Uses,abuses and management of lakes and rivers

Freshwater basins are vulnerable to human-induced change for a number of reasons. They lie at the bottoms of catchments and therefore are subject to the run-off of a large variety of dissolved and particulate substances; shallow basins provide fertile agricultural soils if drained; and public perception, particularly of wetland basins, is of inhospitable places, so that lobbies for drainage are more likely to be effective than those seeking to preserve the habitat. On the other hand, water is so important to human life that there is also strong concern about the fate of freshwater habitats. Freshwater systems are also often open systems capable of faster recovery from disturbance than their terrestrial counterparts.Three lake, river and wetland ecosystems, the Sudd in the Sudan, the Everglades and adjacent swamplands of southern Florida, USA, and the Norfolk Broadland in the UK are examined from the viewpoints of how they are or were used by their indigenous human populations, and the problems they may face or already face. This sites are used to suggest a general model of human impact and to establish approaches to the wise future use and conservation of these and other similar systems.     

Uses of saffron

The uses of saffron through the ages are discussed. Originally prized both as a medicament and as a dyestuff, these applications have declined in modern times; it has also been used as a perfume. The primary market now is as a food spice—by far the world’s most expensive.     

Hyperthermophilic Enzymes: Sources, Uses, and Molecular Mechanisms for Thermostability

Enzymes synthesized by hyperthermophiles (bacteria and archaea with optimal growth temperatures of >80°C), also called hyperthermophilic enzymes, are typically thermostable (i.e., resistant to irreversible inactivation at high temperatures) and are optimally active at high temperatures. These enzymes share the same catalytic mechanisms with their mesophilic counterparts. When cloned and expressed in mesophilic hosts, hyperthermophilic enzymes usually retain their thermal properties, indicating that these properties are genetically encoded. Sequence alignments, amino acid content comparisons, crystal structure comparisons, and mutagenesis experiments indicate that hyperthermophilic enzymes are, indeed, very similar to their mesophilic homologues. No single mechanism is responsible for the remarkable stability of hyperthermophilic enzymes. Increased thermostability must be found, instead, in a small number of highly specific alterations that often do not obey any obvious traffic rules. After briefly discussing the diversity of hyperthermophilic organisms, this review concentrates on the remarkable thermostability of their enzymes. The biochemical and molecular properties of hyperthermophilic enzymes are described. Mechanisms responsible for protein inactivation are reviewed. The molecular mechanisms involved in protein thermostabilization are discussed, including ion pairs, hydrogen bonds, hydrophobic interactions, disulfide bridges, packing, decrease of the entropy of unfolding, and intersubunit interactions. Finally, current uses and potential applications of thermophilic and hyperthermophilic enzymes as research reagents and as catalysts for industrial processes are described.     

The Genus Pluchea: Phytochemistry,Traditional Uses,and Biological Activities

In this review, literature data on phytochemical and biological investigations on the genus Pluchea are compiled. Pluchea is a genus of flowering plants in the Asteraceae family and comprises ca. 80 species distributed mainly in Northern and Southern America, Africa, Asia, and Australia. Sesquiterpenoids and flavonoids are the main constituents of this genus. Compounds isolated from plants of the Pluchea genus display a variety of biological properties, viz., anticancer, antileishmanial, immunosuppressive, antioxidant, anti‐acetylcholinesterase, antimicrobial, trypanocidal, hepatoprotective, cytotoxic, larvicidal, anti‐ulcer, anti‐inflammatory, and antinociceptive activities.     

肉桂的形态特征、用途与造林技术

肉桂系名贵的香药两用植物，桂皮和桂油的市场需求缺口大，在广大亚热带地区具有较大的发展潜力。本文主要介绍肉桂的形态特征、乔木林与矮树木的造林技术及矮树林的管理与更新，为营造肉桂林提供参考。     

Protein crosslinking: Uses in chemistry,biology and biotechnology

Abstract

Protein crosslinking is a part of many biological processes and is also carried out in vitro under several controllable conditions with the help of any of the commercially available bifunctional reagents. Many biotechnological applications utilize stable and/or reusable crosslinked enzymes such as soluble intramolecularly crosslinked enzymes; soluble bioconjugates of enzymes with other enzymes/proteins or polymers; chemically aggregated enzymes, chemically crosslinked enzyme aggregates and crosslinked enzyme crystals. The review after indicating how protein crosslinking is at the heart of such diverse processes/technology concludes with discussion of few applications which are currently drawing considerable attention.