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1.
This paper reviews the interactions of insects with food packaging, and measures which may be taken to limit damage.  相似文献   

2.
Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20 crab gatherers and 30 mollusc gatherers was recorded through open interviews and structured questionnaires. The results showed that the gatherers have an accurate comprehension of tidal phenomenon based on their exploitation of natural resources, which perpetuates through generations.  相似文献   

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Chemosystematics is a common tool in systematics and taxonomy of extant plants. Terpenoids have been found to be especially valuable for chemosystematic investigations of conifers. A review of data in the extensive literature revealed some characteristic distribution patterns of sesqui-, di-, and triterpenoids in extant conifer families. The numerous terpenoids can be assigned to approximately 40 sesquiterpenoid, 17 diterpenoid, and only a few triterpenoid structural classes. Some of these terpenoid classes (e.g., cadinanes, humulanes, labdanes, pimaranes) are unspecific and distributed among all conifers. Other structural classes occur in certain clusters of families (e.g., totaranes in Podocarpaceae, Taxodiaceae, and Cupressaceae s.str.) or were restricted to species of only one conifer family (e.g., cuparanes in Cupressaceae s.str.). Cupressaceae s.str. and Taxodiaceae show great similarities in their terpenoid composition (cedranes, thujopsanes) but can be separated by the occurrence of some sesquiterpenoids (cuparanes, widdranes), which were hitherto known only in Cupressaceae s.str. This supports a monophyletic clade of Cupressaceae s.str. within the major Taxodiaceae/Cupressaceae lineage (= Cupressaceae s.l.). Pinaceae differ from the other conifer families because they commonly lack several diterpenoid classes (phenolic abietanes, tetracyclic diterpenoids) and because they contain some distinct sesquiterpenoids (longicyclanes, sativanes), diterpenoids (cembranes), and triterpenoids (serratanes, lanostanes). With the exception of diterpenoid alkaloids (taxanes), Taxaceae contain terpenoids common in the other conifer families. This supports their inclusion as a separate family in the major conifer clade.  相似文献   

5.
Cellular senescence, a state of irreversible growth arrest triggered by various stressors, engages in a category of pathological processes, whereby senescent cells accumulate in mitotic tissues. Senolytics as novel medicine against aging and various diseases through the elimination of senescent cells has emerged rapidly in recent years. Exercise is a potent anti‐aging and anti‐chronic disease medicine, which has shown the capacity to lower the markers of cellular senescence over the past decade. However, whether exercise is a senolytic medicine for aging and various diseases remains unclear. Here, we have conducted a systematic review of the published literature studying the senolytic effects of exercise or physical activity on senescent cells under various states in both human and animal models. Exercise can reduce the markers of senescent cells in healthy humans, while it lowered the markers of senescent cells in obese but not healthy animals. The discrepancy between human and animal studies may be due to the relatively small volume of research and the variations in markers of senescent cells, types of cells/tissues, and health conditions. These findings suggest that exercise has senolytic properties under certain conditions, which warrant further investigations.  相似文献   

6.
Transglutaminase (EC 2.3.2.13) catalyses an acyl-transfer reaction in which the -carboxamide groups of peptide-bound glutaminyl residues are the acyl donors. The enzyme catalyses in vitro cross-linking in whey proteins, soya proteins, wheat proteins, beef myosin, casein and crude actomysin refined from mechanically deboned poultry meat. In recent years, on the basis of the enzyme's reaction to gelatinize various food proteins through the formation of cross-links, this enzyme has been used in attempts to improve the functional properties of foods. Up to now, commercial transglutaminase has been merely obtained from animal tissues. The complicated separation and purification procedure results in an extremely high price for the enzyme, which hampers a wide application in food processing. Recently studies on the production of transglutaminase by microorganisms have been started. The enzyme obtained from microbial fermentation has been applied in the treatment of food of different origins. Food treated with microbial transglutaminase appeared to have an improved flavour, appearance and texture. In addition, this enzyme can increase shelf-life and reduce allergenicity of certain foods. This paper gives an overview of the development of microbial transglutaminase production, including fermentation and down-stream processing, as well as examples of how to use this valuable enzyme in processing foods of meat, fish and plant origin.  相似文献   

7.
Three different types of pollen extracts are currently being used in the prophylactic treatment of hay fever. A comparative clinical study of their efficacy reveals that all are about equally efficacious. The alum-precipitated pyridine pollen extracts may be slightly better. Since only 14 to 16 injections are required for prophylactic treatment, they may well replace the older aqueous pollen extracts, 20 to 35 injections of which are usually necessary to provide relief.The aqueous pollen in oil repository method of treatment needs only one to four injections for comparable results, but this so-called “one-shot” treatment can only be administered by one who is trained in emulsion therapy and has come to know by experience the proper maximum dose.  相似文献   

8.
 A series of studies, recently reviewed, has established that approximately 60% of the structural genes which are expressed in the sporophytic portion of the angiosperm life cycle are also expressed and exposed to selection in the pollen. Given the haploidy and large population sizes of pollen grains, a substantial portion of the sporophytic genome could thus be periodically exposed to a bacterial type of mass screening. This extraordinary possibility is often subject to some skepticism which may, of course, be justified. However, recent attempts to apply models appear to be inappropriate in this context, in part because these attempts overlook an important source of genetic variation, and also because they assume fixed values for selection and fitness. More recently, studies of pollen/pollen interactions have suggested that what Linskens termed the ”programic phase” may represent an arena for important, and largely unexplored phenomena, some of which are discussed here. Received: 3 June 1996 / Revision accepted: 26 July 1996  相似文献   

9.
Phytochemistry Reviews - The production of safe foods with little or no artificial preservatives is one of the foremost leading challenges for food manufacturing industries because synthetic...  相似文献   

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《植物生态学报》2018,42(4):407
苔藓-蓝藻共生体(BCS)能固氮, 是养分贫瘠地区森林氮输入的不可忽视的来源。BCS关系与固氮能力研究为科学认识生态系统氮输入与氮循环过程和机理提供了新的视角和有效途径, 具有重要的理论价值。然而, BCS关系、固氮作用与机理的研究迄今未受到足够关注, 报道较少, 认识仍然是零星而片段化的。基于系统查阅的相关文献, 该文综述了BCS的种类组成与共生关系类型、固氮能力及所固定氮的去向及其影响因素和作用机理, 指出了存在的问题及需要深入关注和亟待突破的4个研究方向。  相似文献   

12.
Preeclampsia is characterised by new onset hypertension and proteinuria and is a major obstetrical problem for both mother and foetus. Haemolysis elevated liver enzymes and low platelets (HELLP) syndrome is an obstetrical emergency and most cases occur in the presence of preeclampsia. Preeclampsia and HELLP are complicated syndromes with a wide variety in severity of clinical symptoms and gestational age at onset. The pathophysiology depends not only on periconceptional conditions and the foetal and placental genotype, but also on the capability of the maternal system to deal with pregnancy. Genetically, preeclampsia is a complex disorder and despite numerous efforts no clear mode of inheritance has been established. A minor fraction of HELLP cases is caused by foetal homozygous LCHAD deficiency, but for most cases the genetic background has not been elucidated yet. At least 178 genes have been described in relation to preeclampsia or HELLP syndrome. Confined placental mosaicism (CPM) is documented to cause early onset preeclampsia in some cases; the overall contribution of CPM to the occurrence of preeclampsia has not been adequately investigated yet. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.  相似文献   

13.
Dear Editor, During recent decades, a novel mechanism of secretion has been identified in a wide range of mammalian cells. It involves the release of bioactive membrane nanovesicles (30-100 nm), termed exosomes, upon the fusion of multivesicular bodies with the plasma membrane (Thery et al., 2009). Exosomes are implicated in diverse functions, such as scavenging of archaic proteins, intercellular messengers delivering cell-specific signals, and vehicles for transmissible pathogens. Exosomes have also been described in other organisms such as bacte- ria, Drosophila, and fungi.  相似文献   

14.
The sweetpotato surpasses the white potato in its content of fat, carbohydrates, fiber, sugar, starch, calories and the vitamins carotene, riboflavin and pantothenic acid. In 1944, of more than a billion bushels produced throughout the world, over 600 million were raised in China, over 68 million in the United States.  相似文献   

15.
In species in which adults of the two sexes show long-term association, males often engage in acts of assistance (“services”) aimed at females and/or their young in various behavioural contexts that are not reciprocated. We conducted a quantitative review of the primate literature on sex differences in involvement in protection against predation. We found that males were more likely to be at the front of group progressions, especially in contexts of increased risk, were more vigilant, sometimes to the point of becoming sentinels, were more active in mobbing, and were far more likely to counter-attack felids and monkey-eating raptors than females did. Our evaluation showed that these services may be an expression of male parental care or aimed at bonded partners, but we also encountered many cases in which non-sires, unrelated to either females or immatures, provide them. We hence investigate explanations invoking group augmentation or costly signalling. Currently, available data on male anti-predation services in nonhuman primates do not allow us to distinguish among them, although costly signalling better explains data on birds and humans. We develop predictions that will allow more detailed tests of the various hypotheses for this understudied phenomenon.  相似文献   

16.
Cyanobacterial blooms occur when algal densities exceed baseline population concentrations. Cyanobacteria can produce a large number of secondary metabolites. Odorous metabolites affect the smell and flavor of aquatic animals, whereas bioactive metabolites cause a range of lethal and sub-lethal effects in plants, invertebrates, and vertebrates, including humans. Herein, the bioactivity, chemistry, origin, and biosynthesis of these cyanobacterial secondary metabolites were reviewed. With recent revision of cyanobacterial taxonomy by Anagnostidis and Komárek as part of the Süβwasserflora von Mitteleuropa volumes 19(1–3), names of many cyanobacteria that produce bioactive compounds have changed, thereby confusing readers. The original and new nomenclature are included in this review to clarify the origins of cyanobacterial bioactive compounds.Due to structural similarity, the 157 known bioactive classes produced by cyanobacteria have been condensed to 55 classes. This review will provide a basis for more formal procedures to adopt a logical naming system. This review is needed for efficient management of water resources to understand, identify, and manage cyanobacterial harmful algal bloom impacts.  相似文献   

17.
In 1898 the U. S. Department of Agriculture be?an importation of economically important plants for possible cultivation and utilization in the United States. Since then nearly a quarter million introductions have been made, including the hard winter wheats which today are ?rown annually on some 27 million acres, and soybeans which now support a billion-dollar industry.  相似文献   

18.
Equilibrative nucleoside transporters (ENTs) are polytopic integral membrane proteins that mediate the transport of nucleosides, nucleobases, and therapeutic analogs. The best-characterized ENTs are the human transporters hENT1 and hENT2. However, non-mammalian eukaryotic ENTs have also been studied (e.g., yeast, parasitic protozoa). ENTs are major pharmaceutical targets responsible for modulating the efficacy of more than 30 approved drugs. However, the molecular mechanisms and chemical determinants of ENT-mediated substrate recognition, binding, inhibition, and transport are poorly understood. This review highlights findings on the characterization of ENTs by surveying studies on genetics, permeant and inhibitor interactions, mutagenesis, and structural models of ENT function.  相似文献   

19.
A chronological review of the history of research in canine behavioral genetics is presented. Prior to the work of Scott and Fuller, many studies attempted to describe observed results in simple Mendelian terms. More recently, a quantitative mode of inheritance has been ascribed to many behavioral traits, and heritabilities have been calculated in different populations. Studies of behavioral traits are complicated by the effects of learning, which may well explain the reports of low heritability of behavioral traits measured on adults. Both genotype and environment have been shown to play major roles in the expression of behavioral traits. Maternal effects and the sex of an individual have important effects on behavior scores. Breeders usually select for both physical and behavioral traits in the same individuals, and this review includes a summary of reported research on the relationships between physical and mental traits.  相似文献   

20.
Merremia dissecta was first discovered in the Caribbean, then Florida, Mexico, and later in the Old World, where it had been introduced. Historically and currently, the species has been used as a condiment, medicine, and ornamental by an array of cultures. Although the plant has escaped in several areas to become a weed, it continues being sold as an ornament in even those regions. In Argentina, roots ofM. dissecta var. edentata are still used as food by a few indigenous groups. History, uses, and chemistry are discussed regarding these utilizations.
Merremia dissecta (Convolvulaceas): Un condimento, medicina, ornamental, y maleza— Una revista
Resumen  Merremia dissecta fue primeramente descubierta en el Caribe, luego en la Florida, México y más tarde fue introducida en el Viejo Mundo. Históricamente y aún actualmente se ha usado como condimento, medicina, y ornamentatión por varias culturas. A pesar de que en varias áreas se ha transformado en una mala hierba, se continua vendiendo como un ornamento aún en esas areas. En Argentina, as raices deM. dissecta var. edentata aún son usadas como alimento por unos cuantos grupos indígenas. La historia, los usos y la química de estas utilizaciónes son aquí discutidas.
  相似文献   

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