Adult Individuals (adult + individual)

Distribution by Scientific Domains
Distribution within Life Sciences

Selected Abstracts

The burial of Bad Dürrenberg, Central Germany: osteopathology and osteoarchaeology of a Late Mesolithic shaman's grave

M. Porr
Abstract The isolated burial of Bad Dürrenberg is one of the richest Mesolithic graves in Europe. Although it was excavated in the 1930s, new spectacular anthropological and archaeological evidence has emerged during a recent re-study. Firstly, we present here the results of an anthropological re-evaluation of certain features of the skull base and the foramen magnum. Our work has clearly established that the observable features are caused by an anatomical variation that also includes an atlar anomaly. This developmental variation possibly caused various neuropathological symptoms. The Bad Dürrenberg burial consequently represents a unique case of the possible interpretation of abnormal behaviours in a shamanistic fashion in a prehistoric context. Secondly, we have identified the LSAMAT phenomenon (Lingual Surface Attrition of the Maxillary Anterior Teeth) in the adult individual of the burial. The activities leading to this condition are unknown so far. Thirdly, a split roe deer metatarsus among the burial goods was identified as being involved in the preparation or application of red pigment. The lack of polish and other use wear make it likely that it was produced and used as part of the burial ritual. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Spatial organization, group living and ecological correlates in low-density populations of Eurasian badgers, Meles meles

Eloy Revilla
Summary 1,Territoriality and group living are described in a low-density population of Eurasian badgers, Meles meles L., by studying the patterns of spatial grouping and territory marking, as well as the differences between individuals in some of their characteristics (body condition and dispersal) and in their space use (seasonally, periods of activity and interaction between pairs of individuals) under strong seasonal fluctuations in the availability of the key resource (young rabbits, Oryctolagus cuniculus L.). Finally, the role of the spatial distribution of the main prey (young rabbits) in the development of sociality was also studied in order to test some of the assumptions and predictions of the resource dispersion hypothesis (RDH). 2,Badgers were territorial, showing a flexible system of territory marking, which includes the marking of the most used areas (sett-latrines at the centres of activity) and additionally, at the smaller territories, a system of border-latrines in the areas of contact between territories. The maximum use of border-latrines was associated with the reproductive season, and that of sett-latrines with the season of food scarcity. 3,In the study area where badgers had rabbits as main prey, territories were occupied by small groups of animals, formed by one adult female who reproduced, one adult male who also showed signs of reproductive activity, the cubs of the year (if there was reproduction) and some animals born during previous years, which remained in their natal territory until their dispersal (normally during the mating season of their third or fourth year of life). This system was not strictly fixed as males, given the opportunity, expanded their territories to encompass additional females. Territories in another study site were occupied by one adult female (marked), plus the cubs of the year and another adult individual (unmarked). 4,In winter and spring dominant females and subordinates used only a small fraction of their territories, moved short distances, at a low speed and covering small areas per night. These seasons corresponded with the reproduction of rabbits (highest food availability). Dominant females were the only individuals using all the territory available in the summer (lowest food availability), when badgers had the worst body condition. Food availability increased again in autumn, as did body condition, while range sizes were again reduced. Dominant males used the same proportion of their territories over all seasons. However, in winter (reproductive season) they moved faster, over longer distances, and covered larger areas per period of activity. These results indicate that use of space by dominant males was affected by different factors from that of dominant females and subordinates. 5,RDH does not seem to explain group living in our populations because: (a) territoriality in each pair of primary animals was driven by different factors (trophic resources for females and females for males); (b) dominant males acted as expansionists; and (c) territory size was related to its richness and not to patch dispersion. 6,We propose an integrative hypothesis to explain not only group formation but also interpopulation variability in the social organization of badgers within ecological, demographic and behavioural constraints and in the light of current theory on delayed dispersal. [source]

Urethropexy for the management of urethral sphincter mechanism incompetence in the bitch

R. N. White
Urethropexy was performed on 100 bitches for the management of urethral sphincter mechanism incompetence (SMI). The dogs ranged in age from 12 months to nine years (mean 4,5 years). Diagnosis of the condition was based upon clinical, laboratory and contrast radiographic examinations, and clinical response to medical management. In all bitches, incontinence developed in the adult individual and in the majority (89 bitches) after spaying. Radiographic findings were unremarkable in 22 bitches, apart from the presence of an intrapelvic bladder neck. Follow-up periods ranged from 12 months to seven years (mean 2,9 years). Fifty-six bitches were completely cured by surgery, 27 became less incontinent and 17 either failed to respond (nine animals) or showed an initial improvement in urinary function, but then relapsed (eight animals). Nine of these 17 animals underwent a second urethropexy procedure, resulting in a cure in six and an improvement in three cases (follow-up 12 to 41 months, mean 22-2 months). A deterioration in the response rate was observed over time. Postoperative complications were seen in 21 bitches and included an increased frequency of micturition (14 bitches), dysuria (six bitches) and anuria (three bitches). [source]

Flores hominid: New species or microcephalic dwarf?

Robert D. Martin
Abstract The proposed new hominid "Homo floresiensis" is based on specimens from cave deposits on the Indonesian island Flores. The primary evidence, dated at , 18,000 y, is a skull and partial skeleton of a very small but dentally adult individual (LB1). Incomplete specimens are attributed to eight additional individuals. Stone tools at the site are also attributed to H. floresiensis. The discoverers interpreted H. floresiensis as an insular dwarf derived from Homo erectus, but others see LB1 as a small-bodied microcephalic Homo sapiens. Study of virtual endocasts, including LB1 and a European microcephalic, purportedly excluded microcephaly, but reconsideration reveals several problems. The cranial capacity of LB1 (, 400 cc) is smaller than in any other known hominid < 3.5 Ma and is far too small to derive from Homo erectus by normal dwarfing. By contrast, some associated tools were generated with a prepared-core technique previously unknown for H. erectus, including bladelets otherwise associated exclusively with H. sapiens. The single European microcephalic skull used in comparing virtual endocasts was particularly unsuitable. The specimen was a cast, not the original skull (traced to Stuttgart), from a 10-year-old child with massive pathology. Moreover, the calotte does not fit well with the rest of the cast, probably being a later addition of unknown history. Consideration of various forms of human microcephaly and of two adult specimens indicates that LB1 could well be a microcephalic Homo sapiens. This is the most likely explanation for the incongruous association of a small-brained recent hominid with advanced stone tools. Anat Rec Part A, 288A:1123,1145, 2006. © 2006 Wiley-Liss, Inc. [source]

Susceptibility and reactivity in polysensitized individuals following controlled induction

Nannie Bangsgaard
Background: It is uncertain whether polysensitized patients acquire multiple allergies only because of a high degree of exposure to environmental allergens, or because of being highly susceptible to developing contact allergy. Objectives: The aim of this study was to investigate and compare susceptibility and reactivity in polysensitized and monosensitized individuals, and in healthy controls. Patients/methods: We sensitized 66 adult individuals (21 polysensitized, 22 monosensitized, and 23 healthy controls) with diphenylcyclopropenone and assessed challenge responses with visual scoring and ultrasound. We compared sensitization rates using a chi-square test and logistic regression analyses, and calculated linear regression lines of the elicitation responses for each individual. The mean values of the slopes and the intercepts for each group were used to measure the strength of the elicitation response, and were compared using the Mann,Whitney test. Results: Sensitization ratio was equal in the three groups: 57% for the polysensitized, 59% for the monosensitized, and 65% for the healthy control group. There was a lowered elicitation threshold in the polysensitized group compared with that in the monosensitized and healthy control groups and, although not statistically significant, a stronger elicitation response was observed in the polysensitized group. Conclusion: Increased reactivity was found in the polysensitized group, demonstrated by a lowered elicitation threshold, compared with that in the monosensitized and healthy control groups. [source]

Does ethnic origin have an independent impact on hypertension and diabetic complications?

V. Baskar
Aim:, The morbidity and mortality from cardiovascular complications in diabetes reputedly differ with ethnicity. We have evaluated the prevalence of hypertension and vascular complications amongst Afro-Caribbean (AC), Caucasian (C) and Indo-Asian (IA) ethnic subgroups of a district's diabetes population to estimate the impact of ethnic origin as an independent risk variable. Methods:, Of the 6485 registered adult individuals, 6047 had ethnic data available and belonged to one of the three ethnic groups described (AC 9%, C 70% and IA 21%). Statistical analyses were performed using spss version 11.5. Results:, Results are presented as mean ± s.d. or percentage. IAs were younger (AC 63 ± 13, C 61 ± 15 and IA 57 ± 13 years), were less obese (body mass index 30 ± 8, 29 ± 9, 28 ± 6 kg/cm2) and had lower systolic blood pressure (155 ± 25, 149 ± 24, 147 ± 24 mmHg) and lower prevalence of hypertension (82%, 74% and 68%) compared with C, who had lower values than AC (all p < 0.01). Relative to C group, the AC group had higher prevalence of hypertension and microvascular complications but lower macrovascular disease burden, while the IA group had lower hypertension and macrovascular complications but with comparable microvascular disease burden [microvascular (51%, 44% and 46%; p < 0.01) and macrovascular (33%, 40% and 32%; p < 0.001)]. On logistic regression, this effect of ethnic origin on diabetic complications was found to be significant and independent of other risk variables. Conclusion:, Hypertension and diabetic complication rates were different amongst ethnic subgroups. On logistic regression, it was found that the difference in distribution of age and diabetes duration largely accounted for this difference, although ethnic origin remained an independent risk factor. [source]

Morphological variation of the five vole species of the genus Microtus (Mammalia, Rodentia, Arvicolinae) occurring in Greece

ACTA ZOOLOGICA, Issue 3 2009
Stella E. Fraguedakis-Tsolis
Abstract Morphometric data for the five vole species of the genus Microtus living in Greece are old, sparse, poor and insufficiently analysed. This work aims to give the first comprehensive morphometric analysis of body and skull inter- and intraspecific variation for M. (M.) guentheri, M. (M.) rossiaemeridionalis, M. (Terricola) subterraneus, M. (T.) felteni and M. (T.) thomasi, applying multivariate statistics to 28 linear morphometric variables. It was based on ample material (202 adult individuals) using samples from localities that adequately cover the entire distributional range of each species in Greece. The five species and the two subgenera (Microtus and Terricola) were morphometrically clearly distinguished and discriminating variables were revealed. However, morphometrics did not provide robust criteria to infer phylogenetic relations among species. Furthermore, three species, M. (M.) guentheri, M. (M.) rossiaemeridionalis and M. (T.) thomasi, exhibited considerable intraspecific size or shape variation, which was mostly random and not associated with geographical proximity. Comparisons with data in the literature, mainly concerning populations of these species from adjacent areas, indicate that the Greek M. (M.) guentheri, M. (M.) rossiaemeridionalis and M. (T.) thomasi tend to be smaller than their conspecifics, while M. (T.) subterraneus and M. (T.) felteni are about equal in size to their Balkan relatives. [source]

Spatiotemporal patterns of seed dispersal in a wind-dispersed Mediterranean tree (Acer opalus subsp. granatense): implications for regeneration

ECOGRAPHY, Issue 1 2007
Lorena Gómez-Aparicio
Seed dispersal can severely limit the quantity of plant recruits and their spatial distribution. However, our understanding of the role of dispersal in regeneration dynamics is limited by the lack of knowledge of seed deposition patterns in space and time. In this paper, we analyse the spatiotemporal variability of seed dispersal patterns in the Mediterranean maple, Acer opalus subsp. granatense, by monitoring seed rain along two years at a broad spatial scale (2 mountain ranges, 2 populations per range, 4 microhabitats per population). We quantified seed limitation and its components (source and dispersal limitation), and explored dispersal limitation in space by analysing dispersal distances, seed aggregation, and microhabitat seed distribution. Acer opalus subsp. granatense was strongly seed-limited throughout the gradients explored, being always dispersal limitation much higher than source limitation. The distribution of seeds with distance from adult individuals was leptokurtic and right-skewed in all populations, being both kurtosis and skewness higher the year of the highest seed production. Dispersal distances were shorter than expected by random in the four populations, which suggests distance-limited dispersal. Dispersal patterns were highly aggregated and showed a preferential direction around adults. At the microhabitat scale, most seeds accumulated under adult maples. However, there were no more seeds under trees and shrubs other than maple than in open interspaces, implying that established vegetation does not disrupt patterns of seed deposition by physically trapping seeds. When compared with patterns of seedling establishment, limited dispersal ability and inter-annual spatial concordance in seed rain patterns suggest that several potentially safe sites for recruitment have a very low probability of receiving seeds in most maple populations. These findings are especially relevant for rare species such as Acer opalus subsp. granatense, and illustrate how dispersal studies are not only crucial for our understanding of plant population dynamics but also to provide conservation directions. [source]

How do paedomorphic newts cope with lake drying?

ECOGRAPHY, Issue 4 2003
Mathieu Denoël
Paedomorphosis, in which adult individuals retain larval traits, is widespread in newts and salamanders. Most evolutionary models predict the maintenance of this life-history trait in favourable aquatic habitats surrounded by hostile terrestrial environments. Nevertheless, numerous ponds inhabited by paedomorphic individuals are unpredictable and temporary. In an experimental framework, I showed that paedomorphic newts were able to metamorphose and thus survive in the absence of water. However, the mere decrease of water level or the life space do not seem to induce metamorphosis in paedomorphs. On the contrary, drying up induces almost all individuals to move on land and after that to colonize other aquatic sites located nearby. Such terrestrial migrations allow survival in drying conditions without metamorphosis as long as the distances of terrestrial migration are short. These results are consistent with the presence of paedomorphs in drying ponds and are in favor of classic optimality models predicting metamorphosis in unfavorable environments. [source]

Human jaw muscle strength and size in relation to limb muscle strength and size

M. C. Raadsheer
The aim of the present study was to investigate to what extent general factors (e.g. genotype, hormones) and factors at the craniofacial level (e.g. craniofacial size, jaw muscle architecture) contribute to the size and strength of the jaw muscles. A strong relationship of jaw muscle size and strength with that of other muscles would argue for general influences, whereas a weak relationship would argue for craniofacial influences. In 121 adult individuals, moments of maximal bite force, arm flexion force and leg extension force were measured. In addition, thicknesses of jaw muscles, arm flexor muscles and leg extensor muscles were measured using ultrasound. Relationships were assessed by using a principal component analysis. In females, one component was found in which all force moments were represented. Bite force moment, however, loaded very low. In males, two components were found. One component loaded for arm flexion and leg extension moments, the other loaded for bite force moments. In both females and males, only one component was found for the muscle thicknesses in which all muscle groups loaded similarly. It was concluded that the size of the jaw muscles was significantly related to the size of the limb muscles, suggesting that they were both subject to the same general influences. Maximal voluntary bite force moments were not significantly related to the moments of the arm flexion and leg extension forces, suggesting that besides the general influence on the muscle size, variation in bite force moment was also influenced by local variables, such as craniofacial morphology. [source]


EVOLUTION, Issue 3 2006
Charles D. Criscione
Abstract Little is known about actual mating systems in natural populations of parasites or about what constitutes the limits of a parasite deme. These parameters are interesting because they affect levels of genetic diversity, opportunities for local adaptation, and other evolutionary processes. We expect that transmission dynamics and the distribution of parasites among hosts should have a large effect on mating systems and demic structure, but currently we have mostly speculation and very few data. For example, infrapopulations (all the parasites in a single host) should behave as demes if parasite offspring are transmitted as a clump from host to host over several generations. However, if offspring are well mixed, then the parasite component population (all the parasites among a host population) would function as the deme. Similarly, low mean intensities or a high proportion of worms in single infections should increase the selfing rate. For species having an asexual amplification stage, transmission between intermediate and definitive (final) hosts will control the variance in clonal reproductive success, which in turn could have a large influence on effective sizes and rates of inbreeding. We examined demic structure, selfing rates, and the variance in clonal reproductive success in natural populations of Plagioporus shawi, a hermaphroditic trematode that parasitizes salmon. Overall levels of genetic diversity were very high. An a posteriori inference of population structure overwhelmingly supports the component population as the deme, rather than individual infrapopulations. Only a single pair of 597 adult individuals was identified as clones. Thus, the variance in clonal reproductive success was almost zero. Despite being hermaphroditic, P. shawi appears to be almost entirely outcrossing. Genetic estimates of selfing (<5%) were in accordance with the proportion of parasites from single infections. Thus, it appears that individual flukes outcross whenever possible and only resort to selfing when alone. Finally, our data support the hypothesis that aquatic transmission and the use of several intermediate hosts promotes high genetic diversity and well-mixed infrapopulations. [source]

Human attachment security is mediated by the amygdala: Evidence from combined fMRI and psychophysiological measures

Erwin Lemche
Abstract The neural basis of human attachment security remains unexamined. Using event-related functional magnetic resonance imaging (fMRI) and simultaneous recordings of skin conductance levels, we measured neural and autonomic responses in healthy adult individuals during a semantic conceptual priming task measuring human attachment security "by proxy". Performance during a stress but not a neutral prime condition was associated with response in bilateral amygdalae. Furthermore, levels of activity within bilateral amygdalae were highly positively correlated with attachment insecurity and autonomic response during the stress prime condition. We thereby demonstrate a key role of the amygdala in mediating autonomic activity associated with human attachment insecurity. Hum Brain Mapp, 2005. © 2005 Wiley-Liss, Inc. [source]

Major histocompatibility complex class II, fetal skin dendritic cells are potent accessory cells of polyclonal T-cell responses

IMMUNOLOGY, Issue 2 2000
A. Elbe-Bürger
Summary Whereas dendritic cells (DC) and Langerhans cells (LC) isolated from organs of adult individuals express surface major histocompatibility complex (MHC) class II antigens, DC lines generated from fetal murine skin, while capable of activating naive, allogeneic CD8+ T cells in a MHC class I-restricted fashion, do not exhibit anti-MHC class II surface reactivity and fail to stimulate the proliferation of naive, allogeneic CD4+ T cells. To test whether the CD45+ MHC class I+ CD80+ DC line 80/1 expresses incompetent, or fails to transcribe, MHC class II molecules, we performed biochemical and molecular studies using Western blot and polymerase chain reaction analysis. We found that 80/1 DC express MHC class II molecules neither at the protein nor at the transcriptional level. Ultrastructural examination of these cells revealed the presence of a LC-like morphology with indented nuclei, active cytoplasm, intermediate filaments and dendritic processes. In contrast to adult LC, no LC-specific cytoplasmic organelles (Birbeck granules) were present. Functionally, 80/1 DC in the presence, but not in the absence, of concanavalin A and anti-T-cell receptor monoclonal antibodies stimulated a vigorous proliferative response of naive CD4+ and CD8+ T cells. Furthermore, we found that the anti-CD3-induced stimulation of naive CD4+ and CD8+ T cells was critically dependent on the expression of Fc,R on 80/1 DC and that the requirement for co-stimulation depends on the intensity of T-cell receptor signalling. [source]

Masticatory and non-masticatory dental modifications in the epipalaeolithic necropolis of Taforalt (Morocco)

B. Bonfiglioli
Abstract In this study, we used standardized methods to investigate masticatory and non-masticatory dental alterations (chipping, notches, interproximal grooves) in teeth from the epipalaeolithic necropolis of Taforalt (Morocco, about 12,000,11,000 BP). The particular distribution of some of the alterations could be related to avulsion of the upper central incisors, a systematic ritual characterizing all adult individuals of the necropolis. Because of this practice, the functions of the anterior teeth (cutting and tearing portions of food while eating, holding objects, etc.) likely shifted to the posterior teeth. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyx jubatus) and domestic cat (Felis silvestris f. catus)

G. E. Weissengruber
Abstract Structures of the hyoid apparatus, the pharynx and their topographical positions in the lion, tiger, jaguar, cheetah and domestic cat were described in order to determine morphological differences between species or subfamilies of the Felidae. In the lion, tiger and jaguar (species of the subfamily Pantherinae) the Epihyoideum is an elastic ligament lying between the lateral pharyngeal muscles and the Musculus (M.) thyroglossus rather than a bony element like in the cheetah or the domestic cat. The M. thyroglossus was only present in the species of the Pantherinae studied. In the lion and the jaguar the Thyrohyoideum and the thyroid cartilage are connected by an elastic ligament, whereas in the tiger there is a synovial articulation. In adult individuals of the lion, tiger and jaguar the ventral end of the tympanohyal cartilage is rotated and therefore the ventral end of the attached Stylohyoideum lies caudal to the Tympanohyoideum and the cranial base. In newborn jaguars the Apparatus hyoideus shows a similar topographical position as in adult cheetahs or domestic cats. In adult Pantherinae, the Basihyoideum and the attached larynx occupy a descended position: they are situated near the cranial thoracic aperture, the pharyngeal wall and the soft palate are caudally elongated accordingly. In the Pantherinae examined the caudal end of the soft palate lies dorsal to the glottis. Differences in these morphological features between the subfamilies of the Felidae have an influence on specific structural characters of their vocalizations. [source]

Use of trace elements in feathers of sand martin Riparia riparia for identifying moulting areas

Tibor Szép
We investigated whether trace elements in tail feathers of an insectivorous and long-distance migratory bird species could be used to identify moulting areas and hence migratory pathways. We analysed tail feathers from birds of different age and sex collected from a range of different breeding sites across Europe. The site of moult had a large effect on elemental composition of feathers of birds, both at the European and African moulting sites. Analysis of feathers of nestlings with known origin suggested that the elemental composition of feathers depended largely upon the micro-geographical location of the colony. The distance between moulting areas could not explain the level of differences in trace elements. Analysis of feathers grown by the same individuals on the African wintering grounds and in the following breeding season in Europe showed a large difference in composition indicating that moulting site affects elemental composition. Tail feathers moulted in winter in Africa by adults breeding in different European regions differed markedly in elemental composition, indicating that they used different moulting areas. Analysis of tail feathers of the same adult individuals in two consecutive years showed that sand martins in their first and second wintering season grew feathers with largely similar elemental composition, although the amounts of several elements in tail feathers of the older birds was lower. There was no difference between the sexes in the elemental composition of their feathers grown in Africa. Investigation of the trace element composition of feathers could be a useful method for studying similarity among groups of individuals in their use of moulting areas. [source]

Agaricus macrosporus as a potential bioremediation agent for substrates contaminated with heavy metals

MA García
Abstract This study investigated the potential use of the mushroom Agaricus macrosporus for bioextraction of heavy metals from contaminated substrates. Mushrooms were grown (1) in a non-contaminated control substrate, (2) in a substrate with added Cd (10 mg per kg dw), and (3) in a multi-contaminated substrate (Cd, Hg and Pb each at 10 mg kg,1; Cu and Zn each at 20 mg kg,1). Metal contents were determined in fruiting bodies by anodic stripping voltammetry (ASV). In the control substrate, three production waves (,breaks') were obtained, compared with only two in the contaminated substrates; however, total biomass in the Cd-contaminated substrate was similar to that in the control substrate, and only 40% lower (ie still considerable) in the Hg-containing multi-contaminated substrate. Within each break, metal contents were higher in young than in adult individuals. Metal contents were also higher in the hymenophore than in other parts of the fruiting body. The metal content data indicate that A macrosporus effectively extracted Cd, Hg and Cu (though not Pb) from the contaminated substrates. Of particular interest is the tolerance and extraction of Hg, in contrast with plants. These results suggest that fungi such as A macrosporus may be effective for bioremediation of metal-contaminated substrates, though bearing in mind that in many contaminated environments cultivation of mushrooms of this type may be difficult. Copyright © 2005 Society of Chemical Industry [source]

Viscosity and emulsifying capacity in pota and octopus muscle during frozen storage

C Ruiz-Capillas
Abstract The functional quality of pota and octopus muscle during frozen storage for up to 12 months was evaluated periodically by determining viscosity and emulsifying capacity levels. In both species the effect on different anatomical locations (mantle and arms) in mature and young male and female individuals was studied. Apparent viscosity and emulsifying capacity levels were greater in octopus than in pota. While in pota a sharp decrease was observed in viscosity levels, falling to virtually nil, viscosity levels in octopus increased in the first 2 months and only slight decreases were observed at the end of storage. The change in emulsifying capacity, however, was quite similar in the two species, with not very sharp decreases. According to these results, emulsifying capacity measurement could be a suitable technique for showing the changes that occur in the muscle proteins of these species when they are stored frozen. No differences were observed by sex, but there were differences depending on the stage of maturity and anatomical location. Thus pota and octopus mantles present greater stability in frozen storage than the arms, and there is a tendency, although not always significant, that the mantles of young pota and octopus specimens are more stable in frozen storage than the mantles of adult individuals. Copyright © 2003 Society of Chemical Industry [source]

Nucleation and facilitation in salt pans in Mediterranean salt marshes

A.E. Rubio-Casal
Tutin et al. (1992) Abstract. Arthrocnemum macrostachyum is a perennial species acting as a primary colonizer of salt pans in Mediterranean high salt marshes. Salicornia ramosissima, an annual, occurs in salt pans under Arthrocnemum canopies and in open areas. The aim of this study was to analyse, in wild populations and a transplant experiment, how S. ramosissima population dynamics and growth are affected by A. macrostachyum. The environmental conditions within the patches of Arthrocnemum were less stressful than in the open areas, with lower radiation levels and salinity concentrations. In the inner areas of A. macrostachyum patches, density-dependent mortality processes of S. ramosissima seedlings led to low densities of adult individuals with greater morphological development and reproductive success than in open areas. However, at the edges of Arthrocnemum patches facilitation of seedling survival favoured high densities. Environmental stress hindered development, decreased reproduction and premature death. These results are in agreement with the general theory of factors controlling vegetation distribution that biotic interactions dominate in low stress environments, while abiotic interactions dominate under harsher environmental conditions. A. macrostachyum plays an essential role in the succession in these salt pans, facilitating seed production and stimulating nucleation processes in S. ramosissima. [source]

Demographic Characteristics of Lytechinus variegatus (Echinoidea: Echinodermata) from Three Habitats in a North Florida Bay, Gulf of Mexico

MARINE ECOLOGY, Issue 1 2000
Steven D. Beddingfield
Abstract. The population densities, spatial distributions, size frequencies, growth rates, longevity and reproductive activities of sub-populations of the sea urchin Lytechinus variegatus were investigated over a two-year period. Sea urchins were examined in three habitats in Saint Joseph Bay, Florida, which is within the northern limits of their distribution. Densities of sea urchins, which ranged as high as 35 individuals ·,2, fluctuated seasonally at all sites and were higher in seagrass beds comprised of Thalassia testudinum than Syringodium filiforme or on a sand flat. A cold front caused large-scale, catastrophic mortality among adult, and especially juvenile, sea urchins in nearshore habitats of the Bay in the spring of 1993, leading to a dramatic decline in sea urchin densities at the Thalassia seagrass site. The population recovered over 6 months at this site and was attributable to immigration of new adults. Juvenile recruitment displayed both interannual and site-specific variability, with recruitment being highest in seagrass habitats in fall and spring. The most pronounced recruitment event occurred in fall 1993 at the Thalassia site. Spatial distributions of adult individuals ascertained monthly never varied from random in the seagrass beds (T. testudinum and S. filiforme) or during spring, summer or fall months on the sand flat. Nonetheless, aggregations of adult sea urchins were observed on the sand flat in the winter months and were associated with patchy distributions of plant food resources. Juvenile sea urchins (< 25 mm test diameter) exhibited aggregations at all sites and 67 % of all juveniles under 10 mm test diameter (91 of 165 individuals observed) were found under the spine canopies of adults. Measurements of the inducibility of spawning indicated peak gametic maturity in all three sub-populations in spring and summer. Gonad indices varied between habitats and years, but distinct maxima were detected, particularly in spring 1993 and late summer 1994. The mean gonad index of individuals at the Syringodium seagrass site was 2- to 4-fold higher than the other sites in spring 1993 and gonad indices were much higher at all sites in spring of 1993 than 1994. Estimates of growth based on changes in size frequency cohorts coupled with measurements of growth bands on lantern demipyramids indicated that L. variegatus in three habitats of Saint Joseph Bay have similar growth rates and attain a mean test diameter of approximately 35 mm in one year. In contrast to populations within the central biogeographical range of the species, which may attain test diameters up to 90 mm, the largest individuals recorded in Saint Joseph Bay were 60 mm in test diameter, and almost all individuals were no more than 45 mm in test diameter or two years of age. The demographics of L. variegatus in the northern limits of their distribution appear to be strongly influenced by latitudinally driven, low-temperature events and secondarily by local abiotic factors, especially springtime low salinities, which may negatively impact larval development and recruitment. [source]

Variable extent of sex-biased dispersal in a strongly polygynous mammal

Abstract For mammals with a polygynous mating system, dispersal is expected to be male-biased. However, with the increase in empirical studies, discrepancies are arising between the expected and observed direction/extent of the bias in dispersal. In this study, we assessed sex-biased dispersal in red deer (Cervus elaphus) on 13 estates from the Scottish Highlands. A total of 568 adult individuals were genotyped at 21 microsatellite markers and sequenced for 821 bp of the mitochondrial control region. Estimates of population structure with mitochondrial sequences were eight times larger than that obtained with microsatellite data (Fst,-mtDNA = 0.831; Fst,-micros = 0.096) indicating overall male-biased dispersal in the study area. Comparisons of microsatellite data between the sexes indicated a predominance of male-biased dispersal in the study area but values of FST and relatedness were only slighter larger for females. Individual-based spatial autocorrelation analysis generated a similar pattern of relatedness across geographical distances for both sexes, with differences only significant at two distance intervals (25,30 and 70,112 km). Patterns of relatedness differed between estates, male biased-dispersal was detected in eight estates but no sex-biased dispersal was found in the remaining five. Neither population density nor landscape cover was found to be associated with the patterns of relatedness found across the estates. Differences in management strategies that could influence age structure, sex ratio and dispersal behaviour are proposed as potential factors influencing the relatedness patterns observed. This study provides new insights on dispersal of a strongly polygynous mammal at geographical scales relevant for management and conservation. [source]

Population genetic structure of mahogany (Swietenia macrophylla King, Meliaceae) across the Brazilian Amazon, based on variation at microsatellite loci: implications for conservation

Maristerra R. Lemes
Abstract Mahogany (Swietenia macrophylla, Meliaceae) is the most valuable and intensively exploited Neotropical tree. No information is available regarding the genetic structure of mahogany in South America, yet the region harbours most of the unlogged populations of this prized hardwood. Here we report on the genetic diversity within and the differentiation among seven natural populations separated by up to 2100 km along the southern arc of the Brazilian Amazon basin. We analysed the variation at eight microsatellite loci for 194 adult individuals. All loci were highly variable, with the number of alleles per locus ranging from 13 to 27 (mean = 18.4). High levels of genetic diversity were found for all populations at the eight loci (mean HE = 0.781, range 0.754,0.812). We found moderate but statistically significant genetic differentiation among populations considering both estimators of FST and RST, , = 0.097 and , = 0.147, respectively. Estimates of , and , were significantly greater than zero for all pairwise population comparisons. Pairwise ,-values were positively and significantly correlated with geographical distance under the isolation-by-distance model. Furthermore, four of the populations exhibited a significant inbreeding coefficient. The finding of local differentiation among Amazonian mahogany populations underscores the need for in situ conservation of multiple populations of S. macrophylla across its distribution in the Brazilian Amazon. In addition, the occurrence of microgeographical genetic differentiation at a local scale indicates the importance of maintaining populations in their diverse habitats, especially in areas with mosaics of topography and soil. [source]

Polymorphic microsatellite DNA markers for the grey fantail, Rhipidura albiscapa

Abstract We isolated and characterized five polymorphic microsatellite markers for the grey fantail Rhipidura albiscapa from genomic libraries enriched for (AC)n and (GT)n microsatellites. In 34 adult individuals, the number of alleles per locus ranged from eight to 17. Observed and expected heterozygosities ranged from 0.65 to 0.94 and 0.83 to 0.94, respectively. These markers will be useful for analysing extra-pair paternity in fantails. [source]

Prevalence, incidence and persistence of antipsychotic drug prescribing in the Italian general population: retrospective database analysis, 1999,2002,

Mersia Mirandola StatD
Abstract Purpose To investigate the prevalence, incidence and persistence with antipsychotic drug therapy in a large and geographically defined catchment area of Italian general population. Methods All antipsychotic drug prescriptions dispensed during 1999, 2000, 2001 and 2002 were extracted from an administrative prescription database covering a population of 2,640,379 individuals. Antipsychotic drug users were defined as patients who had at least one recorded prescription in the current year. New users were defined as patients receiving a first prescription without any recorded antipsychotic drug treatment in the previous 12 months. Prevalence data were calculated by dividing users by the total number of male and female residents in each age group. Incidence data were calculated as the number of new users divided by the person-time free from antipsychotic drugs in the current year. The cumulative persistence of each medication was calculated by dividing the total prescribed amount of antipsychotic drug by the recommended daily dose, according to each agent's defined daily dose (DDD). Results A progressive rise in prevalence and incidence rates was observed during the 4-year period. In each census year, the prevalence and incidence of prescribing was higher in females than males, and progressively rose with age, with the highest rates in old and very old subjects. The analysis of persistence with therapy revealed that 3176 individuals (78.5%) were occasional antipsychotic drug users, and that occasional use was more frequent among individuals receiving conventional antipsychotic drugs than among individuals receiving novel antipsychotic drugs. This difference was not explained by differences in the occurrence of neurologic adverse reactions, as shown by the concurrent prescribing of anticholinergic drugs, which was fairly similar between the two groups of new drug users. Additionally, we found that conventioal antipsychotic drugs were more often used in older individuals, where occasional use is very frequent, while novel antipsychotic drugs were more often prescribed in young and adult individuals, where regular use is more frequent. Conclusions An epidemiologically relevant proportion of everyday individuals is annually exposed to antipsychotic drugs. The distribution of prevalence and incidence rates by age highlighted an emerging public health issue related to the adverse and beneficial consequences of antipsychotic drug exposure in the elderly. The finding that persistence with therapy was longer in new users of novel antipsychotic drugs compared with new users of conventional agents might be explained by the different demographic and clinical characteristics of individuals receiving these two drug classes and not by the different tolerability profile of these two drug classes. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Self-monitoring of blood glucose; frequency, determinants and self-adjustment of treatment in an adult Swedish diabetic population

Utilisation, determinants of SMBG
Abstract Objective To analyse the utilisation of self-monitoring of blood glucose (SMBG) among adult diabetic subjects. Methods A cross-sectional study with a standardized interview, a physical examination, and an evaluation of medical records comprising all known diabetic subjects living in six defined primary health care districts in southern Sweden. Of 1861 identified subjects aged >25 years, 90.1% participated. Mean age was 66±0.4,yrs; 94% were diagnosed ,30,yrs, and 70.4% were not gainfully employed. Results SMBG was used by 36.3% of all subjects (20.5% regularly, 15.8% sporadically). In 51.8% of cases regularly performing SMBG the results were used for self-adjustment of treatment (SAT). In multiple logistic regression analysis SMBG was related to awareness of illness (OR [95% CI]; 2.64[1.59,4.40]), treatment with insulin (2.52 [1.92,3.29]), and inversely related to age (50,69,yrs; 0.70[0.50,0.99], >70,yrs; 0.40[0.28,0.59]). The strongest independent influence on SAT based on SMBG results was awareness of illness (3.42[1.74,6.74]), followed by duration >10,yrs (1.74[1.28,2.38]), and there was an inverse relation to a multiple disease pattern in terms of cardiocerebrovascular disease and age. Living conditions, social position, or treatment location were not evidently related to SMBG or SAT. Conclusions A large proportion of adult individuals does not use SMBG regularly. Regular SMBG performers do not use it for SAT, and thus the use is not optimized for achieving good glycaemic control and especially with regard to awareness of illness. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Ontogeny of robusticity of craniofacial traits in modern humans: A study of South American populations

Paula N. Gonzalez
Abstract To date, differences in craniofacial robusticity among modern and fossil humans have been primarily addressed by analyzing adult individuals; thus, the developmental basis of such differentiation remains poorly understood. This article aims to analyze the ontogenetic development of craniofacial robusticity in human populations from South America. Geometric morphometric methods were used to describe cranial traits in lateral view by using landmarks and semilandmarks. We compare the patterns of variation among populations obtained with subadults and adults to determine whether population-specific differences are evident at early postnatal ontogeny, compare ontogenetic allometric trajectories to ascertain whether changes in the ontogeny of shape contribute to the differentiation of adult morphologies, and estimate the amount of size change that occurs during growth along each population-specific trajectory. The results obtained indicate that the pattern of interpopulation variation in shape and size is already established at the age of 5 years, meaning that processes acting early during ontogeny contribute to the adult variation. The ontogenetic allometric trajectories are not parallel among all samples, suggesting the divergence in the size-related shape changes. Finally, the extension of ontogenetic trajectories also seems to contribute to shape variation observed among adults. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source]

Spatial patterns and evolutionary processes in southern South America: A study of dental morphometric variation

Valeria Bernal
Abstract The purpose of this article is to examine the patterns of evolutionary relationships between human populations from the later Late Holocene (1,500,100 years BP) of southern South America on the basis of dental morphometric data. We tested the hypotheses that the variation observed in this region would be explained by the existence of populations with different phylogenetic origin or differential action of gene flow and genetic drift. In this study, we analyzed permanent teeth from 17 samples of male and female adult individuals from throughout southern South America. We measured mesiodistal and buccolingual diameters at the base of the crown, along the cement,enamel junction. The results of multiple regression analysis and a mantel correlogram indicate the existence of spatial structure in dental shape variation, as the D2 Mahalanobis distance between samples increases with increasing geographical distance between them. In addition, the correlation test results show a trend toward reduction of the internal variation of samples with increasing latitude. The detected pattern of dental variation agrees with the one expected as an outcome of founder serial effects related to an expansion of range during the initial occupation of southern South America. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]

Prevalence and etiology of acquired anemia in Medieval York, England

Amy Sullivan
Abstract This paper presents three distinct models for the development of acquired anemia: iron-deficiency anemia produced by the inadequate intake and/or absorption of iron, the anemia of chronic disease (ACD) caused by the body's natural iron-withholding defense against microbial invaders, and megaloblastic anemia caused by insufficient intake and/or absorption of vitamin B12 or folic acid. These etiological models are used to interpret the distribution and etiology of anemia among adult individuals interred at the Medieval Gilbertine Priory of St. Andrew, Fishergate, York (n = 147). This bioarchaeological analysis uncovered not only a strong relationship between decreasing status and increasing prevalence of anemia for both men and women, but also identified clear sex-based differences at this site. Within the high-status group, blood and iron loss as a result of rampant parasitism likely produced an environment ripe for the development of iron-deficiency anemia, while the parasitic consumption of vitamin B12 may have caused occasional cases of megaloblastic anemia. As status decreases, the interpretation of anemia becomes more complex, with megaloblastic anemia and ACD emerging as viable, potentially heavy contributors to the anemia experiences of low-status people at St. Andrew's. Apart from status effects, women (especially young women) are disproportionately affected by anemia when compared to men within their own status group and, on average, are also more likely to have experienced anemia than their male peers from other status groups. This suggests that high iron-demand reproductive functions helped to make iron-deficiency anemia a chronic condition in many women's lives irrespective of their status affiliation. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc. [source]

Mating promiscuity and reproductive tactics in female black and gold howler monkeys (Alouatta caraya) inhabiting an island on the Parana river, Argentina

Martin M. Kowalewski
Abstract In several primate species, females mate promiscuously and several adult males peacefully co-reside in the same social group. We investigated female mating behavior in two neighboring multimale,multifemale groups of Alouatta caraya in northern Argentina (27°20,S,58°40,W). All adult individuals in each group were marked with identification anklets and ear tags, and followed for five consecutive full days per month during 20 consecutive months. We recorded 219 copulations for eight resident females in these two groups. Thirty-two percent of matings involved extra-group copulations and 68% were with resident males. During periods when females were likely to conceive and during periods when females were nonfertile (pregnancy and lactation), there were no significant differences in the average number of resident and nonresident males with which they copulated (G -test: Gadj=0.1, df=3, P>0.05). In both of our study groups, adult males were tolerant of the mating activities between resident males and resident females, but acted aggressively and collectively (howling, border vigilance, and fighting) when extragroup males attempted to enter the group and mate with resident females. Given the frequency of extragroup matings, we examined the distance females traveled to engage in these copulations, time engaged in pre- and postcopulatory behavior, and the risk of injury during extragroup copulations. These costs were found to be relatively small. We suggest that female promiscuity is the prime driver or constraint on male reproductive opportunities in this species. Female promiscuity in A. caraya appears to represent a mixed mating strategy that may serve to increase opportunities for genetic diversity between a female's successive offspring as well as minimize the risk of infanticide by spreading paternity estimates across a larger number of adult males. Am. J. Primatol. 72:734,748, 2010. © 2010 Wiley-Liss, Inc. [source]

What limits the spread of two congeneric butterfly species after their reintroduction: quality or spatial arrangement of habitat?

F. Van Langevelde
Abstract Population growth and spread of recently reintroduced species is crucial for the success of their reintroduction. We analysed what limits the spread of two congeneric butterfly species Maculinea teleius and Maculinea nausithous, over 10 years following their reintroduction. During this time, their distributions appeared to be limited to a few sites although it was thought that more suitable habitats were available. Thus, we question, does the quality or the spatial arrangement of their habitat limit their spread? Although adult individuals of both species can select high-quality plots, we show that selection of suitable plots in the area of reintroduction is spatially constrained. A low colonization probability of unoccupied distant plots of high quality was found for both species. The abandonment of occupied plots in Ma. teleius was also found to be dependent on the distance to occupied plots. We conclude that the spatial distribution of the two species during the 10 years following reintroduction was limited by the spatial arrangement of their habitat, rather than by the availability of high-quality plots. The spatial constraints in movement can explain observed source,sink structures when female butterflies deposit their eggs on low-quality plots. We conclude that although these species have very similar life histories, they require different approaches to their conservation due to subtle differences in adult habitat use and movement. Conservation of Ma. teleius should concentrate on improving local habitat quality, whereas conservation of Ma. nausithous is predicted to be more effective by creating a spatial network of suitable habitat plots, such as along road verges. [source]