bluuebunny/crossref_metadata_2025 huggingface dataset:
Cholesterol‐lowering effects of rosuvastatin compared with atorvastatin in patients with type 2 diabetes – CORALL study
Authors: WOLFFENBUTTEL B. H. R. , FRANKEN A. A. M. , VINCENT H. H. ,   THE DUTCH CORALL STUDY GROUP
Published: May 2005

Objectives.  To compare the efficacy of the newest cholesterol‐lowering drug, rosuvastatin (RSV) with atorvastatin (ATV) in subjects with type 2 diabetes.

Design.  A 24‐week, open‐label, randomized, parallel‐group, phase IIIb, multicentre study.

Setting.  Diabetes outpatient clinics of 26 hospitals in the Netherlands.

Subjects.  A total of 263 patients with type 2 diabetes treated with oral agents or insulin, age (mean ± SD) 60 ± 10 years, body mass index (BMI) 31.4 ± 6.1 kg m−2, 46% males.

Intervention.  After a 6‐week dietary lead‐in period, patients were randomized to RSV (n = 131) or ATV (n = 132) treatment in a dose escalation scheme (RSV: 10, 20 and 40 mg or ATV: 20, 40 and 80 mg for 6 weeks each sequentially).

Main outcome measures.  Primary outcome was the change in apolipoprotein B (apoB) and apoB/apolipoprotein A1 (apoA1) ratio, which has been suggested a better predictor for cardiovascular events than total (TC) or low‐density lipoprotein cholesterol (LDL‐C). Secondary outcomes were the changes in other lipid parameters.

Results.  Baseline LDL‐C in the RSV and ATV groups was 4.23 ± 0.98 mmol L−1 and 4.43 ±0.99 mmol L−1, whilst apoB/apoA1 was 0.86 ±0.22 and 0.92 ± 0.35, respectively. A greater reduction in apoB/apoA1 was seen with RSV (−34.9%, −39.2% and −40.5%) than with ATV (−32.4%, −34.7% and −35.8%, P < 0.05 at weeks 12 and 18). Significantly greater reductions in LDL‐C were also seen with RSV (−45.9%, −50.6% and −53.6%) than with ATV (−41.3%, −45.6% and −47.8%, all P < 0.05). The American Diabetes Association (ADA) LDL‐C goal of <2.6 mmol L−1 was reached by 82%, 84% and 92% of patients with RSV and 74%, 79% and 81% with ATV. Triglyceride reductions ranged from 16 to 24% and were not different between treatments. Both treatments were well‐tolerated: nine patients in the RSV and 11 in the ATV group withdrew from treatment because of adverse events after randomization.

Conclusion.  In subjects with type 2 diabetes, greater improvements of apoB/apoA1 and across the lipid profile were observed with RSV compared with ATV.
SLE, atherosclerosis and cardiovascular disease
Authors: FROSTEGÅRD J.
Published: May 2005

Atherosclerosis is an inflammatory disease and the major cause of cardiovascular disease (CVD) in general. Atherosclerotic plaques are characterized by the presence of activated immune competent cells, but antigens and underlying mechanisms causing this immune activation are not well defined. During recent years and with improved treatment of acute disease manifestations, it has become clear that the risk of CVD is very high in a prototypic autoimmune disease, systemic lupus erythematosus (SLE). SLE‐related CVD and atherosclerosis are important clinical problems but may in addition also shed light on how immune reactions are related to premature atherosclerosis and atherothrombosis. A combination of traditional and nontraditional risk factors, including dyslipidaemia (and to a varying degree hypertension, diabetes and smoking), inflammation, antiphospholipid antibodies (aPL) and lipid oxidation are related to CVD in SLE. Premature atherosclerosis in some form leading to atherothrombosis is likely to be a major underlying mechanism, though distinctive features if any, of SLE‐related atherosclerosis when compared with ‘normal’ atherosclerosis are not clear. One interesting possibility is that factors such as inflammation or aPL make atherosclerotic lesions in autoimmune disease more prone to rupture than in ‘normal’ atherosclerosis. Whether premature atherosclerosis is a general feature of SLE or only affects a subgroup of patients remains to be demonstrated. Treatment of SLE patients should also include a close monitoring of traditional risk factors for CVD. In addition, attention should also be paid to nontraditional risk factors such as inflammation and SLE‐related factors such as aPL. Hopefully novel therapeutic principles will be developed that target the causes of the inflammation and immune reactions present in atherosclerotic lesions.
Oculomotor changes are associated to daytime sleepiness in the multiple sleep latency test
Authors: GENNARO LUIGI DE , DEVOTO ALESSANDRA , LUCIDI FABIO , VIOLANI CRISTIANO
Published: May 2005

Sleep onsets in the diurnal multiple sleep latency test (MSLT), following different sleep lengths of the preceding night sleep (8, 5, 4, 3, 2, 1 h) and following the corresponding recovery nights, were considered for a study on changes of oculomotor activity during sleep onset. The study aimed to assess the individual time course in spontaneous blinks (SBs) and slow eye movements (SEMs) during the sleep onset period and also the relationship with sleep latencies in the MSLT. Group analyses compared oculomotor changes between conditions characterized by a different level of daytime sleepiness. The results show a clear inverse relation between the two oculomotor measures, with a linear SB decrease and quadratic SEM increase across the wake–sleep transition. A 150 s sample of SB and SEM activity at the start of MSLT trials correlates with individual subsequent sleep latency. Finally, mean changes in daytime sleepiness as measured by the MSLT are paralleled by coherent oculomotor changes, with a significant linear decrease of SB as sleepiness increases as a consequence of previous sleep reduction. Both individual and group results show that endogenous blinking is associated with moderate changes in daytime sleepiness.
Symptoms of sleep disturbance in persons with Alzheimer's disease and normal elderly
Authors: TRACTENBERG ROCHELLE E. , SINGER CLIFFORD M. , KAYE JEFFREY A.
Published: May 2005

We retrospectively analyzed sleep time and sleep disturbance symptoms in 399 healthy, non‐demented elderly (NDE) and 263 persons with a diagnosis of possible (n = 53) or probable (n = 210) Alzheimer's disease (AD). Our primary objective was to determine differences in subjective sleep disturbance between these samples. Secondary objectives were to determine if subjects with time in bed (TIB) ≤6 h per night reported more sleep disturbance and whether sleep complaints were associated with more severe cognitive and/or functional impairment. The prevalence of ‘sleep problems’ (a single item) was significantly lower in NDE (18.3%) than AD (27.6%), and the proportions of each cohort reporting TIB ≤6 h per night were very low (NDE: 6.0%; AD: 3.5%) and not significantly different. Less TIB was correlated with better cognitive function for AD (P < 0.01), and cognition and function were significantly worse for AD subjects with estimates of >6 h of TIB compared with those with estimates of ≤6 h (P < 0.05). Greater sleep disturbance was correlated with greater functional impairment in both cohorts; but only in AD did greater estimated TIB also correlate with greater functional impairment (all P < 0.05). In general, estimated TIB was not associated with mood in either cohort; however, in both cohorts depression was significantly associated with sleep disturbance symptoms and was significantly worse in those who reported having ‘sleep problems’. There was no association between subjective perception of ‘sleep problems’, the number and frequency of sleep disturbance symptoms, and estimated TIB in either group.
Is the failure to detect stimulus deviance during sleep due to a rapid fading of sensory memory or a degradation of stimulus encoding?
Authors: SABRI MERAV , CAMPBELL KENNETH B.
Published: May 2005

The mismatch negativity (MMN) is thought to reflect the outcome of a system responsible for the detection of change in an otherwise repetitive, homogenous acoustic environment. This process depends on the storage and maintenance of a sensory representation of the frequently presented stimulus to which the deviant stimulus is compared. Few studies have been able to record the MMN in non‐rapid eye movement (NREM) sleep. This pattern of results might be explained by either a rapid fading of sensory memory or an inhibition of stimulus input prior to entry into the cortical MMN generator site. The present study used a very rapid rate of presentation in an attempt to capture mismatch‐related negativity prior to the fading of sensory memory. Auditory event‐related potentials were recorded from 12 subjects during a single sleep period. A 1000 Hz standard stimulus was presented every 150 ms. At random, on 6.6% of the trials, the standard was changed to either a large 2000 Hz or a small 1100 Hz deviant. In wakefulness, the large deviant elicited an extended negativity that was reduced in amplitude following the presentation of the small deviant. This negativity was also apparent during REM sleep following the presentation of the large deviant. These deviant‐related negativities (DRNs) were probably a composite of N1 and MMN activity. During NREM sleep (stage 2 and slow‐wave sleep), only the large deviant continued to elicit a DRN. However this DRN might be overlapped by the initial activity of a component that is unique to sleep, the N350. There was little evidence of the DRN or the MMN during sleep following the presentation of the small deviant. A rapid rate of presentation, therefore, does not preserve the MMN following small deviance within sleep. It is possible that inhibition of sensory input occurs before entry into the MMN generating system in the temporal cortex.
The relationships between memory systems and sleep stages
Authors: RAUCHS GÉRALDINE , DESGRANGES BÉATRICE , FORET JEAN , EUSTACHE FRANCIS
Published: May 2005

Sleep function remains elusive despite our rapidly increasing comprehension of the processes generating and maintaining the different sleep stages. Several lines of evidence support the hypothesis that sleep is involved in the off‐line reprocessing of recently‐acquired memories. In this review, we summarize the main results obtained in the field of sleep and memory consolidation in both animals and humans, and try to connect sleep stages with the different memory systems. To this end, we have collated data obtained using several methodological approaches, including electrophysiological recordings of neuronal ensembles, post‐training modifications of sleep architecture, sleep deprivation and functional neuroimaging studies. Broadly speaking, all the various studies emphasize the fact that the four long‐term memory systems (procedural memory, perceptual representation system, semantic and episodic memory, according to Tulving's SPI model; Tulving, 1995) benefit either from non‐rapid eye movement (NREM) (not just SWS) or rapid eye movement (REM) sleep, or from both sleep stages. Tulving's classification of memory systems appears more pertinent than the declarative/non‐declarative dichotomy when it comes to understanding the role of sleep in memory. Indeed, this model allows us to resolve several contradictions, notably the fact that episodic and semantic memory (the two memory systems encompassed in declarative memory) appear to rely on different sleep stages. Likewise, this model provides an explanation for why the acquisition of various types of skills (perceptual‐motor, sensory‐perceptual and cognitive skills) and priming effects, subserved by different brain structures but all designated by the generic term of implicit or non‐declarative memory, may not benefit from the same sleep stages.
Prediction of melatonin efficacy by pretreatment dim light melatonin onset in children with idiopathic chronic sleep onset insomnia
Authors: VAN DER HEIJDEN KRISTIAAN B. , SMITS MARCEL G. , VAN SOMEREN EUS J. W. , BOUDEWIJN GUNNING W.
Published: May 2005

Research has shown efficacy of melatonin treatment to advance sleep–wake rhythms in insomnia. In healthy adults, direction and magnitude of the phase shift depends on the timing of administration relative to the phase position of the circadian system. Therefore, in the present study we investigated whether in children with chronic sleep onset insomnia (SOI) efficacy of melatonin treatment in the early evening could be predicted from dim light melatonin onset (DLMO), a phase marker of the circadian system. We combined data of two previously published double blind, randomized, placebo‐controlled trials in 110 participants, aged 6–12 years. Sleep was actigraphically estimated, and saliva collected, at baseline and in the third week of a 4‐week treatment period with 5 mg melatonin or placebo at 18:00 or 19:00 hours. Primary outcome measures were pre‐ to post‐treatment changes in dim light melatonin onset (ΔDLMO), sleep onset (ΔSO), sleep latency (ΔSL), and total sleep duration (ΔTSD). Melatonin advanced DLMO with +1:12 h (P < 0.001), SO with +0:42 h (P = 0.004), SL decreased with 25 min (P = 0.019), and TSD did not change significantly, as compared with placebo. In the melatonin‐treated group, but not in the placebo‐treated group, pretreatment DLMO was significantly related to ΔDLMO [F(1, 29) = 7.28, P = 0.012] and ΔSO [F(1, 25) = 7.72, P = 0.010]. The time interval between treatment administration and pretreatment DLMO (INT) was only significantly related to ΔSO [F(1,26) = 5.40, P = 0.028]. The results suggest that in children with SOI, the efficacy of early evening melatonin to advance sleep onset and endogenous melatonin onset increases the later the pretreatment DLMO is.
Birds in the diet of the Eurasian badger Meles meles: a review and meta‐analysis
Authors: HOUNSOME TIM , DELAHAY RICHARD
Published: May 2005

1. We reviewed 110 published studies of badger diet or badger predation of birds. The studies covered most of the Eurasian badger's range, from Ireland east to Japan and from Sweden south to southern Spain.

2. Bird remains were recorded in 2038 cases out of a total 36699 samples of badger faeces and stomachs. The overall percentage frequency of occurrence of bird remains in badger faeces and stomachs was 5.55% for all studies combined, and 7.97% for UK studies. The remains of 45 bird species from 11 orders were recorded.

3. The percentage frequency of occurrence of birds in badger diet increased significantly with latitude. There was no significant relationship between the occurrence of birds in badger diet and season.

4. While the prevalence of birds in the diet of badgers is generally low, the studies reviewed here provide insufficient evidence to assess whether badger predation has an impact on bird populations at a national scale, and experimental approaches to this problem are required.
Age determination and age structure in the edible dormouse Glis glis based on incremental bone lines
Authors: KRYŠTUFEK BORIS , PISTOTNIK MEDEJA , SEDMAK ČASAR KSENIJA
Published: May 2005

1. Absolute age was estimated from incremental bone layers of the mandible in 109 edible dormice Glis glis collected between May and September 1997 in mixed beech and fir forests of central Slovenia.

2. Mandible cross‐sections of juveniles obtained in September showed a great number of vascular canals and no resting lines. In the remaining animals (n = 81), the number of resting lines varied between one and seven, with two or three lines being the most common condition (62% of specimens). Among these adult animals, which hibernated at least once, females attained higher mean (3.3 years) and maximum age (7 years) than males (mean = 2.2, maximum = 6 years).

3. The frequency distribution of age classes suggested unequal reproductive success between years but there was no indication of any lack of litters in years of low mast production.
Expanding ranges of wild and feral deer in Great Britain
Authors: WARD ALASTAIR I.
Published: May 2005

1. It is often stated that wild deer in Great Britain are increasing in range and number. This study presents the first quantified estimate of national range expansion for all six species. From national surveys of deer presence in 10 km squares between 1972 and 2002, the red deer range is estimated to have expanded at a compound rate of 0.3% per year, fallow deer at 1.8%, Chinese water deer at 2.0%, roe deer at 2.3%, Japanese sika at 5.3% and Reeves’ muntjac at 8.2%.

2. Each species is expected to expand its range further for the foreseeable future. The most widespread species, roe deer, is predicted to be present within 79% of all 10 km squares in mainland Britain within 10 years.

3. Deer range expansion brings a combination of benefits and costs, and some degree of management is considered necessary to limit both environmental damage and deer suffering.
The digestive performance of mammalian herbivores: why big may not be that much better
Authors: CLAUSS MARCUS , HUMMEL JÜRGEN
Published: May 2005

1. A traditional approach to the nutritional ecology of herbivores is that larger animals can tolerate a diet of lesser quality due to a higher digestive efficiency bestowed on them by comparatively long ingesta retention times and lower relative energy requirements.

2. There are important physiological disadvantages that larger animals must compensate for, namely a lower gut surface : gut volume ratio, larger ingesta particle size and greater losses of faecal bacterial material due to more fermentation. Compensating adaptations could include an increased surface enlargement in larger animals, increased absorption rates per unit of gut surface, and increased gut motility to enhance mixing of ingesta.

3. A lower surface : volume ratio, particularly in sacciform forestomach structures, could be a reason for the fact that methane production is of significant scope mainly in large herbivores and not in small herbivores with comparably long retention times; in the latter, the substrate for methanogenesis – the volatile fatty acids – could be absorbed faster due to a more favourable gut surface : volume ratio.

4. Existing data suggest that in herbivores, an increase in fibre digestibility is not necessarily accompanied by an increase in overall apparent dry matter digestibility. This indicates a comparative decrease of the apparent digestibility of non‐fibre material, either due to a lesser utilization of non‐fibre substrate or an increased loss of endogenous/bacterial substance. Quantitative research on these mechanisms is warranted in order to evaluate whether an increase in body size represents a net increase of digestive efficiency or just a shift of digestive focus.
The recolonization of Europe by brown bears Ursus arctos Linnaeus, 1758 after the Last Glacial Maximum
Authors: SOMMER R. S. , BENECKE N.
Published: May 2005

1. At the end of the Last Glacial Maximum brown bears Ursus arctos recolonized the glacial landscape of Central and Northern Europe faster than all other carnivorous mammal species of the Holocene fauna. Ursus arctos was recorded in Northern Europe from the beginning of the Late‐Glacial. The recolonization of northern Central Europe may have taken place directly after the maximum glaciation. The distribution of the brown bear was restricted to glacial refugia only during the Last Glacial Maximum, for probably no more than 10 000 years.

2. Genetic analyses have suggested three glacial refugia for the brown bear: the Iberian Peninsula, the Italian Peninsula and the Balkans. Subfossil records of Ursus arctos from north‐western Moldova as well as reconstructed environmental conditions during the Last Glacial Maximum in this area suggest to us a fourth glacial refuge for the brown bear. Because of its connection to the Carpathians, we designate this as the ‘Carpathian refuge’.

3. Due to the low genetic distance between brown bears of northern Norway, Finland, Estonia, north‐eastern Russia and the northern Carpathians (the so‐called eastern lineage), the Carpathians were considered the geographical origin of the recolonization of these regions. During the recolonization of northern Europe the brown bear probably reached these areas rapidly from the putative Carpathian refuge.
Understanding mammalian evolution using Bayesian phylogenetic inference
Authors: KELLY CLINT D.
Published: May 2005

1. Phylogenetic trees are critical in addressing evolutionary hypotheses; however, the reconstruction of a phylogeny is no easy task. This process has recently been made less arduous by using a Bayesian statistical approach. This method offers the advantage that one can determine the probability of some hypothesis (i.e. a phylogeny), conditional on the observed data (i.e. nucleotide sequences).

2. By reconstructing phylogenies using Bayes’ theorem in combination with Markov chain Monte Carlo, phylogeneticists are able to test hypotheses more quickly compared with using standard methods such as neighbour‐joining, maximum likelihood or parsimony. Critics of the Bayesian approach suggest that it is not a panacea, and argue that the prior probability is too subjective and the resulting posterior probability is too liberal compared with maximum likelihood.

3. These issues are currently debated in the arena of mammalian evolution. Recently, proponents and opponents of the Bayesian approach have constructed the mammalian phylogeny using different methods under different conditions and with a variety of parameters. These analyses showed the robustness (or lack of) of the Bayesian approach. In the end, consensus suggests that Bayesian methods are robust and give essentially the same answer as maximum likelihood methods but in less time.

4. Approaches based on fossils and molecules typically agree on ordinal‐level relationships among mammals but not on higher‐level relationships, as Bayesian analyses recognize  the African radiation, Afrotheria, and the two Laurasian radiations, Laurasiatheria and Euarchontoglires, whereas fossils did not predict Afrotheria.
Historic and current habitat use by North Pacific right whales Eubalaena japonica in the Bering Sea and Gulf of Alaska
Authors: SHELDEN KIM E. W. , MOORE SUE E. , WAITE JANICE M. , WADE PAUL R. , RUGH DAVID J.
Published: May 2005

1. To help define areas and ecological parameters critical to the survival and recovery of the remnant population of North Pacific right whales, habitat use was investigated by examining all available sighting and catch records in the south‐eastern Bering Sea (SEBS) and Gulf of Alaska (GOA) over the past two centuries.

2. Based on re‐analyses of commercial whaling records, search effort, and resultant catches and sightings, waters of the: (i) SEBS slope and shelf, (ii) eastern Aleutian Islands and (iii) GOA slope and abyssal plain were important habitat for North Pacific right whales through the late 1960s.

3. Since 1980, the only area where right whales have been seen consistently is on the SEBS middle shelf. However, acoustic detections and single sightings have been reported in all other regions except the SEBS slope and oceanic GOA (areas where little, if any, acoustic and visual effort has occurred).

4. Sightings since 1979 were in waters < 200 m deep which may simply reflect the paucity of search effort elsewhere. From the commercial whaling era to the late 1960s, right whales were commonly seen in waters > 2000 m deep, indicating that their distribution is not restricted to shallow continental shelves.

5. North Pacific right whale sightings through the centuries have been associated with a variety of oceanic features, and there is little in common in the bathymetry of these regions. These whales appear to have a greater pelagic distribution than that observed in the North Atlantic, which may be related to the availability of larger copepods across the SEBS and GOA.
Microsatellite and mitochondrial DNA analyses of the genetic structure of blacktip shark (Carcharhinus limbatus) nurseries in the northwestern Atlantic, Gulf of Mexico, and Caribbean Sea
Authors: KEENEY D. B. , HEUPEL M. R. , HUETER R. E. , HEIST E. J.
Published: May 2005

We investigated the genetic structure of blacktip shark (Carcharhinus limbatus) continental nurseries in the northwestern Atlantic Ocean, Gulf of Mexico, and Caribbean Sea using mitochondrial DNA control region sequences and eight nuclear microsatellite loci scored in neonate and young‐of‐the‐year sharks. Significant structure was detected with both markers among nine nurseries (mitochondrial ΦST = 0.350, P < 0.001; nuclear ΦST = 0.007, P < 0.001) and sharks from the northwestern Atlantic, eastern Gulf of Mexico, western Gulf of Mexico, northern Yucatan, and Belize possessed significantly different mitochondrial DNA haplotype frequencies. Microsatellite differentiation was limited to comparisons involving northern Yucatan and Belize sharks with nuclear genetic homogeneity throughout the eastern Gulf of Mexico, western Gulf of Mexico, and northwestern Atlantic. Differences in the magnitude of maternal vs. biparental genetic differentiation support female philopatry to northwestern Atlantic, Gulf of Mexico, and Caribbean Sea natal nursery regions with higher levels of male‐mediated gene flow. Philopatry has produced multiple reproductive stocks of this commercially important shark species throughout the range of this study.
Measuring polyandry in wild populations: a case study using promiscuous crickets
Authors: BRETMAN AMANDA , TREGENZA TOM
Published: May 2005

Mating rate has important implications for patterns of sexual selection and sexual conflict and hence for issues such as speciation and the maintenance of genetic diversity. Knowledge of natural mating rates can provide insights into the factors driving female mating behaviour. We investigated the level of polyandry in a Spanish population of the field cricketGryllus bimaculatususing microsatellite markers. Two approaches were employed: (i) genotyping the offspring of wild‐caught gravid females to determine the number of males siring the brood and (ii) genotyping sperm stored in the spermathecae of females mated in the wild to estimate the number of mating partners. We compared existing methods for inferring the minimum and probable number of fathers and described a novel probabilistic technique estimating the number of mates by genotyping stored sperm. Using the most conservative allele‐counting method, 71% of females produced offspring sired by at least two males (a minimum mean of 2.4 fathers per clutch), and all females had mated to at least two males with minimum mean estimates of 2.7–5.1 mates per female. Our study reveals high levels of polyandry in the wild and suggests that females mate with more males than sire their offspring.
Range‐wide molecular analysis of the western pond turtle (Emys marmorata): cryptic variation, isolation by distance, and their conservation implications
Authors: SPINKS PHILLIP Q. , SHAFFER H. BRADLEY
Published: May 2005

We analysed phylogeography and population genetic variation across the range of the western pond turtle (Emys marmorata) using rapidly evolving mitochondrial and nuclear DNA sequence data. Nuclear DNA sequences from two unlinked introns displayed extremely low levels of variation, but phylogenetic analyses based on mtDNA recovered four well‐supported and geographically coherent clades. These included a large Northern clade composed of populations from Washington south to San Luis Obispo County, California, west of the Coast Ranges; a San Joaquin Valley clade from the southern Great Central Valley; a geographically restricted Santa Barbara clade from a limited region in Santa Barbara and Ventura counties; and a Southern clade that occurs south of the Tehachapi Mountains and west of the Transverse Range south to Baja California, Mexico. An analysis of molecular variance (amova) based on regional hydrographic units revealed that populations from the Sacramento Valley north to Washington were virtually invariant, with no evidence of population substructure among northern river drainage basins. In other areas,E. marmoratacontains considerable unrecognized variation, particularly in central and southern California and in northern Baja California, Mexico. Our northern clade is congruent with the distribution of the subspeciesEmys marmorata marmorata(Washington–central California). However, no clade is congruent with the distribution of the southern subspeciesEmys marmorata pallidafrom central California–Baja. Thus, recognition of the current subspecies split is not warranted, based on the available genetic evidence. Ouramovaand phylogenetic results, in conjunction with a growing comparative database for other codistributed aquatic taxa, confirm the occurrence of genetic breaks across the Tehachapi Mountains and Transverse Range bounding the southern end of the Great Central Valley, and point to southern California as a rich source of cryptic genetic variation.
Streams over mountains: influence of riparian connectivity on gene flow in the Pacific jumping mouse (Zapus trinotatus)
Authors: VIGNIERI SACHA N.
Published: May 2005

In species affiliated with heterogeneous habitat, we expect gene flow to be restricted due to constraints placed on individual movement by habitat boundaries. This is likely to impact both individual dispersal and connectivity between populations. In this study, a GIS‐based landscape genetics approach was used, in combination with fine‐scale spatial autocorrelation analysis and the estimation of recent intersubpopulation migration rates, to infer patterns of dispersal and migration in the riparian‐affiliated Pacific jumping mouse (Zapus trinotatus). A total of 228 individuals were sampled from nine subpopulations across a system of three rivers and genotyped at eight microsatellite loci. Significant spatial autocorrelation among individuals revealed a pattern of fine‐scale spatial genetic structure indicative of limited dispersal. Geographical distances between pairwise subpopulations were defined following four criteria: (i) Euclidean distance, and three landscape‐specific distances, (ii) river distance (distance travelled along the river only), (iii) overland distance (similar to Euclidean, but includes elevation), and (iv) habitat‐path distance (a least‐cost path distance that models movement along habitat pathways). Pairwise Mantel tests were used to test for a correlation between genetic distance and each of the geographical distances. Significant correlations were found between genetic distance and both the overland and habitat‐path distances; however, the correlation with habitat‐path distance was stronger. Lastly, estimates of recent migration rates revealed that migration occurs not only within drainages but also across large topographic barriers. These results suggest that patterns of dispersal and migration in Pacific jumping mice are largely determined by habitat connectivity.
Spatial genetic structure of northern pike (Esox lucius) in the Baltic Sea
Authors: LAIKRE LINDA , MILLER LOREN M. , PALMÉ ANNA , PALM STEFAN , KAPUSCINSKI ANNE R. , THORESSON GUNNAR , RYMAN NILS
Published: May 2005

The genetic relationships among 337 northern pike (Esox lucius) collected from the coastal zone of the central Baltic region and the Finnish islands of Åland were analysed using five microsatellite loci. Spatial structure was delineated using both traditional F‐statistics and individually based approaches including spatial autocorrelation analysis. Our results indicate that the observed genotypic distribution is incompatible with that of a single, panmictic population. Isolation by distance appears important for shaping the genetic structure of pike in this region resulting in a largely continuous genetic change over the study area. Spatial autocorrelation analysis (Moran's I) of individual pairwise genotypic data show significant positive genetic correlation among pike collected within geographical distances of less than c. 100–150 km (genetic patch size). We suggest that the genetic patch size may be used as a preliminary basis for identifying management units for pike in the Baltic Sea.
Hybrid origin of a parthenogenetic genus?
Authors: MORGAN‐RICHARDS MARY , TREWICK STEVEN A.
Published: May 2005

The origin of the obligate‐parthenogenetic New Zealand stick insect genus Acanthoxyla was investigated using cytogenetics and sequencing of nuclear and mitochondrial DNA. Little mitochondrial DNA sequence variation (COI‐II) was found among seven species of the genus Acanthoxyla and we found no evidence for monophyly of the morphologically distinguished lineages. In contrast, two distinct clades of nuclear sequence (ITS) were obtained, one is restricted to the genus Acanthoxyla, while the other includes sequences obtained from its sister genus Clitarchus. Although Acanthoxyla appears to be diploid (2n = 36–38), it has two ill‐matched chromosome pairs. We hypothesize that two or more hybridization events involving the parental sexual species Clitarchus hookeri and an unknown taxon probably resulted in the formation of the parthenogenetic genus Acanthoxyla. However, the karyotype of Acanthoxyla bears little resemblance to the karyotype of the putative paternal species C. hookeri so the exact nature of Acanthoxyla remains in question.
Genetic diversity and population structure of an insular tree, Santalum austrocaledonicum in New Caledonian archipelago
Authors: BOTTIN L. , VERHAEGEN D. , TASSIN J. , OLIVIERI I. , VAILLANT A. , BOUVET J. M.
Published: May 2005

We present a study of the genetic diversity and structure of a tropical tree in an insular system. Santalum austrocaledonicum is endemic to the archipelago of New Caledonia and is exploited for oil extraction from heartwood. A total of 431 individuals over 17 populations were analysed for eight polymorphic microsatellite loci. The number of alleles per locus ranged from 3 to 33 and the observed heterozygosity per population ranged from 0.01 in Maré to 0.74 in Ile des Pins. The genetic diversity was lowest in the most recent islands, the Loyautés, and highest in the oldest island, Grande Terre, as well as the nearby small Ile des Pins. Significant departures from panmixia were observed for some loci–population combinations (per population FIS = 0–0.03 on Grande‐Terre and Ile des Pins, and 0–0.67 on Loyautés). A strong genetic differentiation among all islands was observed (FST = 0.22), and the amount of differentiation increased with geographic distance in Iles Loyauté and in Grande Terre. At both population and island levels, island age and isolation seem to be the main factors influencing the amount of genetic diversity. In particular, populations from recent islands had large average FIS that could not be entirely explained by null alleles or a Wahlund effect. This result suggests that, at least in some populations, selfing occurred extensively. Conclusively, our results indicate a strong influence of insularity on the genetic diversity and structure of Santalum austrocaledonicum.
Crop‐to‐weed introgression has impacted allelic composition of johnsongrass populations with and without recent exposure to cultivated sorghum
Authors: MORRELL P. L. , WILLIAMS‐COPLIN T. D. , LATTU A. L. , BOWERS J. E. , CHANDLER J. M. , PATERSON A. H.
Published: May 2005

Sorghum halepenseL. (johnsongrass) is one of the world's most noxious weeds, and a paradigm for the potential dangers of crop–weed hybridization. Introduced into the southeastern United States about 200 years ago,S. halepenseis a close relative of cultivated sorghum (Sorghum bicolor). Both artificial crossing and experimental field studies have demonstrated the potential forS. halepense×S. bicolorhybrid formation, but no prior study has addressed the long‐term persistence of sorghum genes in johnsongrass populations. We surveyed 283 loci (on all 10 sorghum linkage groups) to identify 77 alleles at 69 loci that are found in US sorghum cultivars but are absent from a worldwide sampling of johnsongrass genotypes. These putatively cultivar‐specific alleles were present in up to 32.3% of individuals in johnsongrass populations adjacent to long‐term sorghum production fields in Texas and Nebraska. Lower frequencies of cultivar‐specific alleles at smaller numbers of loci are found in johnsongrass populations from New Jersey and Georgia with no recent exposure to cultivated sorghum, suggesting that introgressed sorghum alleles may be dispersed across long distances. The number of cultivar‐specific alleles and extensive multilocus patterns of cultivar‐specific allelic composition observed at both linked and unlinked loci in the johnsongrass populations, are inconsistent with alternatives to introgression such as convergence, or joint retention of ancestral polymorphisms. Naturalized johnsongrass populations appear to provide a conduit by which transgenes from sorghum could become widely disseminated.
Petrogenesis and tectonic implications of Early Cretaceous high‐K calc‐alkaline volcanic rocks in the Laiyang Basin of the Sulu Belt, eastern China
Authors: Guo Feng , Fan Weiming , Wang Yuejun , Li Chaowen
Published: May 2005

Abstract  Early Cretaceous high‐K calc‐alkaline volcanism occurring in the Laiyang Basin north of the Sulu high‐pressure to ultrahigh‐pressure (HP‐UHP) Metamorphic Belt, eastern China, comprises a wide spectrum of rock types, ranging from trachybasalts to trachydacites. The basaltic–andesitic rocks erupted at 107–105 Ma, spanning an SiO2 range of 50.1–59.6% and an MgO range of 2.6–7.2%, and are characterized by large ion lithophile element (LILE; e.g. Ba and K) and light rare earth element (LREE) enrichment, high field strength element (HFSE) depletion and highly radiogenic Sr but non‐radiogenic Nd isotopic compositions (87Sr/86Sr(i) = 0.70750–0.70931; ɛNd(t) = −17.9 − −15.6). The geochemical similarities between these rocks and the earlier Sulu Belt lamprophyres suggest that both types of mafic rocks were derived from similar mantle sources with LILE and LREE enrichment. Thus, the Wulian–Qingdao–Yantai Fault that separates the two terranes at the surface should not be considered as a lithospheric boundary between the North China and Yangtze blocks. The felsic lavas erupted at 93–91 Ma, spanning an SiO2 range of 61.6–67.0% and an MgO range of 1.1–2.6%, and show a trace element geochemistry similar to the basaltic rocks, but with higher radiogenic Sr and even lower Nd isotopic compositions (87Sr/86Sr(i) = 0.70957–0.71109; ɛNd(t) = −19.1 − −17.5), similar to I‐type granitoids in the Sulu Belt. A crustal origin was proposed to explain their compositions (which are comparable to those of experimental slab melts), the >10 Ma eruption interval and the compositional gaps in some elements (e.g. P, Ti and Sr) between them and the older basaltic–andesitic rocks. These melts were derived from predominant metaigneous protoliths containing mafic accumulative counterparts of the basaltic–andesitic and/or lamprophyric magmas. The extensive extrusion of Early Cretaceous high‐K calc‐alkaline rocks in the Laiyang Basin favored an extensional regime in response to the progressive attenuation of the thickened lithosphere and orogenic collapse, as reflected in the development of the basin from a foreland basin (before the end of the Jurassic period) to a fault basin (since the Early Cretaceous period).
Origin of Mesozoic gold mineralization in South Korea
Authors: Choi Seon‐Gyu , Kwon Sung‐Tack , Ree Jin‐Han , So Chil‐Sup , Pak Sang Joon
Published: May 2005

Abstract  The Mesozoic gold–silver deposits in South Korea are closely associated with the Mesozoic granitoids. The Jurassic gold–silver deposits can be distinguished from the Cretaceous ones in terms of occurrence, alteration style, gold fineness, associated mineral assemblage, fluid inclusion and stable isotopic compositions. The Jurassic deposits were formed in mesozonal environments related to deep‐seated granitoids, whereas the Cretaceous ones were formed in epizonal environments related to shallow‐level granitoids. The Jurassic auriferous deposits (about 165–145 Ma) show fluid characteristics typical of an orogenic‐type gold deposit, and were probably generated in a compressional regime caused by an orthogonal convergence of the Izanagi oceanic plate into the Asiatic margin. However, strike‐slip faults and caldera‐related fractures, together with subvolcanic to volcanic activity, may have played an important role in the formation of Cretaceous gold–silver lode deposits (about 110–45 Ma) under a continental arc setting.
Refined Early to Middle Miocene diatom biochronology for the middle‐ to high‐latitude North Pacific
Authors: Watanabe Mahito , Yanagisawa Yukio
Published: May 2005

Abstract  Refined numerical ages of the diatom biohorizons of the Early to Middle Miocene (11–18 Ma) period in the Neogene North Pacific are presented based on the direct correlation between biostratigraphy and magnetostratigraphy at Site 887 on the Patton–Murray Seamount in the northeastern Pacific. Sampling intervals of 0.02–0.04 my allowed the determination of the ages of the biohorizons to be more precise than previous studies. The secondary biohorizons established in the northwestern Pacific have been proven to be useful also in the northeastern Pacific, and are linked to magnetostratigraphy directly for the first time. The refined diatom biochronology established in this study will provide a vital basis for the study of the Neogene marine sediments of the middle‐ to high‐latitude North Pacific, which rarely yield calcareous microfossils. Denticulopsis praedimorpha var. prima n. var. is described.
Geology and geochemistry of Karasugasen lava dome, Daisen–Hiruzen Volcano Group, southwest Japan
Authors: Kimura Jun‐Ichi , Tateno Mamiko , Osaka Isaku
Published: May 2005

Abstract  The geology and geochemistry of pyroclastic flows and fallout tephras formed during the Karasugasen dome eruption in the Daisen–Hiruzen Volcano Group in southwest Japan have been examined in detail. The Karasugasen lava dome erupted at about 26 ka. The eruption began with a vulcanian ash fall, and this was followed by at least eight block and ash flows and a pumice flow. The block and ash flows were produced by the successive collapses of a growing lava dome. This main eruption phase was followed by an eruption of vulcanian ash falls, and finally ended with a sub‐Plinian pumice fall. This eruption sequence is typical of the Daisen Volcano during the last three eruption events, which occurred at 58, 26 and 17 ka. The magma produced during the Karasugasen eruption was a typical adakite, with extremely high Sr/Y ratios and low HREE/LREE ratios compared to normal arc lavas. The chemistry of the Karasugasen lavas is almost identical to other Daisen–Hiruzen lavas that were produced from eruptions over an interval of a million years. The continuous supply of a huge amount of adakitic magma (>100 km3) for such a long period suggests a massive homogeneous source material, such as molten Philippine Sea Plate slab. Slab melting is a plausible mechanism for the production of the adakitic lavas at Karasugasen, and hence the Daisen–Hiruzen Volcano Group.
Rapid tectonics of the Late Miocene Boso accretionary prism related to the Izu–Bonin arc collision
Authors: Yamamoto Yuzuru , Kawakami Shunsuke
Published: May 2005

Abstract  The structure, paleomagnetism and biostratigraphy of the Nishizaki and Kagamigaura formations on the southern Boso Peninsula, central Japan, were investigated to determine the chronographic constraints on the accretion, post‐Late Miocene rotation and regional tectonics in the Izu–Bonin island arc collision zone. The geological structures on the southern Boso Peninsula are characterized by an east–west trending and south‐verging fold and thrust belt that curves toward the northwest–southeast in the northwest extent of the Nishizaki Formation. Two stages of tectonic rotation were revealed by paleomagnetic and structural studies. The first is believed to have occurred after the accretion of the Nishizaki Formation and before the deposition of the Kagamigaura Formation, while the second is confidently correlated with the 1 Ma Izu block collision. The northwest extent of the Nishizaki Formation was rotated clockwise by approximately 65–80°, whereas the rotation was only 25–30° in the east, and 11–13° in the overlying Kagamigaura Formation. Radiolarian biostratigraphy suggests a depositional age of 9.9–6.8 Ma (Upper Miocene period) for the Nishizaki Formation and 4.19‐3.75 Ma (Pliocene period) for the lower Kagamigaura Formation. These results indicate that the age of accretion and first‐stage rotation of the Nishizaki Formation can be constrained to the interval of 6.80–3.75 Ma. This structure most likely represents the northward bending caused by collisions of the Tanzawa and Izu blocks with the Honshu island arc, and suggests rapid processes of accretion, collision, uplift and the formation of new sedimentary basins within a relatively short period of time (2.61–3.05 my).
The rate of fluvial incision during the Late Quaternary period in the Abukuma Mountains, northeast Japan, deduced from tephrochronology
Authors: Yamamoto Takahiro
Published: May 2005

Abstract  River incision into bedrock results in the decrease of burial depths, which can be of critical importance, for example, in the safe long‐term storage of high‐level radioactive waste. For the long‐term prediction of river erosion, it is essential to know the rate of incision during the Late Quaternary period. In the Abukuma Mountains on the forearc side of northeast Japan, a low‐relief peneplain that was uplifted in the Pliocene period is widely developed. Degradational fluvial terraces that are discontinuously distributed along draining rivers are scattered in the study area. The fluvial sediments were mainly transported from the summit regions as debris flows or hyperconcentrated flows. The terrace deposits are capped by a series of eolian veneers containing key tephra beds. From the oldest to the youngest, these tephra beds are the 150–125 ka Iizuna–Kamitaru tephra, the 135–125 ka Hiuchigatake–Tagashira tephra, the 120 ka Adatara–Dake tephra, the 70–80 ka Bandai–Hayama‐2 tephra, the 45 ka Numazawa–Mizunuma tephra and the 42 ka Bandai–Hayama‐1 tephra. Using tephrochronological data, the terraces are divided into three groups: higher, middle and lower. The ages of formation of the higher, middle and lower terraces are estimated to be within marine isotope stage (MIS) 6, MIS 5.4–5.2 and MIS 3 to MIS 2, respectively. The incision rate, calculated from the relative height between the terrace surface and present‐day valley floor fill, is 1.5–0.8 m/10 000 years in the elevations from 350 to 700 m. The calculated rate does not show significant differences between the higher, middle and lower terraces. All the relative heights decrease with increasing elevation, because the erosional rates of streams in the upper reaches are lower than those in downstream reaches where the discharge rates are higher. This value can be regarded as an estimate of the rate of incision in granitic mountains where there is no volcanic or distinct tectonic activity.