastern part of the study area, and carbonate accumulation was characterized by four systematically prograding units. At the very beginning of the late Miocene, the platform tops were re‐flooded. The carbonate system was partially drowned, systematically backstepped, and locally aggraded during part of the late Miocene, the early Pliocene, and the Quaternary. The overall organization of the carbonate sequence geometries, observed in the GoP, display a clear pattern, often referred to as the Oligocene–Neogene stratigraphic signature. This pattern is identical to contemporaneous sedimentary patterns observed in pure carbonate systems such as in the Maldives and in the Bahamas, and also in some siliciclastic systems. Because this pattern is observed in several globally distributed locations, the recognition of the Oligocene–Neogene stratigraphic signature in the GoP demonstrates that the depositional evolution during the late Oligocene–Miocene and the early Pliocene must have been dominantly controlled by eustatic fluctuations.
Platelet transfusion refractoriness
Authors: Hod Eldad , Schwartz Joseph
Published: May 2008

The platelet, a fascinating anucleate cell, is critically important for haemostasis. Platelet transfusions have greatly reduced the incidence of major haemorrhagic complications associated with the management of haematological and oncological disorders. However, some patients fail to receive the full benefit of platelet transfusions because they do not achieve the appropriate platelet count increment following transfusion. This review will discuss the aetiology, diagnosis, and management of refractoriness to platelet transfusion, a complicated problem for both the treating physicians and the transfusion services supporting these patients. Although advances have been made in the diagnosis and treatment of immune‐mediated platelet refractoriness, which is usually caused by anti‐human leucocyte antigen antibodies, non‐immune causes, such as sepsis, remain problematic.
Audit of the peri‐delivery use of unfractionated heparin in women on therapeutic low‐molecular weight heparin
Authors: Lambert J. R. , Austin S. K. , Peebles D. , Cohen H.
Published: May 2008

There is no evidence‐based approach for the optimal management of peri‐delivery anticoagulation in women receiving therapeutic dose of low‐molecular weight heparin (LMWH) during pregnancy. Nevertheless, the maintenance of anticoagulation for the maximal period peri‐delivery appears appropriate in women considered to be at high risk of venous or arterial thromboembolism. We developed a regimen based on fixed thromboprophylactic dose of unfractionated heparin (UFH) peri‐delivery and undertook an audit to evaluate the use and feasibility of this approach and any adverse events. Fixed intravenous thromboprophylactic dose of UFH (15 000 units/24 h) was commenced on the evening prior to a planned delivery [induction of labour or elective caesarean section (CS)], stopped 4 h predelivery and restarted 2–6 h postdelivery. Compliance was good with 32/38 consecutive deliveries managed according to the regimen. There were no cases of postpartum haemorrhage and no thrombosis associated with these 32 deliveries. Twenty‐one patients were delivered by CS (11 elective) and eight patients received epidural/spinal anaesthesia without complication. In conclusion, the fixed thromboprophylactic dose UFH regimen provided maintenance of anticoagulation except for a matter of hours without excessive bleeding risk (conducive to neuroaxial anaesthesia) and was simple, flexible and acceptable to staff and patients.
The use of ecarin chromogenic assay and prothrombinase induced clotting time in the monitoring of lepirudin for the treatment of heparin‐induced thrombocytopenia
Authors: Guy S. , Kitchen S. , Laidlaw S. , Cooper P. , Woolley A. , Maclean R.
Published: May 2008

Lepirudin (r‐hirudin) is one of the two alternative anticoagulants licensed to treat patients with heparin‐induced thrombocytopenia (HIT). Manufacturer’s guidelines state that lepirudin should be monitored using the activated partial thromboplastin time (APTT) ratio. However, several studies have demonstrated a plateau effect of higher concentrations of lepirudin on APTT ratios and variable results when comparing different APTT reagents. This study compares APTT ratios (using two different APTT reagents) with two other commercially available methods for directly quantifying plasma lepirudin levels: ecarin chromogenic assay and prothrombinase‐induced clotting time in 95 samples from five patients receiving lepirudin anticoagulation for HIT.
Antiphospholipid antibodies in adults with immune thrombocytopenic purpura
Authors: Pierrot‐Deseilligny Despujol Carole , Michel Marc , Khellaf Mehdi , Gouault Michèle , Intrator Liliane , Bierling Philippe , Godeau Bertrand
Published: May 2008

To determine the clinical significance of antiphospholipid antibodies (aPL) in patients with immune thrombocytopenic purpura (ITP), anticardiolipin (aCL) (IgG and IgM) and lupus anticoagulant (LA) were sought at diagnosis in 215 ITP adults with platelets <50 × 109/l. aPL (aCL and/or LA) were detected in 55 patients (26%): aCL alone in 39 (18%), aCL and LA in 15 (7%) and LA alone in one (0·5%). LA was significantly associated with high IgG‐aCL levels (P = 0·001). Among age, sex, initial platelet count, bleeding score, acute or chronic ITP outcome, only younger age was significantly associated with LA‐positivity (mean age 29 ± 14 years vs. 45 ± 20 years, P = 0·002). After a median follow‐up of 31 months, 14/215 (7%) patients developed thrombosis (four arterial, 10 venous and/or pulmonary embolism); four of them (29%) had high aCL levels and LA. Multivariate analysis significantly associated thrombosis events only with age [hazard ratio (HR) = 1·6; 95% confidence interval (CI): 1·2–2·4], LA (HR: 9·9; 95% CI: 2·3–43·4) or high IgG‐aCL level (HR: 7·5; 95% CI; 1·8–31·5). Although the thrombosis rate was low, the significant associations between thrombosis and LA or high aCL level suggest that aPL should be tested at ITP diagnosis.
IgG subclasses of anti‐FVIII antibodies during immune tolerance induction in patients with hemophilia A
Authors: van Helden Pauline M. W. , van den Berg H. Marijke , Gouw Samantha C. , Kaijen Paul H. P. , Zuurveld Marleen G. , Mauser‐Bunschoten Evelien P. , Aalberse Rob C. , Vidarsson Gestur , Voorberg Jan
Published: May 2008

The eradication of inhibitory antibodies in patients with haemophilia A can be accomplished by frequent administration of high or intermediate doses of factor VIII (FVIII), so‐called immune tolerance induction (ITI). This study monitored the distribution of IgG subclasses of anti‐FVIII antibodies during ITI. FVIII‐specific antibodies of subclass IgG1 were detected in all inhibitor patients tested, anti‐FVIII IgG4 in 16, IgG2 in 10 and IgG3 in one of 20 patients analysed. Levels of anti‐FVIII IgG1 and IgG4 correlated well with inhibitor titres as measured by Bethesda assay. In low‐titre inhibitor patients, anti‐FVIII antibodies consisted primarily of subclass IgG1 whereas, anti‐FVIII antibodies of subclass IgG4 were more prominent in patients with high titre inhibitors who needed prolonged treatment or who failed ITI. Longitudinal analysis of 14 patients undergoing ITI revealed that the relative contribution of IgG subclasses was constant for most of the patients analysed. In two patients, the relative contribution of IgG4 increased during ITI. Overall, our findings document the distribution and dynamics of anti‐FVIII IgG subclasses during ITI. Future studies will need to address whether monitoring the relative contribution of anti‐FVIII subclasses IgG1 and IgG4 may be useful for the identification of patients who are at risk of failing ITI.
Cytology and outcome of LSIL: cannot exclude HSIL compared to ASC‐H
Authors: Hunter C. , Duggan M. A. , Duan Q. , Power P. , Gregoire J. , Nation J.
Published: May 2008

Objective:  The cytological features associated with clinical outcome of ‘LSIL cannot exclude HSIL (LSIL‐H)’ in comparison with ‘atypical squamous cells cannot exclude HSIL (ASC‐H)’ are incompletely described.

Methods:  LSIL‐H and ASC‐H Pap tests reported in a regional laboratory during a 13‐month period were reviewed by two pathologists. Cytological features suspicious for HSIL were evaluated against a check list of 52 atypical features. All histology over 2 years of follow up for tests reclassified as LSIL‐H and ASC‐H was retrieved to determine clinical outcome. Atypical cytological features were correlated with outcome.

Results:  The review yielded 89 LSIL‐H and 86 ASC‐H. The highest ranked atypical cytological feature in each group was increased nuclear cytoplasmic ratio. Clinical outcome was positive (CIN II/III or AIS) in 44 (49%) LSIL‐H and 33 (38%) ASC‐H. Round (P = 0.02) and naked nuclei (P = 0.009) were significant correlates of outcome amongst LSIL‐H tests, but no feature correlated with outcome in the ASC‐H group.

Conclusions:  LSIL‐H is different to ASC‐H because of the 11% higher frequency of a positive outcome and the cytological features associated with outcome.
Prediction of recurrent disease by cytology and HPV testing after treatment of cervical intraepithelial neoplasia
Authors: Aerssens A. , Claeys P. , Beerens E. , Garcia A. , Weyers S. , Van Renterghem L. , Praet M. , Temmerman M. , Velasquez R. , Cuvelier C.A.
Published: May 2008

Objective:  To assess the role of human papillomavirus (HPV) testing and cytology as predictors of residual/recurrent disease after treatment of high‐grade cervical intraepithelial lesions.

Methods:  One hundred and thirty‐eight women with cervical intraepithelial neoplasia (CIN) grade 2/3 lesion on biopsy were included in a prospective follow‐up study in Belgium and Nicaragua. All women were treated with loop electrosurgical excision procedure (LEEP) and follow‐up visits took place at 6 weeks, 6 months, 1 year and 2 years. During these visits, a Papanicolaou (Pap) smear test was taken, colposcopy was performed and specimens were collected for HPV testing. Cytology, high‐risk (HR) HPV presence, persistent HR HPV infection and combinations of these tests at different time points during follow‐up were correlated with histologically confirmed residual/recurrent disease.

Results:  Thirteen patients (9%) developed residual/recurrent disease during follow‐up. Abnormal cytology at 6 weeks after treatment was significantly correlated with residual/recurrent disease. Nine of thirty‐seven patients with abnormal cytology at 6 weeks had recurrent disease versus three of seventy with a normal cytology [odds ratio (OR): 7.2; 95% confidence interval (CI): 1.8–28.5; P = 0.003). Sensitivity of this test was 75.0%, specificity 70.5%. Combining abnormal cytology and the presence of HR HPV within the first 6 months after treatment gave the best correlation with residual/recurrent disease: of the 54 women with abnormal cytology and/or HR HPV presence within the first 6 months, 11 developed residual/recurrent disease (OR 10.2; 95% CI: 2.2–48.3). Sensitivity of this combination was 84.6% and specificity 65.0%.

Conclusion:  Cytology remains the cornerstone in the early follow‐up after LEEP for CIN lesions of the cervix. HPV testing can add value as it increases the sensitivity of cytology in concomitant testing within the first 6 months.
Terrestrial detritus supports the food webs in lowland intermittent streams of south‐eastern Australia: a stable isotope study
Authors: REID DAVID J. , QUINN GERRY P. , LAKE P. S. , REICH PAUL
Published: May 2008

Large amounts of terrestrial detritus enter many low‐order forested streams, and this organic material is often the major basal resource in the metazoan food webs of such systems. However, despite their apparently low biomass, algae are the dominant food of organisms in a number of aquatic communities which conventionally would have been presumed to be dependent on allochthonous detritus, particularly those in the tropics and also in lowland intermittent streams in arid Australia.

The dual stable isotope signatures (δ13C and δ15N) of potential primary food sources were compared with the isotopic signatures of common aquatic animals in lowland intermittent streams in south‐eastern Australia, in both spring and summer, to determine whether allochthonous detritus was an important nutritional resource in these systems. The isotopic signatures of the major potential allochthonous plant food sources (Eucalyptus, Phalaris and Juncus) overlapped, but were distinct from algae and the dominant macrophytes growing in the study reaches. The isotopic signatures of biofilm were more spatially and temporally variable than those of the other basal resources.

Despite allochthonous detritus having relatively high C : N ratios compared to other potential basal resources, results from isosource mixing model calculations demonstrated that this detritus, and the associated biofilm, were the major energy sources assimilated by macroinvertebrate primary consumers in both spring and summer. The importance of these energy sources was also reflected in animals higher in the food web, including predatory macroinvertebrates and fish. These resources were supplemented by autochthonous sources of higher nutritional value (i.e. filamentous algae and macrophytes, which had relatively low C : N ratios) when they became more prolific as the streams dried to disconnected pools in summer.

The results highlight the importance of allochthonous detritus (particularly from Eucalyptus) as a dependable energy source for benthic macroinvertebrates and fish in lowland intermittent streams of south‐eastern Australia. This contrasts with previous stable isotope studies conducted in lowland intermittent streams in arid Australia, which have reported that the fauna are primarily dependent on autochthonous algae.
Temperature dependence of stream benthic respiration in an Alpine river network under global warming
Authors: ACUÑA V. , WOLF A. , UEHLINGER U. , TOCKNER K.
Published: May 2008

1. Global warming has increased the mean surface temperature of the Earth by 0.6 °C in the past century, and temperature is probably to increase by an additional 3 °C by 2100. Water temperature has also increased, which in turn can affect metabolic rate in rivers. Such an increase in metabolic rate could alter the role of river networks in the global C cycle, because the fraction of allochthonous organic C that is respired may increase.

2. Laboratory‐based incubations at increasing water temperature were used to estimate the temperature dependence of benthic respiration in streams. These experiments were performed on stones taken from seven reaches with different thermal conditions (mean temperature ranging 8–19 °C) within the pre‐alpine Thur River network in Switzerland, June–October 2007.

3. The activation energy of respiration in different reaches along the river network (0.53 ± 0.12 eV, n = 94) was similar, indicating that respiration was constrained by the activation energy of the respiratory complex (E = 0.62 eV). Water temperature and the thickness of the benthic biofilm influence the temperature dependence of respiration and our results suggest that an increase of 2.5 °C will increase river respiration by an average of 20 ± 1.6%.
An exploration of factors that influence the regular consumption of water by Irish primary school children
Authors: Johnston Molloy C. , Gandy J. , Cunningham C. , Glennon Slattery C.
Published: May 2008

Background  Inadequate hydration has been linked to many factors that may impact on children’s education and health. Teachers play an important role in the education and behaviour of children. Previous research has demonstrated low water intake amongst children and negative teachers’ attitudes to water in the classroom. The present study aimed to explore teachers’ knowledge about water and the perceived barriers to allowing children access to water during lesson time.

Methods  In‐depth interviews were conducted with 12 teachers from primary schools in the Midlands of Ireland. Interviews were continued until there was saturation of the data. Thematic analysis of the data was conducted.

Results  Participants had a poor knowledge of hydration requirements and the associated health benefits and effect on concentration. Low water intake amongst teachers and pupils, and barriers such as disruption to class and increased need to urinate, were reported. Teachers identified the hydration effect on learning as the education message most likely to influence the decision to allow water in the classroom.

Conclusions  The issues, opinions and perceived barriers raised by teachers as part of this qualitative research provide a basis for future health promotion around water.
Effect of Oestrogen Receptor Alpha and Beta Agonists on Brain N‐Methyl‐d‐Aspartate Receptors
Authors: Morissette M. , Le Saux M. , Di Paolo T.
Published: May 2008

Previous studies have shown the oestradiol modulation of brain N‐methyl‐d‐aspartate (NMDA) receptors composed of the NR1/2B subunits. The contribution of oestrogen receptor subtypes in this oestradiol modulation of NMDA receptors and its subunits is not known. The following experiments investigated whether an oestrogenic receptor subtype is involved in the oestradiol effect on NMDA receptor specific binding and subunit mRNA levels. Ovariectomised Sprague‐Dawley rats were treated 2 days after ovariectomy for 2 weeks with 17β‐oestradiol, an agonist for oestrogen receptor (ER)α 4,4′,4″‐(4‐propyl‐[1H]‐pyrazole‐1,3,5‐triyl)trisphenol (PPT) or an agonist for ERβ 2,3‐bis(4‐hydroxyphenyl)‐propionitrile (DPN) and compared with control vehicle‐treated ovariectomised and intact rats. Uterus weights, used as a peripheral measure of oestrogenic activity, decreased after ovariectomy and increased by oestradiol and PPT but not DPN treatment. In the hippocampal CA1 oriens and CA1 radiatum, [3H]Ro 25‐6981 specific binding, a NMDA/NR2B ligand, was decreased in ovariectomised compared to intact rats and this was prevented by 17β‐oestradiol or PPT but not DPN treatments; a similar pattern was observed in the CA2/3 and dentate gyrus but did not reach statistical significance. In situ hybridisation of the mRNA of the NMDA/2B subunit in the hippocampus CA1, CA2/3 and dentate gyrus showed a decrease in ovariectomised rats compared to controls and this was also prevented by 17β‐oestradiol and PPT but not DPN treatments. In cingulate and prefrontal cortices, ovariectomy increased [3H]Ro 25‐6981 specific binding compared to intact controls, which was corrected by 17β‐oestradiol treatment but neither by PPT, nor DPN. In the cortical regions, the lack of effect of the ERα or ERβ agonist whereas 17β‐oestradiol was active, suggesting that the oestradiol modulation of cortical NMDA receptors requires both ERs or that this modulation does not involve ERs. In the hippocampus, the results obtained suggest an oestrogenic genomic modulation of NMDA receptors containing the NR2B subunit, implicating an ERα.
Analysis of Selected Genes in Neuroendocrine Tumours: Insulinomas and Phaeochromocytomas
Authors: Hrašćan R. , Pećina‐Šlaus N. , Martić T. Nikuševa , Čolić J. Franekic , Gall‐Trošelj K. , Pavelić K. , Karapandža N.
Published: May 2008

Insulinomas and phaeochromocytomas are neuroendocrine tumours that may be either sporadic or manifestation of a familial cancer syndromes and are both derived from the neural crest. In the present study, gene components of different signalling pathways were investigated in sporadic human insulinomas and phaeochromocytomas to identify the responsible candidates. Ret and k‐ras were tested for activating point mutations, and NF1, p53, BRCA1, nm23‐H1, SDHB and SDHD for loss of heterozygosity (LOH). Twenty‐two sporadic insulinomas and 15 phaeochromocytomas were analysed by the polymerase chain reaction using restriction fragment length polymorphism or dinucleotide repeat polymorphism methods. The results of our analysis demonstrate that the most frequent changes were point mutations of k‐ras: 23% of insulinomas and 62% of phaeochromocytomas harboured k‐ras mutations. The analysis also showed two phaeochromocytomas with point mutations of the ret oncogene. Only one insulinoma showed LOH of NF1, and another showed LOH of p53. Allelic loss of BRCA1 was detected in two insulinomas, and of nm23‐H1 in another insulinoma. Allelic losses of the SDHB gene were present in two phaeochromocytoma and one insulinoma cases and allelic losses of SDHD were present in one phaeochromocytoma case. The changes observed in phaeochromocytomas were more homogenous and confined to k‐ras and ret oncogenes, whereas insulinomas showed more heterogenic situation. Our findings may contribute to a better understanding of the genetic profile of neuroendocrine tumours.
Prepubertal Social Subjugation and Anabolic Androgenic Steroid‐Induced Aggression in Male Rats
Authors: Cunningham R. L. , McGinnis M. Y.
Published: May 2008

Abused children are more prone to abuse drugs, such as anabolic androgenic steroids (AAS), as teenagers and display violence as adults. AAS use has been linked with elevated aggression. Thus, exposure to child abuse and AAS may potentiate aggression. A social subjugation paradigm was used as an animal model of childhood abuse to determine whether prior subjugation increases AAS‐induced aggression in male rats. Prepubertal gonadally intact male rats were exposed to social subjugation, a novel cage experience, or remained undisturbed in their home cages. Experimental males were socially subjugated by being placed in the home cage of an adult male. At puberty, both subjugated and nonsubjugated rats were injected with either the AAS testosterone or vehicle. AAS treatment continued for 5 weeks. Aggression was measured during the last week of AAS exposure. AAS was then discontinued. Aggression was again tested 12 weeks after AAS withdrawal. Aggression was tested under three conditions: (i) physical provocation of the experimental male; (ii) provocation of the intruder male; and (iii) without provocation. Both AAS‐treated males and socially subjugated males displayed significantly more aggression than did controls. Elevated aggression by subjugated males was still present 17 weeks after social subjugation. AAS males also showed increased aggression 12 weeks after AAS withdrawal. However, exposure to both social subjugation and AAS had no long‐term effects on aggression. The results of the present study indicate that social subjugation may have lasting consequences on the expression of adaptive social behaviours.
Two simultaneous hepatitis B virus epidemics among injecting drug users and men who have sex with men in Buenos Aires, Argentina: characterization of the first D/A recombinant from the American continent
Authors: Trinks J. , Cuestas M. L. , Tanaka Y. , Mathet V. L. , Minassian M. L. , Rivero C. W. , Benetucci J. A. , Gímenez E. D. , Segura M. , Bobillo M. C. , Corach D. , Ghiringhelli P. D. , Sánchez D. O. , Ávila M. M. , Peralta L. A. M. , Kurbanov F. , Weissenbacher M. C. , Simmonds P. , Mizokami M. , Oubiña J. R.
Published: May 2008

Summary.  Previous studies have revealed that hepatitis B virus (HBV)/D and HBV/F predominate among blood donors from Buenos Aires, Argentina. In the present study, blood samples from two high‐risk groups were analysed: 160 corresponding to street‐ and hospital‐recruited injecting drug users [81.2% showing the ‘anti‐hepatitis B core antigen (anti‐HBc) only’ serological pattern] and 20 to hepatitis B surface antigen (HBsAg)+/anti‐HBc+ men who have sex with men. HBV genotypes were assigned by polymerase chain reaction amplification followed by restriction fragment length polymorphism and confirmed by nucleotide sequencing of two different coding regions. HBV DNA was detected in 27 injecting drug users (16.9%, occult infection prevalence: 7.7%), and 14 men who have sex with men (70%). HBV/A prevailed among injecting drug users (81.8%) while HBV/F was predominant among men who have sex with men (57.1%). The high predominance of HBV/A among injecting drug users is in sharp contrast to its low prevalence among blood donors (P = 0.0006) and men who have sex with men (P = 0.0137). Interestingly, all HBV/A S gene sequences obtained from street‐recruited injecting drug users encoded the rare serotype ayw1 and failed to cluster within any of the known A subgenotypes. Moreover, one of the HBV strains from a hospital‐recruited injecting drug user was fully sequenced and found to be the first completely characterized D/A recombinant genome from the American continent. Data suggest that two simultaneous and independent HBV epidemics took place in Buenos Aires: one spreading among injecting drug users and another one sexually transmitted among the homosexual and heterosexual population.
Inferring recruitment history from spatial genetic structure within populations of the colonizing treeAlbizia julibrissin(Fabaceae)
Authors: PARDINI E. A. , HAMRICK J. L.
Published: May 2008

Comparative analyses of spatial genetic structure (SGS) among species, populations, or cohorts give insight into the genetic consequences of seed dispersal in plants. We analysed SGS of a weedy tree in populations with known and unknown recruitment histories to first establish patterns in populations with single vs. multiple founders, and then to infer possible recruitment scenarios in populations with unknown histories. We analysed SGS in six populations of the colonizing treeAlbizia julibrissinDurazz. (Fabaceae) in Athens, Georgia. Study sites included two large populations with multiple, known founders, two small populations with a single, known founder, and two large populations with unknown recruitment histories. Eleven allozyme loci were used to genotype 1385 individuals. Insights about the effects of colonization history from the SGS analyses were obtained from correlograms andSpstatistics. Distinct differences in patterns of SGS were identified between populations with multiple founders vs. a single founder. We observed significant, positive SGS, which decayed with increasing distance in the populations with multiple colonists, but little to no SGS in populations founded by one colonist. Because relatedness among individuals is estimated relative to a local reference population, which usually consists of those individuals sampled in the study population, SGS in populations with high background relatedness, such as those with a single founder, may be obscured. We performed additional analyses using a regional reference population and, in populations with a single founder, detected significant, positive SGS at all distances, indicating that these populations consist of highly related descendants and receive little seed immigration. Subsequent analyses of SGS in size cohorts in the four large study populations showed significant SGS in both juveniles and adults, probably because of a relative lack of intraspecific demographic thinning. SGS in populations of this colonizing tree is pronounced and persistent and is determined by the number and relatedness of founding individuals and adjacent seed sources. Patterns of SGS in populations with known histories may be used to indirectly infer possible colonization scenarios for populations where it is unknown.
Phylogeography and local endemism of the native Mediterranean brine shrimp Artemia salina (Branchiopoda: Anostraca)
Authors: MUÑOZ JOAQUÍN , GÓMEZ AFRICA , GREEN ANDY J. , FIGUEROLA JORDI , AMAT FRANCISCO , RICO CIRO
Published: May 2008

There has been a recent appreciation of the ecological impacts of zooplanktonic species invasions. The North American brine shrimp Artemia franciscana is one such alien invader in hyper‐saline water ecosystems at a global scale. It has been shown to outcompete native Artemia species, leading to their local extinction. We used partial sequences of the mitochondrial Cytochrome c Oxidase Subunit 1 (COI or cox1) gene to investigate the genetic diversity and phylogeography of A. salina, an extreme halophilic sexual brine shrimp, over its known distribution range (Mediterranean Basin and South Africa) and to assess the extent of local endemism, the degree of population structure and the potential impact of traditional human saltpan management on this species. We also examined the phylogenetic relationships in the genus Artemia using COI sequences. Our results show extensive regional endemism and indicate an early Pleistocene expansion of A. salina in the Mediterranean Basin. Subsequent population isolation in a mosaic of Pleistocene refugia is suggested, with two or three refugia located in the Iberian Peninsula. Two instances of long‐distance colonization were also observed. Surprisingly, given its strong phylogeographical structure, A. salina showed a signature of correlation between geographical and genetic distance. Owing to strong ‘priority effects’, extensive population differentiation is retained, despite dispersal via migrant birds and human management of saltpans. The foreseeable expansion of A. franciscana is likely to be followed by substantial loss of genetic diversity in Mediterranean A. salina. Large genetic divergences between Mediterranean and South African A. salina suggest that the latter deserves species status.
Genetic variation in Arabidopsis thaliana for night‐time leaf conductance
Authors: CHRISTMAN MAIRGARETH A. , RICHARDS JAMES H. , MCKAY JOHN K. , STAHL ELI A. , JUENGER THOMAS E. , DONOVAN LISA A.
Published: May 2008

Night‐time leaf conductance (gnight) and transpiration may have several adaptive benefits related to plant water, nutrient and carbon relations. Little is known, however, about genetic variation in gnight and whether this variation correlates with other gas exchange traits related to water use and/or native habitat climate. We investigated gnight in 12 natural accessions and three near isogenic lines (NILs) of Arabidopsis thaliana. Genetic variation in gnight was found for the natural accessions, and gnight was negatively correlated with native habitat atmospheric vapour pressure deficit (VPDair), suggesting lower gnight may be favoured by natural selection in drier habitats. However, there were also significant genetic correlations of gnight with daytime gas exchange traits expected to affect plant fitness [i.e. daytime leaf conductance, photosynthesis and intrinsic water‐use efficiency (WUEi)], indicating that selection on daytime gas exchange traits may result in indirect selection on gnight. The comparison of three NILs to their parental genotypes identified one quantitative trait locus (QTL) contributing to variation in gnight. Further characterization of genetic variation in gnight within and among populations and species, and of associations with other traits and native habitats will be needed to understand gnight as a putatively adaptive trait.
Maintenance of clinal variation for shell colour phenotype in the flat periwinkle Littorina obtusata
Authors: PHIFER‐RIXEY M. , HECKMAN M. , TRUSSELL G. C. , SCHMIDT P. S.
Published: May 2008

Clines can signal spatially varying selection and therefore have long been used to investigate the role of environmental heterogeneity in maintaining genetic variation. However, clinal patterns alone are not sufficient to reject neutrality or to establish the mechanism of selection. Indirect, inferential methods can be used to address neutrality and mechanism, but fully understanding the adaptive significance of clinal variation ultimately requires a direct approach. Ecological model systems such as the rocky intertidal provide a useful context for direct experimentation and can serve as a complement to studies in more traditional genetic model systems. In this study, we use indirect and direct approaches to investigate the role of environmental heterogeneity in the maintenance of shell colour polymorphism in the flat periwinkle snail, Littorina obtusata. We document replicated clines in shell colour morph frequencies over thermal gradients at two spatial scales, contrasting with patterns at previously reported microsatellite loci. In addition, experimental results demonstrate that that shell colour has predictable effects on shell temperature and that these differences in temperature, in turn, coincide with patterns of survivorship under episodic thermal stress. Direct manipulation of shell colour revealed that shell colour, and not a correlated character, was the target of selection. Our study provides evidence that spatially varying selection via thermal regime contributes to the maintenance of shell colour phenotype variation in L. obtusata in the sampled areas of the Gulf of Maine.
The contribution of parasitism to selection on floral traits in Heuchera grossulariifolia
Authors: NUISMER S. L. , RIDENHOUR B. J.
Published: May 2008

Parasites are ubiquitous and have well‐documented ecological consequences. In contrast, the extent to which parasites drive phenotypic evolution in hosts remains obscure. We use a recently developed statistical technique – selective source analysis – to analyse the strength of phenotypic selection acting on floral traits in the plant Heuchera grossulariifolia attributable to attack by the seed‐parasitic moth, Greya politella. This analysis spanned 3 years and included two sympatric populations of the host plant H. grossulariifolia that differ in ploidy. Our analyses revealed that attack by G. politella contributed to phenotypic selection for flowering time and floral display size, favouring earlier flowering in the polyploid population, later flowering in the diploid population and increased floral display size in the polyploid population. Although selection imposed by parasite attack was generally quite weak, in one of the 3 years parasites generated a modestly strong selection gradient (β = −0.059) that explained 38.6% of total observed phenotypic selection for earlier flowering in the polyploid population. Together, our results demonstrate parasites can generate significant phenotypic selection, but that such selection may be sporadic across populations and time.
Prostaglandin F2α Stimulates Endothelial Nitric Oxide Synthase Depending on the Existence of Bovine Granulosa Cells: Analysis by Co‐culture System of Endothelial Cells, Smooth Muscle Cells and Granulosa Cells
Authors: Shirasuna K , Yamamoto D , Morota K , Shimizu T , Matsui M , Miyamoto A
Published: May 2008

Contents

Prostaglandin F2α (PGF2α) induces luteolysis in the mid but not in the early luteal phase; despite this, both the early and the mid corpus luteum (CL) have PGF2α receptor (FPr). We previously indicated that the luteal blood flow surrounding the CL drastically increases prior to a decrease of progesterone (P) in the cows, suggesting that an acute increase of luteal blood flow may be an early sign of luteolysis in response to PGF2α and that this may be induced by a vasorelaxant nitric oxide (NO). The aim of this study was to investigate the luteal stage‐dependent and the site‐restricted effect of PGF2α and NO on the mRNA expressions and P secretion. To mimic the local luteal region both of peripheral and central areas of the CL, we utilized co‐cultures using bovine aorta endothelial cells (EC), smooth muscle cells (SMC) and luteinizing granulosa cells (GC) or fully‐luteinized GC. PGF2α stimulated the expression of endothelial NO synthase (eNOS) mRNA at 0.5 h in mix‐cultures of EC and SMC with fully‐luteinized GC but not with luteinizing GC. The expression of eNOS mRNA in EC was increased by PGF2α at 1 h only when EC was cultured together with fully‐luteinized GC but not with luteinizing GC. In all co‐cultures, PGF2α did not affect the mRNA expression of FPr. Treatment of NO donor inhibited P secretion at 0.5 h. In conclusion, the present study suggests that the coexistence of the mature luteal cells (fully‐luteinized GC) with EC/SMC may be crucial for acquiring functional NO synthesis induced by PGF2α.
Evaluation of ‘Section‐Ligation‐Release (SLR)’ Technique Devised for Castration in the Stallion
Authors: Saifzadeh S , Hobbenaghi R , Asri‐Rezaei S , Shokouhi SJ F , Dalir‐Naghadeh B , Rohi S M
Published: May 2008

Contents

A novel technique [Section‐Ligation‐Release (SLR)] was evaluated for castration in the horse. Clinical traits, serum testosterone concentrations after challenge with human chorionic gonadotrophin (hCG), and histopathological changes of the testicular tissue were assessed. Five stallions, aged 24–48 months, were castrated using SLR technique under general anaesthesia. Both spermatic cords in each stallion were exposed at the scrotal neck by two 5‐cm long incisions, followed by sharp dissection through the parietal vaginal tunic. Both vascular and non‐vascular structures in the cords were triple clamped, transected and ligated. Both testes were leftin situ. Serum testosterone concentrations were measured pre‐operatively and at 2 months after castration following IV administration of 1 × 104 IU of hCG. Both testes from each castrate were collected at 2 months for histopathologic examination. SLR castration was successfully achieved. Moderated scrotal and preputial swelling was the only experienced short‐term complication. Serum testosterone concentrations were significantly lower than basal pre‐operative levels at 2 months after castration, and did not respond to hCG. On histopathology, hyalinization of the seminiferous tubules and loss of testicular interstitial tissue were indicative of complete avascular necrosis. This novel primary closure castration technique of stallion is a simple practical method, with minimal post‐operative complications; and could be safely advocated as an alternative to the traditional castration techniques allowing for second intention healing of scrotal wounds.
Changes in Testicular Development, Ultrasonographic and Histological Appearance of the Testis in Buck Kids Immunized Against LHRH Using Recombinant LHRH Fusion Protein
Authors: Ülker H , Küçük M , Yılmaz A , Yörük M , Arslan L , DeAvila DM , Reeves JJ
Published: May 2008

Contents

This study was designed to evaluate the effectiveness of recombinant Ovalbumin‐LHRL (OL) immunization on changes in testicular size, histological appearance and testosterone production in buck kids. Thirty native buck kids at 18 weeks of age were divided into three groups, control (n = 10), immunization (n = 10) and castration (n = 10) groups. Immunized animals received OL protein generated by recombinant DNA technology. Ultrasonographic and histological examinations of the testes were performed. Animals were slaughtered at 44 weeks of age. Semen and epididymides were evaluated for the presence of sperm cells. Immunized animals generated anti‐LHRH antibodies. Testosterone production, testicular and accessory glands development and sperm production were suppressed in the immunized animals (p < 0.01). Semineferous tubule diameters decreased (p < 0.01), basal membrane of the tubule was thickened and hyalinized in immunized kids. Immunization affected ultrasonographic appearance of the testes drastically. While testes of control animals gained their normal ultrasonographic appearance as the age increased, immunized animals had uniform hypoechogenic testicular structure as observed at 18 weeks of age until slaughter. Simultaneous histological and ultrasonographic evaluations indicated that the changes in testicular histology could partly be monitored via ultrasonographic imaging; nevertheless, it is difficult to claim that ultrasonographic image reflects the exact changes in such instances. In conclusion, these results indicate that recombinant OL fusion protein is effective in immunocastration in buck kids and has a potential to be used as an alternative to physical castration. Further researches should be conducted to help assessing reproductive status of testes from ultrasound images.