bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of putative neurotransmitters in the regulation of gastric and intestinal slow waves in conscious dogs
Authors: Liu Shi , Xu Junying , Chen Jiande DZ 
Published: May 2007

AbstractBackground and Aims:  Slow waves play an important role in controlling the frequency and propagation of gastrointestinal contractions. However, mechanisms involved in the modulation of slow wave activity in vivo are still unclear. In this study, the roles of different neurotransmitters in the regulation of gastrointestinal slow waves were investigated in conscious dogs.Methods:  Female dogs implanted with electrodes in the stomach and the small bowel were used in a seven‐session study. Gastrointestinal myoelectrical activity was recorded at baseline and after i.v. saline, atropine, atropine methyl nitrate, guanethidine, Nω‐nitro‐L‐arginine (L‐NNA), ondansetron or naloxone.Results:  Both atropine and atropine methyl nitrate induced tachygastria, bradygastria and arrhythmia. No difference was noted in the effects between atropine and atropine methyl nitrate. L‐NNA increased the dominant frequency of small‐intestinal slow waves but had no effect on gastric slow waves. Guanethidine, ondansetron and naloxone did not affect the dominant frequency, power or percentage of normal gastrointestinal slow waves.Conclusion:  Acetylcholine acting at muscarinic receptors seems to play an important role in the regulation of gastric slow waves. Nitric oxide may play a role in modulating intestinal slow waves but not gastric slow waves. Sympathetic pathways, 5‐HT3 receptors and opioid receptors (especially μ‐opioid receptors) do not play a role in the regulation of gastric or intestinal slow waves under normal physiological conditions.
Mycoplasma pneumonia: Clinical and radiographic features in 39 children
Authors: HSIEH SHU‐CHIANG , KUO YUNG‐TING , CHERN MING‐SHENG , CHEN CHIA‐YUEN , CHAN WING P. , YU CHUN 
Published: May 2007

AbstractBackground: The purpose of the present paper was to evaluate the clinical and chest radiographic features of pediatric patients with serologically proven Mycoplasma pneumoniae pneumonia (mycoplasma pneumonia).Methods: The clinical records and chest radiographs of 39 consecutive patients (19 male, 20 female; age 3–13 years) with serologically positive IgG and IgM mycoplasma pneumonia were reviewed.Results: More than 90% of patients presented with fever and cough and 48% of patients had leukocyte count >10 000/mm3. A C‐reactive protein (CRP) level >0.375 mg/dL was noted in 28 patients (72%). Chest radiographs displayed four different patterns: (i) peribronchial and perivascular interstitial infiltrates (n= 19, 49%); (ii) airspace consolidations (n= 15, 38%); (iii) reticulonodular opacification (n= 3, 8%); and (iv) nodular or mass‐like opacification (n= 2, 5%). Bilateral peribronchial perivascular interstitial infiltrations in central and middle lung zones were frequently seen (n= 19, 49%). Other radiological features were bilateral lesions in 51% of patients, pleural effusion in 23%, and hilar lymphadenopathy in 13%. Means of duration for treatment response and hospitalization were 2.5 and 5 days, respectively.Conclusion: There are various radiological features of mycoplasma pneumonia in children. Bilateral peribronchial and perivascular interstitial infiltrates were most frequently seen in the present patients.
Assessment of variables affecting flow propagation velocity of the left ventricle in healthy children
Authors: HASHIMOTO IKUO , UESE KEI‐ICHIRO , WATANABE SAYAKA , WATANABE KAZUHIRO , HIRONO KEIICHI , ICHIDA FUKIKO , MIYAWAKI TOSHIO 
Published: May 2007

AbstractBackground: The purpose of the present study was to establish the normal values of flow propagation velocity (FPV) in healthy children and examine the variables that affect FPV in clinical situations.Methods: Two hundred and thirty‐ five healthy children and adolescents were assessed (aged 0–22.6 years, mean age 7.4 ± 5.4 years; male, n = 142; female, n = 93). FPV was obtained from an apical four‐chamber view and determined as the slope of aliasing velocity of early diastolic transmitral flow on the color M‐mode using Aloka SSD‐5500 with 5.0 MHz transducer. Aliasing velocity was set at 50–70% of the peak transmitral flow velocity. Peak transmitral flow velocities in early diastole (E) and during atrial contraction (A), and the ratio of early to late peak velocity (E/A) were obtained. Tei index was also measured for analysis of general left ventricular performance. Left ventricular mass index (LVMI) was obtained from conventional echo measurement. E, E/A, Tei index and LVMI were compared with FPV in healthy subjects.Results: FPV obtained from all subjects ranged from 23.7 to 96.0 cm/s (61.3 ± 13.6 cm/s). Normal value of FPV was less dependent on age, body size, heart rate and left ventricular dimension. In contrast, although there was no significant correlation between FPV and ejection fraction, statistically significant correlation was found between FPV, LVMI (P = 0.0008) and Tei index (P = 0.025).Conclusions: FPV is independent of age, body size and heart rate and is useful to assess left ventricular relaxation in children.
Serum zinc levels in children with acute gastroenteritis
Authors: ÖLMEZ AKGÜN , YALÇIN S. SONGÜL , YURDAKÖK KADRIYE , COSKUN TURGAY 
Published: May 2007

AbstractBackground: The aim of the present study was to determine the serum zinc levels on admission and 7–10 days after clinical recovery from acute gastroenteritis of <8 days’ duration.Methods: This prospective study included 82 infants aged 2–24 months who had no associated bacterial infection, chronic disease, prior antibiotic use, moderate or severe malnutrition or dysentery. Forty‐one healthy children formed the control group.Results: The mean serum zinc level on admission (Zn1) was 11.85 ± 2.83 μmol/L and at 7–10 days after recovery (Zn2) was 10.92 ± 2.17 μmol/L; mean serum zinc level of the control group was 11.81 ± 3.45 μmol/L. Zn2 was significantly lower than Zn1, but there was no statistical difference between the mean of the control group and Zn1 and Zn2. When dehydrated patients were excluded from the patient group, Zn1 and Zn2 did not differ. Although asymptomatic, 39% of the control group had low zinc. Serum zinc levels were not affected by sex, age, clinical characteristics of the patients or severity of gastroenteritis.Conclusion: Serum zinc levels of the patients admitted with acute gastroenteritis without any other disease and without moderate or severe malnutrition were not affected by disease state. Gastroenteritis did not further decrease serum zinc levels in patients with asymptomatic or subclinical zinc deficiency.
Clinical spectrum of tuberculous pleural effusion in children
Authors: CHIU CHIH‐YUNG , WU JUN‐HO , WONG KIN‐SUN 
Published: May 2007

AbstractBackground: The aim of this study was to describe the clinical characteristics and potentially diagnostic specimens of pediatric patients with tuberculous pleural effusion (TPE) to make a prompt diagnosis.Methods: Children who had TPE from September 1997 to December 2003 were retrospectively reviewed at a tertiary pediatric facility in northern Taiwan.Results: There were seven boys and six girls and their ages ranged from 10 to 17 years (average, 14.6 years). Tuberculosis contact history was identified in only six patients (46%). Fever (12/92%), cough (9/69%) and malaise (6/46%) were the most common symptoms. Normal leukocyte count was found in 12 patients (92%). Chest radiograph review showed unilateral pleural effusion in 12 patients (92%) but parenchymal involvement was found in nine patients (69%). Most of the pleural fluid analysis showed a lymphocytic exudative effusion (5/6). The acid‐fast bacilli (AFB) stain of sputum, gastric washing, and pleural aspirate was positive in six of 11 (55%), two of seven (29%), and one of five (20%) patients, respectively. Culture of sputum, gastric washing, and pleural aspirate yielded Mycobacterium tuberculosis in four of 11 (36%), two of seven (29%), and two of five (40%) patients, respectively. A total of 6 to 9 months of multiple‐drug therapy for tuberculosis was successful without sequale.Conclusions: Tuberculous pleural effusion usually presents as an acute illness and should always be considered in the differential diagnosis for older children and adolescents with pneumonia. A normal leukocyte count with a lymphocytic exudative effusion may provide a clue to the correct diagnosis of TPE. Diagnostic specimen of sputum seems more effective and sensitive in childhood TPE, especially those having pulmonary involvement.
Microbial communities and geochemical dynamics in an extremely acidic, metal‐rich stream at an abandoned sulfide mine (Huelva, Spain) underpinned by two functional primary production systems
Authors: Rowe Owen F. , Sánchez‐España Javier , Hallberg Kevin B. , Johnson D. Barrie 
Published: May 2007

SummaryAn extremely acidic (pH 2.5–2.75) metal‐rich stream draining an abandoned mine in the Iberian Pyrite Belt, Spain, was ramified with stratified macroscopic gelatinous microbial growths (‘acid streamers’ or ‘mats’). Microbial communities of streamer/mat growths sampled at different depths, as well as those present in the stream water itself, were analysed using a combined biomolecular and cultivation‐based approach. The oxygen‐depleted mine water was dominated by the chemolithotrophic facultative anaerobe Acidithiobacillus ferrooxidans, while the streamer communities were found to be highly heterogeneous and very different to superficially similar growths reported in other extremely acidic environments. Microalgae accounted for a significant proportion of surface streamer biomass, while subsurface layers were dominated by heterotrophic acidophilic bacteria (Acidobacteriacae and Acidiphilium spp.). Sulfidogenic bacteria were isolated from the lowest depth streamer growths, where there was also evidence for selective biomineralization of copper sulfide. Archaeal clones (exclusively Euryarchaeota) were recovered from streamer samples, as well as the mine stream water. Both sunlight and reduced inorganic chemicals (predominantly ferrous iron) served as energy sources for primary producers in this ecosystem, promoting complex microbial interactions involving transfer of electron donors and acceptors and of organic carbon, between microorganisms in the stream water and the gelatinous streamer growths. Microbial transformations were shown to impact the biogeochemical cycling of iron and sulfur in the acidic stream, severely restricting the net oxidation of ferrous iron even when the initially anoxic waters were oxygenated by indigenous acidophilic algae. A model accounting for the biogeochemistry of iron and sulfur in the mine waters is described, and the significance of the acidophilic communities in regulating the geochemistry of acidic, metal‐rich waters is described.
Optimization of parameters in the emulsification process by two different methods
Authors: CARLOTTI M.E. , PATTARINO F. , GASCO M.R. , BRUSASCA P. 
Published: May 2007

SynopsisAn O/W emulsion with a lipopeptidic emulsifier was optimized by means of two different methods, specifically by experimental design and by selective variation of the parameters. Two optimized emulsions were obtained; they had similar values of emulsification (time and rate of homogenization) and amounts of components.RésuméUne émulsion O/E, avec un lipopeptide comme tensioactif, a été optimisée par deux méthodes d'optimisation différentes, notamment par l'experimental design et par la variation selective de certain paramètres. Deux émulsions optimisées ont été ainsi obtenues: ces émulsions ont des valeurs d'emulsification (temp et vitesse d'homogénéisation) et des quantités des composantes très proches.
The Corporatization and Commercialization of Local Body Entities: A Study of Reported Financial Performance
Authors: Hooks Jill , Van Staden Chris 
Published: May 2007

This research examines the financial performance of three entities over a fifteen‐year period. The aim is to determine the influence of corporatization, commercialization and ownership form on the reported financial performance of the three entities. Underpinning this is the premise, derived from the literature, that financial performance and funding can be expected to change following corporatization and commercialization and will reflect the effects of the form of corporate ownership.A comparison of four performance measures shows that the reported financial performance of the entities improved following corporatization and that their gearing changed. Although the entities were initially similar and faced the same regulatory changes, there were definite differences in the resulting financial performance and gearing between the three entities. In general, by the end of the study period the privatized company was the largest and the one with the highest gearing, the highest ROA and the highest profit margin, whereas the public (council‐owned) company was the smallest and had the lowest profitability. The trust‐owned company performed in between these two, but on average its performance was closer to that of the public company. The study concludes that corporatization, commercialization and ownership form influenced financial performance and the level of debt funding.
Enculturated chimpanzees imitate rationally
Authors: Buttelmann David , Carpenter Malinda , Call Josep , Tomasello Michael 
Published: May 2007

Abstract Human infants imitate others’ actions ‘rationally’: they copy a demonstrator's action when that action is freely chosen, but less when it is forced by some constraint (Gergely, Bekkering & Király, 2002). We investigated whether enculturated chimpanzees (Pan troglodytes) also imitate rationally. Using Gergely and colleagues’ (2002) basic procedure, a human demonstrator operated each of six apparatuses using an unusual body part (he pressed it with his forehead or foot, or sat on it). In the Hands Free condition he used this unusual means even though his hands were free, suggesting a free choice. In the Hands Occupied condition he used the unusual means only because his hands were occupied, suggesting a constrained or forced choice. Like human infants, chimpanzees imitated the modeled action more often in the Hands Free than in the Hands Occupied condition. Enculturated chimpanzees thus have some understanding of the rationality of others’ intentional actions, and use this understanding when imitating others.
The leptin melanocortin pathway and the control of body weight: lessons from human and murine genetics
Authors: Oswal A. , Yeo G. S. H. 
Published: May 2007

SummaryThe recent rapid increase in the prevalence of obesity across the world is undoubtedly due to changes in diet and lifestyle. However, it is also indisputable that different people react differently to this change in environment and this variation in response is likely to be genetically determined. While for the majority of people this effect is presumed to be polygenic in origin, there is now strong evidence for a small number of genes having a large effect in some families with severe obesity. Studies of these families, coupled with parallel studies in murine models, have provided novel insights into the molecules involved in the regulation of appetite, energy expenditure and nutrient partitioning. We review here the lessons we have learnt from mouse models of obesity, both naturally occurring and artificially generated through targeted gene deletions, and more importantly from human monogenic syndromes of obesity. These have illuminated the critical role in which the central leptin melanocortin pathway plays in the control of mammalian food intake and body weight.
Risk, Wealth, and Sectoral Choice in Rural Credit Markets
Authors: Boucher Steve , Guirkinger Catherine 
Published: May 2007

AbstractWe model the role of the informal credit sector in developing countries. The informational advantage of informal lenders is portrayed as the ability to monitor borrowers. Monitoring reduces the incentive problem and allows for contracts with lower collateral. This enables informal lenders to serve both individuals who cannot post the collateral required by the formal sector and those who are able but do not want to post collateral. The model is consistent with the conventional view of the informal sector as recipient of spillover demand from the formal sector. It also shows that the informal sector may provide partial insurance as the lower collateral requirement implies greater consumption smoothing for borrowers.
The Optimal Discovery Procedure: A New Approach to Simultaneous Significance Testing
Authors: Storey John D. 
Published: May 2007

SummaryThe Neyman–Pearson lemma provides a simple procedure for optimally testing a single hypothesis when the null and alternative distributions are known. This result has played a major role in the development of significance testing strategies that are used in practice. Most of the work extending single-testing strategies to multiple tests has focused on formulating and estimating new types of significance measures, such as the false discovery rate. These methods tend to be based on p-values that are calculated from each test individually, ignoring information from the other tests. I show here that one can improve the overall performance of multiple significance tests by borrowing information across all the tests when assessing the relative significance of each one, rather than calculating p-values for each test individually. The ‘optimal discovery procedure’ is introduced, which shows how to maximize the number of expected true positive results for each fixed number of expected false positive results. The optimality that is achieved by this procedure is shown to be closely related to optimality in terms of the false discovery rate. The optimal discovery procedure motivates a new approach to testing multiple hypotheses, especially when the tests are related. As a simple example, a new simultaneous procedure for testing several normal means is defined; this is surprisingly demonstrated to outperform the optimal single-test procedure, showing that a method which is optimal for single tests may no longer be optimal for multiple tests. Connections to other concepts in statistics are discussed, including Stein's paradox, shrinkage estimation and the Bayesian approach to hypothesis testing.
Dimension Reduction and Coefficient Estimation in Multivariate Linear Regression
Authors: Yuan Ming , Ekici Ali , Lu Zhaosong , Monteiro Renato 
Published: May 2007

SummaryWe introduce a general formulation for dimension reduction and coefficient estimation in the multivariate linear model. We argue that many of the existing methods that are commonly used in practice can be formulated in this framework and have various restrictions. We continue to propose a new method that is more flexible and more generally applicable. The method proposed can be formulated as a novel penalized least squares estimate. The penalty that we employ is the coefficient matrix's Ky Fan norm. Such a penalty encourages the sparsity among singular values and at the same time gives shrinkage coefficient estimates and thus conducts dimension reduction and coefficient estimation simultaneously in the multivariate linear model. We also propose a generalized cross-validation type of criterion for the selection of the tuning parameter in the penalized least squares. Simulations and an application in financial econometrics demonstrate competitive performance of the new method. An extension to the non-parametric factor model is also discussed.
Use‐dependent control of presynaptic calcium signalling at central synapses
Authors: Scott Ricardo 
Published: May 2007

AbstractVoltage‐gated Ca2+ channels activated by action potentials evoke Ca2+ entry into presynaptic terminals thus briefly distorting the resting Ca2+ concentration. When this happens, a number of processes are initiated to re‐establish the Ca2+ equilibrium. During the post‐spike period, the increased Ca2+ concentration could enhance the presynaptic Ca2+ signalling. Some of the mechanisms contributing to presynaptic Ca2+ dynamics involve endogenous Ca2+ buffers, Ca2+ stores, mitochondria, the sodium–calcium exchanger, extraterminal Ca2+ depletion and presynaptic receptors. Additionally, subthreshold presynaptic depolarization has been proposed to have an effect on release of neurotransmitters through a mechanism involving changes in resting Ca2+. Direct evidence for the role of any of these participants in shaping the presynaptic Ca2+ dynamics comes from direct recordings of giant presynaptic terminals and from fluorescent Ca2+ imaging of axonal boutons. Here, some of this evidence is presented and discussed.
The asymmetry of avian egg‐shape: an adaptation for reproduction on dry land
Authors: Mao Kun‐Ming , Murakami Ayako , Iwasawa Atsushi , Yoshizaki Norio 
Published: May 2007

AbstractThe present study describes the biological meaning of the asymmetrical shape in avian reproduction using quail. During the incubation of eggs, water was gradually lost and the air chamber which appeared in between the inner and outer shell membranes at the blunt end expanded, so that the angle made by the long egg‐axis and the horizontal line increased, presumably because the centre of gravity of the egg contents moved toward the sharp end. The increase in angle occurred in both fertile and infertile eggs, suggesting that this phenomenon occurs irrespective of fertility and is due to the asymmetrical shape. The increase in the volume of the air chamber resulted in an increase in the area of the inner shell membrane at the chamber to satisfy the amount of gas exchange needed by the developing embryo for better hatching. We isolated a 300‐kDa protein from the inner shell membrane. It was produced by cells in the luminal epithelium of the oviductal isthmus and was found in the cortex of the fibres of shell membranes and a lining surrounding the air chamber. The lining comprised a medial layer between the inner and outer shell membranes in uterine eggs. The asymmetrical ellipsoid produces the air chamber at the blunt end of the avian egg during its sojourn in the oviductal isthmus, to maintain the blunt end up after oviposition and to raise that end during incubation in a dry environment, leading to high hatchability.
Thinking ahead: The role and roots of prediction in language comprehension
Authors: Federmeier Kara D. 
Published: May 2007

AbstractReviewed are studies using event‐related potentials to examine when and how sentence context information is used during language comprehension. Results suggest that, when it can, the brain uses context to predict features of likely upcoming items. However, although prediction seems important for comprehension, it also appears susceptible to age‐related deterioration and can be associated with processing costs. The brain may address this trade‐off by employing multiple processing strategies, distributed across the two cerebral hemispheres. In particular, left hemisphere language processing seems to be oriented toward prediction and the use of top‐down cues, whereas right hemisphere comprehension is more bottom‐up, biased toward the veridical maintenance of information. Such asymmetries may arise, in turn, because language comprehension mechanisms are integrated with language production mechanisms only in the left hemisphere (the PARLO framework).