bluuebunny/crossref_metadata_2025_split huggingface dataset:
The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin‐pair synchrony
Authors: Custodio Rodrigo Jose , Junior Carlos Eduardo Martinelli , Milani Soraya Lopes Sader , Simões Aguinaldo Luis , De Castro Margaret , Moreira Ayrton Custodio 
Published: November 2006

SummaryObjective  Studies on the influence of genetic factors on the ontogeny of cortisol circadian rhythm in infants are lacking. This study evaluated the influence of twinning and the heritability on the age of emergence of salivary cortisol rhythm.Design and subjects  A longitudinal study was performed using salivary samples obtained during morning and night, at 2, 4, 8, 12, 16, 20 and 24 weeks of postnatal life in 34 infants, 10 monozygotic (MZ) and 7 dizygotic (DZ) twin pairs. Salivary cortisol was determined by radioimmunoassay (RIA). Zigosity was verified by DNA analysis of at least 13 short tandem repeat polymorphisms. Difference of the emergence of cortisol circadian rhythm, within each twin pair, the intraclass correlation coefficient and the heritability index (h2) were calculated.Results  The mean (± SEM) age of emergence of salivary cortisol circadian rhythm was similar in MZ and DZ (7·8 ± 1·0 vs 7·4 ± 1·3 weeks). Seven pairs showed coincidence of the emergence of cortisol rhythm. Ten pairs were not coincident; among them the within‐pair difference of emergence of salivary circadian rhythm was similar in both MZ and DZ groups. The intraclass correlation coefficients were rMZ = 0·60, P = 0·02; and rDZ = 0·65, P = 0·03, respectively. The heritability index (h2) was 0·21 (ns).Conclusions  Salivary circadian rhythm appeared at the same postnatal age in MZ and DZ twin infants. Although several physiological aspects might be involved, the heritability index, obtained in the present study, suggests less genetic than environmental impact on the age of the onset of the cortisol circadian rhythm. Our data also indicated that each twin‐pair show synchrony because they probably shared prenatal and postnatal environmental synchronizers.
Plant guilds drive biomass response to global warming and water availability in subalpine grassland
Authors: SEBASTIÀ MARIA‐TERESA 
Published: November 2006

Summary

The consequences of global warming and changes in resource availability were investigated in subalpine grasslands in the Pyrenees. These communities are considered to be especially vulnerable to climate change because of their position at the south‐western edge of the semi‐natural grassland biome in Europe.
Changes in patterns of above‐ and below‐ground biomass were assessed for different plant guilds in two experiments, in which turves were transplanted from upland to lowland locations. The first experiment aimed to evaluate general responses to warming and drought, and the second to disentangle the effects of possible underlying mechanisms through resource manipulation by means of a nitrogen × phosphorus fertilization experiment.
The increased above‐ground biomass in grassland turves transplanted to lowlands suggested that biomass production was more temperature‐limited than water‐limited. The enhancement effect found in the upland turves following phosphorus addition supported the hypothesis of a strong limitation arising from reduced nutrient availability, confirming the central role played by phosphorus in these grasslands and its potential importance in the response to global change.
Nitrogen addition did not stimulate total biomass but affected guild composition. Grasses dominated the uplands and at high resource levels, while forbs dominated the lowlands and when water and nutrients decreased. The counterintuitive effect of increased biomass with decreased water in the lowlands was related to shifts in dominance from grasses to forbs, probably enabled by decreased nutrient availability under drought conditions.
Synthesis and applications. Environmental factors interacted in complex ways, producing changes in biomass distribution and guild proportions in subalpine grassland. In addition, the results suggested that the capability of high‐altitude grasslands to provide quality forage in summer time could be threatened in the northern Mediterranean region under climate change conditions because of: (i) a decrease in their reliability as a result of complex biomass interactions with temperature, water and nutrient dynamics; (ii) expected feedback mechanisms; and (iii) compositional shifts.
Local and landscape factors in differently managed arable fields affect the insect herbivore community of a non‐crop plant species
Authors: CLOUGH YANN , KRUESS ANDREAS , TSCHARNTKE TEJA 
Published: November 2006

Summary

The expansion of simplified ecosystems such as intensively managed annual crops plays a big part in driving the global biodiversity crisis. Field‐scale diversification, for example leaving weeds to grow in crops, is one way in which diversity in agro‐ecosystems can be restored. However, little is known about the determinants of the non‐crop plant‐based insect communities within arable fields at local and larger spatial scales, an essential component in extrapolating plant diversity benefits to higher trophic levels.
We investigated how diversification of agro‐ecosystems at the field and landscape levels affects the insect community of the creeping thistle Cirsium arvense. Artificial plots of the host‐plant were established in three regions of Germany in 48 paired organic (diverse, weeds not controlled with herbicides) and conventional (simplified, very low weed density and species richness) wheat fields across a gradient of landscape heterogeneity, from simple arable‐dominated to heterogeneous, diverse landscapes.
Leaf‐feeding herbivores were monitored directly, while stem‐boring herbivores and their parasitoids were quantified by dissecting the stems of the thistles. Land‐use types and naturally occurring thistle stands were mapped within a radius of 1 km around each thistle plot.
Herbivore species richness was enhanced by both organic farming and landscape heterogeneity but not by higher densities of thistles in the landscape. For most of the species, host‐plant plots in organic fields were more likely to be colonized than those in the conventional fields. The enhancement of diversity in organic fields is probably the result of a slightly higher natural cover of the host‐plant Cirsium arvense.
Synthesis and applications. Both diversification of landscape (fewer arable crops, more perennial habitats) and extensification through organic management are effective measures of enhancing arthropod diversity on weeds. The impact of field‐scale agri‐environment schemes on biodiversity should be supplemented by including landscape‐scale diversification programmes to include a minimum level of perennial habitat cover. Biodiversity benefits of organic agriculture rely for a large part on non‐crop plants. Weed populations should be allowed to coexist with the crop to maintain these benefits, which are threatened by more intensive ‘organic’ management, such as heavy mechanical weed control.
Assessing impacts of large herbivores on shrubs: tests of scaling factors for utilization rates from shoot‐level measurements
Authors: BILYEU DANIELLE M. , COOPER DAVID J. , HOBBS N. THOMPSON 
Published: November 2006

Summary

Accurate methods for estimating the intensity of browsing by herbivores are fundamental to understanding the ecology of shrub communities. Quantifying browse utilization on shrubs at large scales is difficult because shrubs have complex, spatially variable growth forms. Most existing methods estimate browsing rate at the scale of linear current‐year shoots or twigs. How such fine‐scale estimates relate to the proportion of current‐year growth consumed from whole plants or plots is often unknown. The relationship is likely to be complex because herbivores selectively browse more productive plants and plant parts.
Using a clipping experiment designed to mimic elk Cervus elaphus browsing, we quantified how utilization estimates at the scale of individual current‐year shoots of two willow species, Salix bebbiana and Salix geyeriana, relate to actual mass removed at the scale of rooted stems. Three approaches to scaling were examined: (i) taking an average, (ii) multiplying by the proportion of shoots clipped and (iii) multiplying by a novel scaling factor that weights utilization by productivity. To address how to scale‐up from stems to plots, we applied the most accurate stem‐level method to elk‐browsed willow and compared plot‐level estimates by two scaling approaches.
In scaling from shoots to stems, the novel scaling factor was most successful and resulted in accurate estimates for up to c. 45% of current annual growth clipped. In scaling from the stem to the plot, elk preference for more productive stems caused a simple average of stem‐level utilization to differ from a productivity‐weighted average by 15%.
Synthesis and applications. In order to reflect accurately the proportion of biomass consumed at a whole‐plant level, fine‐scale estimates of utilization should be weighted by an estimate of pre‐browse productivity, as this is mathematically equivalent to summing pre‐browse and post‐browse mass before calculating the proportion consumed. In developing methods to estimate utilization at plot scales, an important consideration is the choice of sampling unit, which should be both amenable to unbiased sampling and tractable in terms of measuring productivity.
Developmental regulation of the glyoxylate cycle in the human pathogen Penicillium marneffei
Authors: Cánovas David , Andrianopoulos Alex 
Published: November 2006

Summary Penicillium marneffei is a thermally dimorphic opportunistic human pathogen with a saprophytic filamentous hyphal form at 25°C and a pathogenic unicellular yeast form at 37°C. During infection. P. marneffei yeast cells exist intracellularly in macrophages. To cope with nutrient deprivation during the infection process, a number of pathogens employ the glyoxylate cycle to utilize fatty acids as carbon sources. The genes which constitute this pathway have been implicated in pathogenesis. To investigate acetate and fatty acid utilization, the acuD gene encoding a key glyoxylate cycle enzyme (isocitrate lyase) was cloned. The acuD gene is regulated by both carbon source and temperature in P. marneffei, being strongly induced at 37°C even in the presence of a repressing carbon source such as glucose. When introduced into the non‐pathogenic monomorphic fungus Aspergillus nidulans, the P. marneffei acuD promoter only responds to carbon source. Similarly, when the A. nidulans acuD promoter is introduced into P. marneffei it only responds to carbon source suggesting that P. marneffei possesses both cis elements and trans‐acting factors to control acuD by temperature. The Zn(II)2Cys6 DNA binding motif transcriptional activator FacB was cloned and is responsible for carbon source‐, but not temperature‐, dependent induction of acuD. The expression of acuD at 37°C is induced by AbaA, a key regulator of morphogenesis in P. marneffei, but deletion of abaA does not completely eliminate temperature‐dependent induction, suggesting that acuD and the glyoxylate cycle are regulated by a complex network of factors in P. marneffei which may contribute to its pathogenicity.
Hypermutagenesis in mutA cells is mediated by mistranslational corruption of polymerase, and is accompanied by replication fork collapse
Authors: Al Mamun Abu Amar M. , Gautam Satyendra , Humayun M. Zafri 
Published: November 2006

SummaryElevated mistranslation induces a mutator response termed translational stress‐induced mutagenesis (TSM) that is mediated by an unidentified modification of DNA polymerase III. Here we address two questions: (i) does TSM result from direct polymerase corruption, or from an indirect pathway triggered by increased protein turnover? (ii) Why are homologous recombination functions required for the expression of TSM under certain conditions, but not others? We show that replication of bacteriophage T4 in cells expressing the mutA allele of the glyV tRNA gene (Asp→Gly mistranslation), leads to both increased mutagenesis, and to an altered mutational specificity, results that strongly support mistranslational corruption of DNA polymerase. We also show that expression of mutA, which confers a recA‐dependent mutator phenotype, leads to increased lambdoid prophage induction (selectable in vivo expression technology assay), suggesting that replication fork collapse occurs more frequently in mutA cells relative to control cells. No such increase in prophage induction is seen in cells expressing alaVGlu tRNA (Glu→Ala mistranslation), in which the mutator phenotype is recA‐independent. We propose that replication fork collapse accompanies episodic hypermutagenic replication cycles in mutA cells, requiring homologous recombination functions for fork recovery, and therefore, for mutation recovery. These findings highlight hitherto under‐appreciated links among translation, replication and recombination, and suggest that translational fidelity, which is affected by genetic and environmental signals, is a key modulator of replication fidelity.
Achilles tendon imaging
Authors: Harris CA , Peduto AJ 
Published: November 2006

SummaryThe Achilles tendon is the largest and strongest tendon in the body, yet one of the most commonly injured. Tendon degeneration is a relatively common disorder, predisposing to tears and often associated with paratenonitis. Numerous other diseases involve the Achilles tendon, some with classic imaging appearances, others with non‐specific appearances. The aim of this pictorial essay is to review the radiographic, computed tomographic, ultrasonographic and MR appearances of the normal and diseased Achilles tendon.
Familial cerebral cavernous haemangioma diagnosed in an infant with a rapidly growing cerebral lesion
Authors: Ng BHK , Mulyadi E , Pereira JK , Ghedia S , Pinner J , Mowat D , Vonau M 
Published: November 2006

SummaryCavernous haemangiomas of the central nervous system are vascular malformations best imaged by MRI. They may present at any age, but to our knowledge only 39 cases in the first year of life have previously been reported. A familial form has been described and some of the underlying genetic mutations have recently been discovered. We present the clinical features and serial MRI findings of an 8‐week‐old boy who presented with subacute intracranial haemorrhage followed by rapid growth of a surgically proven cavernous haemangioma, mimicking a tumour. He also developed new lesions. A strong family history of neurological disease was elucidated. A familial form of cavernous haemangioma was confirmed by identification of a KRIT 1 gene mutation and cavernous haemangiomas in the patient and other family members. We stress the importance of considering cavernous haemangiomas in the context of intracerebral haemorrhage and in the differential diagnosis of rapidly growing lesions in this age group. The family history is also important in screening for familial disease.
Long‐standing Morel‐Lavallée lesion in the proximal thigh: Ultrasound and MR findings with surgical and histopathological correlation
Authors: Puig J , Pelaez I , Baños J , Balliu E , Casas M , Maroto A , Pedraza S 
Published: November 2006

SummaryA 65‐year‐old man presented with a soft mass in his proximal right thigh. Ultrasonography showed a well‐defined anechoic lesion with slightly internal echoes. On MRI, the mass was hypointense and minimally hyperintense compared with muscle at T1 and hyperintense at T2, with a hypointense peripheral rim on both sequences. No signal loss was observed on T1‐weighted fat‐suppression MRI. The clinical setting, imaging findings and histopathological features were consistent with a long‐standing Morel‐Lavallée lesion.
Sarcomatoid renal cell carcinoma: Rapid dissemination detected on FDG PET‐CT
Authors: Thambugala GM , Mohamed A , O’ Neill GFA , Fulham MJ 
Published: November 2006

SummaryWe present the FDG PET‐CT findings in a patient with persistent pain 7 weeks after a nephrectomy and lymph node dissection for a sarcomatoid renal cell carcinoma. Although conventional imaging was unable to detect evidence of metastatic spread outside the para‐aortic nodes, a PET‐CT scan showed unexpected extensive dissemination. Currently, there are no reports in the literature of the PET‐CT findings in sarcomatoid renal cell carcinomas.
Phonological but not auditory discrimination is impaired in dyslexia
Authors: Paul Isabella , Bott Christof , Heim Sabine , Wienbruch Christian , Elbert Thomas R. 
Published: November 2006

AbstractDeficient phonological skills are considered to be a core problem in developmental dyslexia. Children with dyslexia often demonstrate poorer performance than non‐impaired readers when categorizing speech‐sounds. Using the automatic mismatch response, we show that in contrast to this deficit at the behavioural level, neurophysiological responding in dyslexic children indicates their ability to automatically discriminate syllables. Therefore, the phonological deficit is unlikely to be caused by a temporal deficit or by a noisy functional organization in the respective representational cortex. We obtained measures of reading, spelling and categorical speech‐perception from 58 dyslexic children and 21 control children. The children also participated in magnetoencephalographic measurements while being stimulated acoustically with the syllables /ba/ and /da/ in an oddball paradigm. Mismatch field (MMF) amplitudes between standard and deviant stimuli were obtained. Dyslexic children performed more poorly than control children on all test measures. However, the groups did not differ in MMF amplitude or latency. No correlations were found between MMF amplitudes and behavioural performance.These results were obtained with a large sample size and thus speak robustly against a general deficit in auditory discrimination in dyslexia. These results are compatible with the idea that decoding difficulties occur later in the processing stream where access to the phonological lexicon is attempted.
Relationship between the perifornical hypothalamic area and oral pontine reticular nucleus in the rat. Possible implication of the hypocretinergic projection in the control of rapid eye movement sleep
Authors: Nuñez A. , Moreno‐Balandrán M. E. , Rodrigo‐Angulo M. L. , Garzón M. , De Andrés I. 
Published: November 2006

AbstractThe perifornical (PeF) area in the posterior lateral hypothalamus has been implicated in several physiological functions including the regulation of sleep–wakefulness. Some PeF neurons, which contain hypocretin, have been suggested to play an important role in sleep–wake regulation. The aim of the present study was to examine the effect of the PeF area and hypocretin on the electrophysiological activity of neurons of the oral pontine reticular nucleus (PnO), which is an important structure in the generation and maintenance of rapid eye movement sleep. PnO neurons were recorded in urethane‐anesthetized rats. Extracellular recordings were performed by means of tungsten microelectrodes or barrel micropipettes. Electrical stimulation of the ipsilateral PeF area elicited orthodromic responses in both type I (49%) and type II (58%) electrophysiologically characterized PnO neurons, with a mean latency of 13.0 ± 2 and 8.3 ± 5 ms, respectively. In six cases, antidromic spikes were evoked in type I PnO neurons with a mean latency of 3.2 ± 0.4 ms, indicating the existence of PnO neurons that projected to the PeF area. Anatomical studies showed retrogradely labeled neurons in the PeF area from the PnO. Some of these neurons projecting to the PnO contained hypocretin (17.8%). Iontophoretic application of hypocretin‐1 through a barrel micropipette in the PnO induced an inhibition, which was blocked by a previous iontophoretic application of bicuculline, indicating that the inhibitory action of hypocretin‐1 may be due to activation of GABAA receptors. These data suggest that the PeF area may control the generation of rapid eye movement sleep through a hypocretinergic projection by inhibiting the activity of PnO neurons.
An evaluation of the filtration performance of paediatric breathing system filters using sodium chloride particles at low flows
Authors: Malan C.A. , Wilkes A.R. , Gildersleve C. 
Published: November 2006

Introduction:  A minimum standard has yet to be set for paediatric breathing system filters. An evaluation of adult, paediatric and neonatal filters suggested that paediatric filters may have greater penetrance than adult filters at preset flows (1). Hence, it has been suggested that paediatric filters may be less efficient in the prevention of transmission of infective agents (2). While evaluations have been carried out at flows set by the British Standards Institution (3), concern has been expressed that these are not representative of the flows encountered in clinical practice. The use of more appropriate flows would allow the development of more reliable performance criteria. This study evaluated the pressure drop and penetrance of five filters at flows of 3 and 15 l·min‐1.Methods:  The pressure drop across 15 unused samples of five different filters was measured at a flow of 15 l·min‐1 (RT‐200 Calibration Analyser, Timeter Corp, St Louis, USA). The penetration of sodium chloride particles through five samples of each filter was measured at a flow of 15 l·min‐1 using a ‘Moore's’ Test Rig (CEN Bench Rig, SFP Services, Christchurch, UK) (2). Subsequently, two groups of five of the same filters were tested in parallel using a flow of 15 l·min‐1, thus each filter was tested at a flow of 3 l·min‐1.Results:

Filter type
Pressure drop at 15 l·min‐1 (cmH2O)
Penetrance (%)

15 l·min‐1
Parallel testing, equivalent to 3 l·min‐1

1st group
2nd group

Hygroboy
1.3 (0.2)
1.9 (1.8–3.5)
0.3
0.2

Air safety MIDI
2.7 (0.9)
2.8 (2.4–2.9)
0.2
0.2

Intersurgical
1.9 (0.1)
3.2 (2.9–4.3)
0.4
0.4

Hygrobaby
3.0 (0.3)
3.0 (2.9–4.3)
0.6
0.4

Air safety Neonatal
1.4 (0.1)
10.3 (7.5–12.3)
1.8
1.6

Data are mean (SD) or median (range)Discussion and Conclusions:  The filtration performance of paediatric filters when tested using sodium chloride particles and a gas flow of 3.l min‐1 is more efficient compared to their performance when tested at a gas flow of 15 l·min‐1. Coughing through a filter will produce much higher flows, at which the filters have yet to be evaluated. A minimum standard of performance is yet to be established for paediatric breathing system filters.References  1 Wilkes AR. An assessment of 104 breathing system filters. London: Medicines and Healthcare products Regulatory Agency. Evaluation 04005. March 2004.2 Bennett N, Bingham R. Association of Paediatric Anaesthetists of Great Britain and Ireland. Statement on Paediatric Filters and Breathing Systems. January 2005.3 British Standards Institution. Breathing system filters for anaesthetic and respiratory use – Part I: salt test method to assess filtration performance (BS EN 13328‐1:2001). Milton Keynes, UK: British Standards Institution, 2001.