Values of inland fisheries in the Mekong river basin

Asia has the most productive inland fisheries in the world. The fishery sector contributes significantly to the national economies of the region. Inland fisheries also improve food security by providing a source of protein and a livelihood for millions of people in this part of the world, especially the rural poor. The purpose of this report is to provide information on the biological, economic, social and cultural values of river fisheries in the Lower Mekong Basin, and to identify the main impacts of environmental changes on these values. A review of fisheries-related literature, including project reports and gray literature, was undertaken. More than 800 documents were reviewed, and original information was extracted from 270 of them. The analysis identified a large number of localized studies leading to generic conclusions. The report addresses the basin wide issues and studies. It is then organized by nation, namely, the Chinese province of Yunnan, then Laos, Thailand, Cambodia and Vietnam. It first gives an overview of each country’s economic, fisheries and social situation, then details the values documented for river fisheries in each country

Values of inland fisheries in the Mekong river basin

This report provides an overview of the biological, economical, social and cultural values of river fisheries in the Lower Mekong Basin (Yunan, Laos, Thailand, Cambodia and Vietnam). The report also identifies the main impacts of environmental changes on these values.Inland fisheries, Socioeconomic aspects, Economic analysis, Asia, ISEW, Vietnam, Mekong River Delta, Mekong Delta,

Enzymatic degradation behavior and cytocompatibility of silk fibroin–starch–chitosan conjugate membranes

The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in α-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively.E.T. Baran thanks the Portuguese Foundation for Science and Technology for providing him a PostDoc scholarship (SFRH/BPD/30768/2006). This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)

Growth of a bonelike apatite on chitosan microparticles after a calcium silicate treatment

Bioactive chitosan microparticles can be prepared successfully by treating them with a calcium silicate solution and then subsequently soaking them in simulated body fluid (SBF). Such a combination enables the development of bioactive microparticles that can be used for several applications in the medical field, including injectable biomaterial systems and tissue engineering carrier systems. Chitosan microparticles, 0.6 lm in average size, were soaked either for 12 h in fresh calcium silicate solution (condition I) or for 1 h in calcium silicate solution that had been aged for 24 h before use (condition II). Afterwards, they were dried in air at 60 !C for 24 h. The samples were then soaked in SBF for 1, 3 and 7 days. After the condition I calcium silicate treatment and the subsequent soaking in SBF, the microparticles formed a dense apatite layer after only 7 days of immersion, which is believed to be due to the formation of silanol (Si– OH) groups effective for apatite formation. For condition II, the microparticles successfully formed an apatite layer on their surfaces in SBF within only 1 day of immersion.I.B.L. thanks the Portuguese Foundation for Science and Technology (FCT), for providing her a PhD scholarship (SFRH/BD/9031/2002), the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758) and the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Conjugation of fibroin and starch to chitosan for increasing cell proliferation capacity

[Excerpt] In this study, chitosan conjugates with starch and fibroin were produced for increasing degradability in the presence of physiological enzymes and cell proliferation capacities of biomaterials. The degradation profile was monitored over prolonged time periods and characterization of chemical changes during degradation periods were investigated by spectroscopic methods. Various ratios of starch, fibroin and chitosan (%, (weight/weight)) were prepared. The in vitro cell culture studies were conducted to evaluate biocompatibility and proliferation capacities of conjugate materials. [...]info:eu-repo/semantics/publishedVersio

Identification and differentiation of Trichophyton rubrum clinical isolates using PCR-RFLP and RAPD methods

Trichophyton rubrum represents the most frequently isolated causative agent of superficial dermatophyte infections. Several genotyping methods have recently been introduced to improve the delineation between pathogenic fungi at both the species and the strain levels. The purpose of this study was to apply selected DNA fingerprinting methods to the identification and strain discrimination of T. rubrum clinical isolates. Fifty-seven isolates from as many tinea patients were subjected to species identification by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis and strain differentiation using a randomly amplified polymorphic DNA (RAPD) method, with two primers designated 1 and 6. Using PCR-RFLP, 55 of the isolates studied were confirmed to be T. rubrum. Among those, a total of 40 and five distinct profiles were obtained by RAPD with primers 1 and 6, respectively. The combination of profiles from both RAPD assays resulted in 47 genotypes and an overall genotypic diversity rate of 85.4%. A dendrogram analysis performed on the profiles generated by RAPD with primer 1 showed most of the isolates (87.3%) to be genetically related. PCR-RFLP serves as a rapid and reliable method for the identification of T. rubrum species, while the RAPD analysis is rather a disadvantageous tool for T. rubrum strain typing

All-trans retinoic acid release from biodegradable polyester microcapsules

[Excerpt] Tissue engineering strategies frequently include a scaffold, living cells and bioactive substances to promote cell growth and guide cell differentiation. The encapsulation in carriers enables protects the bioactivity of those substances upon implantation, avoids being transported by the body fluids and also allows controlling the release rate. Encapsulation materials are preferably biodegradable polymers. In this work, all-trans retinoic acid (atRA) was used as a model bioactive agent; since it was shown that atRA enhances the expression of osteocalcin, a specific osteogenic marker. [...]info:eu-repo/semantics/publishedVersio

NMR relaxation rate in the field-induced octupolar liquid phase of spin-1/2 J1-J2 frustrated chains

In the spin-1/2 frustrated chain with nearest-neighbor ferromagnetic exchange J1 and next-nearest-neighbor antiferromagnetic exchange J2 under magnetic field, magnetic multipolar-liquid (quadrupolar, octupolar, and hexadecapolar) phases are widely expanded from the saturation down to a low-field regime. Recently, we have clarified characteristic temperature and field dependence of the NMR relaxation rate 1/T_1 in the quadrupolar phase. In this paper, we examine those of 1/T_1 in the octupolar phase combining field theoretical method with numerical data. The relevance of the results to quasi one-dimensional J1-J2 magnets such as PbCuSO4(OH)2, Rb2Cu2Mo3O12 and Li2ZrCuO4 is shortly discussed.Comment: 6 pages (1 column), 3 figure

Extension of Frohlich's method to 4-fermion interactions

Higher order terms of the transformed electron-phonon Hamiltonian, obtained by performing the Frohlich's transformation, are investigated. The influence of terms discarded by Frohlich (in particular those proportional to the third power of electron-phonon coupling) on the effective Hamiltonian is examined. To this end a second Frohlich-type transformation is performed, which yields, among others, an effective 4-electron interaction. This interaction is reduced to a form admitting solution of thermodynamics. The form of the coupling of the 4-electron interaction is found. By applying standard approximations, it is shown that this interaction is attractive with interaction coupling given by - D_{k_F}^6 / \omega_{k_F}^5, where D_{k} is electron-phonon coupling, \omega_{k}$ is phonon energy and k_F is Fermi momentum. The form of higher order terms of the original Frohlich-transformed H_{e-ph} are also found, up to terms proportional to the 6-th power of the coupling, that is up to those, which yield the effective 4-electron interactions.Comment: REVTeX4, 25 pages; major changes: added section and appendix about the form of 4-fermion interaction coupling, typos correcte