^137Cs,^134Cs在人工海洋小生境中的行为

在自行建立的人工海洋小生境中,采用示踪法综合地研究~(137)Cs、~(134)Cs在人工小生境中的行为。结果表明,~(137)Cs和~(134)Cs具有共同的生理生态行为,并表现出相似的规律、沉积物对~(137)Cs、~(134)Cs的吸附能力甚低,~(137)Cs、~(134)Cs在海洋动物体内趋于全身性的分布。各主要生化物质均能检出~(137)Cs、~(134)Cs。排泄实验后,海洋动物的胃肠、肝(消化腺)~(137)Cs、~(134)Cs损失显著。沉积物表现为解吸-重吸附的过程。     

Decontamination efficiencies of pot-type water purifiers for ¹³¹I, ¹³⁴Cs and ¹³⁷Cs in rainwater contaminated during Fukushima Daiichi nuclear disaster

Rainwater was contaminated by a large release of radionuclides into the environment during the Fukushima Daiichi nuclear disaster. It became a matter of concern for Japan when several water purification plants detected 131I contamination in the drinking water. In the present study, the decontamination efficiency of two easily obtainable commercial water purifiers were examined for rainwater contaminated with 131I, 13?Cs and 13?Cs. The water purifiers removed 94.2-97.8% of the 131I and 84.2-91.5% of the 13?Cs and 13?Cs after one filtration. Seven filtrations removed 98.2-99.6% of the 131I and over 98.0% of the 13?Cs and 13?Cs. From a practical perspective, over the fourth filtrations were not needed because of no significant improvements after the third filtration.     

Phytochemicals: the good, the bad and the ugly?

Phytochemicals are constitutive metabolites that enable plants to overcome temporary or continuous threats integral to their environment, while also controlling essential functions of growth and reproduction. All of these roles are generally advantageous to the producing organisms but the inherent biological activity of such constituents often causes dramatic adverse consequences in other organisms that may be exposed to them. Nevertheless, such effects may be the essential indicator of desirable properties, such as therapeutic potential, especially when the mechanism of bioactivity can be delineated. Careful observation of cause and effect, followed by a coordinated approach to identify the responsible entities, has proved extremely fruitful in discovering roles for phytochemical constituents. The process is illustrated by selected examples of plants poisonous to animals and include the steroidal alkaloid toxin of Veratrum californicum (Western false hellebore), piperidine alkaloids of Lupinus species (lupines), and polyhydroxy indolizidine, pyrrolizidine and nortropane alkaloids of Astragalus and Oxytropis species (locoweeds), Castanospermum australe (Moreton Bay chestnut) and Ipomoea species (morning glories).     

Jiuzhaigou, the Picturesque Valley

Jiuzhaigou covers an area of 720 square kilometers, with an outer-ring protect zone of 600 square kilometers, among which a great majority part is covered with forest. The main gully, more than 50 kilometers long, consists of Shuzheng, Rize arid Zechawa three gullies, forming a shape of "Y". At the end of Zechawa gully lies Changhai (the lake is called "haizi" by the local people) with an eleva-     

Tau phosphorylation, tangles, and neurodegeneration: the chicken or the egg?

Pathological aggregation of the microtubule-associated protein tau is a common feature of many neurodegenerative diseases. Although tau aggregation is associated with abnormal tau phosphorylation, the role of phosphorylation in the initiation of neurodegeneration has been unclear. Now, several animal models and data from human patients provide converging evidence that aberrant tau phosphorylation can cause a neurodegenerative phenotype similar to that seen in human neurodegenerative diseases.     

APPENDIX： Statement delivered from the floor at the Extraordinary Session of the International BioethicsCommittee, UNESCO, Paris, 27- 29 April, 2004

I have heard, over the last two days, from the learned and respected scientists and philosophers here that we must not, indeed cannot expand bioethics to apply to the biosphere, i. e. bioethics is not bio at all, it is anthropocentric ethics.     

Changes in the lichen biota of the Lions Rump area,King George Island,Antarctica, over the last 20 years

Climate changes observed in recent years in the maritime Antarctic have affected the tundra vegetation, including plant communities in which lichens are a dominant component. The results of comparative studies (1988 and 1990 vs. 2007 and 2008) on the dynamics of the lichen biota within the Antarctic Specially Protected Area No. 151 (King George Island, Antarctica) minimally influenced by human impact, are presented. This long-term experiment is aimed at determining the trends and rate of changes on lichen biota induced by climate warming and rapid deglaciation. The most significant changes affecting the lichen biota have taken place in the forefield of a glacier and on the young moraines where in the second period of studies three species (Polyblastia gothica, Thelenella kerguelena, Thelocarpon cyaneum) were not refound. There was also a reduction in the number of other sites for some species (e.g. Leptogium puberulum, Staurothelle gelida) caused by substrate desiccation. On the other hand, there was an increase in the range of pioneering species (e.g. Bacidia chrysocolla, Caloplaca johnstonii, Candelariella aurella, Lecanora dispersa) on young moraines recently uncovered by the retreating glacier. The smallest changes were observed on the cliff rocks near penguin colonies.     

Vegetation changes during the Holocene in the North Ibersá, Corrientes, Argentina

Vegetation changes during the Holocene in the North Iberá, Corrientes, Argentina. Wetlands are very important sites for palynological studies, since they represent one of the most suitable environments for fossil pollen preservation. The aim of this work was to determine, by palynological analysis of lacustrine sediments, the vegetal communities and the predominant environment during the Holocene in NW of Iberá. Two lagoons were studied: San Sebastián and San Juan Poriahú. Sediment samples were obtained with witness using a "Levingstone square-rod sampler", processed with Faegri e Iversen techniques and dated with C14. The palynological graphs were divided in zones using the Tilia program. The palynological analysis allowed visualizing diverse changes in the vegetation: from 6 140 +/- 50 to 5 170 +/- 100 a. C., the NW of Iberá was characterized by marsh-herbaceous vegetation and arboreal vegetation typical of dry vegetation. From 5 170 +/- 100 to 3 460 +/- 60 a. C., a decrease in the species frequency, typical of wet environments, is produced, and the clogging of the waterbody, from 3460 +/- 60 a. C. onwards, while continuing the dominance of herbaceous vegetation typical of these environments, the arboreal pollen, indicates the beginning of a hygrophilous forest development.     

Neuronal cholecystokinin,gastrin-releasing peptide,neurotensin, and β-endorphin in the intestine of the guinea pig

Summary The guinea-pig intestine was found to harbor nerve fibers containing immunoreactive cholecystokinin (CCK), gastrin-releasing peptide (GRP), neurotensin or - endorphin. Such fibers occurred in the myenteric and submucous ganglia and in the smooth muscle. GRP- and CCK-fibers, in addition, were found in the mucosa. Following colchicine treatment, neuronal perikarya in the myenteric ganglia displayed CCK-, GRP-, or -endorphin immunoreactivity. CCK-immunoreactive perikarya were located also in the submucous ganglia. Neurotensin-immunoreactive cell bodies could not be detected. The presence of immunoreactive neuronal perikarya in intramural ganglia indicates that CCK-, GRP- and -endorphin-containing fibers are intrinsic to the gut wall. GRP, neurotensin, and -endorphin were identified in extracts of smooth muscle by immunochemical and Chromatographic analysis.CCK-8, GRP and neurotensin contracted the isolated taenia coli. Tetrodotoxin reduced the response to CCK-8 but not that to GRP and neurotensin, suggesting that the two latter peptides act directly on smooth muscle receptors. The effect of CCK-8 is partly mediated by cholinergic nerves, since not only tetrodotoxin but also atropine greatly reduced the CCK-8-induced contractile response. The substance P (SP) antagonist, (d-Pro², d-Trp^7,9)-SP_1–11 had no effect on the CCK-8-induced contraction of the taenia. CCK-8 enhanced the SP-mediated (atropine-resistant) contractile response to electrical stimulation but not that mediated by acetylcholine. -Endorphin had no effect on the tension of the muscle but reduced the response to electrical stimulation (cholinergic as well as SP-mediated) through a naloxone-sensitive mechanism.While CCK-8 and -endorphin seem to play neuromodulatory roles in the taenia coli, the significance of GRP and neurotensin remains enigmatic.     

Which forest bird species are the main hosts of the tick,Ixodes ricinus,the vector of Borrelia burgdorferi sensu lato,during the breeding season?

Wild birds are important hosts for vector-borne pathogens, especially those borne by ticks. However, few studies have been conducted on the role of different bird species within a community as hosts of vector-borne pathogens. This study addressed individual and species factors that could explain the burden of Ixodes ricinus on forest birds during the reproductive periods of both vectors and hosts. The goal was to identify which bird species contribute the most to the tick population at the community level. Birds were mist-netted on four plots in 2008 and on seven plots in 2009 in two forests (Sénart and Notre Dame, near Paris, France). The dependence of the tick load per bird upon environmental conditions (questing nymph density, year and plot) and on host species traits (species, age, sex, body size, vertical space use, level of innate and acquired immunity) was analysed. Finally, the relative contribution of each bird species to the local dynamics of ticks was estimated, while accounting for their respective abundance. Tick burden differed markedly between bird species and varied according to questing nymph density. Bird species with a high body mass, those that forage low in the vegetation, and those that had a high innate immune response and a high spleen mass were more likely to have a high tick burden. Four species (the Common Blackbird, Turdus merula, the European Robin, Erithacus rubecula, the Song Thrush, Turdus philomelos, and the Winter Wren, Troglodytes troglodytes) hosted more than 90% of the ticks in the local bird community. These species, and particularly T. merula which was host to a high proportion of the nymphs, are likely to contribute significantly to the circulation of pathogens for which they are competent, such as the agent of Lyme borreliosis.     

Distribution of CGRP-, VIP-, DβH-, SP-, and NPY-immunoreactive nerves in the periosteum of the rat

Summary In light of the possible role peripheral nerves may play in bone metabolism, the morphology of calcitonin gene-related peptide (CGRP)-, vasoactive intestinal peptide (VIP)-, substance P (SP)-, neuropeptide Y (NPY)-, and dopamine--hydroxylase (DH)-immunoreactive nerve fibers was examined in whole-mount preparations of periosteum of membranous bones (calvaria, mandible) and long bones (tibia) from the rat. Periosteum from animals treated to remove selectively either the sympathetic or fine-caliber primary afferent nerves was also examined to determine the origin of the nerve fibers. We found a consistent and often dense innervation of the periosteum. The innervation patterns of the calvaria and mandible were similar, with networks of nerves spread across the surface of the bone. Nerves in the tibial periosteum were oriented in the longitudinal axis and were more numerous at the epiphyses than in the mid-shaft region. CGRP-immunoreactive fibers were widely and densely distributed. The presence of populations of CGRP-immunoreactive fibers of differing calibers and perivascular arrangements suggests that such nerves in bone tissues may serve different functions. SP-immunoreactivity was present in a fine network of varicose fibers in the superficial layers of the periosteum. CGRP- and SP-immunoreactive nerve fibers were dramatically reduced in periosteum of capsaicin-treated animals as compared to controls, indicating the sensory origin of these nerves. VIP-immunoreactive nerve fibers were distributed in the periosteum of mandible and calvaria as small networks and individual fine varicose fibers. In tibial periosteum, larger networks of these fibers were visible. VIP-immunoreactive nerve fibers in the periosteum were associated with both vascular and nonvascular elements within the layers of cells closest to the bone, suggesting that VIP may serve more than one function in periosteal tissues. NPY-immunoreactive fibers were largely confined to vascular elements; occasional fibers were observed among the bone-lining cells. DH-immunoreactivity was associated only with blood vessels. VIP-, NPY-, and DH-immunoreactivities were dramatically reduced in the periosteum of guanethidinetreated animals, indicating the sympathetic origin of these nerves.     

Review of the fauna of Rotatoria,Cladocera, and Copepoda of the basin of the Anadyr’ River

The zooplankton composition is studied in the thermokarst, glacial and meteorite lakes, channels, former riverbeds, and hollows in the basin of Anadyr’. We found 174 taxa: 78, Rotatoria, 55, Cladocera, and 41, Copepoda. The most diverse is the lake fauna: 51 taxa of Rotatoria, 48, Cladocera, and 37, Copepoda. The thermokarst Lake Maiorskoe hosts 68 taxa: 31, Rotatoria, 14, Cladocera, and 23, Copepoda, wheras the cold ultraoligotrophic Lake El’gygytgyn features only one species of Cyclop of the group scutifer Cyclops neymanae Strel., and Rotatoria and Cladocera are present as allochtonous forms. The Copepoda illustrate the relations of the Anadyr’ fauna with those of Europe, North America, and Japan.     

Cellular plasticity: the good, the bad, and the ugly? Microenvironmental influences on progenitor cell therapy

Progenitor cell based therapies have emerged for the treatment of ischemic cardiovascular diseases where there is insufficient endogenous repair. However, clinical success has been limited, which challenges the original premise that transplanted progenitor cells would orchestrate repair. In this review, we discuss the basics of endothelial progenitor cell therapy and describe how microenvironmental changes (i.e., trophic and mechano-structural factors) in the damaged myocardium influence progenitor cell plasticity and hamper beneficial therapeutic outcome. Further understanding of these microenvironmental clues will enable optimization of cell therapy at all levels. We discuss current concepts and provide future perspectives for the enhancement of progenitor cell therapy, and merge these advances into a combined approach for ischemic tissue repair.     

Which came first, the lung or the breath?

Lungs are the characteristic air-filled organs (AO) of the Polypteriformes, lungfish and tetrapods, whereas the swimbladder is ancestral in all other bony fish. Lungs are paired ventral derivatives of the pharynx posterior to the gills. Their respiratory blood supply is the sixth branchial artery and the venous outflow enters the heart separately from systemic and portal blood at the sinus venosus (Polypteriformes) or the atrium (lungfish), or is delivered to a separate left atrium (tetrapods). The swimbladder, on the other hand, is unpaired, and arises dorsally from the posterior pharynx. It is employed in breathing in Ginglymodi (gars), Halecomorphi (bowfin) and in basal teleosts. In most cases, its respiratory blood supply is homologous to that of the lung, but the vein drains to the cardinal veins. Separate intercardiac channels for oxygenated and deoxygenated blood are lacking. The question of the homology of lungs and swimbladders and of breathing mechanisms remains open. On the whole, air ventilatory mechanisms in the actinopterygian lineage are similar among different groups, including Polypteriformes, but are distinct from those of lungfish and tetrapods. However, there is extreme variation within this apparent dichotomy. Furthermore, the possible separate origin of air breathing in actinopterygian and 'sarcopterygian' lines is in conflict with the postulated much more ancient origin of vertebrate air-breathing organs. New studies on the isolated brainstem preparation of the gar (Lepisosteus osseus) show a pattern of efferent activity associated with a glottal opening that is remarkably similar to that seen in the in-vitro brainstem preparation of frogs and tadpoles. Given the complete lack of evidence for AO in chondrichthyans, and the isolated position of placoderms for which buoyancy organs of uncertain homology have been demonstrated, it is likely that homologous pharyngeal AO arose in the ancestors of early bony fish, and was pre-dated by behavioral mechanisms for surface (water) breathing. The primitive AO may have been the posterior gill pouches or even the modified gills themselves, served by the sixth branchial artery. Further development of the dorsal part may have led to the respiratory swimbladder, whereas the paired ventral parts evolved into lungs.     

Man, Energy, and Anthropology: I Can Feel the Heat, But Where's the Light?

Anthropology should deal with man holistically, but has failed to do so. The field is unfortunately split between mentalistic and materialistic schools and has not developed a theory to cope with the complexity of large contemporary societies. Energy similarly has been little studied by anthropology because there has been no theory sufficient for the purpose. The thermodynamics of structures far from equilibrium and the dissipative structure model of Ilya Prigogine offer a method for both studying energy in society and dealing with society as a whole. Anthropologists are urged to pursue study of this area because it is critical for an understanding of human destiny . [energy, holism, materialism-mentalism, dissipative structures, complex societies]