bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deconstructing myths on large gulls and their impact on threatened sympatric waterbirds
Authors: Oro D. , Martínez‐Abraín A. 
Published: November 2006

AbstractOwing to increasing population trends and facultative predatory habits, large gulls have been identified as significant agents of change in the alteration of many ecological communities. Often, they are perceived as negatively impacting the population trends of most sympatric waterbirds. Consequently, culling programs have been implemented to remove adults, chicks and eggs intensively. Here, we review the interactions recorded in the literature between the yellow‐legged gullLarus michahellisand 10 sympatric waterbirds in the Mediterranean region, all threatened and classified as species of conservation concern. We also used 177 long‐term population trends derived from previous studies to study the population dynamics of these species and the culling effort performed. We show that gulls negatively affected survival, fecundity, foraging ecology and nesting habitat availability for many species. However, the annual population growth rates of most sympatric waterbirds showed positive values, even at sites where culling has yet to be initiated and local yellow‐legged gull populations are large and increasing. Our results suggest clearly that population increase has not been exclusive of yellow‐legged gulls, especially at the regional level. Yet, growth rates of both yellow‐legged gulls and sympatric waterbirds were positively associated. Strikingly, the population extinction rate was similar between colonies of yellow‐legged gulls and those of sympatric species. Thus, evidence exists to state that the success of gull control programs is relatively low in the long term. We recommend that conservation agencies heed several basic principles of population and community ecology before initiating control, for instance that (1) yellow‐legged gulls have bred historically with other bird species and have likely developed defensive mechanisms against this predator and (2) populations of large gulls are regulated by density‐dependent mechanisms in both space and time. Incoming European environmental policies on fishing discards and rubbish management should control more naturally and efficiently the density of large gulls and the composition of seabird communities in the long term.
A Novel Genetic Study of Chinese Families with Autosomal Recessive Retinitis Pigmentosa
Authors: Abd El‐Aziz M. M. , El‐Ashry M. F. , Chan W. M. , Chong K. L. , Barragan I. , Antiñolo G. , Pang C. P. , Bhattacharya S. S. 
Published: November 2006

SummaryAutosomal recessive retinitis pigmentosa (arRP) is the commonest form of RP worldwide. To date 22 loci have been implicated in the pathogenesis of this disease; however none of these loci independently account for a significant proportion of recessive RP. Linkage studies of arRP in consanguineous families have been mainly based on homozygosity mapping, but this strategy cannot be applied in the case of non‐consanguineous families. Therefore, we implemented a systematic approach for identifying the disease locus in three non‐consanguineous Chinese families with arRP. Initially, linkage analysis using SNPs/microsatellite markers or mutation screening of known arRP genes excluded all loci/genes except RP25 on chromosome 6. Subsequently a whole genome scan for the three families using the 10K GeneChip Mapping Array was performed, in order to identify the possible disease locus. To the best of our knowledge this is the first report on the utilisation of the 10K GeneChip to study linkage in non‐consanguineous Chinese arRP. This analysis indicates that the studied families are probably linked to the RP25 locus, a well defined arRP locus in other populations. The identification of another ethnic group linked to RP25 is highly suggestive that this represents a major locus for arRP.
Neurotrophin and Trk neurotrophin receptors in the inner ear of Salmo salar and Salmo trutta
Authors: Catania S. , Germanà A. , Cabo R. , Ochoa‐Erena F. J. , Guerrera M. C. , Hannestad J. , Represa J. , Vega J. A. 
Published: November 2006

AbstractNeurotrophins (NTs) and their signal transducing Trk receptors play a critical role in the development and maintenance of specific neuronal populations in the nervous system of higher vertebrates. They are responsible for the innervation of the inner ear cochlear and vestibular sensory epithelia. Neurotrophins and Trks are also present in teleosts but their distribution in the inner ear is unknown. Thus, in the present study, we used Western‐blot analysis and immunohistochemistry to investigate the expression and cell localization of both NTs and Trk receptors in the inner ear of alevins of Salmo salar and Salmo trutta. Western‐blot analysis revealed the occurrence of brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT‐3), but not nerve growth factor (NGF), as well as all three Trk receptors, i.e. TrkA, TrkB and TrkC, the estimated molecular weights of which were similar to those expected for mammals. Specific immunoreactivity for neurotrophins was detected mainly in the sensory epithelia. In particular, BDNF immunoreactivity was found in the maculae of the utricle and saccule, whereas NT‐3 immunoreactivity was present in the sensory epithelium of the cristae ampullaris. As a rule the sensory epithelia of the inner ear lacked immunoreactivity for Trks, thus excluding possible mechanisms of autocrinia and/or paracrinia. By contrast, overlapping subpopulations of neurons in the statoacoustic ganglion expressed TrkA (about 15%), TrkB (about 65%) and TrkC (about 45%). The present results demonstrate that, as in mammals and birds, the inner ear of teleosts expresses the components of the neurotrophin–Trk system, but their roles remain to be elucidated.
Recent geography determines the distribution of some flying Hymenoptera in the Tuscan Archipelago
Authors: Dapporto L. , Wolf H. , Strumia F. 
Published: November 2006

AbstractThe aim of this paper is to examine whether current and/or Pleistocene geography affects the pattern of species richness and composition in two families of flying Hymenoptera in the Tuscan Archipelago (Italy). Faunistic data were obtained from the literature and from our own surveys. We used the Spearman rank correlation test to assess the influence on the richness of present‐day and Pleistocene island area and isolation. Moreover, we searched for patterns of similarity among the six examined islands of Tuscan Archipelago, with the adjacent Tuscan mainland and Sardinia and Corsica islands by cluster analysis (UPGMA) and by parsimony analysis of endemicity (PAE). Moreover, we verified whether the percentage of typical species of Tuscany and Sardo‐Corsican area is related to the recent and/or palaeogeographical distances of the islands from the two main fauna source pools. Isolation is the best predictor for species richness while Pleistocene area and Pleistocene isolation do not show any significant correlation. Cluster analysis and PAE show a biogeographic pattern where generally Capraia and Montecristo group together with Corsica, while Elba, Giglio, and Pianosa group with Tuscan mainland. Recent geography seems to also affect fauna compositions. Indeed the incidence of Tuscan and Sardo‐Corsican species is related to the present‐day island distance to Tuscany and Corsica. In conclusion, we strongly suggest that colonization of these islands acted by dispersal from Tuscany and Corsica, using Elba island as a stepping stone.
Foraging modes as suites of coadapted movement traits
Authors: Cooper W. E. 
Published: November 2006

AbstractThe nature and evolutionary bases of foraging modes remain uncertain despite intensive study. Whether species can be assigned to one of two foraging modes, ambush and active foraging, or to multiple modes, and whether modes exist or are extremes on continua of movements variables have been highly controversial. Bimodality of avian movements per minute (MPM) was claimed to support discreteness of modes, but lizards exhibit extensive unimodal variation. I present data for 58 lizard species on average speed (AS), speed while moving (MS), MPM and per cent time moving. Correlated evolution has occurred between the frequency, duration and speed of foraging movements, suggesting that these traits represent a coadapted suite of foraging movements. Cluster analysis using AS, MPM and per cent time moving assigned species to clusters isomorphic with traditional ambush and active foraging. Large empty regions in foraging space suggest that foraging modes represent adaptive peaks of suites of coevolved traits. All variables differed across clades and modes. Variation within taxa and modes suggests that historical and ecological factors determine modes. When MS replaces AS, four species change from ambush to the active cluster. Foraging modes are not fixed, discrete traits because substantial quantitative variation occurs within modes. All single movement variables are lognormally distributed, indicating that bimodality of single variables is not required for the existence of distinct foraging modes. As data on new taxa accumulate, gaps between clusters may be reduced and/or new modes identified. Currently, the two‐mode paradigm remains appealing due to its broad explanatory power and simplicity.
Niche overlap and resource partitioning between two sympatric fox species in southern Brazil
Authors: Vieira E. M. , Port D. 
Published: November 2006

AbstractMechanisms that favour the co‐occurrence of morphologically and ecologically similar species in South America are potentially relevant, because two or more species often occur in sympatry. In the present study, we investigated possible mechanisms of resource partitioning between two sympatric species of foxes, the crab‐eating foxCerdocyon thousand the pampas foxPseudalopex gymnocercus, in the National Park of Aparados da Serra in southern Brazil (29°10′S, 50°05′W). We considered three main niche dimensions – habitat, diet and time – and evaluated the overlap between the two species in these dimensions. We conducted the study from June 2000 to October 2001 in an area composed of open grasslands andAraucariaforests. We studied the foxes by using a combination of scat analysis and direct observation. A comparison of their diet indicated that it was very similar for both species in all seasons (Pianka's indexes ranging from 0.920 to 0.957). The most common food item for both species of foxes was rodents, followed by coleopterans, birds and plant remains (seeds and fruits). As expected by the niche‐complementarity hypothesis, we detected differences along other niche axes.Pseudalopex gymnocercusseemed to occur only in open areas, including grasslands and dirt roads, whereasC. thouswas more generalist in habitat use, occurring both inside and at the edge of forests. However, both fox species were common in grassland habitats, where they might compete for resources. The differences were more marked for activity time, with the crab‐eating fox being significantly more nocturnal (circular mean of time of sighting=23:39 h,se=56 min) than the pampas fox (circular mean=19:56 h,se=64 min; Watson'sF=6.06,P=0.02). We suggest that the largerC.thouscould be limiting the activity ofP.gymnocercusby interference competition.
Demography and environmental stochasticity: empirical estimates of survival in three grassland rodents
Authors: Reed A. W. , Slade N. A. 
Published: November 2006

AbstractEnvironmental stochasticity in vital rates influences the dynamics of structured populations. Stochastic models of population dynamics often assume that vital rates vary independently, an assumption that may be violated in many populations. We estimated the survival of three species of grassland rodents – deer mouse Peromyscus maniculatus, white‐footed mouse Peromyscus leucopus and western harvest mouse Reithrodontomys megalotis– using a long‐term dataset. We used these data to assess the level of cross correlation and autocorrelation in stage‐specific survival rates and the correlation between survival and selected environmental variables. We found little evidence of correlation among survival estimates in any species or correlation between survival and environmental variables. In contrast to other species in the region, our analyses suggest that survival rates in deer mice, white‐footed mice and western harvest mice vary independently throughout the year.
Reproduction in the short‐nosed fruit bat in relation to environmental factors
Authors: Bumrungsri S. , Bumrungsri W. , Racey P. A. 
Published: November 2006

AbstractThe reproductive pattern of the short‐nosed fruit bat Cynopterus brachyotis in a tropical dry evergreen rainforest in Thailand (13°N) is characterized by seasonal bimodal polyoestry with postpartum oestrus. The first lactation period occurred in March–April, but the timing of the second varied between years: September–October in 1998 and July–August in 1999. Females may experience reproductive delays after the second parturition. Females attained sexual maturity at 6–7 months of age and gave birth for the first time at about 11–12 months, and are able to produce two young a year. Females born in April gave birth as early as March the following year. Those born in August–September first gave birth in July–August the following year. Males attained sexual maturity when they were a year old. Testis size was significantly positively correlated with photoperiod. The body weight of mature males varied cyclically, was higher during breeding periods and was significantly correlated with testis size. The first parturition coincided with the onset of the annual rains and the second occurred in the middle of the rainy season. Both lactation and weaning periods correspond with high food availability. A significantly higher percentage of reproductive females, earlier parturition, greater synchrony of lactation, higher body mass of lactating females, more abundant, larger and heavier juveniles, and heavier mature males were recorded in 1999 compared with 1998. The El Niño Southern Oscillation resulted in a prolonged and severe drought early in 1998, and induced mast fruiting in 1999 that led to higher reproductive success. Photoperiod may regulate the reproductive rhythm in male C. brachyotis, although experimental studies are required to verify this.
An ecomorphological analysis of extant small carnivorans
Authors: Friscia A. R. , Van Valkenburgh B. , Biknevicius A. R. 
Published: November 2006

AbstractAn ecomorphological study of extant small carnivorans demonstrates that dietary groups can be distinguished using quantitative morphological characters. Small (<10 kg) modern carnivorans were divided into three dietary classes: carnivores, insectivores and omnivores/hard‐object feeders. Statistical analyses revealed differences between these classes including longer carnassial blades in carnivorans, as opposed to larger molar grinding areas, larger post‐canine dentitions, and wider fourth premolars in omnivores/hard‐object feeders. Insectivores are not consistently distinguished from other dietary types, although they do tend to have weaker dentaries and shorter temporalis muscle moment arms. These trends can be used to help interpret morphologies of taxa of uncertain ecologies, including fossil taxa.
Recovery of a rodent community in an agro‐ecosystem after flooding
Authors: Zhang M. , Wang K. , Wang Y. , Guo C. , Li B. , Huang H. 
Published: November 2006

AbstractThe Dongting Lake region is one of the areas prone to flood disaster in China. Despite the frequent occurrence of flooding in this area, few studies have analysed its effects on rodent communities, especially their recovery after withdrawal of floodwaters. We carried out a study of rodent recovery after flooding of the Dongting Lake region in 1998. Rodent population monitoring in the flooded countryside of the Dongting Lake region was conducted during 1998–2001. The census was conducted in Anzao polder of Anxian County in Hunan Province, where the dike burst in 1998 and thousands of hectares of farmland were flooded from July to October. The results indicate that flood disaster could provide important changes in rodent community structure. Firstly, species abundance in the post‐flood area became less than in the normal area. Striped field mice Apodemus agrarius colonized the flooded area in farmland until March 2000, and Norway rats Rattus norvegicus and house mice Mus musculus occurred in July and December 2000, respectively. The degree of the effect on the rodent community in residential premises is less than that in farmland. However, the rodent community in the flooded area could recover and become similar to the normal community. The recovery of rodent species composition was faster in residential premises than in farmland after flooding. Secondly, there was a similar tendency of the dominant concentration indices between post‐flood and normal areas. Thirdly, inundation for a long period could reduce the species diversity of the rodent community in farmland. The significant difference in abundance was continued to 2000 in post‐flooded farmland; however, the influence on the rodent community in residential premises was less and their diversity indices did not differ in 1999. Similarity indices indicated that variation between post‐flood and normal areas had been gradually becoming low from 1999 to 2001. Finally, the monitoring data showed that rodent populations in the flooded area were less than those in the normal area in the first step after withdrawal of floodwaters. However, the rodent population increased rapidly in the flooded area, and became greater than that in the unflooded area in half a year. The population in the flooded area also increased faster than that in unflooded neighbouring area after the application of rodenticide. Another phenomenon was that the population density of rodents could reach levels greater than the normal area, and may continue for more than 2 years. Flood disasters could reduce population densities and species abundance, species diversity and evenness, while increasing dominant concentration indices of the rodent community. However, after 3 years, the rodent community structure became similar to that in the non‐flooded area, except for high density. The recovery of rodent communities in residential premises was faster than that in farmland for a lesser degree of flooding.
Oral administration of a potent and selective non‐peptidic BACE‐1 inhibitor decreases β‐cleavage of amyloid precursor protein and amyloid‐β production in vivo
Authors: Hussain Ishrut , Hawkins Julie , Harrison David , Hille Christopher , Wayne Gareth , Cutler Leanne , Buck Tania , Walter Daryl , Demont Emmanuel , Howes Colin , Naylor Alan , Jeffrey Philip , Gonzalez Maria I. , Dingwall Colin , Michel Anton , Redshaw Sally , Davis John B. 
Published: November 2006

AbstractGeneration and deposition of the amyloid β (Aβ) peptide following proteolytic processing of the amyloid precursor protein (APP) by BACE‐1 and γ‐secretase is central to the aetiology of Alzheimer's disease. Consequently, inhibition of BACE‐1, a rate‐limiting enzyme in the production of Aβ, is an attractive therapeutic approach for the treatment of Alzheimer's disease. We have designed a selective non‐peptidic BACE‐1 inhibitor, GSK188909, that potently inhibits β‐cleavage of APP and reduces levels of secreted and intracellular Aβ in SHSY5Y cells expressing APP. In addition, we demonstrate that this compound can effectively lower brain Aβin vivo. In APP transgenic mice, acute oral administration of GSK188909 in the presence of a p‐glycoprotein inhibitor to markedly enhance the exposure of GSK188909 in the brain decreases β‐cleavage of APP and results in a significant reduction in the level of Aβ40 and Aβ42 in the brain. Encouragingly, subchronic dosing of GSK188909 in the absence of a p‐glycoprotein inhibitor also lowers brain Aβ. This pivotal first report of central Aβ lowering, following oral administration of a BACE‐1 inhibitor, supports the development of BACE‐1 inhibitors for the treatment of Alzheimer's disease.
cAMP/protein kinase A signalling pathway protects against neuronal apoptosis and is associated with modulation of Kv2.1 in cerebellar granule cells
Authors: Jiao Song , Liu Zheng , Ren Wen‐Hua , Ding Yu , Zhang Yu‐Qiu , Zhang Zhi‐Hong , Mei Yan‐Ai 
Published: November 2006

AbstractPreviously, we have reported that apoptosis of cerebellar granular neurons induced by incubation in 5 mm K+ and serum‐free medium (LK‐S) was associated with an increase in the delayed rectifier K+ current (IK). Here, we show that IK associated with apoptotic neurons is mainly encoded by a Kv2.1 subunit. Silencing Kv2.1 expression by small interfering RNA reduces IK and increases neuron viability. Forskolin is able to decrease the IK amplitude recording from neurons of both the LK‐S and control group, and prevents apoptosis of granule cells that are induced by LK‐S. Dibutyryl cAMP mimicks the effect of forskolin on the modulation of IK and, accordingly, the inhibitor of protein kinase A, H‐89, aborts the neuron‐protective effect induced by forskolin. Whereas the expression of Kv2.1 was silenced by Kv2.1 small interfering RNA, the inhibition of forskolin on the current amplitude was significantly reduced. Quantitative RT‐PCR and whole‐cell recording revealed that the expression of Kv2.1 was elevated in the apoptotic neurons, and forskolin significantly depressed the expression of Kv2.1. We conclude that the protection against apoptosis via the protein kinase A pathway is associated with a double modulation on IK channel properties and its expression of α‐subunit that is mainly encoded by the Kv2.1 gene.
Green tea polyphenol (–)‐epigallocatechin‐3‐gallate promotes the rapid protein kinase C‐ and proteasome‐mediated degradation of Bad: implications for neuroprotection
Authors: Kalfon Limor , Youdim Moussa B. H. , Mandel Silvia A. 
Published: November 2006

AbstractThe aim of the present study was to gain a deeper insight into the cell signaling pathways involved in the neuroprotection/neurorescue activity of the major green tea polyphenol (–)‐epigallocatechin‐3‐gallate (EGCG). EGCG (1 μm) caused an immediate (30 min) down‐regulation (∼40%) of Bad protein levels, and a more pronounced reduction after 24 h (55%) in the human neuroblastoma cell line SH‐SY5Y. Co‐treatment with EGCG and the protein synthesis inhibitor cycloheximide prominently shortened Bad half‐life, with as little as 30% of the Bad protein content remaining after 2 h, suggesting an effect of EGCG on Bad protein degradation. Accordingly, the proteasome inhibitors MG‐132 and lactacystin damped Bad down‐regulation by EGCG. The general protein kinase C (PKC) inhibitor GF109203X, or the down‐regulation of conventional and novel PKC isoforms, abolished EGCG‐induced Bad decline. However, no inhibition was seen with the cell‐permeable myristoylated pseudosubstrate inhibitor of the atypical PKCζ isoform. The enforced expression of Bad for up to 72 h rendered the cells more susceptible to serum deprivation‐induced cell death, whereas EGCG treatment significantly improved cell viability (up to 1.6‐fold). The present study reveals a novel pathway in the neuroprotective mechanism of the action of EGCG, which involves a rapid PKC‐mediated degradation of Bad by the proteasome.