Network of the core: mapping and visualizing the core of scientific domains

In this article, we propose mapping and visualizing the core of scientific domains using social network analysis techniques derived from mathematical graph theory. In particular, the concept of Network of the Core is introduced which can be employed to visualize scientific domains by constructing a network among theoretical constructs, models, and concepts. A Network of the Core can be used to reveal hidden properties and structures of a research domain such as connectedness, centrality, density, structural equivalence, and cohesion, by modeling the casual relationship among theoretical constructs. Network of the Core concept can be used to explore the strengths and limitations of a research domain, and graphically and mathematically derive the number research hypotheses. The Network of the Core approach can be applied to any domain given that the investigator has a deep understanding of the area under consideration, a graphical or conceptual view (in the form of a network of association among the theoretical constructs and concepts) of the scientific domain can be obtained, and an underlying theory is available or can be constructed to support Network of the Core formation. Future research directions and several other issues related to the Network of the Core concept are also discussed.     

A distributed mobility control scheme in LISP networks

The locator identifier separation protocol (LISP) has been made as an identifier-locator separation scheme for scalable Internet routing. However, the LISP was originally designed for fixed network environment, rather than for mobile network environment. In particular, the existing LISP mobility control schemes use a centralized map server to process all the control traffics, and thus they are intrinsically subject to some limitations in mobile environment, such as large overhead of mapping control traffics at central map server and degradation of handover performance. To overcome these problems, we propose a distributed mobility control scheme in LISP networks. In the proposed scheme, we assume that a mobile host has a hierarchical endpoint identifier which contains the information of its home network domain. Each domain has a distributed map server (DMS) for distributed mapping management of Endpoint Identifiers (EIDs) and Locators (LOCs). For roaming support, each DMS maintains a home EID register and a visiting EID register which are used to keep the EID-LOC mappings for mobile hosts in the distributed manner. For performance analysis, we compare the control traffic overhead (CTO) at map servers, the signaling delay required for EID-LOC mapping management, and the handover delay for the existing and proposed schemes. From numerical results, it is shown that the proposed distributed scheme can give better performance than the existing centralized schemes in terms of CTO, total signaling delay for EID-LOC mapping management, and handover delay.     

Distributed mapping management of identifiers and locators in mobile‐oriented Internet environment

Many schemes have recently been proposed for the separation of identifier (ID) and locator (LOC), which include the Host Identity Protocol, the Identifier‐Locator Network Protocol, and the Locator Identifier Separation Protocol. However, all of these schemes were originally designed in fixed network environment, rather than mobile network environment. In particular, these schemes are based on a centralized map server that is used as an anchor point for mobile nodes, and thus intrinsically subject to some limitations in a mobile environment. In this paper, we propose a distributed ID‐LOC mapping management scheme in a mobile‐oriented Internet environment. In the proposed scheme, we assume that a host has a globally unique and hierarchical Host ID (HID) that contains the information of its home network domain. Each network domain has a distributed map server for distributed management of ID‐LOC mappings. For roaming support, each distributed map server maintains its own home HID register and visiting HID register, which are used to keep the mappings of HID and LOCs for mobile nodes in the distributed manner. By performance analysis, it is shown that the proposed distributed scheme can give better performance than the existing centralized schemes in terms of ID‐LOC binding update and data delivery costs. Copyright © 2012 John Wiley & Sons, Ltd.     

Selected functional properties of waxy corn and potato starches after illumination with linearly polarised visible light

Aqueous suspensions (30%) of waxy corn and potato starches were illuminated for 5–50 h with linearly polarised visible light (λ > 500 nm). Molecular weights (M?_w) and radii of gyration (R?_g) of the amylopectin and amylose fractions of illuminated waxy corn starch, and the amylopectin, intermediate, and amylose fractions of illuminated potato starch were measured by high‐performance size exclusion chromatography coupled with multiangle laser light scattering and refractive index detection. The weight‐average molecular weight (M?_w) and radius of gyration (R?_g) of the amylopectin fraction of native waxy corn starch were 14.45 × 10⁷ and 161.1 nm respectively. After 15 h of illumination a decrease in M?_w (5.80 × 10⁷) and R?_g (117.6 nm) was observed. Illumination for 25 h, led to an increase in M?_w (7.60 × 10⁷) and R?_g (134.0 nm). Further illumination, up to 50 h resulted in a slight decrease in M?_w (6.74 × 10⁷). The molecular weight and radius of gyration of the amylopectin fraction of native potato starch were 21.30 × 10⁷ and 207 nm respectively. Illumination for 15 h led to a decrease in M?_w (14.87 × 10⁷) and R?_g (141.5 nm), followed by an increase in both values after 25 h (18.97 × 10⁷, 146.6 nm) and 50 h (19.69 × 10⁷, 207.1 nm) of illumination. Illumination influenced the swelling power, solubility, susceptibility to α‐amylolysis and X‐ray diffractogram of the starches. A varying increase in the solubility passed through a minimum after 25 h of illumination. The X‐ray diffraction pattern and susceptibility to enzymatic hydrolysis of waxy corn starch did not change, but in potato starch a gradual, illumination time‐dependent increase in the amylolysis rate took place. This effect could result from the reduction in crystallinity of the starch as indicated by the X‐ray diffraction pattern. Copyright © 2003 Society of Chemical Industry     

Molecular structure and physicochemical properties of Hylon V and Hylon VII starches illuminated with linearly polarised visible light

Aqueous suspensions (30 g/100 g) of Hylon V and Hylon VII high amylose corn starches were illuminated with linearly polarized visible light for 5, 15, 25 and 50 h. For each native and illuminated starch sample, weight average molecular weight, M_w, and hydrodynamic radius, R_g, of starch polysaccharide molecules were measured by high pressure size exclusion chromatography coupled with multiangle laser light scattering and refractometric detectors (HPSEC-MALLS-RI). Additionally, X-ray diffraction patterns, intrinsic viscosity, kinetic of alpha-amylolysis together with iodine binding properties and distribution of amylopectin structural units were established for each starch sample. Changes in molecular weight M_w of starch polysaccharide chains eluted under whole polysaccharide peaks and values of intrinsic viscosity of corresponding starch samples observed in the course of illumination indicated that illumination of both starches studied, with linearly polarized visible light (LPVL), induced first depolymerysation followed by repolymerisation reaction of starch polysaccharide chains. Illumination induced rearrangements of the molecular structure of polysaccharide chains of illuminated Hylon V and Hylon VII starches led to significant changes of their physicochemical properties as compared with native starches.     

Mapping ICT knowledge infrastructure in South Asia

Information Communication Technology (ICT) has a significant impact on the socioeconomic development of a country. However, the inequitable access to ICT still remains a major issue in developing countries. In this context, this study examines ICT knowledge infrastructure in South Asia from a network point of view. Existing research on ICTs are useful in understanding the common facts, but are limited in revealing the hidden structures and properties of the ICT research domain in South Asia. The hidden structures and properties, like key players, network of key players for scientific collaborations, and their network characteristics are analyzed and synthesized in this study. This study applies the mixed approach of Social Network Analysis techniques and Triple Helix indicators on scholarly papers obtained from the Web of Science database. Further, burst detection algorithm is applied on keywords appearing in the titles of the South Asian ICT scholarly papers to understand the emerging trends in the ICT research domain. This study helps in providing a better understanding of current trends, strengths, and weaknesses of ICT in South Asia, which provides a better understanding to bridge the digital divide and achieve socioeconomic development through ICT.     

Hydrodynamic design of ballbearing cage pockets

This paper reports results of a theoretical study of hydrodynamic load capacity and power consumed in a ball bearing straight sided annular cage pocket. Design curves show how these quantities vary with eccentricity ratio, radial clearance and cage depth and enable suitable pocket proportions to be chosen     

Short-Term Ingestion of Essential Amino Acid Based Nutritional Supplements or Whey Protein Improves the Physical Function of Older Adults Independently of Gut Microbiome

Scope : Dietary proteins and essential amino acids (EAAs) are the major nutritional supplements that support the growth and activity of gut microbes contributing to the wellbeing of their host. This study hypothesizes that daily supplementation of the diet with either EAAs or whey protein for 12 weeks would improve the gut microbiome of older adults. Methods and results : The stool samples are processed and subjected to Illumina-based 16S ribosomal ribonucleic acid (rRNA) gene amplicon sequencing. In both groups, the most abundant families are found in order of relative abundance included: Bacteroidaceae, Lachnospiraceae, Ruminococcaceae, Prevotellaceae, Rikenellaceae, Enterobacteriaceae, Oscillospiraceae, Tannerellaceae, and Akkermansiaceae, which indicate that these subjects are able to maintain a same healthy microbial diversity in their guts. A significant finding is a reduction of proinflammatory cytokine, interleukin-18 (IL-18) in the EAAs group. It also uses the standard 6-min walking test (6MWT) as a measure of cardiopulmonary fitness. At the end of the study, the subjects in the EAAs group perform significantly better in the 6MWT as compared to the whey group. Conclusion : It seems plausible that the improved physical performance and reduced proinflammatory cytokine, IL-18 seen in the EAAs group, are independent of changes in gut microbiota.     

The Involvement of Insulin-Like Growth Factor 1 and Nerve Growth Factor in Alzheimer’s Disease-Like Pathology and Survival Role of the Mix of Embryonic Proteoglycans: Electrophysiological Fingerprint,Structural Changes and Regulatory Effects on Neurotrophins

Alzheimer’s disease (AD)-associated neurodegeneration is triggered by different fragments of amyloid beta (Aβ). Among them, Aβ (25–35) fragment plays a critical role in the development of neurodegeneration—it reduces synaptic integrity by disruption of excitatory/inhibitory ratio across networks and alters the growth factors synthesis. Thus, in this study, we aimed to identify the involvement of neurotrophic factors—the insulin-like growth factor 1 (IGF-1) and nerve growth factor (NGF)—of AD-like neurodegeneration induced by Aβ (25–35). Taking into account our previous findings on the neuroprotective effects of the mix of proteoglycans of embryonic genesis (PEG), it was suggested to test its regulatory effect on IGF-1 and NGF levels. To evaluate the progress of neurodegeneration, in vivo electrophysiological investigation of synaptic activity disruption of the entorhinal cortex–hippocampus circuit at AD was performed and the potential recovery effects of PEG with relative structural changes were provided. To reveal the direct effects of PEG on brain functional activity, the electrophysiological pattern of the single cells from nucleus supraopticus, sensomotor cortex and hippocampus after acute injection of PEG was examined. Our results demonstrated that after i.c.v. injection of Aβ (25–35), the level of NGF decreased in cerebral cortex and hypothalamus, and, in contrast, increased in hippocampus, prompting its multidirectional role in case of brain damage. The concentration of IGF-1 significantly increased in all investigated brain structures. The administration of PEG balanced the growth factor levels accompanied by substantial restoration of neural tissue architecture and synaptic activity. Acute injection of PEG activated the hypothalamic nucleus supraopticus and hippocampal neurons. IGF-1 and NGF levels were found to be elevated in animals receiving PEG in an absence of amyloid exposure. We suggest that IGF-1 and NGF play a critical role in the development of AD. At the same time, it becomes clear that the neuroprotective effects of PEG are likely mediated via the regulation of neurotrophins.