bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resource regulation by a twig‐girdling beetle has implications for desertification
Authors: DUVAL B. D. , WHITFORD W. G. 
Published: March 2008

Abstract 1. Resource regulation by insects is the phenomenon by which herbivory enhances resources for the progeny of the herbivore. This report provides an example of resource regulation with implications for desertification in the Chihuahuan Desert of North America.2. Female Oncideres rhodosticta beetles chew girdles around mesquite (Prosopis glandulosa) stems before ovipositing in those stems. The mesquite plants respond by producing compensatory stems below the girdle. Mesquite volume was significantly correlated with the total number of beetle girdles across a suite of low shrub density grassland and high shrub density dune sites, and plants in dune sites had more old and new girdles than mesquite in grasslands.3. Smaller, younger shrubs in grassland responded more vigorously to girdling than did larger, older shrubs in dune landscapes. Stems on shrubs within grassland produced significantly more and longer compensatory stems per girdle than stems on shrubs in dunes. Soil capture by individual plants positively correlated with stem density, and stem density is increasing in the younger plants as a response to beetle damage.4. This study suggests that the interaction between O. rhodosticta and mesquite is an example of resource regulation that increases the stem density and soil capture ability of mesquite. Because the conversion of productive grasslands to mesquite dune landscapes is one of the most important drivers of desertification in the Chihuahuan Desert, feedbacks between organisms that promote an increase in the size and soil capture ability of mesquite may exacerbate desertification.
Polymorphism: a weak influence on worker aggregation level in ants
Authors: DEPICKÈRE STÉPHANIE , RAMÍREZ ÁVILA G. MARCELO , FRESNEAU DOMINIQUE , DENEUBOURG JEAN‐LOUIS 
Published: March 2008

Abstract 1. Aggregation of individuals, a basic behaviour in social species, plays an essential role in many aspects of animal life (reproduction, defence, and alimentation). Understanding how this phenomenon is modulated is important to comprehend the social organisation of the group.2. In social insects, aggregation is influenced by environmental (e.g. the light level) and social (e.g. polyethism in monomorphic ants) factors. Ants display a great variation of biological characteristics (e.g. queen number, polymorphism, division of labour, etc.) that are likely to influence the level of inter‐attraction and so the aggregation.3. The present research focused on one biological characteristic: the morphological castes (minors, majors), testing the hypothesis that minors will aggregate more than majors due to their greater need to fight against the loss of heat and to increase their self‐protection.4. Aggregation experiments were conducted on two highly polymorphic species, Atta sexdens rubropilosa and Solenopsis interrupta, using the two extreme morphological castes (majors and minors).5. All castes exhibited a low level of aggregation: 40–50% of workers assembled for both species, the biggest cluster involving 20% of the total population. The lack of difference between morphological castes in the aggregation shows the weak influence of polymorphism on the interactions between ants.6. It is concluded that the main factor modulating the aggregation behaviour is polyethism, i.e. the division of labour associated with the presence of an outside‐the‐nest experience: workers that only take care of the brood, without outside world experience (brood‐tenders) assembling more than foraging workers (foragers).
Involvement of Hofbauer cells and maternal T cells in villitis of unknown aetiology
Authors: Kim J‐S , Romero R , Kim M R , Kim Y M , Friel L , Espinoza J , Kim C J 
Published: February 2008

Aims:  The nature of villitis of unknown aetiology (VUE) is intriguing in terms of its aetiology, origin of inflammatory cells and immunophenotype of T cells involved. The aim was to determine the origin of macrophages and the immunophenotype of T lymphocytes in VUE associated with various complications of pregnancy.Methods and results:  Placentas with VUE (n = 45) were studied by chromogenic in‐situ hybridization (CISH) for Y chromosome (DYZ1) and immunohistochemistry for CD14, CD68, Ki67 (n = 10; all from male neonates) and a panel of T‐cell antigens (CD3, CD4 and CD8) (n = 35). All of the placentas from male neonates showed CISH+ signals from Y chromosomes in the majority of macrophages, but not in lymphocytes, indicating that the macrophages were of fetal origin. Many macrophages of the affected chorionic villi were Ki67+, suggesting that they are hyperplastic Hofbauer cells. Among the lymphocytes, CD8+ T cells outnumbered CD4+ T cells in all placentas with different obstetrical conditions.Conclusions:  We define primary components of VUE as maternal CD8+ T cells and hyperplastic Hofbauer cells. We propose that VUE is a unique inflammatory reaction where the leucocytes from two hosts are key partners, analogous to either allograft rejection or graft‐versus‐host disease.
Propagule deposition along river margins: linking hydrology and ecology
Authors: Gurnell Angela , Thompson Ken , Goodson Joanne , Moggridge Helen 
Published: February 2008

Summary

Research has highlighted the importance of buoyancy for hydrochorous propagule dispersal, but recently the river bed has been identified as a significant store of viable propagules.
Over four consecutive 4‐month periods, deposited propagules (predominantly seeds) and sediment were sampled at 78 river bed, bank face and bank top sites within three river reaches in two catchments. Species of deposited propagules were compared with the propagule bank and standing vegetation to identify ‘new’ species.
Forty‐four percent of deposited propagule species were not present in the vegetation and the largest proportions were deposited in winter. New propagules showed a higher proportion of species that establish long‐term seed banks and produce light seeds, a higher proportion of R‐strategists, and a lower proportion of C‐strategists than species in the vegetation.
Ordination of propagule species abundance data revealed differences in samples between reaches; bed and bank locations; and sampling periods. Within depositional samples there were significant positive correlations between average C scores and the proportion of species producing relatively heavy, short‐lived seeds and scores on an ordination axis describing a gradient from channel bed to bank top.
Correlations and multiple regression models between species richness and abundance of deposited propagules (total and new), and the quantity and calibre of river‐deposited sediment, demonstrated a direct link between propagule deposition and hydraulic conditions during inundation.
Synthesis. Riparian connectivity of river flows, varying hydraulic conditions and temporary storage of propagules are all complex components of hydrochorous propagule dispersal in the study reaches. Flood flows can transfer sediment particles and non‐buoyant, viable propagules from the river into the riparian zone. Propagules can pass in and out of storage within the channel bed and margins through a variety of dispersal processes and can then settle out of the water in suitable depositional environments generating distinct spatial and temporal patterns in total propagule deposition. New propagules show greatest floristic similarity to propagule bank and bed samples. They are preferentially smaller, lighter and form longer term seed banks, making them particularly suitable for long distance transport over prolonged time periods and for widespread dispersal across river margins.
Ultrastructural Features of Atretic Follicles in the Sexually Immature Ostrich (Struthio Camelus)
Authors: Madekurozwa M. ‐C. , Kimaro W. H. 
Published: February 2008

SummaryThe aim of this study was to describe the ultrastructural features of atresia in follicles of the immature ostrich (12–14 months old); a ratite that displays seasonal, precocious ovarian activity. The early stage of atresia in primordial, pre‐vitellogenic and vitellogenic follicles was characterized by the accumulation of lipid droplets in the granulosa cells. Granulosa cells with condensed cytoplasm and nuclei were a prominent feature during the intermediate phase of atresia. The degenerating follicles were then infiltrated by stroma during the terminal stages of atresia. The results of this study provide further information on the morphology of atretic ovarian follicles in the immature ostrich.
PCR primers for identification of Sirococcus conigenus and S. tsugae, and detection of S. conigenus from symptomatic and asymptomatic red pine shoots
Authors: Smith D. R. , Stanosz G. R. 
Published: February 2008

SummaryRegions of diversity in the internal transcribed spacer (ITS) sequences of Sirococcus species were exploited to design primer pairs used in a PCR‐based method for the identification of the conifer shoot blight pathogen Sirococcus conigenus and the closely related fungus Sirococcus tsugae. The specificity of each primer pair for the respective fungus, detection limits and utility for detection from host material were confirmed. The S. conigenus primers were then used to detect this pathogen in tissues of symptomatic or apparently healthy red pine shoots collected at six locations in Wisconsin and Michigan and results compared with those obtained using a cultural assay. For needles, bark and wood of symptomatic shoots, the mean frequencies of detection of S. conigenus using the PCR‐based methods were consistent (≥7.5 out of 10) and always greater than for the cultural assay. Detection from symptomatic shoots using the cultural assay was more frequent from needles than from bark or wood. Both the PCR‐based method and the cultural assay detected S. conigenus in similar frequencies from asymptomatic shoots, although less frequently than from symptomatic shoots. The efficiency of the PCR‐based method and its utility for direct testing of host material should make it particularly useful in areas where multiple shoot blight pathogens are found.
UNRAVELLING THE PATHOPHYSIOLOGY OF COMPLEX REGIONAL PAIN SYNDROME: FOCUS ON SYMPATHETICALLY MAINTAINED PAIN
Authors: Gibbs Gael F , Drummond Peter D , Finch Philip M , Phillips Jacqueline K 
Published: February 2008

SUMMARY

In diseases such as complex regional pain syndrome (CRPS), where neuropathic pain is the primary concern, traditional pain classifications and lesion descriptors are of limited value. To obtain better treatment outcomes for patients, the underlying pathophysiological mechanisms of neuropathic pain need to be elucidated and analysed so that therapeutic targets can be identified and specific treatments developed.
In the present review, we examine the current literature on sympathetically maintained pain (SMP), a subset of neuropathic pain, within the context of CRPS. Evidence from both human and animal studies is presented and discussed in terms of its support for the existence of SMP and the mechanistic information it provides.
We discuss three current hypotheses that propose both a site and method for sympathetic–sensory coupling: (i) direct coupling between sympathetic and sensory neurons in the dorsal root ganglion; (ii) chemical coupling between sympathetic and nociceptive neuron terminals in skin; and (iii) the development of a‐adrenoceptor‐mediated supersensitivity in nociceptive fibres in skin in association with the release of inflammatory mediators.
Finally, we propose a new hypothesis that integrates the mechanisms of chemical coupling and a‐adrenoceptor‐mediated supersensitivity. This hypothesis is based on previously unpublished data from our laboratory showing that a histological substrate suitable for sympathetic–sensory coupling exists in normal subjects. In the diseased state, the nociceptive fibres implicated in this substrate may be activated by both endogenous and exogenous noradrenaline. The mediating a‐adrenoceptors may be expressed on the nociceptive fibres or on closely associated support cells.
CALCIUM SPARKLETS IN ARTERIAL SMOOTH MUSCLE
Authors: Santana Luis F , Navedo Manuel F , Amberg Gregory C , Nieves‐Cintrón Madeline , Votaw V Scott , Ufret‐Vincenty Carmen A 
Published: February 2008

SUMMARY

Voltage‐dependent, L‐type Ca2+ channels (LTCC) play an essential role in arterial smooth muscle contraction and, consequently, the regulation of arterial diameter, tissue perfusion and blood pressure. However, the spatial organization of functional LTCC in arterial myocytes is incompletely understood.
Total internal reflection fluorescence and swept‐field confocal microscopy revealed that the opening of a single or a cluster of LTCC produces local elevations in [Ca2+]i called Ca2+ sparklets. In arterial myocytes, Ca2+ sparklets are produced by the opening of Cav1.2 channels.
The Ca2+ sparklet activity is bimodal. In low activity mode, rare stochastic openings of solitary LTCC produce limited Ca2+ influx (‘low activity Ca2+ sparklets’). In contrast, discrete clusters of LTCC associated with protein kinase Ca (PKCa) operate in a sustained, high‐activity mode resulting in substantial Ca2+ influx (‘persistent Ca2+ sparklets’).
The Ca2+ sparklet activity varies regionally within a myocyte depending on the relative activities of nearby PKCa and opposing protein phosphates 2A and 2B.
Low‐ and high‐activity persistent Ca2+ sparklets modulate local and global [Ca2+]i in arterial smooth muscle, suggesting that this Ca2+ signal may play an important role in the regulation of vascular function.
Levodopa improves skilled hand functions in the elderly
Authors: Floel Agnes , Vomhof Peter , Lorenzen Arne , Roesser Nina , Breitenstein Caterina , Knecht Stefan 
Published: February 2008

AbstractThe endogenous dopamine system is a potent modulator of motor function and learning. Previous studies have demonstrated that, in the elderly, age‐related degeneration of the nigrostriatal dopamine system may contribute to deficits in execution of skilled motor functions. The present double‐blind, randomized cross‐over study examined whether pharmacologically replenishing dopamine improves the execution of complex motor tasks. Twenty healthy young and 20 healthy elderly subjects were studied in two different sessions: (i) after three doses of levodopa (each 100 mg levodopa plus 25 mg carbidopa) and (ii) after three doses of placebo. For each session, subjects completed a functional motor test that reflects hand activities of daily living (Jebsen‐Taylor test). In the elderly, but not in the young, Jebsen‐Taylor test performance improved significantly (4%) with levodopa compared with placebo, particularly for fine motor functions. Attention to the task, level of fatigue, and positive and negative feelings were similar between sessions. These results demonstrate that increasing the dopaminergic drive pharmacologically may be helpful when the motor system is challenged in the ageing process.
Premotor transcranial direct current stimulation (tDCS) affects primary motor excitability in humans
Authors: Boros Klára , Poreisz Csaba , Münchau Alexander , Paulus Walter , Nitsche Michael A. 
Published: February 2008

AbstractRecent studies have shown that repetitive transcranial magnetic stimulation (rTMS) over the premotor cortex (PM) modifies the excitability of the ipsilateral primary motor cortex (M1). Transcranial direct current stimulation (tDCS) is a new method to induce neuroplasticity in humans non‐invasively. tDCS generates neuroplasticity directly in the cortical area under the electrode, but might also induce effects in distant brain areas, caused by activity modulation of interconnected areas. However, this has not yet been tested electrophysiologically. We aimed to study whether premotor tDCS can modify the excitability of the ipsilateral M1 via cortico‐cortical connectivity. Sixteen subjects received cathodal and anodal tDCS of the PM and eight subjects of the dorsolateral prefrontal cortex. Premotor anodal, but not premotor cathodal or prefrontal tDCS, modified selectively short intracortical inhibition/intracortical facilitation (SICI/ICF), while motor thresholds, single test‐pulse motor‐evoked potential and input–output curves were stable throughout the experiments. Specifically, anodal tDCS decreased intracortical inhibition and increased paired‐pulse excitability. The selective influence of premotor tDCS on intracortical excitability of the ipsilateral M1 suggests a connectivity‐driven effect of tDCS on remote cortical areas. Moreover, this finding indirectly substantiates the efficacy of tDCS to modulate premotor excitability, which might be of interest for applications in diseases accompanied by pathological premotor activity.
Laryngeal mask airway insertion in children: comparison between rotational, lateral and standard technique
Authors: GHAI BABITA , MAKKAR JEETINDER KAUR , BHARDWAJ NEERJA , WIG JYOTSNA 
Published: February 2008

SummaryBackground:  The purpose of the study was to compare the success and ease of insertion of three techniques of laryngeal mask airway (LMA) insertion; the standard Brain technique, a lateral technique with cuff partially inflated and a rotational technique with cuff partially inflated.Methods:  One hundred and sixty‐eight ASA I and II children aged 6 months to 6 years undergoing short elective surgical procedures lasting 40–60 min were included in the study. A standard anesthesia protocol was followed for all patients. Patients were randomly allocated into one of the three groups i.e. standard (S), rotational (R) and lateral (L). The primary outcome measure of the study was success rate at the first attempt using three techniques of LMA insertion. Secondary outcomes measures studied were overall success rate, time before successful LMA insertion, complications and maneuvers used to relieve airway obstruction.Results:  Successful insertion at the first attempt was significantly higher in group R (96%) compared with group L (84%) and group S (80%) (P = 0.03). Overall success rate (i.e. successful insertion with two attempts) was 100% for group R, 93% for group L and 87% for group S (P = 0.03). Time for successful insertion was significantly lower in group R compared with group L and S (P < 0.001). The incidence of complications was lower in group R.Conclusions:  A rotational technique with partially inflated cuff is associated with the highest success rate of insertion and lowest incidence of complications and could be the technique of first choice for LMA insertion in pediatric patients.
Pediatric laryngospasm
Authors: HAMPSON‐EVANS DARRYL , MORGAN PATRICK , FARRAR MARK 
Published: February 2008

SummaryPediatric laryngospasm is an anesthetic emergency. It is a relatively common phenomenon that occurs with varying frequency dependent on multiple factors. In view of this and the clear risks to the patient when it occurs, a consensus committee has been established to determine the evidence based management of this condition. This article will cover the definition, causes and recognition of laryngospasm and the evidence behind a proposed algorithm for its' management.
Intraoperative gastric tonometric examinations in children and infants with a new probe, combined with measurement of the endtidal PCO2
Authors: KIRÁLY ÁGNES , BODA DOMOKOS , TÁLOSI GYULA , BODA KRISZTINA 
Published: February 2008

SummaryBackground:  Important progress relating to the early prediction of postoperative complications was recently achieved through the combined use of endtidal PCO2 (PETCO2) and gastric tonometry. The aim of this article was to present results obtained with a new tonometric instrument, proving its feasibility and extending its use to the control of anesthetized infants and children.Methods:  The new tonometric probe, which is balloon free, consists basically of silicone rubber tubing. The room air initially inside the tubes of the probe equilibrates with the PCO2 of the body cavity throughout its full length. The PCO2 content of the gastric cavity (PgCO2) and simultaneously PETCO2 were measured with a microcapnograph. A total of 108 measurements were performed intraoperatively on 25 infants and young children operated on at the Surgical Unit of the Department of Pediatrics. The patients were divided into elective surgery cases <2 years of age, group I; elective surgery cases >2 years of age, group II; and acute surgery cases, independently of age, group III. To examine the degree of agreement between the measurements, Pearson’s correlation coefficients were determined and Bland–Altman analysis was performed. A mixed model repeated measurements anova was used to compare the differences between the groups.Results:  PETCO2 and PgCO2 for groups I and II were nearly identical, and statistically not significantly different (mean difference 0.10 mmHg and 0.85 mmHg, P = 0.96 and 0.45, respectively), whereas the corresponding data for group III differed significantly from those for groups I and II (P = 0.03 and 0.001, respectively). On Bland–Altman analysis, the bias value for groups proved to be statistically significantly different (P = 0.001).Conclusions:  The tested new probe worked very well in small children. The clinical implications of the large gaps found between PETCO2 and PgCO2 values in acutely ill children and children undergoing elective operations must be investigated further.
Management of critically ill children with traumatic brain injury
Authors: ORLIAGUET GILLES A. , MEYER PHILIPPE G. , BAUGNON THOMAS 
Published: February 2008

SummaryThe management of critically ill children with traumatic brain injury (TBI) requires a precise assessment of the brain lesions but also of potentially associated extra‐cranial injuries. Children with severe TBI should be treated in a pediatric trauma center, if possible. Initial assessment relies mainly upon clinical examination, trans‐cranial Doppler ultrasonography and body CT scan. Neurosurgical operations are rarely necessary in these patients, except in the case of a compressive subdural or epidural hematoma. On the other hand, one of the major goals of resuscitation in these children is aimed at protecting against secondary brain insults (SBI). SBI are mainly because of systemic hypotension, hypoxia, hypercarbia, anemia and hyperglycemia. Cerebral perfusion pressure (CPP = mean arterial blood pressure – intracranial pressure: ICP) should be monitored and optimized as soon as possible, taking into account age‐related differences in optimal CPP goals. Different general maneuvers must be applied in these patients early during their treatment (control of fever, avoidance of jugular venous outflow obstruction, maintenance of adequate arterial oxygenation, normocarbia, sedation–analgesia and normovolemia). In the case of increased ICP and/or decreased CPP, first‐tier ICP‐specific treatments may be implemented, including cerebrospinal fluid drainage, if possible, osmotic therapy and moderate hyperventilation. In the case of refractory intracranial hypertension, second‐tier therapy (profound hyperventilation with PaCO2 < 35 mmHg, high‐dose barbiturates, moderate hypothermia, decompressive craniectomy) may be introduced, after a new cerebral CT scan.