bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal Variation in Mate Choice of Photinus ignitus Fireflies
Authors: Cratsley Christopher K. , Lewis Sara M. 
Published: January 2005

AbstractMate choice by either sex may vary with changes in the associated costs and benefits, determined by factors such as the availability of potential mates and variation in mate quality. We examined seasonal variation in operational sex ratio, courtship behavior, spermatophore mass, egg count, and the relationship between morphological traits and mating success in Photinus ignitus fireflies to determine if mate choice in either sex varied with the availability and relative reproductive investment of fertilizable females and sexually active males. Successfully mating males had larger lanterns than unsuccessful males when the operational sex ratio was male‐biased. In addition, female responsiveness to male signals increased as the number of courting males decreased, and male spermatophore mass decreased with body size across the mating season. Successfully mating females had larger body mass than unsuccessful females. Female body mass predicted egg count and female rejection by males increased as the season progressed and female size decreased. These results suggest that both male and female P. ignitus exhibit mate choice, and that such choice is influenced by seasonal variation in the abundance and quality of potential mates.
Evolution of Classical Polyandry: Three Steps to Female Emancipation
Authors: Andersson Malte 
Published: January 2005

(Invited Article)AbstractIn classical polyandry, sex roles are reversed and a female reproduces with several males, each of whom raises his offspring with little or no help from her. This mating system occurs in some fishes and birds, and it is of great interest in relation to parental investment, sex role and sexual selection theory. The evolution of classical polyandry, however, is debated and not well understood. It is here suggested to generally take place in three main steps. (1) First evolvesmale care for eggs, for reasons that differ between fishes and birds. (2) Second,a female becomes able to lay more eggs than a male can accommodate.This can happen, for example, by evolution of male pregnancy or smaller body size, or by female production of more or larger eggs, made possible by larger female body size or more food. Polyandry in several taxa is associated with shift to a habitat rich in food during the breeding season, to novel specialised foraging methods, or to both. A favourable food situation may be crucial for evolution of classical polyandry. (3) In step three,females compete to lay two or more clutches in sequence for different males. Successful polyandrous females obtain more offspring, spreading traits that enhance success in competition over males. Step three may be most likely in species with small body size, for reasons of reproductive constraints and seasonality. Evolution of classical polyandry appears to have followed these steps in shorebirds, coucals and pipefishes, but the reasons why certain species differ from their close phylogenetic relatives in being polyandrous are far from clear. Behavioural and ecological studies of additional species, and detailed phylogenies of taxa with diverse mating systems including polyandry, are needed for testing these ideas.
Influence of crop residue ration supplementation on the attainment of puberty and postpartum reproductive activities of Red Sokoto goats
Authors: Malau‐Aduli B. S. , Eduvie L. O. , Lakpini C. A. M. , Malau‐Aduli A. E. O. 
Published: January 2005

SummaryThe general objective of this study was to come up with an appropriate, affordable and locally available crop residue supplementation package that would enhance reproductive performance in small ruminants. Specifically, 28 Red Sokoto weaner does between 3 and 4 months of age weighing between 2 and 3 kg were used in the first experiment to determine the influence of crop residue supplementation on age and weight at puberty as determined by blood progesterone levels. In the second experiment, another 28 adult does (≥2 years old) of the same breed in the same flock with lactation numbers between 1 and 3 were used to determine the length of postpartum acyclic period. In both experiments, a 3 × 2 factorial experimental design comprising three dietary supplements (A, B, C) at two feeding levels (1% and 2% of body weight) fed in addition to a basal diet of Digitaria smutsii hay and natural pasture ad libitum with an unsupplemented negative control group (D) and four goats per treatment was utilized. In ration A, a conventional concentrate supplement consisting of maize, wheat offal, cottonseed cake and bonemeal was utilized; in rations B and C, the supplement consisted of guinea‐corn bran, cowpea husk and groundnut haulms; and maize offal, groundnut shells and groundnut haulms respectively. Unsupplemented (ration D) weaner does reached puberty at a later age and had lighter body weights than all the others. Weaner does on ration 2A (concentrate fed at 2% of body weight) attained puberty at the earliest age and heaviest body weight, although the age at puberty was not significantly different from those on rations 1A (concentrate fed at 1% body weight), 1C and 2C. Blood progesterone profiles before and after puberty ranged from 0.05 to 9.0 ng/ml, respectively, and was highest in does fed rations A and C and least in the unsupplemented does. The mean interval between kidding and initiation of ovarian activity was 54.28 ± 17.61 days and the mean interval between kidding and conception was 63.04 ± 25.34 days. Only 25% of the unsupplemented does conceived again during the period under study compared with 100% in rations 1A, 2A, 1C and 2C; 75% in ration 2B and 50% in ration 1B. It was concluded that implementation of supplementary feeding in the dry season improves reproductive performance in the Red Sokoto doe. Furthermore, ration C, a crop residue‐based ration, was a suitable dry season supplementation alternative to the expensive conventional concentrate ration for the smallholder goat farmer in the subhumid tropics of Nigeria.
Engaging Australian physicians in evidence‐based medicine: a representative national survey
Authors: Toulkidis V. , Donnelly N. J. , Ward J. E. 
Published: January 2005

AbstractAim: To assess Australian adult physicians’ views about evidence‐based medicine (EBM) and quality improvement (QI).Background: Cross‐sectional postal survey of two hundred and forty‐four randomly selected Australian physicians (78.5% response rate).Method: Physicians’ views about the promotion of EBM and QI and their impact on patient care, strategies to support better clinical practice and self‐reported understanding of EBM terms.Results: Sixty‐eight per cent (95% confidence interval (CI): 62–74%) of physicians had a positive view of the current promotion of EBM in Australia. Significantly fewer (45%; 95% CI: 38–51%) were so positive about QI (P < 0.001). Although 74% (95% CI: 68–79%) indicated that EBM improves patient care, significantly fewer (46%; 95% CI: 40–53%) held this view with respect to QI (P < 0.001). Although 70% (95% CI: 64–76%) of physicians agreed they had adequate skills to search for evidence, significantly fewer (21%; 95% CI: 17–27%) agreed they had sufficient time to do so (P < 0.001). EBM skills were positively associated with involvement in teaching. Physicians were significantly more positive about approaches exclusive to themselves compared with those involving other disciplines.Conclusions: Although Australian physicians have positive views of EBM, QI appears less well regarded. Initiatives to improve quality and safety that incorporate principles and language of EBM will likely be received better by physicians than isolated QI. Further enhancement of EBM requires concomitant attention to physician training, workplace infrastructure and supportive professional development. (Intern Med J 2005; 35: 9–17)
Prostaglandin D2 mediates neuronal protection via the DP1 receptor
Authors: Liang Xibin , Wu Liejun , Hand Tracey , Andreasson Katrin 
Published: January 2005

AbstractCyclo‐oxygenases (COXs) catalyze the first committed step in the synthesis of the prostaglandins PGE2, PGD2, PGF2α, PGI2 and thomboxane A2. Expression and enzymatic activity of COX‐2, the inducible isoform of COX, are observed in several neurological diseases and result in significant neuronal injury. The neurotoxic effect of COX‐2 is believed to occur through downstream effects of its prostaglandin products. In this study, we examined the function of PGD2 and its two receptors DP1 and chemoattractant receptor‐homologous molecule expressed on Th2 cells (CRTH2) (DP2) in neuronal survival. PGD2 is the most abundant prostaglandin in brain and regulates sleep, temperature and nociception. It signals through two distinct G protein‐coupled receptors, DP1 and DP2, that have opposing effects on cyclic AMP (cAMP) production. Physiological concentrations of PGD2 potently and unexpectedly rescued neurons in paradigms of glutamate toxicity in cultured hippocampal neurons and organotypic slices. This effect was mimicked by the DP1‐selective agonist BW245C but not by the PGD2 metabolite 15d‐PGJ2, suggesting that neuroprotection was mediated by the DP1 receptor. Conversely, activation of the DP2 receptor promoted neuronal loss. The protein kinase A inhibitors H89 and KT5720 reversed the protective effect of PGD2, indicating that PGD2‐mediated neuroprotection was dependent on cAMP signaling. These studies indicate that activation of the PGD2 DP1 receptor protects against excitotoxic injury in a cAMP‐dependent manner, consistent with recent studies of PGE2 receptors that also suggest a neuroprotective effect of prostaglandin receptors. Taken together, these data support an emerging and paradoxical neuroprotective role of prostaglandins in the CNS.
Rotenone‐induced caspase 9/3‐independent and ‐dependent cell death in undifferentiated and differentiated human neural stem cells
Authors: Li Jiang , Spletter Maria L. , Johnson Delinda A. , Wright Lynda S. , Svendsen Clive N. , Johnson Jeffrey A. 
Published: January 2005

AbstractWe used human neural stem cells (hNSCs) and their differentiated cultures as a model system to evaluate the mechanism(s) involved in rotenone (RO)‐ and camptothecin (CA)‐induced cytotoxicity. Results from ultrastructural damage and terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling (TUNEL) staining indicated that RO‐induced cytotoxicity resembled CA‐induced apoptosis more than H2O2‐induced necrosis. However, unlike CA‐induced, caspase 9/3‐dependent apoptosis, there was no increased activity in caspase 9, caspase 3 or poly (ADP‐ribose) polymerase (PARP) cleavage in RO‐induced cytotoxicity, in spite of time‐dependent release of cytochrome c and apoptosis‐inducing factor (AIF) following mitochondrial membrane depolarization and a significant increase in reactive oxygen species generation. Equal doses of RO and CA used in hNSCs induced caspase 9/3‐dependent apoptosis in differentiated cultures. Time‐dependent ATP depletion occurred earlier and to a greater extent in RO‐treated hNSCs than in CA‐treated hNSCs, or differentiated cultures treated with RO or CA. In conclusion, these results represent a unique ultrastructural and molecular characterization of RO‐ and CA‐induced cytotoxicity in hNSCs and their differentiated cultures. Intracellular ATP levels may play an important role in determining whether neural progenitors or their differentiated cells follow a caspase 9/3‐dependent or ‐independent pathway in response to acute insults from neuronal toxicants.
Increased expression of phospholipase D1 in the brains of scrapie‐infected mice
Authors: Jin Jae‐Kwang , Kim Nam‐Ho , Min Do Sik , Kim Jae‐Il , Choi Jin‐Kyu , Jeong Byung‐Hoon , Choi Seung‐Il , Choi Eun‐Kyoung , Carp Richard I. , Kim Yong‐Sun 
Published: January 2005

AbstractMitochondrial dysfunction and free radical‐induced oxidative damage are critical factors in the pathogenesis of neurodegenerative diseases. Recently, phospholipid breakdown by phospholipase D (PLD) has been recognized as an important signalling pathway in the nervous system. Here, we examined the expression of PLD and alteration of membrane phospholipid in scrapie brain. We have found that protein expression and enzyme activity of PLD1 were increased in scrapie brains compared with controls; in particular, there was an increase in the mitochondrial fraction. PLD1 in mitochondrial membranes from scrapie brains, but not from control brains, was tyrosine phosphorylated. Furthermore, the concentration of mitochondrial phospholipids such as phosphatidylcholine and phosphatidylethanolamine was increased and the content of phosphatidic acid, a product of PLD activity, was up‐regulated in the mitochondrial membrane fractions. Immunohistochemically, PLD1 immunoreactivity was significantly increased in activated astrocytes in both cerebral cortex and hippocampus of scrapie brains. Taken together, these results suggest that PLD activation might induce alterations in mitochondrial lipids and, in turn, mediate mitochondrial dysfunction in the brains of scrapie‐infected mice.
The basic helix‐loop‐helix transcription factor Nex‐1/Math‐2 promotes neuronal survival of PC12 cells by modulating the dynamic expression of anti‐apoptotic and cell cycle regulators
Authors: Uittenbogaard Martine , Chiaramello Anne 
Published: January 2005

AbstractThe basic helix‐loop‐helix transcription factor Nex1/Math‐2 belongs to the NeuroD subfamily, which plays a critical role during neuronal differentiation and maintenance of the differentiated state. Previously, we demonstrated that Nex1 is a key regulatory component of the nerve growth factor (NGF) pathway. Further supporting this hypothesis, this study shows that Nex1 has survival‐inducing properties similar to NGF, as Nex1‐overexpressing PC12 cells survive in the absence of trophic factors. We dissected the molecular mechanism by which Nex1 confers neuroprotection upon serum removal and found that constitutive expression of Nex1 maintained the expression of specific G1 phase cyclin‐dependent kinase inhibitors and concomitantly induced a dynamic expression profile of key anti‐apoptotic regulators. This study provides the first evidence of the underlying mechanism by which a member of the NeuroD‐subfamily promotes an active anti‐apoptotic program essential to the survival of neurons. Our results suggest that the survival program may be viewed as an integral component of the intrinsic programming of the differentiated state.
Synaptopodin, a molecule involved in the formation of the dendritic spine apparatus, is a dual actin/α‐actinin binding protein
Authors: Kremerskothen Joachim , Plaas Christian , Kindler Stefan , Frotscher Michael , Barnekow Angelika 
Published: January 2005

AbstractSynaptopodin (SYNPO) is a cytoskeletal protein that is preferentially located in mature dendritic spines, where it accumulates in the spine neck and closely associates with the spine apparatus. Formation of the spine apparatus critically depends on SYNPO. To further determine its molecular action, we screened for cellular binding partners. Using the yeast two‐hybrid system and biochemical assays, SYNPO was found to associate with both F‐actin and α‐actinin. Ectopic expression of SYNPO in neuronal and non‐neuronal cells induced actin aggregates, thus confirming a cytoplasmic interaction with the actin cytoskeleton. Whereas F‐actin association is mediated by a central SYNPO motif, binding to α‐actinin requires the C‐terminal domain. Notably, the α‐actinin binding domain is also essential for dendritic targeting and postsynaptic accumulation of SYNPO in primary neurons. Taken together, our data suggest that dendritic spine accumulation of SYNPO critically depends on its interaction with postsynaptic α‐actinin and that SYNPO may regulate spine morphology, motility and function via its distinct modes of association with the actin cytoskeleton.
Age‐dependent sensitivity of the developing brain to irradiation is correlated with the number and vulnerability of progenitor cells
Authors: Fukuda Aya , Fukuda Hirotsugu , Swanpalmer Janos , Hertzman Sven , Lannering Birgitta , Marky Ildiko , Björk‐Eriksson Thomas , Blomgren Klas 
Published: January 2005

AbstractIn a newly established model of unilateral, irradiation (IR)‐induced injury we compared the outcome after IR to the immature and juvenile brain, using rats at postnatal days 9 or 23, respectively. We demonstrate that (i) the immature brains contained more progenitors in the subventricular zone (SVZ) and subgranular zone (SGZ) compared with the juvenile brains; (ii) cellular injury, as judged by activation of caspase 3 and p53, as well as nitrotyrosine formation, was more pronounced in the SVZ and SGZ in the immature brains 6 h after IR; (iii) the number of progenitor and immature cells in the SVZ and SGZ decreased 6 h and 7 days post‐IR, corresponding to acute and subacute effects in humans, respectively, these effects were more pronounced in immature brains; (iv) myelination was impaired after IR at both ages, and much more pronounced after IR to immature brains; (v) the IR‐induced changes remained significant for at least 10 weeks, corresponding to late effects in humans, and were most pronounced after IR to immature brains. It appears that IR induces both an acute loss of progenitors through apoptosis and a perturbed microenvironment incompatible with normal proliferation and differentiation, and that this is more pronounced in the immature brain.
β‐Site APP cleaving enzyme up‐regulation induced by 4‐hydroxynonenal is mediated by stress‐activated protein kinases pathways
Authors: Tamagno Elena , Parola Maurizio , Bardini Paola , Piccini Alessandra , Borghi Roberta , Guglielmotto Michela , Santoro Gianni , Davit Annalisa , Danni Oliviero , Smith M. A. , Perry G. , Tabaton Massimo 
Published: January 2005

Abstract4‐Hydroxynonenal (HNE), an aldehydic product of lipid peroxidation, up‐regulates expression of the β‐site APP cleaving enzyme (BACE‐1), an aspartyl protease responsible for the β‐secretase cleavage of amyloid precursor protein (AβPP), and results in increased levels of amyloid β (Aβ) peptide. The mechanisms underlying this remain unclear but are of fundamental importance because prevention of BACE‐1 up‐regulation is viewed as an important therapeutic strategy. In this study, we exposed NT2 neurons to a range of HNE concentrations (0.5–5 µm) that elicited an up‐regulation of BACE‐1 expression, a significant increase in intracellular and secreted levels of Aβ peptides as well as apoptosis involving poly‐ADP ribose polymerase cleavage and activation of caspase 3. To delineate the molecular events involved in HNE‐mediated BACE‐1 activation, we investigated the involvement of stress‐activated protein kinases (SAPK), signal transducers and activators of transcription (STAT) and serine–threonine kinase B/phosphatidylinositol phosphate 3 kinase (Akt/PtdIns3K). Using specific pharmacological inhibitors, our results show that activation of c‐Jun N‐terminal kinases and p38MAPK., but not STAT or Akt/PtdIns3K, pathways mediate the HNE‐dependent up‐regulation of BACE‐1 expression. Therefore, HNE, an oxidative stress mediator detected in vivo in the brains of Alzheimer's disease patients, may play a pathogenetic role in Alzheimer's disease by selectively activating SAPK pathways and BACE‐1 that regulate the proteolytic processing of AβPP.
A Modeling Framework for Supply Chain Simulation: Opportunities for Improved Decision Making*
Authors: Van Der Zee D. J. , Van Der Vorst J. G. A. J. 
Published: January 2005

ABSTRACTOwing to its inherent modeling flexibility, simulation is often regarded as the proper means for supporting decision making on supply chain design. The ultimate success of supply chain simulation, however, is determined by a combination of the analyst's skills, the chain members' involvement, and the modeling capabilities of the simulation tool. This combination should provide the basis for a realistic simulation model, which is both transparent and complete. The need for transparency is especially strong for supply chains as they involve (semi)autonomous parties each having their own objectives. Mutual trust and model effectiveness are strongly influenced by the degree of completeness of each party's insight into the key decision variables. Ideally, visual interactive simulation models present an important communicative means for realizing the required overview and insight. Unfortunately, most models strongly focus on physical transactions, leaving key decision variables implicit for some or all of the parties involved. This especially applies to control structures, that is, the managers or systems responsible for control, their activities and their mutual attuning of these activities. Control elements are, for example, dispersed over the model, are not visualized, or form part of the time‐indexed scheduling of events. In this article, we propose an alternative approach that explicitly addresses the modeling of control structures. First, we will conduct a literature survey with the aim of listing simulation model qualities essential for supporting successful decision making on supply chain design. Next, we use this insight to define an object‐oriented modeling framework that facilitates supply chain simulation in a more realistic manner. This framework is meant to contribute to improved decision making in terms of recognizing and understanding opportunities for improved supply chain design. Finally, the use of the framework is illustrated by a case example concerning a supply chain for chilled salads.
Applying Process Knowledge for Yield Variation Reduction: A Longitudinal Field Study*
Authors: Field Joy M. , Sinha Kingshuk K. 
Published: January 2005

ABSTRACTThe widespread recognition of the detrimental effects of high yield variation in advanced manufacturing technology settings, both in terms of cost and management of production processes, underscores the need to develop effective strategies for reducing yield variation. In this article, we report the findings of a longitudinal field study in an electromechanical motor assembly plant where we examined how the application of process knowledge by production work teams can reduce yield variation. We propose and provide an operationalizion of a strategy to identify the sequence of particular types of actions—actions to control the mean followed by actions to control the variance—that work teams should pursue over time to apply process knowledge for reducing yield variation. The results of our empirical analysis show that yield variation was significantly reduced on three of the four production lines at the manufacturing plant that served as our research site. Differences in strategies for applying process knowledge help explain the different results on each of the production lines.