bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of ossification sequences in salamanders and urodele origins assessed through event‐pairing and new methods
Authors: Germain Damien , Laurin Michel
Published: February 2009

SUMMARY
Ossification sequences of the skull in extant Urodela and in Permo‐Carboniferous Branchiosauridae have already been used to study the origin of lissamphibians. But most of these studies did not consider some recent methods developed to analyze the developmental sequences within a phylogenetic framework. Here, we analyze the ossification sequences of 24 cranial bones of 23 extant species of salamanders using the event‐pairing method. This reveals new developmental synapomorphies for several extant salamander taxa and ancestral sequences for Urodela under four alternative reference phylogenies. An analysis with the 12 bones for which ossification sequence data are available in urodeles and in the branchiosaurid Apateon is also performed in order to compare the ancestral condition of the crown‐group of Urodela to the sequence of Apateon. This reveals far more incompatibilities than previously suggested. The similarities observed between some extant salamanders and branchiosaurids may result from extensive homoplasy, as the extreme variation observed in extant Urodela suggests, or be plesiomorphic, as the conservation of some ossification patterns observed in other remotely related vertebrates like actinopterygians suggests. We propose a new, simpler method based on squared‐change optimization to estimate the relative timing of ossification of various bones of hypothetical ancestors, and use independent‐contrasts analysis to estimate the confidence intervals around these times. Our results show that the uncertainty of the ancestral ossification sequence of Urodela is much greater than event‐pairing suggests. The developmental data do not allow to conclude that branchiosaurids are closely related to salamanders and their limited taxonomic distribution in Paleozoic taxa precludes testing hypotheses about lissamphibian origins. This is true regardless of the analytical method used (event‐pairing or our new method based on squared‐change parsimony). Simulations show that the new analytical method is generally more powerful to detect evolutionary shifts in developmental timing, and has lower Type I error rate than event‐pairing. It also makes fewer errors in ancestral character value or state assignment than event‐pairing.
Leptin stimulatesXenopuslung development: evolution in a dish
Authors: Torday J.S. , Ihida‐Stansbury Kaori , Rehan Virender K.
Published: February 2009

SUMMARYThe transition from uni‐ to multicellular organisms required metabolic cooperativity through cell‐cell interactions mediated by soluble growth factors. We have empirically demonstrated such an integrating mechanism by which the metabolic hormone leptin stimulates lung development, causing the thinning of the gas exchange surface and the obligate increase in lung surfactant synthesis. All of these processes have occurred both phylogenetically and developmentally during the course of vertebrate lung evolution from fish to man. Here we show the integrating effects of the environmentally sensitive, pleiotropic hormone leptin on the development of theXenopus laevistadpole lung. The process described in this study provides a mechanistically integrated link between the metabolic regulatory hormone leptin and its manifold downstream effects on a wide variety of physiologic structures and functions, including locomotion and respiration, the cornerstones of land vertebrate evolution. It provides physiologic selection pressure at multiple levels to progressively generate Gene Regulatory Networks both within and between organs, from cells to systems. This model provides a cipher for understanding the evolution of complex physiology.
Acute Confusional Migraine May Be a Presenting Feature of CADASIL
Authors: Sathe Swati , DePeralta Edgar , Pastores Gregory , Kolodny Edwin H.
Published: February 2009

Objective.— Characterize the phenomenon of acute confusional migraine (ACM) among Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients and emphasize the possibility of CADASIL in adults with ACM.

Background.— ACM, well described in children, has rarely been reported in adults. Although 30‐60% of CADASIL patients have migraine, acute confusional state during migraine has not been described. We describe 7 patients with ACM that complicated up to 50% of the migraine episodes.

Design/Methods.— Detailed neurologic evaluation was performed in 20 CADASIL patients; International Classification of Headache Disorders 2nd edition criteria were used to diagnose migraine.

Results.— The mean age was 51 years. Fourteen patients reported headache and 11 met the criteria for migraine (mean age of onset 25). Seven patients experienced concomitant confusion, within 3 years of migraine onset. Confusion occurred either abruptly or insidiously, at the onset of aura or headache, lasting for 2‐48 hours, and ending abruptly. These episodes were stereotypic, characterized by disorientation with agitation, and retrograde amnesia for the episodes. Patients reported disorientation to time and place, inability to recognize friends and relatives, difficulty with finding directions home, fear of getting lost, inability to analyze traffic lights or tell time. Patients reliably predicted the episodes and felt the need to seek a safe place for protection. Severity of the episodes progressed, but a striking improvement occurred after the first stroke.

Conclusion.— ACM may be a presenting feature and important clue, enabling CADASIL to be recognized up to a decade or earlier than at present. Therefore, a brain MRI and/or testing for Notch3 mutations should be considered in adult patients with ACM.
Posttraumatic Stress Disorder in Migraine
Authors: Peterlin B. Lee , Tietjen Gretchen E. , Brandes Jan L. , Rubin Susan M. , Drexler Ellen , Lidicker Jeffrey R. , Meng Sarah
Published: February 2009

Objective.— To evaluate the relative frequency of posttraumatic stress disorder (PTSD) in episodic migraine (EM) and chronic daily headache (CDH) sufferers and the impact on headache‐related disability.

Background.— Approximately 8% of the population is estimated to have PTSD. Recent studies suggest a higher frequency of PTSD in headache disorders. The association of PTSD and headache‐related disability has not been examined.

Methods.— A prospective study was conducted at 6 headache centers. PTSD was assessed using the life events checklist and PTSD checklist, civilian version (PCL‐C). We compared data from EM to CDH, and migraine with PTSD to migraine without PTSD. The PHQ‐9 was used to assess depression, and headache impact test (HIT‐6) to assess disability.

Results.— Of 767 participants, 593 fulfilled criteria for EM or CDH and were used in this analysis. The mean age was 42.2 years and 92% were women. The frequency of PTSD was greater in CDH than in EM (30.3% vs 22.4%, P = .043), but not after adjusting for demographics and depression (P = .87). However, participants with major depression and PTSD were more likely to have CDH than EM (24.6% vs 15.79%, P < .002). Disability was greater in migraineurs with PTSD, even after adjustments (65.2 vs 61.7, P = .002).

Conclusion.— The frequency of PTSD in migraineurs, whether episodic or chronic, is higher than the historically reported prevalence of PTSD in the general population. In addition, in the subset of migraineurs with depression, PTSD frequency is greater in CDH sufferers than in episodic migraineurs. Finally, the presence of PTSD is independently associated with greater headache‐related disability in migraineurs.
Economic Burden of Transformed Migraine: Results From the American Migraine Prevalence and Prevention (AMPP) Study
Authors: Munakata Julie , Hazard Elisabeth , Serrano Daniel , Klingman David , Rupnow Marcia F.T. , Tierce Jonothan , Reed Michael , Lipton Richard B.
Published: February 2009

Objective.— To evaluate the impact of incident transformed migraine on health care resource utilization, medication use, and productivity loss. In addition, the study estimates the total direct and indirect costs associated with transformed migraine.

Background.— Emerging evidence indicates that migraine may be a chronic progressive disorder characterized by escalating frequency of headache attacks, often termed transformed migraine. Little is known about the economic impact of transformed migraine.

Methods.— AMPP is a 5‐year, national, longitudinal survey study of headache in the US. The study utilized data from the 2006 follow‐up survey based on an initial sample of 14,544 adults identified as having migraine in either the 2004 screening or 2005 baseline survey. A diagnosis of migraine was assigned based on criteria proposed by the International Classification of Headache Disorders, 2nd Edition. Participants completed self‐administered, validated questionnaires on headache features, frequency, impairment, resource use, medication use, and productivity loss. Direct and indirect headache‐related costs were estimated using unit cost assumptions from the PharMetrics Patient‐Centric database, wholesale acquisition costs (Red Book), and wage data from the US Bureau of Labor Statistics. Those who developed transformed migraine were compared with those who did not develop transformed migraine in the 1‐2 year interval between screening/baseline and follow‐up.

Results.— A total of 7796 (54%) identified migraine cases completed the 2006 follow‐up survey. Of those cases, 359 (4.6%) developed transformed migraine. Participants who developed transformed migraine reported significantly more primary care visits, neurologist or headache specialist visits, pain clinic visits, and emergency room visits compared with participants whose migraine remained episodic. Hospital nights and urgent care visits did not reach statistical significance. Transformed migraine participants reported significantly more time missed at work or school because of headaches and more time where work or school productivity was reduced by >50% in the previous 3 months because of headaches. Average per‐person annual total costs, including direct and indirect costs, were 4.4‐fold greater for those who developed transformed migraine ($7750) compared with those who remained episodic ($1757).

Conclusion.— Transformed migraine exacts a significantly higher economic toll on patients and health care systems compared with other forms of migraine. Our findings support the need to prevent migraine progression and to provide appropriate management and treatment of transformed migraine.
Defining Refractory Migraine: Results of the RHSIS Survey of American Headache Society Members
Authors: Schulman Elliott A. , Lee Peterlin B. , Lake Alvin E. , Lipton Richard B. , Hanlon Alexandra , Siegel Sherry , Levin Morris , Goadsby Peter J. , Markley Herbert G.
Published: February 2009

Objectives.— To gauge consensus regarding a proposed definition for refractory migraine proposed by Refractory Headache Special Interest Section, and where its use would be most appropriate.

Background.— Headache experts have long recognized that a subgroup of headache sufferers remains refractory to treatment. Although different groups have proposed criteria to define refractory migraine, the definition remains controversial. The Refractory Headache Special Interest Section of the American Headache Society developed a definition through a consensus process, assisted by a literature review and initial membership survey.

Design.— A 12‐item questionnaire was distributed at the American Headache Society meeting in 2007 during a platform session and at the Refractory Headache Special Interest Section symposium. The same questionnaire was subsequently sent to all American Headache Society members via e‐mail. A total of 151 responses from AHS members form the basis of this report. The survey instrument was designed using Survey Monkey. Frequencies and percentages of the survey were used to describe survey responses.

Results.— American Headache Society members agreed that a definition for refractory migraine is needed (91%) that it should be added to the International Classification of Headache Disorders‐2 (86%), and that refractory forms of non‐migraine headache disorders should be defined (87%). Responders believed a refractory migraine definition would be of greatest value in selecting patients for clinical drug trials. The current refractory migraine definition requires a diagnosis of migraine, interference with function or quality of life despite modification of lifestyle factors, and adequate trials of acute and preventive medicines with established efficacy. The proposed criteria for the refractory migraine definition require failing 2 preventive medications to meet the threshold for failure. Although 42% of respondents agreed with the working definition of refractory migraine, 43% favored increasing the number to 3 (50%) or 4 (26%) preventive treatment failures. When respondents were asked if they felt that the proposed definition was appropriate to select patients for invasive procedures (patent foramen ovale repair or stimulators) only 44% agreed.

Conclusions.— There is a consensus for a need for a definition for refractory migraine and that it should be added to the International Classification of Headache Disorder‐2. There was also general agreement by the responders that refractory forms of non‐migraine headache disorders should be defined.
D variants at the RhD vestibule in the weak D type 4 and Eurasian D clusters
Authors: Flegel Willy A. , Von Zabern Inge , Doescher Andrea , Wagner Franz F. , Strathmann Klaus P. , Geisen Christof , Palfi Miodrag , Písačka Martin , Poole Joyce , Polin Helene , Gabriel Christian , Avent Neil D.
Published: February 2009

BACKGROUND:One branch of theRHDphylogenetic tree is represented by theweak D type 4cluster of alleles with F223V as the primordial amino acid substitution. F223V as well as a large number of further substitutions causing D variants are located at the extracellular RhD protein vestibule, which represents the entrance to the transmembraneous channel of the RhD protein.

STUDY DESIGN AND METHODS:RHDandRHCEnucleotide sequences were determined from genomic DNA and cDNA. D epitope patterns were established with commercial monoclonal anti‐D panels.

RESULTS:TheRHDallelesDOL‐1andDOL‐2had the two amino acid substitutions M170T (509T>C) and F223V (667T>G) in common.DOL‐2harbored the additional substitution L378V (1132C>G). Both alleles were observed in Africans and are probably evolutionary related.DMIcarried M170I (510G>A), which differed from the DOL‐typical substitution. DFW and DFL harbored the substitutions H166P (497A>C) and Y165C (494A>G). The antigen densities of DOL‐1, DFL, and DFW were only moderately reduced.

CONCLUSION:DOL‐1andDOL‐2belong to theweak D type 4cluster ofRHDalleles. Together withDMI,DFL, andDFWthey represent D variants with amino acid substitutions located at extracellular loops 3 or 4 lining the RhD protein vestibule. These substitutions were of minor influence on antigen density while adjacent substitutions in the transmembraneous section caused weak D antigen expression. All these D variants were partial D and alloanti‐D immunizations have been observed in DOL‐1, DMI, and DFL carriers. The substitution at position 170 causes partial D although located deep in the vestibule.
Prevalence, Clinical Correlates, and Prognosis of Discrete Upper Septal Thickening on Echocardiography: The Framingham Heart Study
Authors: Diaz Tulio , Pencina Michael J. , Benjamin Emelia J. , Aragam Jayashri , Fuller Deborah L. , Pencina Karol M. , Levy Daniel , Vasan Ramachandran S.
Published: February 2009

The upper interventricular septum may be prominent in elderly individuals, a finding referred to as discrete upper septal thickening (DUST). We examined the prevalence, clinical and echocardiographic correlates, and prognostic significance of DUST in a community‐based sample. We evaluated Framingham Study participants who underwent routine echocardiography. In 3562 Framingham Study participants (mean age 58 years, 57% women), DUST was observed in 52 participants. The clinical correlates of DUST were increasing age (odds ratio [OR] per 10 year increment 2.59, 95% confidence intervals [CI] 1.64–4.08) and systolic blood pressure (OR per SD increment 1.55, 95% CI 1.15–2.09). DUST was positively associated with left ventricular (LV) fractional shortening and mitral annular calcification but inversely with LV diastolic dimensions (P < 0.02 for all). On follow‐up (mean 15 years), 732 individuals died (33 with DUST) and 560 experienced a cardiovascular disease (CVD) event (18 with DUST). Adjusting for cardiovascular risk factors, DUST was not associated with CVD or mortality risk (P > 0.30 for both). The follow‐up component of our study suggests that DUST is not independently associated with adverse prognosis.
The Role of Speckle Tracking Strain Imaging in Cardiac Pacing
Authors: Tops Laurens F. , Delgado Victoria , Bax Jeroen J.
Published: February 2009

In recent years, concerns have been raised about possible harmful effects of long‐term right ventricular (RV) apical pacing. These detrimental effects may be related to changes in left ventricular (LV) mechanics during RV apical pacing. As a consequence, alternative RV pacing sites have been proposed, and in selected patients an upgrade from RV to biventricular pacing may be considered. Novel two‐dimensional (2D) speckle tracking strain imaging allows detailed evaluation of LV mechanics, including LV mechanical dyssynchrony, LV strain and LV torsion. In this review, the role of speckle tracking strain imaging in the evaluation of LV function in patients with RV apical pacing will be reviewed. The effects of RV apical pacing on LV mechanical dyssynchrony, LV strain and LV torsion will be discussed. In addition, the role of speckle tracking strain imaging in the selection of the optimal (alternative) RV pacing site and in the selection of patients who may benefit from an upgrade from RV apical pacing to biventricular pacing will be reviewed.
Speckle Tracking in the Evaluation of Left Ventricular Dyssynchrony
Authors: Nesser Hans‐Joachim , Winter Siegmund
Published: February 2009

A number of echocardiographic techniques have been introduced to determine left ventricular dyssynchrony (LVD) and to improve selection of patients for CRT. During the last years tissue Doppler imaging (TDI) has been used as the most preferred technique to quantify LVD, but results with nonresponder rates below 30% have been shown only in small studies based on high experience. Angle of incidence dependency, noise, artifacts, and tethering motion of adjacent segments are the main limitations of TDI influencing selection of patients for CRT. Although strain TDI is not affected by translation or tethering, accurate measurement of regional strain is also limited. Two‐dimensional (2D) strain imaging based on novel speckle tracking echocardiography (STE) is a relatively new tool to define regional myocardial strain and to quantify dyssynchrony based on a more robust technique and avoiding angle of incidence. Current studies are promising to use strain or vector velocity imaging derived from STE for qualitative and quantitative assessment of LVD and follow‐up studies as well. If one compare different types of strain components at present, radial strain imaging seems to be the most promising technique to determine LVD and to predict positive response to CRT. Furthermore, STE offers an insight into rotational mechanics of the dyssynchronous ventricle. Although clinical studies using 2D strain have analyzed LVD related to various conditions, measures are based on a 2D data set. Three‐dimensional strain imaging, based on speckle tracking will probably open a new door to assess patients with heart failure and LVD.
Nitridation of AEAlSi for Production of AEAlSiN3:Eu2+ Nitride Phosphors (AE=Ca, Sr)
Authors: Watanabe Hiromu , Imai Motoharu , Kijima Naoto
Published: February 2009

The nitridation process of Eu‐doped AEAlSi (AE=Ca and/or Sr) was investigated by thermogravimetry–differential thermal analysis to improve the method for synthesis of AEAlSiN3:Eu2+ nitride phosphors. The nitridation reactivity was dependent on alkaline earth elements. For SrxEuyCa1−x−yAlSi with a high Sr content, nitridation proceeded efficiently at 1100°–1150°C, close to the melting point of the intermetallic compounds. As nitridation of Si or Al intermetallics usually proceeds via the diffusion‐controlled surface reaction, sudden rupture of the diffusion barrier, the surface nitride layer, at the melting point could cause a marked change in the reaction rate and dependence on nitrogen partial pressure. The order of reactivity at temperatures close to the melting point agreed with the order of vapor pressure of alkaline earth elements at the melting point. A highly efficient process for large‐scale production of SrxCa1−xAlSiN3:Eu2+ phosphor was developed taking advantage of the characteristic nitridation reaction at the melting point.
Identification of Forensically Informative SNPs in the Domestic Dog Mitochondrial Control Region*
Authors: Webb Kristen M. , Allard Marc W.
Published: February 2009

Abstract:  Dog hair is often found at crime scenes either due to the dog’s involvement in the crime or secondary transfer. As little nuclear DNA is present in shed hair, a 1000 base pair fragment of the mitochondrial control region (mtCR) from 552 dogs was assessed for forensically useful sequence variation. Through pairwise alignment to a standard reference sequence, existing haplotypes were further described and 36 new haplotypes and 24 new single nucleotide polymorphisms were identified. The probability of exclusion was found to be 0.957. Breeds were found to have similar sequences, although not identical. No genetic basis was found for grouping dogs by either purebred or mixed or geographic location within the continental United States. Our research demonstrates that the domestic dog mtCR has not been thoroughly surveyed for sequence variation and that a single database comprised of purebred and mixed breed dogs is sufficient for the continental United States.
Crack Propagation in Teeth: A Comparison of Perimortem and Postmortem Behavior of Dental Materials and Cracks*
Authors: Hughes Cris E. , White Crystal A.
Published: February 2009

Abstract:  This study presents a new method for understanding postmortem heat‐induced crack propagation patterns in teeth. The results demonstrate that patterns of postmortem heat‐induced crack propagation differ from perimortem and antemortem trauma‐induced crack propagation patterns. Dental material of the postmortem tooth undergoes dehydration leading to a shrinking and more brittle dentin material and a weaker dentin‐enamel junction. Dentin intertubule tensile stresses are amplified by the presence of the pulp cavity, and initiates crack propagation from the internal dentin, through the dentin‐enamel junction and lastly the enamel. In contrast, in vivo perimortem and antemortem trauma‐induced crack propagation initiates cracking from the external surface of the enamel toward the dentin‐enamel junction where the majority of the energy of the crack is dissipated, eliminating the crack’s progress into the dentin. These unique patterns of crack propagation can be used to differentiate postmortem taphonomy‐induced damage from antemortem and perimortem trauma in teeth.
Effect of recombinant human bone morphogenetic protein‐7 (rhBMP‐7) on the viability, proliferation and differentiation of osteoblast‐like cells cultured on a chemically modified titanium surface
Authors: Togashi Adriane Y. , Cirano Fabiano R. , Marques Marcia M. , Pustiglioni Francisco E. , Lang Niklaus P. , Lima Luiz A. P. A.
Published: February 2009

Aim: The aim of the present study was to assess the influence of the chemical characteristics and roughness of titanium surfaces on the viability, proliferation and differentiation of osteoblast‐like cells cultured in a medium supplemented with recombinant human bone morphogenetic protein‐7 (rhBMP‐7).

Material and methods: Osteo‐1 cells were grown on titanium disks presenting with the following surfaces: (1) machined, (2) coarse grit‐blasted and acid‐attacked (SLA) and (3) chemically modified SLA (SLAmod) in the absence or presence of 20 ng/ml rhBMP‐7 in culture medium. The viability and number of osteo‐1 cells were evaluated after 24 h. Analyses of total protein content (TP) and alkaline phosphatase (AP) activity at 7, 14 and 21 days, collagen content at 7 and 21 days and mineralized matrix formation at 21 days were performed.

Results: Cell viability (P=0.5516), cell number (P=0.3485), collagen content (P=0.1165) and mineralized matrix formation (P=0.5319) were not affected by the different surface configurations or by the addition of rhBMP‐7 to the medium. Osteo‐1 cells cultured on SLA surfaces showed a significant increase in TP at 21 days. The ALPase/TP ratio (P=0.00001) was affected by treatment and time.

Conclusion: The results suggest that the addition of rhBMP‐7 to the culture medium did not exert any effect on the viability, proliferation or differentiation of osteoblast‐like cells grown on the different surfaces tested. All titanium surfaces analyzed allowed the complete expression of the osteoblast phenotype such as matrix mineralization by osteo‐1 cells.
Influence of etched microgrooves of uniform dimension on in vitro responses of human gingival fibroblasts
Authors: Lee Suk‐Won , Kim Su‐Yeon , Lee Myung‐Hyun , Lee Keun‐Woo , Leesungbok Richard , Oh Namsik
Published: February 2009

Objective: The purpose of this study was to investigate the influence of titanium (Ti) substrata with etched surface microgrooves on in vitro responses of human gingival fibroblasts.

Material and methods: Commercially pure Ti discs with surface microgrooves 15, 30, and 60 μm in width were fabricated using photolithography. Microgrooves 15 μm in widths were designed to be 3.5 μm in depth, whereas microgrooves 30 and 60 μm in width varied between 5 and 10 μm in depth. The entire surface of the microgrooved Ti substrata was further acid etched and used as the five experimental groups in this study (E15/3.5, E30/5, E30/10, E60/5, and E60/10), whereas the smooth and acid‐etched Ti discs were both used as the control (NE0 and E0). Human gingival fibroblasts were cultured on all groups of substrata on successive timelines. Fibroblast adhesion and morphology was analyzed using confocal laser scanning microscopy (CLSM). Cell adhesion and proliferation were analyzed and compared using crystal violet staining and sulforhodamine B protein staining assays, respectively.

Results: In CLSM, the cells in E30/10 and E60/10 were observed to be able to readily descend into and form focal adhesions inside the microgrooves, whereas the cells in E15/3.5 were mostly found on the ridge tops. Cell adhesion was significantly increased in E60/10 compared with that in NE0 or E0 at 4‐h incubation. Cell proliferation was significantly increased in E60/10 and E15/3.5 compared with NE0 or E0 after 72 and 96 h of culture.

Conclusion: This study indicates that Ti substrata with etched microgrooves 60 μm in width and 10 μm in depth significantly enhance human gingival fibroblast adhesion and proliferation.
Life course dental caries determinants and predictors in children aged 12 years: a population‐based birth cohort
Authors: Peres Marco Aurélio , Barros Aluisio J , Peres Karen Glazer , Araújo Cora LP , Menezes Ana MB
Published: February 2009

Abstract – Objective: To investigate the main dental caries life course determinants and predictors of dental caries at age 12.

Methods: This study was nested in a population‐based birth cohort started in 1993 in Pelotas, Brazil. A sample of 359 children was followed‐up. Dental examinations and interviews were performed at 6 and at 12 years old. Dental caries (DMFT) at 12 years old was the outcome. Exploratory variables included socioeconomic and demographic variables at birth, children’s nutritional and development characteristics, primary dental caries, oral health related behaviors and dental service use at age 6 and 12. Poisson regression was used in order to provide relative risk ratio estimates. Attributable risk or etiology fraction and population attributable risk for both main early life variables were calculated. Dental caries prediction (DMFT ≥ 1) at 12 years old was tested using logistic regression analyses.

Results: Children who presented height‐for‐age deficit at 12 months (RR 1.50 CI: 95% = 1.03–2.18), children who showed a DMFT of 1–3 and 4–19 at 6 years (RR = 2.01; CI: 95% = 1.33–3.03, and RR = 2.66; CI: 95% = 1.81–2.53, respectively) and those children aged 12 in the highest tertile of proportion of teeth experiencing gingival bleeding (RR = 1.58; CI: 95% = 1.11–2.24) presented a higher level of dental caries at age 12. Attributable risk for dental caries at age 12 were 79.1% and 74.2% for deficit in height for age at 12 months and for primary dental caries at age 6 years respectively; population attributable risk for dental caries at age 12 were 3.1% for deficit in height for age at 12 months and 64.9% for primary dental caries at age 6. The level of accuracy in predicting dental caries at age 12 by using life course socioeconomic, behavioral and clinical data was modest.

Conclusions: The results of this study support the hypothesis linking social, biological and behavioral exposures and dental caries at 12 years old. In addition, the findings reinforce the lack of accuracy of dental caries predictors therefore limiting the individuals high‐risk approach as a public health strategy.
Vegetation succession in a newly exposed Danube riverbed
Authors: Gergely A. , Hahn I. , Mészáros‐Draskovits R. , Simon T. , Szabó M. , Barabás S.
Published: February 2009

Abstract. This paper describes vegetation development after a severe drop in water level. Diversion of the Danube river in 1992 resulted in a substantial water level reduction and the appearance of new terrestrial habitats in the Szigetköz region, a unique part of the Danube Valley in Hungary. Plant colonization was very rapid in the recently exposed river bed, where the establishment of a new willow thicket zone took only 4 yr. Our results clearly indicate that the elevation/moisture gradient is primarily responsible for the small‐scale vegetation heterogeneity that developed as succession proceeded. Further changes in vegetation patterns will be determined by the position of the water level as a result of water management.
Implications from the Buell‐Small Succession Study for vegetation restoration
Authors: Pickett S.T.A. , Cadenasso M. L. , Bartha S.
Published: February 2009

Abstract. Succession is relevant to restoration because managers have to prevent, enhance or replace natural vegetation dynamics. Features of a permanent plot study of post‐agricultural succession in central New Jersey, USA, illustrate important implications of vegetation dynamics for restoration. In the past, such implications had to be drawn from chronosequences and coarse resolution studies, neither of which exposes the local contingencies relevant to site specific restoration. However, the fine scale and continuous nature of the current study reveal that succession is highly contingent on historical and local spatial heterogeneity. For example, the absence of one generally expected dominant stage, the demise of shrubs without replacement by later successional tree species, and the long and multimodal persistence of individual species suggest that neither the relay floristic or initial floristic models of succession is adequate to guide restoration. At the local scale, volleys of species appear through the succession, and reflect spatial contingencies such as neighboring vegetation and edge relationships, and patchy behavior of different functional groups. The role of introduced species and of plant consumers are additional sources of local contingency. These local and time‐specific behaviors in the vegetation are the patterns that restorationists must understand either to choose appropriate reference states, to prevent unexpected local dynamics, or to design interventions that are appropriate to the specific site of interests.
Secondary succession on sandy old‐fields in Hungary
Authors: Csecserits Anikó , Rédei Tamás
Published: February 2009

Abstract. Development of semi‐natural vegetation has recently been a primary concern of restoration efforts. A primary management question is whether active intervention is required or spontaneous secondary succession could suffice. We studied 54 old‐fields in central Hungary, which differed in time since abandonment but which had similar environmental conditions and management histories. The sites were grouped into four age groups according to the time elapsed since cultivation abandonment: 1–5, 6–10, 11–23 and 24–33 yr. In each old‐field we recorded the species and estimated their abundances. We grouped species in two ways: according to life form (annuals, biennials, perennials, woody plants) and according to coenological behaviour (weeds, sand and steppe generalists, specialists). We analysed the changes in species number and abundance in these categories as a function of site age.

Contrary to other successional studies, the total number of species did not change significantly among the four age groups. A significant change was detected between the first two age groups as to life‐form composition. Species number and abundance of annuals decreased, while the perennials and woody plants increased. As to coenological behaviour, species number changed only in the first two age groups, while abundance changed in the first three. Weeds quickly disappeared and specialists established and spread, while the species number and abundance of generalists did not change significantly. We concluded that the basic shifts in species composition are almost completed within 10 yr. Most of the late successional species colonized and weeds disappeared. We conclude that there was no need for active intervention in this system: the spontaneous secondary succession leads to semi‐natural vegetation.
Spontaneous vegetation succession in human‐disturbed habitats: A pattern across seres
Authors: Prach Karel , Pyšek Petr , Bastl Marek
Published: February 2009

Abstract. Vegetation samples from 15 successional seres in various disturbed habitats in the western part of the Czech Republic were analysed to detect possible trends. For particular seres, data on species cover were available from the onset to 10–76 yr of succession. All seres started on bare ground. Species which attained at least 1% cover in any sere in any year were used as input data for Canonical Correspondence Analysis, assessing the effect of time as the environmental variable, for Detrended Correspondence Analysis and TWINSPAN classification. Two distinct groups ofseres were distinguished: ‘ruderal’, occurring in agricultural, industrial or urban landscapes altered by men, usually on fertile sites; and ‘non‐ruderul’, occurring in less altered, mostly forested landscapes, usually on acid, nutrient‐poor and wetter soils. The former type of succession starts with ruderal annuals, being followed by ruderal perennials. In the latter case non‐ruderal clonal perennials prevail from the onset of succession. The landscape frame is emphasized, beside site environmental conditions, as influencing the type of succession. The character of species attaining dominance in succession, participation of dominant woody plants and the character of late successional stages, i.e. features important from the point of view of potential restoration of human‐disturbed habitats, are discussed.
Vegetation changes following sheep grazing in abandoned mountain meadows
Authors: Krahulec František , Skálová Hana , Herben Tomáš , Hadincová Věra , Wildová Radka , Pecháčková Sylvie
Published: February 2009

Abstract. Sheep grazing was investigated as an alternative to traditional management of meadows in the Krkonoše Mts. Until the second World War these meadows were mown in mid‐summer and grazed by cattle for the rest of the season. Subsequent abandonment of the meadows has resulted in decreasing species richness. Degradation phases of the former communities have been replacing the original species‐rich vegetation. Significant changes were apparent six years after the introduction of sheep grazing. In grazed plots the proportion of dominant herbs (Polygonum bistorta and Hypericum maculatum) decreased and grasses (Deschampsia cespitosa, Festuca rubra, Agrostis capillaris, Anthoxanthum alpinum) increased. The increase in grasses was positively correlated with an increase in several herbs. The proportion of some herbs increased despite being selectively grazed (Adenostyles alliariae, Melandrium rubrum, Veratrum lobelianum). Any losses caused by grazing of mature plants were probably compensated by successful seedling establishment. Cessation of grazing resulted in significant changes in vegetation within three years. The cover of nitrophilous tall herbs and grasses (e.g. Rumex alpestris, Holcus mollis, Deschampsia cespitosa, Geranium sylvaticum) increased in the abandoned plots. In the plots grazed for nine years cover of species‐rich mountain meadow species increased (e.g. fine‐leaved grasses, Campanula bohemica, Potentilla aurea, Viola lutea, Silene vulgaris). The main conservation risk is the expansion of a competitive species with low palatability, Deschampsia cespitosa. This species can be suppressed by a combination of grazing and mowing. In order for grazing to be effective, the number of sheep should be proportional to meadow production. This may be difficult to maintain as production is variable and is impossible to predict at the beginning of a growing season. A large part of the biomass may thus remain intact in some years. Negative effects of grazing may be, at least partly, eliminated by a combination of cutting and grazing.
The role of spontaneous vegetation succession in ecosystem restoration: A perspective
Authors: Prach Karel , Bartha Sándor , Joyce Chris B. , Pyšek Petr , van Diggelen Rudy , Wiegleb Gerhard
Published: February 2009

Abstract. The paper summarizes ideas which were discussed during the ‘Spontaneous Succession in Ecosystem Restoration’ conference and elaborated through further discussion among the authors. It seeks to promote the integration of scientific knowledge on spontaneous vegetation succession into restoration programs. A scheme illustrating how knowledge of spontaneous succession may be applied to restoration is presented, and perspectives and possible future research on using spontaneous vegetation succession in ecosystem restoration are proposed. It is concluded that when implementing spontaneous succession for ecological restoration the following points must be considered: setting clear aims; evaluation of environmental site conditions; deciding whether spontaneous succession is an appropriate way to achieve the aims; prediction of successional development; monitoring of the results. The need for interdisciplinary approaches and communication between scientists, engineers and decision‐makers is emphasized.
Restoring riparian meadows currently dominated by Artemisia using alternative state concepts ‐ the establishment component
Authors: Chambers Jeanne C. , Linnerooth Amy R.
Published: February 2009

Abstract. We evaluated the potential for restoring riparian grass and sedge meadows currently dominated by Artemisia tridentata var. tridentata with an experiment in which we burned sites with low, intermediate, and high water tables, i.e., dry, intermediate, and wet sites. To define the alternative states and thresholds for these ecosystems, we examined burning and water table effects on both abiotic variables and establishment of grasses adapted to relatively high (Poa se‐cunda ssp. juncifolia), intermediate (Leymus triticoides), or low (L. cinereus) water tables. Wet sites had lower soil temperatures and higher soil water contents than dry sites. Burning increased soil temperatures on all sites. Undershrub microsites on control plots had the lowest temperatures, while former undershrub microsites on burn plots had the highest temperatures. Surface soil water was low on burn plots early in the growing season due to desiccation, but higher at deeper depths after active plant growth began. Emergence was generally greater on wet sites, but survival was microsite‐ and species‐specific. Undershrub microsites on control plots facilitated emergence and first‐year survival, but seedlings that survived initially harsh conditions on burn plots had similar numbers alive at the end. In general, favorable environments and establishment of species adapted to mesic conditions indicate that wet sites represent an alternative state of the naturally occurring dry meadow ecosystem type, and can be restored to grass and sedge meadows. Harsh environments and lack of establishment of species adapted to mesic conditions indicate that dry sites have crossed a threshold and may represent a new ecosystem type. Understory vegetation and seed banks on dry sites have been depleted, and restoration will require burning and reseeding with species adapted to more xeric conditions.
Nutrient limitation in boreal plant communities and species influenced by scything
Authors: Øien Dag‐Inge , Moen Asbjørn
Published: February 2009

Abstract. The nutrient status was studied in permanent plots of four plant communities, two rich‐fen communities and two wooded grassland communities, all formerly used for haymaking. The concentrations of N, P and K in plant material of dominant and subdominant species (above‐ and below‐ground) were measured in plots experimentally scythed annually or biennially for two decades, and in plots unscythed for four decades. Three of the communities had an N:P ratio of 14 or less, indicating N‐limitation; the most fertile grassland community had particularly low values for the N:P ratio (6–12), as did a majority of the species, including all tall‐herb species. A species‐rich community of fen‐margin vegetation in the lowest productive rich fen, had an N: P ratio of 17–19 in the above‐ground biomass, which indicates P‐limitation of nutrients. Molinia caerulea and Thalictrum alpinum were found to be the vascular plants with the highest N:P ratio, indicating P‐limitation of nutrients. Calculations of N:K and K:P ratios indicated possible K‐limitation in the rich‐fen communities, especially for Thalictrum alpinum, the species with the highest N:K value. No expected change from N‐ to P‐limited growth was found; in contrast, a reduction in the N:P ratio was found in the annually scythed plots of the rich fens, suggesting that reduced biomass production is mainly a result of disturbance by scything. As expected, a reduction in the concentration of K was detected in the scythed plots.
A chromaticity‐based technique for estimation of above‐ground plant biomass
Authors: Tomasel F.G. , Paruelo J.M. , Abras G. , Ballarín V. , Moler E.
Published: February 2009

Abstract. This paper presents a new and simple technique to derive quantitative estimates of green or dry biomass using colour information from digital pictures. This pixel‐counting technique is based on the association of particular plant material with a representative region on a two‐dimensional colour space, and applies to cases of non‐overlapping canopies. The efficacy of the method is demonstrated using sets of samples obtained from both field and laboratory studies. It is shown that application of the proposed approach results in a highly linear relationship between pixel count and foliar area for both green and non‐green material [r= 0.99 (p < 0.001)]. Analysis of images from a short‐grass steppe shows a high correlation between pixel count and measured values of green biomass [r= 0.95 (p < 0.001)]. The method outlined here allows for a substantial improvement in the speed of sample evaluation to estimate biomass both in the field and in the laboratory. It also provides a non‐destructive alternative to monitor plant cover and biomass in open canopies.
Site quality effects on post‐fire regeneration of Pinus brutia forest on a Greek island
Authors: Spanos Ioannis A. , Radoglou Kalliopi M. , Raftoyannis Yannis
Published: February 2009

Abstract. Natural stands of Pinus brutia were compared to burned areas after a great fire in 1985 on the island of Thasos, North Greece, in relation to site quality effects on the success of natural regeneration and understorey vegetation. The number of seedlings in the natural stands of P. brutia was 1124/ha against 3188/ha in the burned area. In both cases natural regeneration was successful. Under the canopy of P. brutia forests the predominant shrubs were Quercus coccifera and vPhillyrea latifolia. A high percentage (up to 40%) of the total area was covered by these species. In the burned areas, 12 yr after the wildfire of 1985, Cistus incanus and C. salvifolius played a significant role in the survival of P. brutia seedlings. These species had covered the burned area long before the pine seed germination.
Abandonment alters community composition and canopy structure of Swiss calcareous fens
Authors: Diemer Matthias , Oetiker Karin , Billeter Regula
Published: February 2009

Abstract.We compared the plant species composition, productivity and canopy structure of seven mown sites to a chronosequence of 20 abandoned calcareous fens in northeastern Switzerland. Cessation of mowing led to an 18% decline in overall plant species richness and the diversity of most functional groups. Abandonment did not lead to marked increases of above‐ground productivity, but rather selectively favoured certain functional groups. On abandoned fens biomass of grasses increased nearly threefold, at the expense of biomass ofCyperaceaeandJuncaceae, which declined by 30% compared to mown fens, while forb biomass remained unaffected. Litter mass increased more than 15‐fold in fallows, while canopy height increased by 50%. The foliage in abandoned fens was oriented more horizontally and had a lower overall cover. However, these successional changes were never dependent upon the age of the fallow. Furthermore, nearly all traits differed significantly on regional and local spatial scales, suggesting that floristic and (meso‐)climatic differences obscure or override successional trajectories in these species‐rich wetlands.
Spatial analysis of eucalypt dieback at Coranderrk, Australia
Authors: Martin Rachel A.U. , Burgman Mark A. , Minchin Peter R.
Published: February 2009

Abstract. The cause of tree disease in any location is difficult to diagnose because of the multiplicity of potential causes. Spatial analysis provides useful evidence on the significance, scale and shape of patterns for disease diagnosis. This study explores the causes of dieback through spatial analysis of tree health at Coranderrk Reserve, an example of an important conservation reserve on the urban fringe of Melbourne, Victoria. Ca. 200 trees were sampled at two sites and measured for position, diameter and height in each of two different community types. An index of tree health was developed, and each tree was assigned a value of health. Dead trees were categorized based on state of decay. Correlograms using Moran's I found significant spatial structure at both study sites. The study employed a method of analysis that compares the spatial patterns in dead and living trees. When all dead trees were eliminated from the analysis, significant spatial pattern was found only at one site. The spatial structures obtained were compared with those expected from the different possible causes of tree dieback. Some potential explanations were eliminated. The results illustrate how spatial analysis may make useful contributions to disease diagnosis if employed systematically together with other modes of investigation.