bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of gum exudates from three selected plant species from Tanzania for food and pharmaceutical applications
Authors: Mbuna Julius J , Mhinzi Gaspar S 
Published: January 2003

AbstractAuthenticated gum samples from three plant species from Tanzania were analysed and their potential for food, pharmaceutical and other applications was determined by comparing their physicochemical properties with those of commercial Acacia gums from Tanzania, gum karaya and the specifications demanded by the international regulatory bodies for gum arabic for food and pharmaceutical applications. The gum exudate from Dichrostachys cinerea meets some specifications (moisture content, solubility, insoluble matter and ash) demanded for the identity and purity of gum arabic as stipulated by the international regulatory bodies. The aqueous solution of the gum possesses solubility and viscosity similar to commercial gum arabic. Similarly, the properties of Sterculia quinqueloba gum meet a number of the specifications demanded for gum karaya, except that it contains high levels of tannin which would limit its usefulness in food and pharmaceutical applications. The properties of the gum exudate from Acacia pseudofistula, on the other hand, are different from those of Tanzanian commercial Acacia gums.© 2002 Society of Chemical Industry
Modeling and simulation of mixed traffic on a prioritized shared medium
Authors: J. Evans Jeffrey , Hood Cynthia S. 
Published: January 2003

AbstractNetwork access systems (NAS) such as digital loop carriers (DLC) are increasingly utilizing a shared medium, such as Hybrid Fiber Coax (HFC) to provide point‐to‐multi‐point access from the public switched telephone network (PSTN) to the end user (consumer). New services, such as direct access to the packet switched network (PSN, WWW) have been added to DLC equipment in such a way as to provide for a prioritized set of services over a shared medium in an effort to take advantage of otherwise unused bandwidth. The introduction of such services requires the modeling and analysis of these network access systems. This becomes complex when considering the variability in different service type traffic characteristics. This work identifies a traffic engineering problem of prioritized circuit switched and packet switched (PSTN/PSN) traffic over the same shared medium as it may relate to “perceived” quality of service (QoS). Copyright © 2002 John Wiley & Sons, Ltd.
Trunking of TDM and narrowband services over IP Networks
Authors: Aweya James 
Published: January 2003

AbstractThe recent interest in IP as the vehicle for transporting TDM and narrowband services stems from the possibility of using a common transport network for voice, video, and data, and the flexibility with which new services can be introduced. A key step in the evolution of networks towards a ‘broadband’ IP‐based environment is the ‘graceful’ interworking of the IP networks with the existing networks and services, particularly with the circuit switched telephone network. A ‘graceful’ interworking approach is one whose complexity is minimal and preserves the user's perceived quality of service (QoS). To interwork with a circuit switched network whose services are pre‐dominantly time‐sensitive, the IP network must essentially behave as a transparent ‘link’ in the end‐to‐end connection. This paper presents an overview of the main technical problems to be addressed when trunking TDM and narrowband services over IP networks. Copyright © 2002 John Wiley & Sons, Ltd.
Friendship networks and social, school and psychological adjustment in Chinese junior high school students
Authors: Liu Mowei , Chen Xinyin 
Published: January 2003

AbstractThe purpose of the study was to examine friendship networks and their associations with social, academic and psychological adjustment in Chinese high school students. A sample of 296 eighth grade students, aged 14 years, in two junior high schools in Shanghai, P. R. China, participated in this study. Information on social functioning, social preference, leadership, school‐related competence and problems, academic achievement, and psychological adjustment including loneliness and perceived competence was obtained from multiple sources. By using a computer‐based network analysis program, NEGOPY, friendship groups, liaisons, dyads and isolates were identified. It was found that children who belonged to friendship groups differed from those who had only one or two mutual friends and those who were completely isolated on indexes of social, emotional and school adjustment. Compared with dyads who had mutual friends, group members had higher scores on social and school competence and lower scores on learning problems and loneliness, suggesting that friendship networks might represent a phenomenon distinct from dyadic relationships. Finally, children who had behavioral and academic problems had difficulties not only in getting involved in group networks but also in establishing mutual friendships in the class. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 5–17, 2003.
Beyond parents and peers: The role of important non‐parental adults (VIPs) in adolescent development in China and the United States
Authors: Chen Chuansheng , Greenberger Ellen , Farruggia Susan , Bush Kevin , Dong Qi 
Published: January 2003

AbstractTo understand cross‐cultural differences and similarities in the social contexts for adolescent development, 201 American and 502 Chinese 11th graders were surveyed about a non‐parental adult who had played an important role in their lives (VIPs). Results showed that, compared to adolescents' VIPs in the United States, their Chinese counterparts were more likely to be teachers, to provide support in education‐related areas, and to be considered role models. Chinese VIPs were also reported to exhibit fewer problem behaviors and depressive symptoms and express a higher level of sanctions against adolescent problem behaviors than American VIPs. Adolescents in both cultures reported that their VIPs' positive qualities surpassed those of parents and peers. VIPs' characteristics (e.g., sanctions, problem behavior, warmth, and depressed mood) were significantly associated with adolescent outcomes. These results suggest that although there are cross‐cultural differences in the nature of VIPs, VIPs are a very important part of social context for adolescent development in both the United States and China. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 35–50, 2003.
Learning and motivation of Chinese students in Hong Kong: A longitudinal study of contextual influences on students' achievement orientation and performance
Authors: Salili Farideh , Lai Man Kin 
Published: January 2003

AbstractThe purpose of this study was to investigate the effects of medium of instruction and ability grouping (banding) of schools on students' learning and achievement orientation. A total of 1,807 male and female seventh graders studying in different school bands, using either English or Chinese as a medium of instruction (EMI and CMI respectively) participated in this study over a period of 3 years. They were administered measures of self‐regulated learning strategies, goal orientation, general self‐efficacy, anxiety in learning history as well as measures of self‐efficacy, attitude, and motivation in learning English. The results showed that students studying in upper band schools (i.e., low‐ability schools) used fewer strategies in learning, had lower self‐efficacy, higher surface goal and lower attainment scores than those in lower band schools. In addition, they had less positive attitude, lower levels of motivation and were more anxious in learning English and history than their counterparts in lower bands. The results also showed that CMI students made more use of learning strategies than EMI students. All students, regardless of school types or gender, rated higher on performance goal than any other goals in all 3 years. These findings and others were interpreted in terms of sociocultural values and context of learning in Hong Kong. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 51–70, 2003.
THE INTERSECTION OF SPHERES IN A SPHERE AND A NEW GEOMETRIC MEANING OF THE ARF INVARIANT
Authors: OGASA EIJI 
Published: January 2003

Let [Formula: see text] be a 3-sphere embedded in the 5-sphere S5 (i = 1,2). Let [Formula: see text] and [Formula: see text] intersect transversely. Then the intersection [Formula: see text] is a disjoint collection of circles. Thus we obtain a pair of 1-links, C in [Formula: see text], and a pair of 3-knots, [Formula: see text] in S5 (i = 1, 2). Conversely let (L1, L2) be a pair of 1-links and (X1, X2) be a pair of 3-knots. It is natural to ask whether the pair of 1-links (L1, L2) is obtained as the intersection of the 3-knots X1 and X2 as above. We give a complete answer to this question. Our answer gives a new geometric meaning of the Arf invariant of 1-links. Let f : S3 → S5 be a smooth transverse immersion such that the self-intersection C consists of double points. Suppose that C is a single circle in S5. Then f-1(C) in S3 is a 1-knot or a 2-component 1-link. There is a similar realization problem. We give a complete answer to this question.
REINHABITING RELIGION: GREEN SISTERS, ECOLOGICAL RENEWAL, AND THE BIOGEOGRAPHY OF RELIGIOUS LANDSCAPE
Authors: Taylor Sarah McFarland 
Published: January 2003

AbstractThis article explores the growing movement of environmentally activist Roman Catholic women religious in North America and the implications of this movement for theorizing new directions in religion and culture. Sisters' creative efforts to conserve traditional religious and cultural forms while opening up these forms to "greener" (ecologically-minded) interpretations reveals the very protean process of religious meaning-making. It also subsequently challenges more static and conventional theoretical models of religion. In particular, the author documents and analyzes the intertwining of bioregional philosophies of "reinhabitation," expressions of American Catholic religious life, and manifestations of "green culture." Integrating geographic, ethnographic, and historical methodologies, the author argues that when researchers approach the study of religion as "biogeographers," they discover complex levels of religious understanding and expression that are otherwise overlooked. Significantly, it is these frequently-missed dimensions of the religious landscape that more accurately reflect the "living and lived" quality of religion.
THE VARIETIES OF NATURE EXPERIENCE
Authors: Griffiths Joanna 
Published: January 2003

AbstractThis paper focuses on the assertion of the Norwegian philosopher Arne Naess (1989: 20) that "ethics follow from how we experience the world." I discuss what the statement might mean when applied to Naessian Deep Ecology. There follows a discussion of the close cohesion between experience and practice in Naessian thought. I attend to Naess's descriptions of the relationship between mystical nature experience and "ecological enlightenment," in which he suggests that an intense union with nature will lead the experiencing individual to enact Deep Ecological thought, as Naess formulates it. I seek to amplify the definition of mystical nature experience with reference to William James's The Varieties of Religious Experience, and particularly to James's assertions about the effects of religious experience on individual action. Naess (1986: 225-239) has cited James's work as a significant influence on his understanding of the terms "self" and "experience." Is Naess advocating a need to reeducate people to experience nature, in the hope that environmental awareness will increase accordingly? What experience of nature would inspire an environmental ethic? I conclude by arguing that Naess's reformative agenda stands in a complex relationship to the emphasis on individual, mystical nature experience as the catalyst to "ecological enlightenment." This complexity has not been satisfactorily resolved within Naessian Deep Ecology.
CHILDREN AND TREES IN NORTH INDIA
Authors: Gold Ann Grodzins 
Published: January 2003

AbstractRural children in Rajasthan, North India, express their connections with trees through storytelling and other artistic media, as well as recognizing trees' multiple uses in everyday life. In both imaginative and pragmatic views, trees are seen as vulnerable and requiring protection, but also as shelters for all creatures and bounteous givers of many blessings. Children's perceptions of trees and nature are shaped by local history in which narratives of deforestation are integral to political changes. Current government initiatives to promote environmental awareness and ecological regeneration also influence young people, who take these lessons to heart.
SnailprecedesSlugin the genetic cascade required for the specification and migration of theXenopusneural crest
Authors: Aybar Manuel J. , Nieto M. Angela , Mayor Roberto 
Published: January 2003

The complex sequence of inductive events responsible for the generation of the neural crest at the border between the neural plate and the epidermis,triggers a genetic cascade involving several families of transcription factors. Two members of the Snail family, Snail andSlug, have both been implicated in this cascade. In chick andXenopus, loss- and gain-of-function experiments have provided evidence that Slug plays a key role in neural crest development. However, in contrast to the chick, Snail rather than Slug is expressed in the premigratory neural crest in the mouse and, in Xenopus,Snail precedes Slug expression in this population. Thus, in order to study the function of Snail in neural crest development inXenopus, we have carried out conditional gain- and loss-of-function experiments using different Snail constructs fused to a glucocorticoid receptor element.We show that Snail is able to induce the expression ofSlug and all other neural crest markers tested (Zic5, FoxD3,Twist and Ets1) at the time of specification. This activation is observed in whole embryos and in animal caps, in the absence of neural plate and mesodermal markers. We show that Snail is required for neural crest specification and migration and that it works as a transcriptional repressor. These functions have been previously attributed to Slug. However, Slug alone is unable to induce other neural crest markers in animal cap assays, and we show that Snail and Slug can be functionally equivalent when tested in overexpression studies. This suggests that, in Xenopus embryos, at least some of the functions previously attributed to Slug can be carried out by Snail. This is additionally supported by rescue experiments in embryos injected with dominant-negative constructs that indicate that Snail lies upstream of Slug in the genetic cascade leading to neural crest formation and that it plays a key role in crest development.
Neurohormonal and glutamatergic neuronal control of the cardioarterial valves in the isopod crustaceanBathynomus doederleini
Authors: F.-Tsukamoto Yoko , Kuwasawa Kiyoaki 
Published: January 2003

SUMMARYThe heart of Bathynomus doederleini gives rise to an anterior median artery (AMA), one pair of anterior lateral arteries (ALAs) and five pairs of lateral arteries (LAs). Cardioarterial valves are located at the junctions between the heart and arteries, each composed of a pair of muscular flaps. All valves of the AMA and the ALAs receive valve excitatory(constrictor) nerves (VEs). The valves of the ALAs receive dual innervation from both constrictor and inhibitor (dilator) nerves, while the valves of the AMA receive innervation from a constrictor nerve alone. The effects of candidate neurohormones on cardioarterial valves were examined by measuring the pressure in each artery at which haemolymph flows out of the heart through the valve. Serotonin, octopamine, norepinephrine, glutamate (Glu) and proctolin constricted the cardioarterial valves and thus decreased the arterial pressure in all the arteries. Dopamine also decreased the arterial pressure of arteries except for the ALAs, in which pressure was increased. Among the neurohormones exerting excitatory effects on the valves, only Glu depolarized the membrane potential of valve muscle cells. The glutamatergic agonists kainate and quisqualate also depolarized the valve muscle cells of the AMA. Excitatory junctional potentials produced in the valves of the AMA in response to the stimulation of a VE were blocked by the glutamatergic antagonists Joro spider toxin and MK-801. Glu is the likeliest candidate for a neurotransmitter for the VEs.
Localization and characterization of phenamil-sensitive Na+influx in isolated rainbow trout gill epithelial cells
Authors: Reid Scott D. , Hawkings G. S. , Galvez F. , Goss G. G. 
Published: January 2003

SUMMARYPercoll density-gradient separation, combined with peanut lectin agglutinin(PNA) binding and magnetic bead separation, was used to separate dispersed fish gill cells into sub-populations. Functional characterization of each of the sub-populations was performed to determine which displayed acid-activated phenamil- and bafilomycin-sensitive Na+ uptake. Analysis of the mechanism(s) of 22Na+ influx was performed in control and acid-activated (addition of 10 mmoll-1 proprionic acid) cells using a variety of Na+ transport inhibitors (ouabain, phenamil,HOE-694 and bumetanide) and a V-type ATPase inhibitor (bafilomycin). We found that cells migrating to a 1.03-1.05 g ml-1 Percoll interface[pavement cells (PVCs)] possessed the lowest rates of Na+ uptake and that influx was unchanged during either bafilomycin (10 nmoll-1) treatment or internal acidification with addition of proprionic acid (10 mmoll-1). Mitochondria-rich (MR) cells that migrated to the 1.05-1.09 g ml-1 interface of the Percoll gradient demonstrated acidification-activated bafilomycin and phenamil-sensitive Na+ influx. Further separation of the MR fraction into PNA+ and PNA- fractions using magnetic separation demonstrated that only the PNA- cells (α-MR cells)demonstrated phenamil-and bafilomycin-sensitive acid-activated 22Na+ uptake. We confirm the coupling of a V-type H+-ATPase with phenamil-sensitive Na+ uptake activity and conclude that high-density α-MR cells function in branchial Na+ uptake in freshwater fish.
Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle
Authors: Costanzo Jon P. , Baker Patrick J. , Dinkelacker Stephen A. , Lee Richard E. 
Published: January 2003

SUMMARYHatchlings of the painted turtle (Chrysemys picta) commonly hibernate in their shallow, natal nests. Survival at temperatures below the limit of freeze tolerance (approximately -4°C) apparently depends on their ability to remain supercooled, and, whereas previous studies have reported that supercooling capacity improves markedly with cold acclimation, the mechanistic basis for this change is incompletely understood. We report that the crystallization temperature (Tc) of recently hatched(summer) turtles acclimated to 22°C and reared on a substratum of vermiculite or nesting soil was approximately 5°C higher than the Tc determined for turtles acclimated to 4°C and tested in winter. This increase in supercooling capacity coincided with elimination of substratum (and, in fewer cases, eggshell) that the hatchlings had ingested; however, this association was not necessarily causal because turtles reared on a paper-covered substratum did not ingest exogenous matter but nevertheless showed a similar increase in supercooling capacity. Our results for turtles reared on paper revealed that seasonal development of supercooling capacity fundamentally requires elimination of ice-nucleating agents (INA) of endogenous origin: summer turtles, but not winter turtles, produced feces(perhaps derived from residual yolk) that expressed ice-nucleating activity. Ingestion of vermiculite or eggshell, which had modest ice-nucleating activity, had no effect on the Tc, whereas ingestion of nesting soil, which contained two classes of potent INA, markedly reduced the supercooling capacity of summer turtles. This effect persisted long after the turtles had purged their guts of soil particles, because the Tc of winter turtles reared on nesting soil (mean ±S.E.M.=-11.6±1.4°C) was approximately 6°C higher than the Tc of winter turtles reared on vermiculite or paper. Experiments in which winter turtles were fed INA commonly found in nesting soil showed that water-soluble, organic agents can remain fully active for at least one month. Such INA may account for the limited supercooling capacity(Tc≈-7.5°C) we found in turtles overwintering in natural nests and may therefore pose a formidable challenge to the winter survival of hatchling C. picta.
The blood volumes of the primary and secondary circulatory system in the Atlantic codGadus morhuaL., using plasma bound Evans Blue and compartmental analysis
Authors: Skov P. V. , Steffensen J. F. 
Published: January 2003

SUMMARYThe volume of the primary (PCS) and secondary (SCS) circulatory system in the Atlantic cod Gadus morhua was determined using a modified dye dilution technique. Cod (N=10) were chronically cannulated in the second afferent branchial artery with PE-50 tubing. Evans Blue dye was bound to harvested fish plasma at a concentration of 1 mg dye ml-1plasma, and injected at a concentration of 1 mg kg-1 body mass. Serial sampling from the cannula produced a dye dilution curve, which could be described by a double exponential decay equation. Curve analysis enabled the calculation of the primary circulatory and total distribution volume. The difference between these volumes is assumed to be the volume of the SCS. From the dilution curve, it was also possible to calculate flow rates between and within the systems. The results of these experiments suggest a plasma volume in the PCS of 3.42±0.89 ml 100 g-1 body mass, and in the SCS of 1.68±0.35 ml 100 g-1 body mass (mean ± S.D.) or approximately 50% that of the PCS. Flow rates to the SCS were calculated as 2.7% of the resting cardiac output. There was an allometric relationship between body mass and blood volumes. Increasing condition factor showed a tendency towards smaller blood volumes of the PCS, expressed as percentage body mass, but this was not evident for the volume of the SCS.
Mechanoreceptors involved in the hindwing-evoked escape behaviour in cricket,Gryllus bimaculatus
Authors: Hiraguchi Tetsutaro , Yamaguchi Tsuneo , Takahata Masakazu 
Published: January 2003

SUMMARYMechanoreceptors involved in the escape jumping evoked by hindwing stimulation have been investigated in the field cricket Gryllus bimaculatus. By partial ablation of the hindwing, we found that a mechanosensory system relevant to the escape behaviour was localized on specific veins of the hindwing tip. Scanning electron microscopy revealed three types of mechanoreceptive sensillae on the corresponding region. Based on their morphology, type I and type III sensillae were judged to be trichoid and chaetic sensillae, respectively. Type II sensillae were newly found in this study, having a twisted shaft with a socket-like structure at its base. They existed almost exclusively on the tip and middle regions of the hindwing. The conduction velocity of type II units was significantly smaller than that of type I units. One cycle of sinusoidal deflection of a single type II sensilla at frequencies in the range of 10-120 Hz caused the sensory unit to discharge a single or a few spikes that were not directly correlated with any specific direction of hair movement nor specific deflection angle. The response probability decreased with the stimulus frequency to be less than 0.1 at 0.2 Hz. The results suggest that type II sensillae would serve as contact mechanoreceptors with a low-cut filter property to obtain general information on the presence of stimuli on the hindwing tip rather than specific information on their precise positioning or movement.