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1.
Natural history, across disciplines, is essential for the continuation of science, especially as we attempt to identify the myriad of threats that biodiversity faces in this rapidly changing world. Recording the natural history of birds is perhaps the most prominent, widespread and long‐standing pursuit of this activity. Yet, there is a distinct decrease in publishing of natural history in the ornithological sciences. Concomitantly, the natural history information being published is often in small and regional journals, less accessible by the global ornithological community. We argue that historical natural history needs a modern reinvigoration, and should focus on placing natural history observations in the context of an anthropogenically altered world – ‘unnatural history’. This includes, but is not limited to, behavioural adaptations, novel diet choices, hybridization and novel adaptations to urbanization. Here, we elaborate on natural history's place in modern ornithology, how this relates to citizen science and the potential cost of ignoring it. Ultimately, increased accessibility of natural history observations, encouragement of amateur ornithologists' participation in professional societies (and vice versa) and targeted citizen science projects are potential mechanisms by which to reinvigorate natural history in 21st century ornithology.  相似文献   

2.
Predictive models in invasion biology rely on knowledge of the life history and ecological role of invading species. However, species may change in key traits as they invade a new region, making prediction difficult. For marine invertebrate invaders there have been too few comparative studies to determine whether change in key traits is the exception or the rule. Here we examined populations of the intertidal barnacle Chthamalus proteus in three locations in its native range in the Caribbean and Atlantic, and in the Hawaiian Islands, where it has recently invaded, as a model system for such comparative studies. We measured body size, fecundity, population density and vertical distribution, compared habitat use and investigated aspects of the barnacle’s ecological role in Curaçao, Panama and Brazil and the main Hawaiian Islands. In terms of these measures, the barnacle has undergone little change in its invasion of Hawaii. Thus, if this barnacle had been studied in its native range, predictions about its spread in Hawaii could have been made. As little was known about this barnacle in either its native range or Hawaii, we also carried out studies of its larval life history, fecundity, growth, and mortality. Based on this work, we predict that this barnacle will continue to spread, aided by vessel traffic, throughout the Hawaiian Islands and elsewhere in the Pacific.  相似文献   

3.
As we have seen, natural antibodies first emerged as an experimental phenomenon without a plausible theoretical explanation. They were originally denied the status of antibody; then, adjustments to the side-chain theory transformed them from a curiosity into a foundation of the theory. However, in accommodating natural antibodies, Ehrlich had opened several holes in his mechanism of antibody formation.Thus, by 1905, natural antibodies were clearly established as problematic. From the practical standpoint, it seemed unwise to maintain an identity between normal and immune antibodies, given the therapeutic differences in their avidity. With the decline of Ehrlich's theory of antibody formation and the spread of Landsteiner's hapten technique for the production of antibodies against artificial antigens after World War I, the theoretical possibility of their existence as other than anomaly seemed more remote than ever. However, outside the theory and despite clinical considerations, natural antibodies remained a perplexing experimental phenomenon.49  相似文献   

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The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities.  相似文献   

6.
Abstract

Myrmarachne melanotarsa, an ant‐like jumping spider (Salticidae) from East Africa, is an accurate mimic of Crematogaster sp. and associates unusually closely with its models. M. melanotarsa is remarkable in that it forms dense aggregations and builds large nest complexes (numerous individually‐occupied nests connected to each other by silk). Other salticids (Pseudicius spp., Menemerus spp.) live with M. melanotarsa in the same nest complex. These aggregations, which can exceed 50 conspecific individuals per colony, are considerably larger than those few previously described, and seem to have primarily a protective function. We provide baseline information on the natural history of M. melanotarsa, paying particular attention to predatory behaviour and association with Crematogaster sp., and fit this within current theory on the function of sociality in spiders. Other unusual behaviour of M. melanotarsa includes “mouthing”, in which the spider opens and closes its chelicerae while pressing its mouthparts against nest silk. We investigated the role of prior presence of Crematogaster sp. on nest silk in eliciting this previously unreported behaviour.  相似文献   

7.
In this article, I describe changes in patterns of alcohol use and abuse among Navajo Indians from the mid-1960s to the late 1990s. The prevalence of alcohol dependence continues to be higher than in the general U.S. population, but remission is also common, as it was in the 1960s and previously. Men have substantially higher rates of alcohol dependence than women. The former engage in heavy drinking largely in response to the heavy drinking of those around them. The latter drink excessively largely as a response to psychiatric disorders, depression, and abuse by a partner or husband. As increasing numbers of people have moved to reservation and border towns, a youth culture has developed in which alcohol use is initiated by teenagers with their peers rather than, as in the past, with older kinsmen. Alcohol use has thus been freed from the constraints imposed by both isolation and family obligations.  相似文献   

8.
Despite the emphasis on inbreeding avoidance and competition for mates in explaining primate dispersal, little is known about how dispersal and mating interconnect in humans. I examine the link between dispersal and marriage using life history data from Oakham, MA (1750–1850). I find that dispersal status, timing, and destination were linked to marital status, timing, and spouse's place of origin. Men, unmarried individuals, and individuals with spouses from Oakham were less likely to disperse than their counterparts. Individuals with spouses from Oakham also married earlier than others. For women, dispersal and marriage often coincided, and women were more likely to disperse to their spouses' town of origin than were men. Although dispersal coincided with marriage in at least two-thirds of dispersal events, the majority of cases were inconsistent with both inbreeding avoidance and mating competition explanations. Where one of these explanations was still plausible, dispersal seemed more likely linked to competition for mates than to inbreeding, with resource availability also likely shaping dispersal, and male control of resources contributing to sex biases in dispersal.  相似文献   

9.
Shmuelof L  Krakauer JW 《Neuron》2011,72(3):469-476
Here we argue that general principles with regard to the contributions of the cerebellum, basal ganglia, and primary motor cortex to motor learning can begin to be inferred from explicit comparison across model systems and consideration of phylogeny. Both the cerebellum and the basal ganglia have highly conserved circuit architecture in vertebrates. The cerebellum has consistently been shown to be necessary for adaptation of eye and limb movements. The precise contribution of the basal ganglia to motor learning remains unclear but one consistent finding is that they are necessary for early acquisition of novel sequential actions. The primary motor cortex allows independent control of joints and construction of new movement synergies. We suggest that this capacity of the motor cortex implies that it is a necessary locus for motor skill learning, which we argue is the ability to execute selected actions with increasing speed and precision.  相似文献   

10.
Marrazzo JM 《Anaerobe》2011,17(4):186-190
Bacterial vaginosis (BV) is a common cause of vaginitis and increases women's risk of pelvic inflammatory disease, adverse pregnancy outcomes, and risk of STD/HIV acquisition. The etiology of BV is unclear, though it is believed to involve loss of vaginal hydrogen peroxide-producing lactobacilli and acquisition of complex bacterial communities that include many fastidious BV-associated bacteria (BVAB) that have recently been detected using PCR methods. Treatment failure (persistence) is common, and may be facilitated by unprotected sex. Potential contributions to BV and BV persistence include (1) sexual partners as a reservoir for BVAB; (2) specific sexual practices, including male partners' condom use; and (3) the composition of the vaginal microbiota involved in BV. Specific BVAB in the Clostridiales order may predict BV persistence when detected pre-treatment, and have been detected in men whose female partners have BV. BVAB may be associated with unprotected sexual behavior and failure of BV to resolve in women, supporting the hypothesis that BVAB colonization of male genitalia may serve as a reservoir for re-infection of female partners. Moreover, specific sexual practices may favor vaginal colonization with certain BVAB that have been associated with persistence. This review provides background on BV, and discusses the epidemiologic and microbiologic data to support a role for acquisition of BVAB and how this process might differ among subsets of women.  相似文献   

11.
The aim of this study was to assess the natural history of the SCO2 deficiency in relation to the genotype in a cohort of 62 patients with SCO2 mutations (36 this study, 26 previous reports).A novel, milder phenotype (disease onset delayed until one year after birth, nonspecific encephalomyopathy, and 2–4 year survival period) associated with compound heterozygosity of the common p.E140K and a novel p.M177T mutations extends the range of symptoms of the SCO2 deficiency.The prevalence of SCO2 deficiency in Poland is relatively high. A search for SCO2 mutations in patients with histology resembling SMA appears to efficiently improve the detection rate.  相似文献   

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14.
Cytokinin ribosides (N6-substituted adenosine derivatives) have been shown to have anticancer activity both in vitro and in vivo. This study presents the first systematic analysis of the relationship between the chemical structure of cytokinins and their cytotoxic effects against a panel of human cancer cell lines with diverse histopathological origins. The results confirm the cytotoxic activity of N6-isopentenyladenosine, kinetin riboside, and N6-benzyladenosine and show that the spectrum of cell lines that are sensitive to these compounds and their tissues of origin are wider than previously reported. The first evidence that the hydroxylated aromatic cytokinins (ortho-, meta-, para-topolin riboside) and the isoprenoid cytokinin cis-zeatin riboside have cytotoxic activities is presented.Most cell lines in the panel showed greatest sensitivity to ortho-topolin riboside (IC50 = 0.5–11.6 μM). Cytokinin nucleotides, some synthesized for the first time in this study, were usually active in a similar concentration range to the corresponding ribosides. However, cytokinin free bases, 2-methylthio derivatives and both O- and N-glucosides showed little or no toxicity. Overall the study shows that structural requirements for cytotoxic activity of cytokinins against human cancer cell lines differ from the requirements for their activity in plant bioassays. The potent anticancer activity of ortho-topolin riboside (GI50 = 0.07–84.60 μM, 1st quartile = 0.33 μM, median = 0.65 μM, 3rd quartile = 1.94 μM) was confirmed using NCI60, a standard panel of 59 cell lines, originating from nine different tissues. Further, the activity pattern of oTR was distinctly different from those of standard anticancer drugs, suggesting that it has a unique mechanism of activity. In comparison with standard drugs, oTR showed exceptional cytotoxic activity against NCI60 cell lines with a mutated p53 tumour suppressor gene. oTR also exhibited significant anticancer activity against several tumour models in in vivo hollow fibre assays.  相似文献   

15.
We present new evidence concerning the evolution of adult height across Spanish regions for the 1950–1980 male and female birth cohorts, using the augmented sample of the European Community Household Panel (ECHP) for Spain. This augmented sample, available only for the year 2000, contains self-reported height data representative at the Autonomous Community level. The average heights of these two sets of birth cohorts, female and male, are found to increase by 1.7 and 1.6 cm/decade, respectively. Making available a new dataset of quinquennial mean heights will allow researchers to study the determinants of population heights by means of a within-country analysis.  相似文献   

16.
In this study we have examined the reception of Mendelism in France from 1900 to 1940, and the place of some of the extra-Mendelian traditions of research that contributed to the development of genetics in France after World War II. Our major findings are:
(1)  Mendelism was widely disseminated in France and thoroughly understood by many French biologists from 1900 on. With the notable exception of Lucien Cuénot, however, there were few fundamental contributions to the Mendelian tradition, and virtually none from about 1915 to the midthirties. Prior to 1900, Cuénot's work was already marked by a striking interest in physiological mechanisms; his physiological preoccupations played a considerable role in his account of the inheritance of coat color and of susceptibility to tumors in mice. His analysis of the roles of the many genes involved in pigment formation was developed with an eye to one of the first models of the metabolic reactions involved. It yielded one of the earliest suggestions that the steps controlled by single genes involve enzymes as the products of genes.
(2)  The inflexible structure of the French universities played an important role in discouraging research in genetics and in the failure to train the post-World War I generation in that discipline.
(3)  During this period the disciplines of physiology, microbiology, and causal embryology were dominant in French experimental biology. The issues that were most prominent within these disciplines—differentiation and development, regulation of growth and morphology, infection and assimilation—were not easily treated within genetics. The failure of Mendelism to resolve a variety of legitimate explanatory issues to the satisfaction of serious investigators trained in the dominant French disciplines also contributed to the failure of Mendelism to penetrate French science. The violent anti-Mendelian polemics put forward by many of the most committed neo-Lamarckians raised many of the same issues regarding the supposed insufficiency of Mendelism. Cuénot's reluctance to encourage his students to pursue careers in genetics illustrates the compound nature of the resistance.
Despite the absence of a developed tradition of Mendelian research, a French school of molecular genetics had developed by the 1950s. It flourished outside the university system at the Institut Pasteur, the Institut de Biologie physico-chimique, and the CNRS (though some of its leading figures had university connections), and it was only beginning to enter into university curricula. The most important indigenous research that informed the new tradition was that of Eugène Wollman on paraheredity of phage infection and lysogeny, of André Lwoff on the physiology and nutritional requirements of protozoa and bacteria, and the embryologically influenced genetic investigations of Boris Ephrussi. The conceptual and methodological resources of the French school were enriched by this background; a full understanding of the products of the fifties, we believe, requires a proper appreciation of these antecedents. Molecular genetics in France grew out of the Pasteurian tradition of microbiology and the highly developed tradition of causal embryology as modified by Ephrussi. Both of these traditions were extra-Mendelian and not anti-Mendelian, but they both shared a number of the problems and assumptions that were at the center of the extremist resistance to Mendelism. In many respects, then, it is more fruitful to see the entry of French biology into molecular genetics as a development of its microbial-physiological and causal-embryological traditions, coopting the tools and techniques of genetics, rather than the other way around.  相似文献   

17.
Chemical conjugation with poly(ethylene glycols) (PEGs) are established procedures to facilitate solubilisation of hydrophobic compounds. Such techniques for PEGylation have been applied to polyhydroxybutyrate. ‘BioPEGylation’ of such polyhydroxyalkanoates (PHAs) to form natural–synthetic hybrids has been demonstrated through the addition of PEGs to microbial cultivation systems. The strategic addition of certain PEGs not only supports hybrid synthesis but may also provide a technique for control of PHA composition and molecular mass, and by extension, their physico-mechanical properties. PHA composition and molecular mass control by PEGs is dependent upon the polyethers’ molecular mass, loading in the cultivation system, time of introduction and microbial species. Hybrid characterisation studies are in their infancy, but results to date suggest that PHA–PEG hybrids have subtle, but significant, differences in their physiochemical and material properties as a consequence of the PEGylation.  相似文献   

18.
Three trips were taken to central Mexico to search for natural enemies ofLeptinotarsa decemlineata (Say), in 1980, 1983, and 1985. 18 natural enemy species were found associated with 10 species ofLeptinotarsa. Asopine pentatomids dominate the collections, followed by tachnid parasites and hemipteran and coleopteran predators. Natural enemies may play a major role in regulating populations ofLeptinotarsa in Mexico. Their adaptability to northern climates is unclear.   相似文献   

19.
In Venezuela, mammals represent an important group of wildlife with high anthropogenic pressures that threaten their permanence. Focused on the need to generate baseline information that allows us to contribute to document and conserve the richness of local wildlife, we conducted a mammalogical inventory in Yurubí National Park, located in Yaracuy State in Venezuela. We carried out fieldworks in three selected vegetation types: an evergreen forest at 197m, a semi-deciduous forest ranging between 100-230m, and a cloud forest at 1 446m. We used Victor, Sherman, Havahart and pitfall traps for the capture of small non-volant mammals and mist nets for bats. In addition, we carried out interviews with local residents and direct-indirect observations for medium-large sized mammals. At least 79 species inhabit the area, representing 28% of the species recorded for the North side of the country. Chiroptera (39 spp.), Carnivora (13 spp.) and Rodentia (9 spp.) were the orders with the highest richness, as expected for the Neotropics. The evergreen forest had the greatest species richness (n=68), with a sampling effort of 128 net-hours, 32 bucket-days, 16 hours of observations, and three persons interviewed, followed by cloud forest (n=45) with 324 net-hours, 790 traps-night, 77 bucket-days, 10 hours of observations, and one person interviewed. The lowest richness value was in the semi-deciduous forest (n=41), with 591 traps-night, 15 net-hours, 10 hours of observations and three persons interviewed. Data and observations obtained in this inventory (e.g., endemism, species known as "surrogate species" threatened in Venezuela) give an important role at the Yurubí National Park in the maintenance and conservation of local ecosystems and wildlife, threatened by human pressures in the Cordillera de la Costa.  相似文献   

20.
Molecular Dynamics (MD) simulations were carried out for human acetylcholinesterase (hAChE) and its complex with Axillaridine–A, in order to dynamically explore the active site of the protein and the behaviour of the ligand at the peripheral binding site. Simulation of the enzyme alone showed that the active site of AChE is located at the bottom of a deep and narrow cavity whose surface is lined with rings of aromatic residues while Tyr72 is almost perpendicular to the Trp286, which is responsible for stable π -π interactions. The complexation of AChE with Axillaridine-A, results in the reduction of gorge size due to interaction between the ligand and the active site residues. The gorge size was determined by the distance between the center of mass of Glu81 and Trp286. As far as the geometry of the active site is concerned, the presence of ligand in the active site alters its specific conformation, as revealed by stable hydrogen bondings established between amino acids. With the increasing interaction between ligand and the active amino acids, size of the active site of the complex decreases with respect to time. Axillaridine-A, forms stable π -π interactions with the aromatic ring of Tyr124 that results in inhibition of catalytic activity of the enzyme. This π -π interaction keeps the substrate stable at the edge of the catalytic gorge by inhibiting its catalytic activity. The MD results clearly provide an explanation for the binding pattern of bulky steroidal alkaloids at the active site of AChE.  相似文献   

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