bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic systemic D‐galactose exposure induces memory loss, neurodegeneration, and oxidative damage in mice: Protective effects of R‐α‐lipoic acid
Authors: Cui Xu , Zuo Pingping , Zhang Qing , Li Xuekun , Hu Yazhuo , Long Jiangang , Packer Lester , Liu Jiankang 
Published: March 2006

AbstractChronic systemic exposure of D‐galactose to mice, rats, and Drosophila causes the acceleration of senescence and has been used as an aging model. However, the underlying mechanism is as yet unclear. To investigate the mechanisms of neurodegeneration in this model, we studied cognitive function, hippocampal neuronal apoptosis and neurogenesis, and peripheral oxidative stress biomarkers and also the protective effects of the antioxidant R‐α‐lipoic acid. Chronic systemic exposure of mice to D‐galactose (100 mg/kg, s.c., 7 weeks) induced a spatial memory deficit, an increase in cell karyopyknosis, apoptosis, and caspase‐3 protein levels in hippocampal neurons, a decrease in the number of new neurons in the subgranular zone in the dentate gyrus, a reduction of migration of neural progenitor cells, and an increase in death of newly formed neurons in the granular cell layer. The D‐galactose exposure also induced an increase in peripheral oxidative stress, including an increase in malondialdehyde and decreases in total antioxidative capabilities (T‐AOC), total superoxide dismutase (T‐SOD), and glutathione peroxidase (GSH‐Px) activities. A concomitant treatment with lipoic acid ameliorated cognitive dysfunction and neurodegeneration in the hippocampus and also reduced peripheral oxidative damage by decreasing malondialdehyde and increasing T‐AOC and T‐SOD, without an effect on GSH‐Px. These findings suggest that chronic D‐galactose exposure induces neurodegeneration by enhancing caspase‐mediated apoptosis and inhibiting neurogenesis and neuron migration, as well as increasing oxidative damage. In addition, D‐galactose‐induced toxicity in mice is a useful model for studying the mechanisms of neurodegeneration and neuroprotective drugs and agents. © 2006 Wiley‐Liss, Inc.
Phosphorylation of the nicotinic acetylcholine receptor in myotube‐cholinergic neuron cocultures
Authors: Lanuza Maria A. , Gizaw Rahel , Viloria Alexa , González Carmen M. , Besalduch Núria , Dunlap Veronica , Tomàs Josep , Nelson Phillip G. 
Published: March 2006

AbstractAcetylcholine receptor (AChR) stability in the postsynaptic membrane is affected by serine kinases. AChR are phosphorylated by protein kinase C (PKC) and PKA, and we have shown that activation of PKA and PKC have opposite effects on AChR stability and that this may play some role in the selective, activity‐dependent synapse loss that occurs during development of the neuromuscular junction. Myotube cultures with and without added spinal motor neurons were probed with immunoaffinity‐purified antibodies prepared against phosphorylated peptides with amino acid sequences from different AChR subunits. Different treatments activating PKC (phorbol 12‐myristate 13‐acetate; PMA) or PKA (dibutyryl cyclic adenosine monophosphate; cAMP) or blocking electrical activity (tetrodotoxin; TTX) of the cocultures were chosen because of their known effects, direct or indirect, on receptor stability. We asked whether the phospho‐specific antibody staining in conjunction with α‐bungarotoxin (BTX) identification of AChR aggregates could provide a direct demonstration of changes in receptor phosphorylation produced by the treatments. We found that PMA treatment did increase phosphorylation of the delta subunit and cAMP increased phosphorylation of the epsilon subunit relative to total BTX labeling in muscle‐nerve cocultures, but not in muscle‐only cultures. Blockade of electrical activity with TTX increased the incidence of aggregates that showed no phospho‐epsilon staining. Myotube cultures grown in the absence of neurons did not show the responses of myotubes in cocultures. The results show that manipulations that alter receptor stability also produce changes in receptor phosphorylation. We suggest that phosphorylation may be a mechanism mediating the changes in receptor stability. © 2006 Wiley‐Liss, Inc.
Extinction or adaptation? Three decades of change in shifting cultivation in Sarawak, Malaysia
Authors: Hansen T. S. , Mertz O. 
Published: March 2006

AbstractShifting cultivation is commonly believed to be disappearing in Southeast Asia, but appears relatively persistent in some areas with alternative economic opportunities. This paper analyses how three decades of development have influenced both the decline and persistence of shifting cultivation in Sarawak, Malaysia. Changes in land use and demography are analysed in two Iban shifting cultivation communities, which differ in access to markets, off‐farm work, and in their proximity to large‐scale land development. Although the Sarawak State Government's policies to limit shifting cultivation have not proven effective, introduction of compulsory school attendance, investment in infrastructure and associated access to markets and employment opportunities have gradually changed local livelihoods, now composed of subsistence and commercial farming, land development and connections to local and international labour markets. Shifting cultivation of hill rice has persisted in both communities despite other economic opportunities and has been maintained for a range of reasons. However, increasing permanent migration of younger people and pressure on land from land development may gradually end shifting cultivation, particularly in more developed areas. Copyright © 2006 John Wiley & Sons, Ltd.
Sustainability under threat? The dynamics of environmental change and food production in peri‐urban Kano, northern Nigeria
Authors: Maconachie R. A. , Binns T. 
Published: March 2006

AbstractIn Nigeria, Africa's most populous country, peri‐urban livelihood strategies have increasingly become recognized as important survival mechanisms for a wide range of actors in the context of rapid urban population growth. Based on field research, which illuminates local actors' knowledge and perceptions of land degradation, this paper identifies some of the key forces that are currently shaping the process of peri‐urban change. The paper seeks to examine the social, economic and cultural contexts of land degradation in peri‐urban areas, with specific reference to recent developments in and around the bourgeoning city of Kano in northern Nigeria. Particular issues of concern include the competition for key resources and its impact on the environment, together with related implications for levels of poverty, livelihoods and peri‐urban food security. Since the concept of land degradation is a social construction, with different meanings for different individuals, a more critical evaluation of how the knowledge, understanding and perceptions of local actors drive behaviour and affect land‐use decisions at the micro‐level is essential if sustainable environmental policies for the future are to be initiated. Copyright © 2006 John Wiley & Sons, Ltd.
Eco‐localism and the shaping of sustainable social and natural environments in North‐East Thailand
Authors: Parnwell M. J. G. 
Published: March 2006

AbstractAccording to Fred Curtis (2003, p. 83), ‘the road to environmental sustainability lies in the creation of local, self‐reliant, community economies’, a phenomenon he has labelled ‘eco‐localism’. Eco‐localism focuses on place‐specific responses to place‐specific challenges, set at the scale of the community, with its place‐specific history, culture, social fabric and local ecosystem. It argues the need for a local social economics, which has the capability to protect, maintain, enhance or rehabilitate local resources and environments. Curtis identifies a need to explore the means and potential for taking the eco‐localism idea from principle to practice. This paper seeks to add some empirical meat to Curtis's theoretical bones. The paper uses a case study from North‐East Thailand to describe the sequential ‘crowding out’ and ‘clawing back’ of social institutional control of local development and its social and environmental consequences. It places worsening problems of environmental degradation, resource depletion and social differentiation in the context of the dynamics of spatial integration and modern economic development. It then describes how processes of neo‐localism, congruent with recent changes in the wider Thai and international context, have been responsible for reversing a number of ecological problems and strengthening sammakee, or communal harmony, principally by means of Buddhist institutions and principles. The empirical case‐study fits very neatly with Curtis's theoretical eco‐localism construct. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of Exfoliated Monomer Casting Polyamide 6/Na+‐Montmorillonite Nanocomposites by Anionic Ring Opening Polymerization
Authors: Liu Andong , Xie Tingxiu , Yang Guisheng 
Published: March 2006

AbstractSummary: In this work, a novel method using water as a pre‐dispersant of pristine sodium montmorillonite (Na+‐MMT) and ε‐caprolactam (CL) monomer was developed for the preparation of exfoliated monomer casting polyamide 6 (MCPA6)/MMT nanocomposites via in situ anionic ring opening polymerization. The dispersion effect of MMT in the MCPA6 matrix was investigated by means of X‐ray diffraction (XRD), as well as transmission electronic microscopy (TEM). The results indicated that nanoscale dispersed MMT was successfully achieved in the MCPA6 matrix. Furthermore, the addition of a small amount of MMT dramatically improved the thermal stability of MCAP6. Analysis using differential scanning calorimetry (DSC) and XRD indicated that nanoscale dispersed MMT sheets acted as heterogeneous nucleation agents, which favored the formation of the γ‐crystalline form of the MCPA6 matrix.MMT dispersing sketch in the course of polymerization.magnified imageMMT dispersing sketch in the course of polymerization.
AFM Study on the Interactions Across Interfaces Containing Attached Polymer Chains
Authors: Oréfice Rodrigo L. , Clark Arthur E. , Brennan Anthony B. 
Published: March 2006

AbstractSummary: Interactions between surfaces with attached polymers are very common in both biological and engineering fields. These types of interactions are critical in processes such as coagulation and flocculation in mineral processing, biological recognition in metabolic processes and stress transference in polymer composites, among others. Although many mechanisms have been proposed to explain phenomena occurring at the interfaces on a molecular level, few experimental procedures can give direct information about them. In this work, interactions occurring at interfaces containing attached polymer chains, such as the ones that are present in polymer composites, were studied by using AFM. In order to identify the effect of the structure of the interface on phenomena such as stress transference and energy dissipation, polymers with different molar mass, areal density and chemical architecture were synthesized and attached to substrates and AFM cantilevers. Force‐distance curves, obtained by AFM, provided some fundamental information about the mechanisms involved when polymers attached to different surfaces interact. Results showed that chains grafted on different surfaces can interact via entanglements and intersegmental bonding. Based upon the application of the AFM modified technique, interfaces containing polymers, such as in polymer composites, can be designed and optimized through the manipulation of its structure to achieve new roles in the performance of systems.
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Non‐Isothermal Crystallization Behavior of Poly(L‐lactic acid) in the Presence of Various Additives
Authors: Tsuji Hideto , Takai Hiroki , Fukuda Norio , Takikawa Hirofumi 
Published: March 2006

AbstractSummary: The effects of various additives: poly(D‐lactic acid) (PDLA), talc, fullerene C60, montmorillonite, and various polysaccharides, on the non‐isothermal crystallization behavior of poly(L‐lactic acid) (PLLA), during both the heating of melt‐quenched films from room temperature, and the cooling of as‐cast films from the melt, was investigated. When the melt‐quenched PLLA films were heated from room temperature, the overall PLLA crystallization was accelerated upon addition of PDLA or the stereocomplex crystallites formed between PDLA and PLLA, the mixtures containing PDLA, and the mixture of talc and montmorillonite. No significant effects on the overall PLLA crystallization were observed for talc, C60, montmorillonite, and the mixtures containing C60. Such rapid completion of the overall PLLA crystallization upon addition of the aforementioned additives can be ascribed to the increased density (number per unit volume or area) of PLLA spherulites. When the as‐cast PLLA films were cooled from the melt, the overall PLLA crystallization completed rapidly, upon addition of PDLA, talc, C60, montmorillonite, and their mixtures. Such rapid overall PLLA crystallization is attributable to the increased density of the PLLA spherulites and the higher nucleation temperature for PLLA crystallization. In contrast, the addition of various polysaccharides has no significant effect, or only a very small effect, on the overall PLLA crystallization during heating from room temperature or during cooling from the melt. This finding means that the polysaccharides can be utilized as low‐cost fillers for PLLA‐based materials, without disturbing the crystallization of the PLLA. The effect of additives in accelerating the overall PLLA crystallization during cooling from the melt, decreased in the following order: PDLA > talc > C60 > montmorillonite > polysaccharides.Polarization optical photomicrographs of pure PLLA, and the PLLA‐F film, with the fullerene additive, during cooling from the melt (Process IIB). Both of the photomicrographs were taken at 120 °C.magnified imagePolarization optical photomicrographs of pure PLLA, and the PLLA‐F film, with the fullerene additive, during cooling from the melt (Process IIB). Both of the photomicrographs were taken at 120 °C.
Hydrolytic Degradation of Amorphous Films of L‐Lactide Copolymers with Glycolide and D‐Lactide
Authors: Saha Swapan K. , Tsuji Hideto 
Published: March 2006

AbstractSummary: Films of poly(L‐lactic acid) (PLLA) and copolymers of L‐lactide (LLA) with either glycolide [P(LLA‐GA)](81/19) or D‐lactide [P(LLA‐DLA)](77/23) were prepared and an effect of comonomer type on the hydrolytic degradation of the films was studied in phosphate‐buffered solutions at 37 °C. The degraded films were investigated using gravimetry (weight loss and water absorption), gel permeation chromatography, DSC, X‐ray diffractometry, tensile testing and polarization optical microscopy. To exclude the effects of molecular weight and crystallinity on hydrolytic degradation, the films were prepared from polymers with similar molecular weights and were made amorphous by melt quenching. It was found that the hydrolytic degradation rate decreased in the order P(LLA‐GA) > P(LLA‐DLA) > PLLA. The hydrolytic degradation rate constant of PLLA and LLA copolymer films increased with increasing the water absorption (hydrophilicity), or with decreasing the initial glass transition temperature or the L‐lactyl unit sequence length, indicating that the hydrolytic degradation rate of the copolymers was closely related to these three parameters. The crystallization of P(LLA‐GA) film occurred within hydrolytic degradation for 20 weeks.Mn of PLLA and LLA copolymer films as a function of hydrolytic degradation time.magnified imageMn of PLLA and LLA copolymer films as a function of hydrolytic degradation time.
Dendritic pruning of the medial amygdala during pubertal development of the male Syrian hamster
Authors: Zehr Julia L. , Todd Brigitte J. , Schulz Kalynn M. , McCarthy Margaret M. , Sisk Cheryl L. 
Published: March 2006

AbstractThe medial amygdala (Me), a brain region essential for mating behavior, changes in size during puberty. In pre‐, mid‐, and late pubertal (21, 35, and 49 days of age) male Syrian hamsters, we examined neuronal structure in Me and protein levels of spinophilin and synaptophysin in the amygdaloid complex for evidence of synaptic plasticity coincident with behavioral and physiological development. Body weight, testes weight, and testosterone levels increased during puberty. Mounting behavior, including ectopic, nonintromittive, and intromittive mounts, also increased. Neuronal structure in the posterodorsal medial amygdala (MePD) was assessed in Golgi‐impregnated neurons. Pruning occurred during puberty in the number of dendrites emanating from the cell body and in terminal dendritic spine densities. Approximately half of all MePD neurons analyzed had an axon emanating from a dendrite rather than the cell body. However, prepubertal males were more likely to have the axon emanating from a higher order dendritic segment (secondary or tertiary) than were mid‐ and late pubertal males. Finally, protein levels in the amygdaloid complex varied with pubertal age. Spinophilin decreased, while synaptophysin and GAPDH protein levels increased. These results suggest that puberty is a period of dramatic synaptic plasticity in Me. Specifically, pruning of dendrites and spines, in combination with axonal changes, is likely to modify the afferent influences and electrophysiological properties of Me neurons. Because the Me is an integral component of a social behavior neural network, these changes may be related not only to sexual behavior, but also to other behaviors that mature during puberty, including aggressive, risk‐taking, fear‐related, and parental behaviors. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Living with lifting: mothers' perceptions of lifting and back strain in childcare
Authors: Griffin Susan D. , Price Vikki J. 
Published: March 2006

AbstractThe methods a mother selects to physically care for her young children may subject her to back strain or injury depending on the methods she selects. Little is known about what motivates mothers to select particular child‐care methods and equipment. The aim of this qualitative study was to explore the choices mothers of young children make in this area and their experiences using the methods they select. Nine mothers completed a brief questionnaire and participated in a semi‐structured interview. Analysis of the data revealed a number of motivating factors that were considered before making a final decision on what method to use. Rarely were issues related to posture and back care considered. Primarily, mothers chose methods based on what was best for the child, without consideration of their own needs. Consideration of the effect of a method on their back was given only when they experienced back strain. Further research is required to investigate the best methods for lifting and handling young children while providing maximum protection for the mothers' backs. Copyright © 2000 Whurr Publishers Ltd.
Using problem‐based learning to improve educational outcomes
Authors: Watson Diane E. , West Daniel J. 
Published: March 2006

AbstractAs the health care industry and the occupational therapy profession experience rapid change and growth, our professional preparation and continuing education must prepare graduates and therapists for an evolving practice environment. By exploring and evaluating alternative teaching methods and their impact on educational outcomes, occupational therapy educators demonstrate their commitment to improving the quality of student education. This article proposes that the traditional educational paradigm prepared clinicians for the old health care environment, and that problem‐based learning (PBL) is an educational strategy that could prepare occupational therapists for success in a new practice environment that values cost, quality, and customer satisfaction. The PBL approaches used by various international occupational therapy educators are reviewed to highlight the strategies that have been implemented to achieve educational objectives that parallel the requirements of this new practice environment. Copyright © 1996 Whurr Publishers Ltd.
The relationship between daily occupational affective experiences and subjective well‐being
Authors: Lo Jin‐Ling 
Published: March 2006

AbstractActive participation in daily occupations is one of the primary concepts of occupational therapy. In this study, 60 subjects' affective experiences in their daily occupation were compared with their subjective well‐being measures. It was found that the subjects' occupational affective experiences related significantly to their well‐being measures, especially those focusing on the affective aspect. The percentage of happy experiences was the best predictor of well‐being measures.Active participation had a significant effect on people's well‐being, but its effect on daily occupational affective experience was not so remarkable. Implications of these results for occupational therapy are discussed. Copyright © 1996 Whurr Publishers Ltd.
Current trends in the practice of home health care of occupational therapists treating patients who have had a stroke
Authors: Moulton Christina 
Published: March 2006

AbstractThe present study was designed to examine current practices in home health care among occupational therapists in the United States of America treating patients who have had a stroke. On any given day an estimated 1 237 100 patients receive home health care in the USA. This makes home health care a rapidly expanding industry of the 1990s. One of the most significant populations with whom occupational therapists work are patients who have had a stroke. General guidelines for occupational therapists working in home health care include: environmental safety, motor coordination, sensory deficits, perception, cognition, ADL/IADL, and leisure activities. Two hundred surveys were sent to registered occupational therapists working in home health care in the Midwestern region of the USA. Forty‐three of the returned surveys were used in the data analysis. The results indicated that therapists are utilising an adaptive approach to treatment techniques within an eclectic frame of reference. Remedial techniques, such as Neurodevelopmental Therapy (NDT), were used often by therapists. The results also indicated that the most frequently used evaluations were standardised tests. Non‐reimbursement of services was found to be a result of the patients' insurance not covering occupational therapy services. Further research regarding psychosocial issues with this population in home health care was indicated. Copyright © 1997 Whurr Publishers Ltd.