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Selected AbstractsFood Security in China and Contingency Planning: the Significance of Grain ReservesJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 3 2006Hendrik J. Bruins China is inhabited by ca 20 percent of the world population, but has only 7 percent of global arable land and only 6.6 percent of global freshwater resources. These unfavourable relationships between population size and the basic resources for food production , soil and water , require careful food security and contingency planning by the Chinese authorities. The country has been remarkably successful in raising its food production since 1949 at a faster rate (400 percent) than the increase in its population (240 percent). This has basically been achieved by increasing the yields per unit area with enhanced fertilizer use, as the total size of arable land has been decreasing in recent years. Though China attempts to be largely self-sufficient in food grain production, two possible contingency scenarios are suggested that might cause grave problems: (1) severe multi-annual drought; (2) reduced chemical fertilizer manufacturing. If Chinese food production would drop as a result by, say, 33 percent, famine, the dreaded scourge throughout Chinese history, might recur. A shortage of ca 150 million tons of food grains cannot easily be buffered by the volume of food grains annually traded on the world market, ca 240 million tons. Much of this amount tends to be committed already to traditional buyers, as most countries in the world have to import food grains. Cash reserves, therefore, may not guarantee food purchases, because global grain reserves are limited and declining. The formation and maintenance of large internal food grain reserves in China, common in its tradition and ancient history, seem the only realistic contingency planning strategy to avert famine in case of a severe decline in its food production in future crisis years. [source] Stress-induced responses of human skin fibroblasts in vitro reflect human longevityAGING CELL, Issue 5 2009Pim Dekker Summary Unlike various model organisms, cellular responses to stress have not been related to human longevity. We investigated cellular responses to stress in skin fibroblasts that were isolated from young and very old subjects, and from offspring of nonagenarian siblings and their partners, representatives of the general population. Fibroblasts were exposed to rotenone and hyperglycemia and assessed for senescence-associated ,-galactosidase (SA-,-gal) activity by flow cytometry. Apoptosis/cell death was measured with the Annexin-V/PI assay and cell-cycle analysis (Sub-G1 content) and growth potential was determined by the colony formation assay. Compared with fibroblasts from young subjects, baseline SA-,-gal activity was higher in fibroblasts from old subjects (P = 0.004) as were stress-induced increases (rotenone: P < 0.001, hyperglycemia: P = 0.027). For measures of apoptosis/cell death, fibroblasts from old subjects showed higher baseline levels (Annexin V+/PI+ cells: P = 0.040, Sub-G1: P = 0.014) and lower stress-induced increases (Sub-G1: P = 0.018) than fibroblasts from young subjects. Numbers and total size of colonies under nonstressed conditions were higher for fibroblasts from young subjects (P = 0.017 and 0.006, respectively). Baseline levels of SA-,-gal activity and apoptosis/cell death were not different between fibroblasts from offspring and partner. Stress-induced increases were lower for SA-,-gal activity (rotenone: P = 0.064, hyperglycemia: P < 0.001) and higher for apoptosis/cell death (Annexin V+/PI, cells: P = 0.041, Annexin V+/PI+ cells: P = 0.008). Numbers and total size of colonies under nonstressed conditions were higher for fibroblasts from offspring (P = 0.001 and 0.024, respectively) whereas rotenone-induced decreases were lower (P = 0.008 and 0.004, respectively). These data provide strong support for the hypothesis that in vitro cellular responses to stress reflect the propensity for human longevity. [source] Auto-transplantation of the uterus in the domestic pig (Sus scrofa): Surgical technique and early reperfusion eventsJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2006Caiza Almén Wranning Abstract Aim:, To develop a method for auto-transplantation of the uterus in the pig and to evaluate the early reperfusion events after short-term cold ischemia. Methods:, The bicornate uterus, with the cervix but without ovaries, was dissected and isolated with its bilateral feeding and draining vessels. The uterine arteries were cannulated in situ and the uterus was flushed with heparinized Ringer Acetate. It was stored at 4°C for 1,2 h during continuous flushing. The uterus was then placed in its original pelvic position and the uterine arteries and veins were anastomosed end-to-end to their origin. During approximately 100 min of reperfusion, blood samples and tissue biopsies were taken for monitoring of reperfusion events and detection of ischemia-reperfusion injuries. Results:, Out of 19 auto-transplanted pigs, seven were considered well flushed and were kept for cold ischemia. Of these seven, four showed satisfactory reperfusion judged by change in gross appearance and presence of appropriate venous blood flow. Analysis of blood-gas and metabolite parameters and histology indicated that at least two of these transplants were well reperfused, with no severe ischemia-reperfusion injuries. Conclusion:, In this first report ever on auto-transplantation of the pig uterus it is demonstrated that an acceptable reperfusion can be achieved. Furthermore, it is suggested that because of the large total size of the pig uterus with long uterine horns and the small size of the vessels available for re-anastomosis, the pig is a fairly difficult model for further studies on transplantation of the uterus. [source] SIZE INCREMENTS DUE TO INTERINDIVIDUAL FUSIONS: HOW MUCH AND FOR HOW LONG?,JOURNAL OF PHYCOLOGY, Issue 4 2010Bernabé Santelices Size increments following interindividual fusions appear as a general benefit for organisms, such as coalescing seaweeds and modular invertebrates, with the capacity to fuse with conspecifics. Using sporelings of the red algae Gracilaria chilensis C. J. Bird, McLachlan et E. C. Oliveira and Mazzaella laminarioides (Bory) Fredericq, we measured the growth patterns of sporelings built with different numbers of spores, and the magnitude and persistence of the size increments gained by fusions. Then we studied three morphological processes that could help explain the observed growth patterns. Results indicate that in these algae, coalescence is followed by immediate increase in total size of the coalesced individual and that the increment is proportional to the number of individuals fusing. However, the size increments in sporelings of both species do not last >60 d. Increasing reductions of marginal meristematic cells and increasing abundance of necrotic cells in sporelings built with increasing numbers of initial spores are partial explanations for the above growth patterns. Since sporelings formed by many spores differentiate erect axes earlier and in larger quantities than sporelings formed by one or only a few spores, differentiation, emergence, and growth of erect axes appear as a more likely explanation for the slow radial growth of the multisporic sporelings. Erect axis differentiation involves significant morphological and physiological changes and a shift from radial to axial growth. It is concluded that the growth pattern exhibited by these macroalgae after fusion differs from equivalent processes described for other organisms with the capacity to fuse, such as modular invertebrates. [source] The fin whale Balaenoptera physalus (L. 1758) in the Mediterranean SeaMAMMAL REVIEW, Issue 2 2003GIUSEPPE NOTARBARTOLO-DI-SCIARA ABSTRACT 1.,The ecology and status of fin whales Balaenoptera physalus in the Mediterranean Sea is reviewed. The species' presence, morphology, distribution, movements, population structure, ecology and behaviour in this semi-enclosed marine region are summarized, and the review is complemented with original, previously unpublished data. 2.,Although the total size of the fin whale population in the Mediterranean is unknown, an estimate for a portion of the western basin, where most of the whales are known to live, was approximately 3500 individuals. High whale densities, comparable to those found in rich oceanic habitats, were found in well-defined areas of high productivity. Most whales concentrate in the Ligurian-Corsican-Provençal Basin, where their presence is particularly noticeable during summer; however, neither their movement patterns throughout the region nor their seasonal cycle are clear. 3.,Based on genetic studies, fin whales from the Mediterranean Sea are distinct from North Atlantic conspecifics, and may constitute a resident population, separate from those of the North Atlantic, despite the species' historical presence in the Strait of Gibraltar. Fin whales are known to calve in the Mediterranean, with births peaking in November but occurring at lower rates throughout the year. They feed primarily on krill Meganyctiphanes norvegica which they capture by diving to depths in excess of 470 m. It is suggested that the extensive vertical migratory behaviour of its main prey may have influenced the social ecology of this population. 4.,Known causes of mortality and threats, including collisions with vessels, entanglement in fishing gear, deliberate killing, disturbance, pollution and disease, are listed and discussed in view of the implementation of appropriate conservation measures to ensure the species' survival in the region. [source] Cavity backed dual slot antenna for gain improvementMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010Jin Xin Li Abstract A simple method of gain improvement for the cavity backed slot antenna based on the substrate integrated waveguide technique has been presented in this article. By using dual slot at the cavity edges to substitute a single slot at the cavity center as the radiating element, gain of the cavity backed slot antenna has been improved about 1.7 dB whereas its total size is little reduced. The proposed antenna has high radiation performance and keeps the advantages low profile, easy integration, and low cost fabrication. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2767,2769, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25582 [source] Compact band-notched ultra-wideband printed antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007Yi Ding Abstract A novel and compact ultra-wideband (UWB) printed monopole antenna with extended band-notched designs is presented. The antenna with a total size of 20 mm × 35 mm operates in a band from 3 to over 11 GHz (VSWR , 2), and shows omnidirectional radiation with a low cross-polarization in the range of the operated band. Measured results indicate that the antenna presents a notched-band from 5.1 to 6 GHz for VSWR , 3:1, which covers the wireless local area network (WLAN) band. The notched-band is produced by an embedded resonant cell (ERC). Experimental results show that the band-notched function can be controlled by adjusting the length of the ERC and area of the slot. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2686,2689, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22842 [source] Minimizing makespan on a single batch processing machine with nonidentical job sizesNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 3 2001Guochuan Zhang Abstract We deal with the problem of minimizing makespan on a single batch processing machine. In this problem, each job has both processing time and size (capacity requirement). The batch processing machine can process a number of jobs simultaneously as long as the total size of these jobs being processed does not exceed the machine capacity. The processing time of a batch is just the processing time of the longest job in the batch. An approximation algorithm with worst-case ratio 3/2 is given for the version where the processing times of large jobs (with sizes greater than 1/2) are not less than those of small jobs (with sizes not greater than 1/2). This result is the best possible unless P = NP. For the general case, we propose an approximation algorithm with worst-case ratio 7/4. A number of heuristics by Uzosy are also analyzed and compared. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 226,240, 2001 [source] Aquaculture information sources for small-scale fish farmers: the case of GhanaAQUACULTURE RESEARCH, Issue 13 2009Kwamena K Quagrainie Abstract The Ghana ministry of fisheries and the ministry of Agriculture provide free extension services and other technical services to fish farmers in Ghana, e.g. producing fingerlings at government-operated fish hatcheries for sale to farmers. Non-governmental organizations and universities have also provided some technical assistance to fish farmers in efforts towards the development of aquaculture in Ghana. The study identified the various sources of aquaculture information to Ghanaian fish farmers and examined the factors that affected their decision to utilize these alternative sources of information. Using choice modelling techniques, the study found that the probability of farmers seeking information on aquaculture from the Ghana government increases with literacy by about 43% more than with illiteracy and by about 34% with an increase in total size of ponds. The probability that a literate farmer will choose to obtain aquaculture information from a non-governmental organization decreased by about 10% compared with an illiterate farmer. The probability of choosing ,other sources' for aquaculture information increased by about 27% for farmers residing in Ashanti region compared with farmers in the Brong-Ahafo region but the probability of farmers seeking information from ,other sources' decreased with literacy and number of years farming. [source] Calix[4]arene-Based Bis[2]catenanes: Synthesis and Chiral ResolutionCHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2007Olena Molokanova Abstract The exclusive formation of hydrogen-bonded dimers between tetraaryl and tetratosylurea calix[4]arenes has been used to prepare a series of ten "bisloop" tetraurea calix[4]arenes 3, in which adjacent phenylurea groups are covalently linked through ,,,-dioxyalkane chains. This dimerization with tetratosylurea 2 as template preorganizes the alkenyl residues of tetra(m -alkenyloxyphenyl) ureas 1 and enables their selective connection in high yield (up to 95,%) by olefin metathesis followed by hydrogenation. The "bisloop" calixarenes 3 also exclusively form heterodimers with 1. Thus, in a separated metathesis/hydrogenation sequence, a series of 14 cyclic bis[2]catenanes 4, in which two calix[4]arenes are connected through their wide rims by two pairs of interlocked rings (total size 29 to 41 atoms), were prepared in yields of up to 97,%. Optical resolution of these chiral bis[2]catenanes was studied by HPLC on chiral stationary phases. The single-crystal X-ray structure of one example (4(P,10)) confirmed the interlocking rings and revealed that the hydrogen-bonded dimeric capsule of the calix[4]arene can be "completely" opened. [source] | ||||||||||