bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tripartite biogeographical index: a new tool for quantifying spatio‐temporal differences in distribution patterns
Authors: Schils Tom 
Published: March 2006

AbstractAims  First, to develop an index that quantifies biogeographical patterns based on the basic descriptors of presence/absence distribution patterns (F, frequency; C, connectivity; G, grouping). Second, to test the proposed biogeographical index on a data set of macrophyte communities in the Arabian Sea using distribution data of macro‐algae and seagrasses throughout the Indian Ocean.Location  Arabian Sea (regional macrophyte community data) and the larger Indian Ocean (oceanic distribution data).Methods  The proposed index is derived from the Tulloss tripartite similarity index. The tripartite biogeographical index (TBI = √F × C × G) is calculated for a specific taxon and incorporates several fundamental parameters of presence/absence data in grid cell (block) patterns. TBI accounts for the relative abundance of a taxon, the average grouping of its occurrences, the average of minimal absence intervals between taxon presences and the largest coherent cluster of taxon occurrences, and also incorporates dispersal aspects. The macrophytes from the case study are among the best documented marine organisms in the Indian Ocean. The regional distribution data from the Arabian Sea result from exhaustive species lists from Masirah Island (Oman) and the Socotra Archipelago (Yemen).Results  TBI values fit a linear scale corresponding to the proportional presence and the distributional spread of taxa within a given geographical area. The three functions that constitute TBI can be evaluated separately or in association with TBI, to give detailed information on the important factors that characterize the biogeographical distribution of a taxon (or larger entities consisting of multiple taxa such as communities). The case study on Arabian macrophytes clarifies the use and explanatory power of the index.Main conclusions  The biogeographical descriptors can be combined into an index which accurately quantifies taxon occurrences and distribution types on a single linear scale from rare/scattered to abundant/grouped. Together with its three functions, the index allows for a non‐arbitrary selection of taxa and taxon groupings based on their distribution pattern. The analysis of TBI values for the Arabian macrophyte communities confirms previous biogeographical findings and enables more detailed statistical analyses of the distribution data.
Determinants of regional species richness: an empirical analysis of the number of hawkmoth species (Lepidoptera: Sphingidae) on the Malesian archipelago
Authors: Beck Jan , Kitching Ian J. , Eduard Linsenmair K. 
Published: March 2006

AbstractAims Major patterns and determinants of the species richness of Sphingidae in the Malesian archipelago were investigated, including a distinction of richness patterns between subfamilies and range‐size classes.Location Southeast Asia, Malesia.Methods Using a compilation of specimen‐label data bases, geographic information system (GIS)‐supported estimates of distributional ranges for all Sphingidae species of Southeast Asia were used to assess the species richness of islands. Range maps for all species and checklists for 114 islands can be found athttp://www.sphingidae‐sea.biozentrum.uni‐wuerzburg.de. Potential determinants of the species richness of islands were tested with general linear models.Results The estimated species richness of islands in the region is determined by biogeographical association, seasonality, availability of rain forest and island size. Species–area relationships are linear on a semi‐logarithmic representation, but not on a double‐logarithmic scale. Species richness of all sphingid subfamilies is influenced by biogeography. The presence of large rain‐forest areas affects mainly Smerinthinae, whereas distance from continental Asia is conspicuously irrelevant for this group. Widespread rather than geographically restricted species shape the overall distribution patterns of species richness. The altitudinal range of islands does not significantly affect species‐richness patterns, but its potential effects on geographically restricted species are discussed.Main conclusions As well as being affected by climatic and vegetation parameters, sphingid species richness is strongly influenced by a historical, directional dispersal process from continental Southeast Asia to the Pacific islands. This process did not apply equally to species of different taxonomic groups or range sizes. Widespread species decline in species richness towards the south‐east, whereas geographically restricted species exhibit an inverse pattern of species richness, probably because speciation becomes more important in this group within the more isolated island groups.
Determinants of local abundance in a major radiation of Australian passerines (Aves: Meliphagoidea)
Authors: Symonds Matthew R.E. , Johnson Christopher N. 
Published: March 2006

AbstractAim To identify the factors that contribute to variation in abundance (population density), and to investigate whether habitat breadth and diet breadth predict macroecological patterns in a suborder of passerine birds (Meliphagoidea).Location Australia (including Tasmania).Methods Mean abundance data were collated from site surveys of bird abundance (the Australian Bird Count); range size and latitudinal position data from published distribution maps; and body mass and diet breadth information from published accounts. A diversity index of habitats used (habitat breadth) was calculated from the bird census data. We used bivariate correlation and multiple regression techniques, employing two phylogenetic comparative methods: phylogenetic generalized least squares and independent contrasts.Results Body mass and latitude were the only strong predictors of abundance, with larger‐bodied and lower‐latitude species existing at lower densities. Together, however, body mass and latitude explained only 11.1% of the variation in mean abundance. Range size and habitat breadth were positively correlated, as were diet breadth and body mass. However, neither range size, nor habitat breadth and diet breadth, explained patterns in abundance either directly or indirectly.Main conclusions Levels of abundance (population density) in meliphagoid birds are most closely linked to body mass and latitudinal position, but not range size. As with many other macroecological analyses, we find little evidence for aspects of niche breadth having an effect on patterns of abundance. We hypothesize that evolutionary age may also have a determining effect on why species tend to be rarer (less abundant) in the tropics.
Fire disturbance disrupts co‐occurrence patterns of terrestrial vertebrates in Mediterranean woodlands
Authors: Sarà Maurizio , Bellia Enrico , Milazzo Andrea 
Published: March 2006

AbstractAim This paper uses null model analysis to explore the pattern of species co‐occurrence of terrestrial vertebrate fauna in fire‐prone, mixed evergreen oak woodlands.Location TheErico–Quercion ilicisof the Mediterranean belt (50–800 m a.s.l.) in the Madonie mountain range, a regional park in northern Sicily (37°50′ N, 14°05′ E), Italy.Methods The stratified sampling of vertebrates in a secondary succession of recent burned areas (BA, 1–2 years old), intermediate burned areas (INT, 4–10 years old) and ancient burned areas (CNB, > 50 years old), plus forest fragments left within burned areas (FF, 1–2 years old) permitted the comparison of patterns of species co‐occurrence using a set of separate presence/absence matrices. First, the breeding avifauna derived from standardized point counts was analysed using Stone & Roberts’C‐score, and by a null model algorithm (fixed/equiprobable). Secondly, the analysis was repeated using all vertebrate species recorded in the succession.Results Sixty‐five species were recorded in the 2‐year study period in the four sample treatments. Birds were found to make up the largest component (63%) of the recorded assemblage. The BA treatment had the lowest species richness, followed in order by the small, medium and large FFs, and then by the CNBs. For both analyses (birds and total vertebrates), theC‐scores were quite small and not significantly different from those that could be expected by chance in the BA and INT burned areas; this indicates a random co‐occurrence among vertebrates of those assemblages. Contrariwise, for both analyses in the CNBs, theC‐scores were large and significantly different from the simulated indices, thereby indicating a non‐random co‐occurrence pattern (segregation) of vertebrates in the undisturbed woodlands. In addition,C‐score values for the surviving FFs show a significant aggregation of species.Main conclusions The null model analyses highlighted a new aspect of fire disturbance in Mediterranean woodland ecosystems: the disruption in patterns of co‐occurrence in the terrestrial vertebrate community. Wildfire alters community organization, inducing, for at least 10 years, a random aggregate of species. Communities re‐assemble themselves, showing the occurrence of species segregation at least 50 years after fire.
Biogeographical analysis of the flea beetle genus Chaetocnema in the Afrotropical Region: distribution patterns and areas of endemism
Authors: Biondi Maurizio , D'Alessandro Paola 
Published: March 2006

AbstractAim  The areal distributions of Chaetocnema species in the Afrotropical Region have been analysed with the aims of determining the distribution patterns (chorotypes) and identifying the most important areas of endemism for this flea beetle genus in sub‐Saharan Africa.Location  Data were collected in sub‐Saharan Africa, including Madagascar.Methods  The Afrotropical Region was divided into 103 5° quadrats (operative geographical units, or OGUs). A presence–absence matrix of the Afrotropical Chaetocnema species in the OGUs was analysed by cluster analysis (Baroni Urbani & Buser index and the WPGMA clustering method) to generate distribution pattern data based on similarity of distribution. The most important areas of endemism were identified by parsimony analysis of endemicity.Results  The general distribution of Chaetocnema in the Afrotropical Region was found to be associated with moist environments and montane grasslands. Most species exhibit restricted geographical ranges. Cluster analysis revealed 120 spatial distributions that can be grouped into 13 distinct distribution patterns (chorotypes). The most important areas of endemism for Chaetocnema in sub‐Saharan Africa according to the present parsimony analysis of endemicity are: (1) central and eastern Madagascar [endemicity rate (ER) = 61.1%], (2) Western Cape Province (ER = 36.4%), (3) southern Drakensberg (ER = 26.7%), (4) the Shaba Region (ER = 16.7%), and (5) the North‐Kivu Region (ER = 5.0%).Main conclusions  There are 123 known species of Chaetocnema in the Afrotropical Region, more than in any other zoogeographical region. About 91% of the species are endemic and they generally exhibit a restricted and often very localized geographical range. The remaining 9% of the species are represented by seven species that also inhabit northern Africa and/or the Arabian peninsula (C. bilunulata Demaison, C. ganganensis Bechyné, C. ljuba Bechyné, C. pulla Chapuis, C. tarsalis Wollaston, and C. wollastoni Baly), three species that widely inhabit the Palaearctic Region (C. conducta (Motschulsky), C. schlaeflini (Stierlin), and C. tibialis (Illiger)), and two species that were introduced (C. confinis Crotch, and C. picipes Stephens).
Recent changes in the distribution of a marine gastropod, Patella rustica Linnaeus, 1758, and their relationship to unusual climatic events
Authors: Lima Fernando P. , Queiroz Nuno , Ribeiro Pedro A. , Hawkins Stephen J. , Santos António M. 
Published: March 2006

AbstractAim  Recent colonization of northern Portuguese shores by Patella rustica Linnaeus, 1758, led to the bridging of a historical gap in the distribution known since the 1900s. Long‐term oceanographic data collected over the last half‐century were examined in order to detect possible mechanisms for the observed change in its distribution.Location  This study was carried out along the entire Portuguese coastline, from 41°50′ to 37°06′ N. Time‐series of hydrographical variables (sea surface temperature and salinity) were derived for the Atlantic coast of the Iberian Peninsula.Methods  Abundance and size‐frequency distributions of the newly observed limpet populations were compared with those from well‐established populations in southern Portugal. Anomalies were computed for sea surface temperature (1950–2000) and sea surface salinity (1958–2001) data, covering the whole Atlantic coast of the Iberian Peninsula. An upwelling index (1967–2005) was derived for a single location within the distributional gap of P. rustica. Split moving window analysis was performed to detect significant discontinuities in hydrographical data sets.Results  Patella rustica has gradually been expanding in northern Iberia, and in the late 1990s the historical gap in distribution in northern Portugal was bridged. Size‐frequency distribution differed between historical and recent populations, the latter lacking small‐sized individuals. At the same time, several anomalous oceanographic events occurred off the Portuguese coast and were probably related to this expansion.Main conclusions  Although sea surface temperature might be a major determinant of the reproductive success of P. rustica and hence its dispersal potential, it is more likely that a coincidence of several factors occurring in the late 1990s provided exceptional conditions that allowed the geographical expansion of this species.
Re‐approaching the small island effect
Authors: Triantis K. A. , Vardinoyannis K. , Tsolaki E. P. , Botsaris I. , Lika K. , Mylonas M. 
Published: March 2006

AbstractAim  To propose a new approach to the small island effect (SIE) and a simple mathematical procedure for the estimation of its upper limit. The main feature of the SIE is that below an upper size threshold an increase of species number with increase of area in small islands is not observed.Location  Species richness patterns from different taxa and insular systems are analysed.Methods  Sixteen different data sets from 12 studies are analysed. Path analysis was used for the estimation of the upper limit of the SIE. We studied each data set in order to detect whether there was a certain island size under which the direct effects of area were eliminated. This detection was carried out through the sequential exclusion of islands from the largest to the smallest. For the cases where an SIE was detected, a log‐log plot of species number against area is presented. The relationships between habitat diversity, species number and area are studied within the limits of the SIE. In previous studies only area was used for the detection of the SIE, whereas we also encompass habitat diversity, a parameter with well documented influence on species richness, especially at small scales.Results  An SIE was detected in six out of the 16 studied cases. The upper limit of the SIE varies, depending on the characteristics of the taxon and the archipelago under study. In general, the values of the upper limit of the SIE calculated according to the approach undertaken in our study differ from the values calculated in previous studies.Main conclusions  Although the classical species–area models have been used to estimate the upper limit of the SIE, we propose that the detection of this phenomenon should be undertaken independently from the species–area relationship, so that the net effects of area are calculated excluding the surrogate action of area on other variables, such as environmental heterogeneity. The SIE appears when and where area ceases to influence species richness directly. There are two distinct SIE patterns: (1) the classical SIE where both the direct and indirect effects of area are eliminated and (2) the cryptic SIE where area affects species richness indirectly. Our approach offers the opportunity of studying the different factors influencing biodiversity on small scales more accurately. The SIE cannot be considered a general pattern with fixed behaviour that can be described by the same model for different island groups and taxa. The SIE should be recognized as a genuine but idiosyncratic phenomenon.
PC1/3 and PC2 Gene Expression and Post‐Translational Endoproteolytic Pro‐Opiomelanocortin Processing is Regulated by Photoperiod in the Seasonal Siberian Hamster (Phodopus sungorus)
Authors: Helwig M. , Khorooshi R. M. H. , Tups A. , Barrett P. , Archer Z. A. , Exner C. , Rozman J. , Braulke L. J. , Mercer J. G. , Klingenspor M. 
Published: March 2006

AbstractA remarkable feature of the seasonal adaptation displayed by the Siberian hamster (Phodopus sungorus) is the ability to decrease food intake and body weight (by up to 40%) in response to shortening photoperiod. The regulating neuroendocrine systems involved in this adaptation and their neuroanatomical and molecular bases are poorly understood. We investigated the effect of photoperiod on the expression of prohormone convertases 1 (PC1/3) and 2 (PC2) and the endoproteolytic processing of the neuropeptide precursor pro‐opiomelanocortin (POMC) within key energy balance regulating centres of the hypothalamus. We compared mRNA levels and protein distribution of PC1/3, PC2, POMC, adrenocorticotrophic hormone (ACTH), α‐melanocyte‐stimulating hormone (MSH), β‐endorphin and orexin‐A in selected hypothalamic areas of long day (LD, 16 : 8 h light : dark), short day (SD, 8 : 16 h light : dark) and natural‐day (ND, photoperiod depending on time of the year) acclimated Siberian hamsters. The gene expression of PC2 was significantly higher within the arcuate nucleus (ARC, P < 0.01) in SD and in ND (versus LD), and is reflected in the day length profile between October and April in the latter. PC1/3 gene expression in the ARC and lateral hypothalamus was higher in ND but not in SD compared to the respective LD controls. The immunoreactivity of PC1/3 cleaved neuropeptide ACTH in the ARC and PC1/3‐colocalised orexin‐A in the latyeral hypothalamus were not affected by photoperiod changes. However, increased levels of PC2 mRNA and protein were associated with higher abundance of the mature neuropeptides α‐MSH and β‐endorphin (P < 0.01) in SD. This study provides a possible explanation for previous paradoxical findings showing lower food intake in SD associated with decreased POMC mRNA levels. Our results suggest that a major part of neuroendocrine body weight control in seasonal adaptation may be effected by post‐translational processing mediated by the prohormone convertases PC1/3 and PC2, in addition to regulation of gene expression of neuropeptide precursors.
Characteristics and outcome of unplanned extubation in ventilated preterm and term newborns on a neonatal intensive care unit
Authors: VELDMAN ALEX , TRAUTSCHOLD TINA , WEIß KATJA , FISCHER DORIS , BAUER KARL 
Published: March 2006

SummaryBackground : Unplanned extubation events (UEE) are a serious hazard to patient safety, especially on a neonatal intensive care unit (NICU), where reestablishing a secure airway can be difficult. The following study was undertaken to analyze characteristics of UEE and develop prevention strategies.Methods : A retrospective cohort study on a level III single center NICU was undertaken. Patient records of a 12‐month period from December 2003 to December 2004 were analyzed using a standardized evaluation form. Fischer's exact t‐test and the Mann–Whitney U‐Ranked Sum test were used for statistical analysis.Results : One hundred and four neonates with a total ventilation time of 14 495 h were included in this study. Of these patients 12 UEE were observed (1 UEE/1208 h of ventilation time). Neither median birth weight [1445 g (range 460–4650) vs 1755 g (range 460–3570 g)] nor median gestational age [31.5 weeks (range 25.6–39.6 weeks) vs 32.7 weeks (range 23.9–41.5 weeks)] differed significantly between neonates with UEE compared with the total group. When the UEE occurred, the neonates were cared for by experienced nursing staff with a median of 10 years nursing experience. The workload for the individual nurse was high: during shifts when UEE happened, each nurse had to take care of 3.85 patients (range 1.8–5 patients). This workload was higher than the average of 3 (range 1.6–6) patients/nurse during the study period. The most frequently reported reason for UEE was difficult fixation of the tracheal tube (TT) (four patients), followed by handling of the infant by nursing staff or physiotherapy (two patients) or an active infant in whom dislocation of the TT occurred without external manipulations (three patients). In three instances, the reason for the UEE was not documented.Of the 12 UEE observed in 10 patients, three required immediate reintubation, five were managed with nasal continuous positive airway pressure and four did not require further respiratory support. Of those who required support, FiO2 increased by 14% over baseline compared with the FiO2 prior to UEE.Conclusions : Inadequate TT fixation could be identified as the main contributor to UEE and should be targeted in prevention strategies. The reintubation rate after UEE was only 25%. Overall, UEE did not result in an adverse outcome in terms of mortality. Length of stay on NICU was significantly longer in UEE patients.
Unusual complication during pediatric thoracoscopy
Authors: MUKHTAR AHMED M. , DESSOUKY NABIL M. 
Published: March 2006

SummaryA small infant with congenital cystic adenomatoid was scheduled for thoracoscopic resection of the lung cyst. During carbon dioxide insufflation, there was a sharp rise of endtidal carbon dioxide which was followed by marked hypoxemia and bradycardia due to occlusion of the tracheal tube with blood. The plan changed to open thoracotomy and total pneumonectomy. Despite several reports, which addressed successful thoracoscopic cystic lung resection, its safety remain to be determined.
Charge density alterations in human hair fibers: an investigation using electrostatic force microscopy
Authors: Longo V. M. , Monteiro V. F. , Pinheiro A. S. , Terci D. , Vasconcelos J. S. , Paskocimas C. A. , Leite E. R. , Longo E. , Varela J. A 
Published: March 2006

SynopsisA new method for high‐resolution analyses of hair surface charge density under ambient conditions is presented in this paper. Electrostatic force microscopy (EFM) is used here to analyze changes in surface charge density in virgin hair, bleached hair, and hair treated with a cationic polymer. The atomic force microscopy technique is used concomitantly to analyze morphological changes in hair roughness and thickness. The EFM images depict exactly how the polymer is distributed on the surface of the hair fiber. The EFM's powerful analytical tools enabled us to evaluate the varying degrees of interaction between the hair fiber surface charge density and the cationic polymer. The surface charge density and the polymer's distribution in the hair fibers are presented in the light of EFM measurements.