bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protandry promotes male pollination success in a moth‐pollinated orchid
Authors: JERSÁKOVÁ J. , JOHNSON S. D. 
Published: March 2007

SummaryTemporal separation of male and female phases in hermaphrodite flowers (dichogamy) is proposed to reduce self‐pollination, both within and among flowers. Darwin and later workers suggested that protandry (the most common form of dichogamy, in which the male phase precedes the female phase) should be most effective in reducing geitonogamous (between‐flower) self‐pollination when pollinators forage upwards from older female‐phase flowers to younger male‐phase flowers on vertical inflorescences.We tested this hypothesis by manipulating the extent of protandry in artificial inflorescences of the orchidSatyrium longicaudaLindl. and using stained pollen to quantify self‐pollination and pollen export.Upper flowers of non‐protandrous inflorescences received more self‐pollen through geitonogamy than lower flowers, unlike protandrous inflorescences. Protandry reduced absolute levels of self‐pollination, as the amount of removed pollen involved in self‐pollination was three times greater in non‐protandrous than in protandrous inflorescences. This high level of self‐pollination reduced the pollen available for export, as the ratio of pollen export to self‐pollination declined with increasing self‐pollination, indicating the occurrence of pollen discounting.This study represents the first direct measurement of the effects of protandry on the pollination process, and indicates that the evolution of protandry in plants could be driven strongly by the consequences of this trait for male mating success.
Eastward Ho: phylogeographical perspectives on colonization of hosts and parasites across the Beringian nexus
Authors: Waltari Eric , Hoberg Eric P. , Lessa Enrique P. , Cook Joseph A. 
Published: March 2007

AbstractThe response of Arctic organisms and their parasites to dramatic fluctuations in climate during the Pleistocene has direct implications for predicting the impact of current climate change in the North. An increasing number of phylogeographical studies in the Arctic have laid a framework for testing hypotheses concerning the impact of shifting environmental conditions on transcontinental movement. We review 35 phylogeographical studies of trans‐Beringian terrestrial and freshwater taxa, both hosts and parasites, to identify generalized patterns regarding the number, direction and timing of trans‐continental colonizations. We found that colonization across Beringia was primarily from Asia to North America, with many events occurring in the Quaternary period. The 35 molecular studies of trans‐Beringian organisms we examined focused primarily on the role of glacial cycles and refugia in promoting diversification. We address the value of establishing testable hypotheses related to high‐latitude biogeography. We then discuss future prospects in Beringia related to coalescent theory, palaeoecology, ancient DNA and synthetic studies of arctic host–parasite assemblages highlighting their cryptic diversity, biogeography and response to climate variation.
Sedimentary architecture and 3D ground‐penetrating radar analysis of gravelly meandering river deposits (Neckar Valley, SW Germany)
Authors: KOSTIC BORIS , AIGNER THOMAS 
Published: March 2007

AbstractSedimentological outcrop analysis and sub‐surface ground‐penetrating radar (GPR) surveys are combined to characterize the three‐dimensional sedimentary architecture of Quaternary coarse‐grained fluvial deposits in the Neckar Valley (SW Germany). Two units characterized by different architectural styles are distinguished within the upper part of the gravel body, separated by an erosional unconformity: (i) a lower unit dominated by trough‐shaped depositional elements with erosional, concave‐up bounding surfaces that are filled by cross‐bedded sets of mainly openwork and filled framework gravel; and (ii) an upper unit characterized by gently inclined sheets of massive and openwork gravels with thin, sandy interlayers that show lateral accretion on a lower erosional unconformity. The former is interpreted as confluence scour pool elements formed in a multi‐channel, possibly braided river system, the latter as extensive point bar deposits formed by the lateral migration of a meandering river channel. The lateral accretion elements are locally cut by chute channels mainly filled by gravels rich in fines, and by fine‐grained abandoned channel fills. The lateral accretion elements are associated with gravel dune deposits characterized by steeply inclined cross‐beds of alternating open and filled framework gravel. Floodplain fines with a cutbank and point bar morphology cover the gravel deposits. The GPR images, revealing the three‐dimensional geometries of the depositional elements and their stacking patterns, confirm a change in sedimentary style between the two stratigraphic units. The change occurred at the onset of the Holocene, as indicated by 14C‐dating of wood fragments, and is related to a re‐organization of the fluvial system that probably was driven by climatic changes. The integration of sedimentological and GPR results highlights the heterogeneity of the fluvial deposits, a factor that is important for modelling groundwater flow in valley‐fill aquifers.
Controls on natural levée development in the Columbia River, British Columbia, Canada
Authors: FILGUEIRA‐RIVERA MANUEL , SMITH NORMAN D. , SLINGERLAND RUDY L. 
Published: March 2007

AbstractNatural levées of the Columbia River near Golden, British Columbia, were investigated to identify the mechanisms that control levée development and morphology. Topographic profiles of 12 levée pairs were surveyed, and measurements of water‐surface elevation, flow velocity, flow direction and turbidity were obtained during an average magnitude flood (1·2 years recurrence interval). Sedimentation rates and grain‐size distributions were measured from sediment traps placed along levée‐to‐floodbasin transects. Results show that water and sediment exchange between the channel and floodbasin was mainly by advection. During flooding, local floodbasins behave more as efficient water pathways than water storage features, resulting in down‐valley floodbasin flows capable of limiting basinward growth of levées. Levée shape results primarily from two independent factors: (1) maximum channel water stage, which limits levée height; and (2) floodbasin hydraulics, which control width. In the Columbia River, the competence of floodbasin flows results in relatively narrow and steep levées. Natural levées grow under two general conditions of deposition as governed by flood‐stage elevation relative to levée‐crest elevation: front loading and back loading. During large floods when crests are inundated, front loading preferentially aggrades the proximal portions of levées with sediment directly from the channel, thus increasing levée slope. During average or below‐average floods when many levée crests are not overtopped, back loading preferentially aggrades the distal levée areas and floodbasin floor, reducing levée slope. In the study area, a balance between front and back loading sustains these narrow and steep levée shapes for long periods, reflecting an equilibrium between hydraulic regime, floodplain morphology and deposition.
Dispersal Potential is Affected by Growth‐Hormone Transgenesis in Coho Salmon (Oncorhynchus kisutch)
Authors: Fredrik Sundström L. , Lõhmus Mare , Johnsson Jörgen I. , Devlin Robert H. 
Published: March 2007

AbstractPotential ecological consequences on the natural environment of fast‐growing transgenic fish with elevated intrinsic growth rates is an important question should such fish be allowed in commercial production systems. One trait that will strongly affect the spatial extent of consequences is the propensity of transgenic fish to disperse. We addressed this question in three experiments using different measures of spatial dispersal where we compared very young genotypically wild coho salmon with transgenic conspecifics in terms of: (i) group cohesion, (ii) exploratory behavior, and (iii) up‐ and downstream movements. Transgenic fish were more loosely aggregated, more likely to explore, and less likely to swim upstream, but equally likely to disperse downstream compared with genetically wild fish. These results show that dispersal behavior has been affected by transgenesis and that transgenic fish therefore may venture into habitats previously not used by wild fish. Given the importance of dispersal in ecological risk‐assessment of transgenic fish, continued work within this area is warranted and experimental habitats should mimic the potential receiving natural habitats to which transgenic fish are likely to escape or be released to.
Consistency in Egg Rejection Behaviour: Responses to Repeated Brood Parasitism in the Blackcap (Sylvia atricapilla)
Authors: Honza Marcel , Požgayová Milica , Procházka Petr , Tkadlec Emil 
Published: March 2007

AbstractTo evaluate host responses towards repeated brood parasitism we experimentally parasitized and continuously videotaped blackcap nests in two consecutive trials. The ejection of a foreign egg was the most common response (94.5%) in both trials, but desertion (4.1%) and acceptance (1.4%) also occurred. The general method of ejection was puncturing. In 9.8% of identified ejections, already punctured eggs stuck to the abdominal feathers of the incubating bird and were carried out of the nest. Females were responsible for the majority of ejections in both trials and their response time was significantly shorter than that of males. Blackcaps exhibited consistency in the sex responsible for egg ejection over the two trials; but in five (20.8%) experiments individuals changed their behaviour. Repeatability for host responses within the nest was very high. In ejections accomplished by the same bird, the response was significantly quicker in the second trial, indicating the presence of certain learning abilities. Our results suggest that cuckoo hosts are quite consistent in their responses towards parasitic eggs when parasitized repeatedly within one breeding attempt.
CAN SERUM INFLAMMATORY PARAMETERS ESTIMATE OUTCOME OF PLEURODESIS IN MESOTHELIOMA?
Authors: Bilgin Mehmet , Hasdiraz Leyla , Ozkaya Muharrem , Oguzkaya Fahri 
Published: March 2007

Background:  As pleurodesis causes systemic inflammation and is associated with considerable cost and morbidity during long‐term follow up, the identification of patients who will experience an unsuccessful pleurodesis would be desirable. This study was aimed to investigate whether systemic inflammatory reaction induced by insuflation of talc into the pleura can predict the outcome of pleurodesis.Methods:  A total of 58 consecutive patients (26 men, 32 women) with malignant pleural mesothelioma underwent video‐assisted thoracoscopy under general anaesthesia with monopulmonary ventilation between the years 2003 and 2006. Four grammes of asbestos‐free and sterile talc were insuflated into the pleural space under direct vision. To assess the success of pleurodesis, chest radiographs were obtained at the 8th and 30th postoperative days. Venous blood samples were drawn both on admission and at the 24th hour after pleurodesis for the analysis of white blood cells, erythrocyte sedimentation rate and C‐reactive protein.Results:  The mean age (standard deviation) of patients was 59.0 ± 12.0 years. Pleurodesis was achieved (no effusion on chest radiograph) in 43 of 58 patients (74.1%)(group I), whereas it was unsuccessful in the remaining 15 patients (25.9%)(group II). There was a significant difference between two groups for basal and postpleurodesis levels of measured inflammatory parameters, C‐reactive protein and erythrocyte sedimentation rate (for each, P < 0.05). However, the difference was not significant for white blood cells between the groups.Conclusion:  Serum levels of inflammatory parameters (C‐reactive protein and erythrocyte sedimentation rate) may be used to predict the success of pleurodesis in patients with malign mesothelioma who underwent thoracoscopic talc poudrage.
ANTIMICROBIAL ACTIVITY OF CEFAZOLIN‐IMPREGNATED MESH GRAFTS
Authors: Kilic Dilek , Agalar Canan , Ozturk Eylem , Denkbas Emir B. , Cime Abdullah , Agalar Fatih 
Published: March 2007

Background:  The aim of this study is the preparation and characterization of cefazolin‐impregnated meshes (Surgipro; Tyco Healthcare USSC, Norwalk, CT, USA) to be used as antimicrobial devices.Methods:  During the impregnation, poly(dl‐lactide‐co‐glycolide) solution with cephazolin in dichloromethane was used as coating material. In vitro release experiment was carried out first; later cefazolin‐impregnated meshes were evaluated for the characteristics of antimicrobial efficacy and in the last part of the study native and cefazolin‐impregnated meshes were implanted in the rats. Cefazolin content was proposed as the effective parameter to control the cefazolin release rate and it was concluded that the higher amounts of initial cefazolin content caused higher release rates. In all cases (or with different cefazolin content for each mesh), the release rates were very rapid in the first 24 h and in the following periods rather slow release rates were obtained.Results:  Antimicrobial activity was increased in the case of cefazolin‐impregnated form and this efficiency was also increased by the higher amount of cefazolin in certain mesh pieces. Similar antimicrobial activities were observed in the in vitro studies.Conclusion:  In this study, almost all of the cefazolin‐impregnated mesh grafts showed very high antimicrobial activity compared with the bare mesh (or mesh without cefazolin).
TREATMENT OF PROFUSE EPISTAXIS IN PATIENTS IRRADIATED FOR NASOPHARYNGEAL CARCINOMA
Authors: Wong George K. C. , Chan Kin K. , Yu Simon C. H. , Tsang Raymond K. Y. , Poon Wai S. 
Published: March 2007

Background:  Profuse epistaxis in patients with nasopharyngeal carcinoma (NPC) previously treated with radiotherapy (RT) can be life threatening. Surgical means to prevent rebleeding may at times be difficult and unsuccessful. We aim to investigate the characteristics of this group of patients and our experience of endovascular embolization technique in the management of epistaxis in this group of patients.Methods:  A retrospective review of all nasopharyngeal carcinoma patients presented with profuse epistaxis during follow up after radiotherapy was carried out in a regional neurosurgical centre in Hong Kong. Seventeen patients were included for the analysis within the recent 6‐year period. The age of patients was 55.5 ± 8.358 years (mean ± standard deviation). The sex ratio was 5:1 (M : F). Diagnostic catheter angiography was carried out in all 17 patients. Endovascular embolization was carried out in 11 patients with the joint decision of the otolaryngologist and neurointerventionist in charge .Results:  Four patients underwent main trunk occlusion for internal carotid pseudoaneurysm. Seven patients underwent embolization of branches of external carotid artery. One patient required another session of external carotid artery embolization 1 month later. There was one inpatient death because of pneumonia and hepatic encephalopathy. With our protocol, there were only two patients (11.7%) with delayed rebleed at 2 and 5 months, respectively. Both patients had advanced diseases and died.Conclusion:  In irradiated patients with nasopharyngeal carcinoma presenting with profuse epistaxis, angiography had a high yield of pseudoaneurysm or hypervascularity and these lesions could be safely managed through endovascular embolization.
SURGICAL REPAIR FOLLOWED BY FUNCTIONAL REHABILITATION FOR ACUTE AND CHRONIC ACHILLES TENDON INJURIES: EXCELLENT FUNCTIONAL RESULTS, PATIENT SATISFACTION AND NO RERUPTURES
Authors: Jacob Korula Mani , Paterson Roger 
Published: March 2007

Background:  We evaluated 46 patients who underwent surgical repair of the Achilles tendon at our institution during a 4.5‐year period, followed by early weight bearing, aiming to assess their return to activities, rerupture rate and satisfaction.Methods:  A cohort of 46 patients who underwent Achilles tendon repair at our institution during a 4.5‐year period, with a modified triple mini‐Becker suture technique, for both acute as well as chronic Achilles tendon ruptures were studied. These patients were reviewed at a minimum of 2.5 years follow up (average 4.5 years ranging from 2.5 to 6.5 years), by chart review and questionnaire, to determine the functional outcome as well as patient satisfaction following an active postoperative protocol involving full weight‐bearing ambulation in a controlled ankle motion walker and active stretching, followed by a graduated strengthening programme.Results:  We found a very high level of satisfaction, with few minor complications and no reruptures in either the early or the delayed repair groups.Conclusion:  We believe that surgical repair using this technique associated with an early return to protected full weight‐bearing ambulation and an active early rehabilitation programme provides not only excellent functional results, patient satisfaction and a zero rerupture rate, but also much less morbidity in the first 3 months and a quicker overall recovery compared with non‐operative treatment.
Direct‐to‐consumer advertising under the radar: the need for realistic drugs policy in Australia
Authors: Mackenzie F. J. , Jordens C. F. C. , Ankeny R. A. , McPhee J. , Kerridge I. H. 
Published: March 2007

AbstractDirect‐to‐consumer advertising of prescription medicines (DTCA‐PM) is currently banned in Australia. DTCA‐PM is thought to increase health‐care costs by increasing demand for drugs that are both expensive and potentially harmful. However, DTCA‐PM is occurring in Australia despite the current prohibition. We argue that successful regulation of the practice has been undermined as a result of changes brought about by the ongoing communications revolution, the increasing centrality of patient choice in medical decision‐making and the impossibility of drawing and maintaining a sharp distinction between information and advertising. The prohibition is further threatened by recent international trade agreements. These factors make DTCA‐PM inevitable and legislative and professional bodies need to acknowledge this to create a more effective health‐care policy.
Emerging therapies in the long‐term management of hyperuricaemia and gout
Authors: Stamp L. K. , O’Donnell J. L. , Chapman P. T 
Published: March 2007

AbstractGout is a common chronic arthritis that can lead to significant disability. Gout is one of the few rheumatological conditions that can be diagnosed with certainty, has a known cause and can be cured with appropriate therapy. Hypouricaemic agents reduce uric acid concentrations through inhibiting uric acid production (allopurinol) or enhancing uric acid excretion (probenecid, benzbromarone). Allopurinol is the most commonly used hypouricaemic agent but at recommended doses often fails to reduce adequately uric acid concentrations and prevent acute attacks of gout. The use of probenecid is limited by lack of efficacy in renal impairment. In the last few years, new agents in the management of hyperuricaemia and gout have become available. Febuxostat, a new xanthine oxidase inhibitor, is an effective hypouricaemic agent although further data are required for patients with renal impairment and other significant medical conditions. Rasburicase, a recombinant uricase (which catalyses the conversion of uric acid to the more readily excreted allantoin) is available for prevention of tumour lysis syndrome. However, its repeated use, as would be required in chronic gout, is limited by antigenicity. A less antigenic PEGylated uricase can rapidly reduce serum uric acid concentrations and promote resorption of tophi. However, further information with regard to the long‐term risks and benefits of these agents is required. These agents may ultimately be used in the short term to rapidly deplete urate stores (induction therapy) followed by long‐term therapy with an alternative hypouricaemic agent to prevent subsequent accumulation of uric acid (maintenance therapy).
Supply of inpatient geriatric medical services in Australia
Authors: Gray L. , Moore K. , Smith R. , Dorevitch M. 
Published: March 2007

AbstractThis study summarizes the findings of a national survey of inpatient geriatric services in Australia conducted in 2001. These data are unique as there are no uniform administrative data systems available to provide this information. Eight hundred and eighty‐eight hospitals were surveyed and full responses were received from 690, representing 78% of hospitals and 85% of all hospital beds. The results illustrated wide variation in the style and level of provision of services among hospitals and across regional and state jurisdictions.
Evaluating plant–soil feedback together with competition in a serpentine grassland
Authors: Casper Brenda B. , Castelli Jeffrey P. 
Published: March 2007

AbstractPlants can alter biotic and abiotic soil characteristics in ways that feedback to change the performance of that same plant species relative to co‐occurring plants. Most evidence for this plant–soil feedback comes from greenhouse studies of potted plants, and consequently, little is known about the importance of feedback in relation to other biological processes known to structure plant communities, such as plant–plant competition. In a field experiment with three C4 grasses, negative feedback was expressed through reduced survival and shoot biomass when seedlings were planted within existing clumps of conspecifics compared with clumps of heterospecifics. However, the combined effects of feedback and competition were species‐specific. Only Andropogon gerardii exhibited feedback when competition with the clumps was allowed. For Sorghastrum nutans, strong interspecific competition eliminated the feedback expressed in the absence of competition, and Schizachyrium scoparium showed no feedback at all. That arbuscular mycorrhizal (AM) fungi may play a role in the feedback was indicated by higher AM root colonization with conspecific plant neighbours. We suggest that feedback and competition should not be viewed as entirely separate processes and that their importance in structuring plant communities cannot be judged in isolation from each other.
Majority Voting over Publicly Provided Goods, Redistribution, and Income Taxation
Authors: CALABRESE STEPHEN M. 
Published: March 2007

AbstractFederal, state, and many local governments make decisions that involve taxation, redistribution, and provision of public goods. Positive models to study these issues encounter the well‐known problem that majority‐voting equilibrium (MVE) may fail to exist in such multidimensional models. In this paper, with reasonable restrictions on preferences, I provide sufficient conditions for the existence of an MVE in a model with linear income tax and government expenditure policies that affect individual labor/leisure choices. My majority‐voting result takes account of the possibility that low‐skill individuals will drop out of the labor force under some tax and expenditure configurations.
Centralization vs. Decentralization: A Principal‐Agent Analysis
Authors: TOMMASI MARIANO , WEINSCHELBAUM FEDERICO 
Published: March 2007

AbstractThe decision to allocate policy jurisdictions to different levels of government is related to a number of trade‐offs between the advantages and disadvantages of centralized versus decentralized provision of public services. A trade‐off central to many discussions is that between the internalization of externalities under centralization versus an “accountability” advantage of decentralization. In this paper we formalize this trade‐off in the context of a class of principal–agent models known as common agency.