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Many Aspects (many + aspect)
Selected AbstractsTerminology Influences Many Aspects of the Market/Incentives DebateAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2010D. L. Segev No abstract is available for this article. [source] A test of the relationship between seasonal rainfall and saguaro cacti branching patternsECOGRAPHY, Issue 4 2003Taly Dawn Drezner Reproductive output, as well as photosynthetically active radiation interception and CO2 uptake, increase as saguaro cacti Carnegiea gigantea (Engelm.) Britt. and Rose branch, and branching increases with increasing moisture. The Sonoran Desert experiences distinct summer and winter precipitation regimes that vary in both geography and scale. Many aspects of saguaro ecology are known to depend on the summer rains, which has resulted in an emphasis on summer rains in the literature. Similarly, branching studies have been limited geographically to areas that receive relatively high amounts of summer rainfall. These studies, therefore, attribute branching patterns to the summer (or possibly annual) rains, and conclusions reflect the summer precipitation bias. Environmental variability in space was explored in the present study to investigate saguaro branching patterns. I collected height and branching data in thirty saguaro populations across their American range. Stepwise regression was used to determine which climate, vegetation and soil variables best predict branching. Contrary to the literature, this study found that winter precipitation, particularly from January to April, was the best predictor of branching, not summer or annual rain. Surprisingly, the relationship between the summer monsoons (July and August precipitation) and branching was negative. This is likely due to the fact that summer and winter rainfall patterns are geographically distinct. Winter precipitation appears to play a key role in branching, and thus in seed production. This suggests that saguaros benefit from moisture during the winter, possibly utilizing cold-season rains for increasing their reproductive output through branching, and challenging the view that the summer rains dominate virtually every aspect of the saguaro life-cycle, and creating a more balanced view of saguaro ecology. [source] Erythropoiesis and red cell function in vertebrate embryosEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005R. Baumann Abstract All vertebrate embryos produce a specific erythroid cell population , primitive erythrocytes , early in development. These cells are characterized by expression of the specific embryonic haemoglobins. Many aspects of primitive erythropoiesis and the physiological function of primitive red cells are still enigmatic. Nevertheless, recent years have seen intensive efforts to characterize in greater detail the molecular events underlying the initiation of erythropoiesis in vertebrate embryos. Several key genes have been identified that are necessary for primitive and the subsequent definitive erythropoiesis, which differs in several aspect from primitive erythropoiesis. This review gives in its first part a short overview dealing with comparative aspects of primitive and early definitive erythropoiesis in higher and lower vertebrates and in the second part we discuss the physiological function of primitive red cells based mainly on results from mammalian and avian embryos. [source] Heparin and Heparan Sulfate BiosynthesisIUBMB LIFE, Issue 4 2002Kazuyuki Sugahara Abstract Heparan sulfate is one of the most informationally rich biopolymers in Nature. Its simple sugar backbone is variously modified to different degrees depending on the cellular conditions. Thus, it matures to have an enormously complicated structure, which most likely exhibits a considerable number of unique overlapping sequences with peculiar sulfation profiles. Such sequences are recognized by specific complementary proteins, which form a huge group of "heparin-binding proteins," and the sugar sequences in turn support unique functions of the respective proteins through specific interactions. The heparan sulfate sequences are not directly encoded by genes, but are created by elaborate biosynthetic mechanisms, which ensure the generation of these indispensable sequences. In heparan sulfate biosynthesis, the tetrasaccharide sequence (GlcA-Gal-Gal-Xyl-), designated the protein linkage region, is first assembled on a specific Ser residue at the glycosaminoglycan attachment site of a core protein. A heparan sulfate chain is then polymerized on this fragment by alternate additions of GlcNAc and GlcA through the actions of glycosyltransferases with overlapping specificities encoded by the tumor suppressor EXT family genes. Then follow various modifications by N -deacetylation and N -sulfation of glucosamine, C5-epimerization of GlcA and multiple O -sulfations of the component sugars. Recent studies have achieved purification of several, and molecular cloning of most, of the enzymes responsible for these reactions. Some of these enzymes are bifunctional. The availability of cDNA probes has facilitated elucidation of the crystal structures for two of the biosynthetic enzymes, demonstration of their intracellular location, and their occurrence in complexes to achieve rapid and efficient synthesis of complex sugar sequences. Genomic structure and transcript analysis have shown the existence of multiple isoforms for most of the sulfotransferases. Many aspects of the heparan sulfate biosynthetic scheme are shared by the structural analog heparin, which is synthesized in mast cells and some other mammalian cells and is several-fold higher degree of polymerization and more extensive modification than heparan sulfate. [source] Reproductive ecology of the reef manta ray Manta alfredi in southern MozambiqueJOURNAL OF FISH BIOLOGY, Issue 1 2010A. D. Marshall The application of a photographic identification methodology using the unique ventral surface markings (natural spot patterns) of an observed population in southern Mozambique enabled many aspects of the reproductive ecology of reef manta rays Manta alfredi to be examined. The region encompassing the study site was identified as a mating ground for M. alfredi based on observations of mating events and fresh mating scars on females. The distribution of these pectoral fin scars was highly biased and indicated a strong lateralized behavioural trait, with 99% of these scars occurring only on the left pectoral fin. No other elasmobranch has been reported to display behavioural lateralization. The study region also acts as a birthing ground, with individuals typically giving birth in the austral summer period after a gestation of c. 1 year. Reproductive periodicity in M. alfredi was most commonly biennial, but a few individuals were pregnant in consecutive years, confirming an annual ovulatory cycle. The production of a single pup appears to be the normal situation, although observations in the wild as well as during opportunistic dissections of individuals killed by fisheries revealed that two pups are conceived on occasion. Many aspects of the study have contributed to the limited baseline data currently available for this species and have highlighted the potential need for more conservative conservation strategies. [source] Oceanic migration and spawning of anguillid eelsJOURNAL OF FISH BIOLOGY, Issue 9 2009K. Tsukamoto Many aspects of the life histories of anguillid eels have been revealed in recent decades, but the spawning migrations of their silver eels in the open ocean still remains poorly understood. This paper overviews what is known about the migration and spawning of anguillid species in the ocean. The factors that determine exactly when anguillid eels will begin their migrations are not known, although environmental influences such as lunar cycle, rainfall and river discharge seem to affect their patterns of movement as they migrate towards the ocean. Once in the ocean on their way to the spawning area, silver eels probably migrate in the upper few hundred metres, while reproductive maturation continues. Although involvement of a magnetic sense or olfactory cues seems probable, how they navigate or what routes they take are still a matter of speculation. There are few landmarks in the open ocean to define their spawning areas, other than oceanographic or geological features such as oceanic fronts or seamounts in some cases. Spawning of silver eels in the ocean has never been observed, but artificially matured eels of several species have exhibited similar spawning behaviours in the laboratory. Recent collections of mature adults and newly spawned preleptocephali in the spawning area of the Japanese eel Anguilla japonica have shown that spawning occurs during new moon periods in the North Equatorial Current region near the West Mariana Ridge. These data, however, show that the latitude of the spawning events can change among months and years depending on oceanographic conditions. Changes in spawning location of this and other anguillid species may affect their larval transport and survival, and appear to have the potential to influence recruitment success. A greater understanding of the spawning migration and the choice of spawning locations by silver eels is needed to help conserve declining anguillid species. [source] Guidelines for species descriptions of diplomonad flagellates from fishJOURNAL OF FISH DISEASES, Issue 1 2002S L Poynton Diplomonad flagellates are common commensals of the digestive tract, and less common pathogenic parasites occurring in the digestive tract and systemically in numerous fish species. Many aspects of infections are poorly understood, including host-flagellate specificity, geographic ranges, and pathogenicity of different species. Much confusion is attributable to inadequate determination of genus and species. Although older literature reports Hexamita, Octomitus and Spironucleus from fish, recent studies confirm only Spironucleus. To address this problem, we describe ultrastructural features of trophozoites permitting reliable identification to genus and species, and techniques for their elucidation. Pioneering work by Brugerolle and colleagues established that genera can be distinguished by transmission electron microscopy (TEM). We now demonstrate that at the species level, surface ornamentations (especially at the posterior end of the body), and the pattern of bands of microtubules accompanying the flagellar pocket (in transverse section through the middle of the body), are of particular taxonomic value. Both scanning and TEM are essential for robust species descriptions and type material must be deposited in a recognized reference collection. Taxonomic studies are enhanced by in vitro culture, with tolerance and optimum for different conditions providing important supplementary information. Molecular characterization of fish diplomonads is in its infancy. [source] A role of local signalling in the establishment and maintenance of the asymmetrical architecture of a neuronJOURNAL OF NEUROCHEMISTRY, Issue 3 2007Eun-Mi Hur Abstract Significant progress has been made in the identification of intrinsic and extrinsic factors involved in the development of nervous system. It is remarkable that the establishment and maintenance of the asymmetrical architecture of a neuron is coordinated by a limited repertoire of signalling machineries. However, the details of signalling mechanisms responsible for creating specificity and diversity required for proper development of the nervous system remain largely to be investigated. An emerging body of evidence suggests that specificity and diversity can be achieved by differential regulation of signalling components at distinct subcelluar localizations. Many aspects of neuronal polarization and morphogenesis are attributed to localized signalling. Further diversity and specificity of receptor signalling can be achieved by the regulation of molecules outside the cell. Recent evidence suggests that extracellular matrix molecules are essential extrinsic cues that function to foster the growth of neurons. Therefore, it is important to understand where the signalling machineries are activated and how they are combined with other factors in order to understand the molecular mechanism underlying neuronal development. [source] Deaths associated with restraint use in health and social care in the UK.JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 1 2003The results of a preliminary survey Many aspects of the management of acutely disturbed behaviour have only relatively recently come under systematic scrutiny. Perhaps regrettably one of the last amongst the range of strategies that may be employed to be subjected to rigorous examination has been physical restraint. Considerable debate has recently taken place around what represents good practice in this sensitive and controversial area but the continuing dearth of research in some aspects of this area of practice has meant that this discussion has arguably been over reliant on ,expert' opinion. Questions continue regarding some fundamental issues of restraint, including the relative risks involved in alternative approaches, and anxieties have been expressed about the potential for injuries and death to result from restraint. This article outlines the results of a survey that sought to explore the incidence of deaths associated with restraint in health and social care settings in the UK. The outcome of an initial analysis of the cases identified is then discussed, with reference to the literature on restraint-related deaths, in order to identify the implications for practice. [source] Effect of cell seeding concentration on the quality of tissue engineered constructs loaded with adult human articular chondrocytesJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 1 2008Sebastian Concaro Abstract Many aspects of the process of in vitro differentiation of chondrocytes in three-dimensional (3D) scaffolds need to be further investigated. Chitosan scaffolds were produced by freeze-drying 3% w/v 90% DDA chitosan gels. The effect of the cell seeding concentration was evaluated by culturing human adult chondrocytes in chitosan scaffolds After the first passage, cells were seeded into chitosan scaffolds with a diameter of 8 mm. The final cell seeding concentration per cm3 of chitosan scaffold was: Group A, 3 × 106; Group B, 6 × 106; Group C, 12 × 106; and Group D, 25 × 106 cells. After 14 and 28 days in 3D culture, the constructs were assesed for collagen, glucosaminoglycans and DNA content. The mechanical properties of the constructs were determined using a dynamic oscillatory shear test. The histological aspect of the constructs was evaluated using the Bern score. The collagen and GAG concentration increased, varying the cell seeding concentration. There was a significant increase in proteoglycan and hydroxyproline production between groups C and D. The sulphated GAG content increased significantly in the group D as compared to the other groups. The mechanical properties of the different constructs increased over time, from 9.6 G,/kPa at 14 days of 3D culture to 14.6 G,/kPa at 28 days under the same culture conditions. In this study we were able to determine that concentrations of 12,25 million cells/cm2 are needed to increase the matrix production and mechanical properties of human adult chondrocytes under static conditions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Lateral inhibition in the astogeny of conical multistiped graptolitesLETHAIA, Issue 1 2000Øyvind Hammer Conical multistiped graptolites (in particular Rhabdinopora) grow in patterns which can be understood using a lateral inhibition model based on diffusion of nutrients or pheromones around the colony. Many aspects of rhabdosome morphology are explained with this model. These include branching and the distribution of branching points, the morphology of bifurcations, the almost constant spacing of stipes, the high rate of branching in early stages, the variation in expansion rate, and regeneration patterns after damage. For the first time, a full three-dimensional computer simulation of graptolite growth has been accomplished, assuming biologically justified processes instead of formal growth rules. The simulations indicate that dissepiments were instrumental in controlling rhabdosome shape, but not sufficient to keep its horizontal section perfectly circular. [source] Multiple paternity in loggerhead turtle (Caretta caretta) nests on Melbourne Beach, Florida: a microsatellite analysisMOLECULAR ECOLOGY, Issue 2 2002M. K. Moore Abstract Many aspects of sea turtle biology are difficult to measure in these enigmatic migratory species, and this lack of knowledge continues to hamper conservation efforts. The first study of paternity in a sea turtle species used allozyme analysis to suggest multiple paternity in loggerhead turtle (Caretta caretta) clutches in Australia. Subsequent studies indicated that the frequency of multiple paternity varies from species to species and perhaps location to location. This study examined fine-scale population structure and paternal contribution to loggerhead clutches on Melbourne Beach, FL, USA using microsatellite markers. Mothers and offspring from 70 nests collected at two locations were analysed using two to four polymorphic microsatellite loci. Fine-scale population differentiation was not evident between the sampled locations, separated by 8 km. Multiple paternity was common in loggerhead nests on Melbourne Beach; 22 of 70 clutches had more than one father, and six had more than two fathers. This is the first time that more than two fathers have been detected for offspring in individual sea turtle nests. Paternal genotypes could not be assigned with confidence in clutches with more than two fathers, leaving the question of male philopatry unanswered. Given the high incidence of multiple paternity, we conclude that males are not a limiting resource for this central Florida nesting aggregate. [source] Ocular toxoplasmosis: in the storm of the eyePARASITE IMMUNOLOGY, Issue 12 2006L. A. JONES SUMMARY Ocular toxoplasmosis (OT) can occur in the children of mothers infected with Toxoplasma gondii during pregnancy. It is not limited to the congenitally infected, but can also occur following adult-acquired infection or as a result of disease reactivation in immune-compromised and pregnant individuals. Many aspects of immune privilege in the eye, including constitutive TGF-, expression and reduced MHC class 1 expression, would appear at first to favour parasite survival. Conversely, many of the mechanisms that control parasite multiplication in other anatomical sites, such as nitric oxide expression, IFN-, and TNF-,, are known to disrupt immune privilege and are associated with ocular damage. Taking into account the opposing needs of limiting parasite multiplication and minimizing tissue destruction we review the pathogenesis of OT in the murine model. [source] Water deficits and hydraulic limits to leaf water supplyPLANT CELL & ENVIRONMENT, Issue 2 2002J. S. Sperry Abstract Many aspects of plant water use , particularly in response to soil drought , may have as their basis the alteration of hydraulic conductance from soil to canopy. The regulation of plant water potential (,) by stomatal control and leaf area adjustment may be necessary to maximize water uptake on the one hand, while avoiding loss of hydraulic contact with the soil water on the other. Modelling the changes in hydraulic conductance with pressure gradients in the continuum allows the prediction of water use as a function of soil environment and plant architectural and xylem traits. Large differences in water use between species can be attributed in part to differences in their ,hydraulic equipment' that is presumably optimized for drawing water from a particular temporal and spatial niche in the soil environment. A number of studies have identified hydraulic limits as the cause of partial or complete foliar dieback in response to drought. The interactions between root:shoot ratio, rooting depth, xylem properties, and soil properties in influencing the limits to canopy water supply can be used to predict which combinations should optimize water use in a given circumstance. The hydraulic approach can improve our understanding of the coupling of canopy processes to soil environment, and the adaptive significance of stomatal behaviour. [source] Project management practice, generic or contextual: A reality checkPROJECT MANAGEMENT JOURNAL, Issue 1 2008Claude Besner Abstract The purpose of this research is to contribute to a better understanding of project management practice by investigating the use of project management tools and techniques and the levels of support provided by organizations for their use. The study examines both general levels of use and variations among project types and contexts. Many aspects of project management practice are common to most projects in most contexts, while others vary significantly among different types of projects and among projects in different contexts. The purpose of this paper is to present empirical results that show both the common elements and the significant variations. The paper is based on a survey of 750 project management practitioners. The use of tools and techniques is seen here as an indicator of the realities of practice. The study found some aspects of practice to be common across all types of projects and all contexts, but on this background of similar patterns of practice, several statistically significant differences have also been identified. The primary focus of this paper is on these variations in practice. [source] Adequacy Indices for Dialysis in Acute Renal Failure: Kinetic ModelingARTIFICIAL ORGANS, Issue 5 2010Malgorzata Debowska Abstract Many aspects of the management of renal replacement therapy in acute renal failure (ARF), including the appropriate assessment of dialysis adequacy, remain unresolved, because ARF patients often are not in a metabolic steady state. The aim of this study was to evaluate a system of adequacy indices for dialysis in ARF patients using urea and creatinine kinetic modeling. Kinetic modeling was performed for two different fictitious patients (A and B) with characteristics described by the average parameters for two patient groups and for two blood purification treatments: sustained low efficiency daily dialysis (SLEDD) in Patient A and continuous venovenous hemofiltration (CVVH) in Patient B, based on data from a clinical report. Urea and creatinine generation rates were estimated according to the clinical data on the solute concentrations in blood. Then, using estimated generation rates, two hypothetical treatments were simulated, CVVH in Patient A and SLEDD in Patient B. KT/V, fractional solute removal (FSR) and equivalent renal clearance (EKR) were calculated according to the definitions developed for metabolically unstable patients. CVVH appeared as being more effective than SLEDD because KT/V, FSR, and EKR were higher for CVVH than SLEDD in Patients A and B. Creatinine KT/V, FSR, and EKR were lower and well correlated to the respective indices for urea. Urea and creatinine generation rates were overestimated more than twice in Patient A and by 30,40% in Patient B if calculated assuming the metabolically stable state than if estimated by kinetic modeling. Adequacy indices and solute generation rates for ARF patients should be estimated using the definition for unsteady metabolic state. EKR and FSR were higher for urea and creatinine with CVVH than with SLEDD, because of higher K·T and minimized compartmental effects for CVVH. [source] Impact of caring for a school-aged child with a disability: Understanding mothers' perspectivesAUSTRALIAN OCCUPATIONAL THERAPY JOURNAL, Issue 2 2010Helen Bourke-Taylor Aim:,Children with a disability are reliant on a capable, healthy and well-resourced carer. Most often the child's mother provides the care that ensures the child's health, service access and community integration are attended to successfully. Through in-depth interviews with mothers and professionals, this study explores issues that challenge the mother's performance in her very important role as a caregiver. Method:,Qualitative methodology(n = 8)resulted in verbatim transcriptions that were analysed and categorised, and common themes were derived. Results:,Participants identified a multitude of challenges related to issues surrounding the child, maternal characteristics, the family, services and the community. Emotional distress and mental health issues were reported. Conclusion:,Many aspects of caregiving can be relentless and challenging. Occupational therapy clinical implications aimed at supporting mothers and their children are discussed. [source] A comparative study of corporate social responsibility in Bangladesh and PakistanCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 2 2009Malik Asghar Naeem Abstract Making a contribution to sustainable development through good corporate social responsibility presents businesses with a challenge, particularly in developing countries. This paper measures the sensitivity to corporate social responsibility amongst businesses operating in Bangladesh and Pakistan through a review of written policies of both listed local firms and multinational corporations operating there. We use the Global Compact supplemented by relevant parts of the Global Reporting Initiative Sustainability Reporting Guidelines to benchmark companies and countries. Significant differences are found between local listed companies and multinational corporations. However, all companies are seen to be failing to engage with many aspects of corporate social responsibility related to sustainable development. Specific deficiencies relate to anti-corruption, gender equality, child labor, community giving and the formal representation of workers. Few differences are found between the approaches taken by companies in Bangladesh and Pakistan. Given the development needs of the region we point to businesses being unwilling or unable to adopt sufficiently robust corporate social responsibility and point to a role for both government and civil society. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment. [source] Shaggy/GSK-3, kinase localizes to the centrosome and to specialized cytoskeletal structures in DrosophilaCYTOSKELETON, Issue 6 2006Yves Bobinnec Abstract The assembly of a functional bipolar mitotic spindle requires an exquisite regulation of microtubule behavior in time and space. To characterize new elements of this machinery we carried out a GFP based "protein trap" screen and selected fusion proteins which localized to the spindle apparatus. By this method we identified Shaggy, the Drosophila homologue of glycogen synthase kinase-3, (GSK-3,), as a component of centrosomes. GSK-3, acting in the Wingless signaling pathway is involved in a vast range of developmental processes, from pattern formation to cell-fate specification, and is a key factor for cell proliferation in most animals. We exploited our Shaggy::GFP Drosophila line to analyze the subcellular localizations of GSK-3,/Shaggy and shed light on its multiple roles during embryogenesis. We found that Shaggy becomes enriched transiently in a variety of specialized cytoskeletal structures of the embryo, including centrosomes throughout mitosis, suggesting that this kinase is involved in the regulation of many aspects of the cytoskeleton function. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] Technological Maturity and Development without Research: The Challenge for Malaysian ManufacturingDEVELOPMENT AND CHANGE, Issue 2 2000Suresh Narayanan Propelled largely by direct investment via multinationals, Malaysia's manufacturing sector has grown rapidly and is changing its output-mix. In 1992, the share of high-tech products in Malaysian manufacturing exceeded that of Japan, Korea or Taiwan. However, this ,maturity' was acquired without a strong research base. This article provides a framework which looks at the role of research and development (R&D) in conferring technological maturity and assesses the progress Malaysian manufacturing has made in this regard. The authors find that while multinationals have transferred many aspects of production, they have been slow in transferring R&D expertise. Neither has indigenous innovation filled this gap. Consequently, the long-term sustainability of the industrial transformation process in Malaysia is in jeopardy. The article concludes with suggestions for corrective policies. [source] Cloning and characterization of voltage-gated calcium channel alpha1 subunits in Xenopus laevis during developmentDEVELOPMENTAL DYNAMICS, Issue 11 2009Brittany B. Lewis Abstract Voltage-gated calcium channels play a critical role in regulating the Ca2+ activity that mediates many aspects of neural development, including neural induction, neurotransmitter phenotype specification, and neurite outgrowth. Using Xenopus laevis embryos, we describe the spatial and temporal expression patterns during development of the 10 pore-forming alpha1 subunits that define the channels' kinetic properties. In situ hybridization indicates that CaV1.2, CaV2.1, CaV2.2, and CaV3.2 are expressed during neurula stages throughout the neural tube. These, along with CaV1.3 and CaV2.3, beginning at early tail bud stages, and CaV3.1 at late tail bud stages, are detected in complex patterns within the brain and spinal cord through swimming tadpole stages. Additional expression of various alpha1 subunits was observed in the cranial ganglia, retina, olfactory epithelium, pineal gland, and heart. The unique expression patterns for the different alpha1 subunits suggests they are under precise spatial and temporal regulation and are serving specific functions during embryonic development. Developmental Dynamics 238:2891,2902, 2009. © 2009 Wiley-Liss, Inc. [source] Identification of candidate secreted factors involved in trigeminal placode inductionDEVELOPMENTAL DYNAMICS, Issue 10 2007Kathryn L. McCabe Abstract Cranial ectodermal placodes are critical for normal development of the peripheral nervous system of the head. However, many aspects of the molecular and tissue interactions involved in their induction have yet to be elucidated. The trigeminal placode is induced by an unidentified secreted factor(s) from the dorsal neural tube. To determine candidates that may be involved in this induction process, we have performed reverse transcriptase-polymerase chain reaction (RT-PCR) and whole-mount in situ hybridization to screen for receptors expressed by uninduced presumptive trigeminal level ectoderm. We have found that receptors for fibroblast growth factors, insulin-like growth factors, platelet-derived growth factors, Sonic hedgehog, the transforming growth factor-beta superfamily, and Wnts all are expressed in patterns consistent with a role in trigeminal placode formation. This RT-PCR screen for candidate receptors expressed in presumptive trigeminal ectoderm is the first systematic screen to identify potential interactions underlying induction of the trigeminal placode and represents a critical step for understanding this complex process. Developmental Dynamics 236:2925,2935, 2007. © 2007 Wiley-Liss, Inc. [source] Sexual dimorphism of g-protein subunit Gng13 expression in the cortical region of the developing mouse ovaryDEVELOPMENTAL DYNAMICS, Issue 7 2007Akihiro Fujino Abstract In our search for genes required for the development and function of mouse gonads, we identified Gng13 (guanine nucleotide binding protein 13, gamma), a gene with an embryonic expression pattern highly restricted to the ovary. Based on reverse transcriptase-polymerase chain reaction (RT-PCR) and whole-mount in situ hybridization, Gng13 is expressed in both XX and XY gonads at embryonic day (E) 11.5, but becomes up-regulated in the XX gonad by E12.5. Expression is retained after treatment with busulfan, a chemical known to eliminate germ cells, pointing to the soma as a site of Gng13 transcription. In situ hybridization of embryonic ovarian tissue sections further localized the expression to the cortex of the developing XX gonad. Gng13 expression in the adult is also highly restricted. Northern blot analyses and Genomic Institute of the Novartis Research Foundation expression profiling of adult tissues detected very high expression in the cerebrum and cerebellum, in addition to, a weaker signal in the ovary. Gng13 belongs to a well-known family of signal transduction molecules with functions in many aspects of development and organ physiology. Here, we report that, in the developing mouse embryo, expression of Gng13 mRNA is highly restricted to the cortex of the XX gonad during sexual differentiation, suggesting a role for this gene during ovarian development. Developmental Dynamics 236:1991,1996, 2007. © 2007 Wiley-Liss, Inc. [source] Polymersomes as viral capsid mimicsDRUG DEVELOPMENT RESEARCH, Issue 1 2006Fariyal Ahmed Abstract Polymersomes are self-assembled polymer shells composed of block copolymer amphiphiles. These synthetic amphiphiles have a similar amphiphilicity to lipids, but they have much larger molecular weights and so for this reason, plus many others reviewed here, comparisons of polymersomes to viral capsids composed of large polypeptide chains seem increasingly more appropriate. The wide range of polymers being used to make polymersomes is summarized together with descriptions of physical properties such as stability and permeability. Emerging studies of in vivo stealthiness and programmed disassembly for controlled release are also elaborated here together with a summary of targeting in vitro. Comparisons of polymersomes to viral capsids are shown to encompass many aspects of current designs. Drug Dev. Res. 67:4,14, 2006. © 2006 Wiley-Liss, Inc. [source] Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)ACTA ZOOLOGICA, Issue 2 2008Gabe S. Bever Abstract Bever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). ,Acta Zoologica (Stockholm) 88: 000,000 Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative. [source] Toward a Dynamic Learning Perspective of EntrepreneurshipENTREPRENEURSHIP THEORY AND PRACTICE, Issue 4 2005Jason Cope This conceptual article introduces a dynamic learning perspective of entrepreneurship that builds upon existing "dominant" theoretical approaches to understanding entrepreneurial activity. As many aspects of entrepreneurial learning remain poorly understood, this article maps out and extends current boundaries of thinking regarding how entrepreneurs learn. It presents key conclusions from emergent empirical and conceptual work on the subject and synthesizes a broad range of contributory adult, management, and individual learning literature to develop a robust and integrated thematic conceptualization of entrepreneurial learning. Three distinctive, interrelated elements of entrepreneurial learning are proposed,dynamic temporal phases, interrelated processes, and overarching characteristics. The article concludes by demonstrating how a "learning lens" can be applied to create further avenues for research in entrepreneurship from a learning perspective. [source] An evaluation of European air pollution regulations for particulate matter monitored from a heterogeneous networkENVIRONMETRICS, Issue 8 2009Sujit K. Sahu Abstract Statistical methods are needed for evaluating many aspects of air pollution regulations increasingly adopted by many different governments in the European Union. The atmospheric particulate matter (PM) is an important air pollutant for which regulations have been issued recently. A challenging task here is to evaluate the regulations based on data monitored on a heterogeneous network where PM has been observed at a number of sites and a surrogate has been observed at some other sites. This paper develops a hierarchical Bayesian joint space,time model for the PM measurements and its surrogate between which the exact relationship is unknown, and applies the methods to analyse spatio -temporal data obtained from a number of sites in Northern Italy. The model is implemented using MCMC techniques and methods are developed to meet the regulatory demands. These enablefull inference with regard to process unknowns, calibration, validation, predictions in time and space and evaluation of regulatory standards. Copyright © 2008 John Wiley & Sons, Ltd. [source] The European computer driving licence and the use of computers by dental studentsEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 1 2009G. S. Antonarakis Abstract The use of computers within the dental curriculum for students is vital for many aspects of their studies. The aim of this study was to assess how dental students who had obtained the European computer driving licence (ECDL) qualification (an internationally-recognised standard of competence) through taught courses, felt about the qualification, and how it changed their habits vis-à-vis computers, and information and communication technology. This study was carried out as a descriptive, one-off, cross-sectional survey. A questionnaire was distributed to 100 students who had successfully completed the course, with questions pertaining to the use of email, word processing and Internet for course-works, Medline for research, computer based learning, online lecture notes, and online communication with members of staff, both before and after ECDL qualification. Scaled responses were given. The attitudes of students towards the course were also assessed. The frequencies and percentage distributions of the responses to each question were analysed. It was found that dental students who follow ECDL teaching and successfully complete its requirements, seem to increase the frequency with which they use email, word processing and Internet for course works, Medline for research purposes, computer based learning, online lecture notes, and online communication with staff. Opinions about the ECDL course varied, many dental students finding the course easy, enjoying it only a little, but admitting that it improved their computer skills. [source] Self-reported changes in clinical behaviour by undergraduate dental students after video-based teaching in paediatric dentistryEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 3 2005M. Kalwitzki Abstract, Four cohorts of undergraduate students (n = 113) were filmed on video tapes whilst performing paediatric treatments. Selected parts of these tapes were shown the day after. Thus, within one term each student was able to view his performance on a videotape as well as those of fellow students. After completion of the clinical course in paediatric dentistry students were asked by means of a questionnaire about behavioural changes in their clinical work regarding different topics. Considerable changes in behaviour were reported for various topics. Most of the students emphasised the viable role of the video for changing their behaviour. This was especially true for aspects of verbal and non-verbal communication where mainly female students benefited. Moreover, video was thought to have been useful for improving capacities to deal with patients in fear or pain and for ergonomics. About two-thirds of the students (64.6%) thought that watching the video had made it easier for them to put theoretical knowledge into action. Video does not seem to play an important role for confirmation and maintenance of behaviour patterns. In conclusion however, it can be stated that video has a high impact on the modification of behaviour patterns of undergraduate students for many aspects of clinical work. The use of video can thus attribute to dental education in an effective way. [source] Osteopontin is produced by mast cells and affects IgE-mediated degranulation and migration of mast cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2008Akiko Nagasaka Abstract Osteopontin (OPN), originally discovered in bone as an extracellular matrix protein, was identified in many cell types in the immune system, presumably being involved in many aspects of pathogenesis of inflammatory and immune diseases. Mast cells are also involved in such pathological aspects by secreting multiple mediators. However, it has not been determined whether mast cells produce OPN and whether it affects their function. To test this, we used murine fetal skin-derived cultured mast cells (FSMC) and bone marrow-derived cultured mast cells. We found that OPN was spontaneously produced by FSMC and inducible by ionomycin and Fc,RI aggregation in bone marrow-derived cultured mast cells. In the presence of mast cell growth factors, FSMC were similarly generated from both OPN-deficient (OPN,/,) and -sufficient (OPN+/+) mice without significant differences in yield, purity, granularity, and viability. Using OPN,/, FSMC, we found that recombinant OPN augmented IgE-mediated degranulation and induced FSMC chemotaxis. Both effects were mediated by OPN receptors (i.e. CD44 and integrin,,v). IgE-mediated passive cutaneous anaphylaxis was significantly reduced in OPN,/, mice compared with OPN+/+ mice, indicating physiological relevance of OPN. These results indicate that OPN is a mast cell mediator, enhances mast cell responses to antigen, and thus may influence mast cell-related pathological conditions. See accompanying commentary at http://dx.doi.org/10.1002/eji200738131 [source] | ||||||||||||||||||||||||||||||||||||||||||||||