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1.
A Pine-wood (Pinus sylvestris) fragment from Mannheim-Vogelstang (Germany) of early Magdalenian age shows traces of modification that could be related to a bow. Those are for example a smoothing of a face opposite to an unmodified face, the correction of a deviation on one of the lateral sides and a notch that could have served to fix a rope. Nevertheless, some characteristics make this interpretation uncertain. For example, the piece can only represent a fragment of a bow, but the lower end is too damaged to have conserved any traces of breaking or working. A reconstruction of the piece shows that the bow wouldn't have been longer than around 110 cm, which is quite small but documented for several ethnic groups as well as for children's bows. His power reaches 25-30 lbs (British pounds). As for the chronological position of the piece, the oldest direct traces of archery are the 12.680-11.590 calBP old arrows from Stellmoor and the 8000 calBP old bows of Holmegård. The invention of the bow as early as the Upper Palaeolithic has however been postulated for a long time.  相似文献   

2.
Huxtable R  Möller M 《Bioethics》2007,21(3):117-126
The Dutch case of Brongersma presents novel challenges to the definition and evaluation of voluntary euthanasia since it involved a doctor assisting the suicide of an individual who was (merely?) ‘tired of life’. Legal officials had called on the courts to ‘set a principled boundary’, excluding such cases from the scope of permissible voluntary euthanasia, but they arguably failed. This failure is explicable, however, since the case seems justifiable by reference to the two major principles in favour of that practice, respect for autonomy and beneficence. Ultimately, it will be argued that those proponents of voluntary euthanasia who are wary of its use in such circumstances may need to draw upon ‘practical’ objections, in order to erect an otherwise arbitrary perimeter. Furthermore, it will be suggested that the issues raised by the case are not peculiarly Dutch in nature and that, therefore, there are lessons here for other jurisdictions too.  相似文献   

3.
Although much research has been carried out on Australopithecus afarensis locomotion, no consensus has yet been reached. Our new critic study on femoral material brings to the fore a strictly bipedal behaviour within this taxon. Our results are based on the pertinence of human anatomical characteristics among A. afarensis and on the absence of characteristics revealing arboreal displacement. These results have emerged from our different observation and interpretation of some preceding authors concerning the anatomy of these fossil hominids. It is important to underline that apomorphic characteristics of this species are difficult to interpret. They must not however be used to support the idea of arboreal displacement simply based on the fact of a no totally human morphe. We believe that present day humans do not necessarily reflect the earliest strict bipedal anatomic model. An the other hand, it appears that the disagreement between the two locomotor hypothesis for A. afarensis that are bipedalism and arboreal displacement, facing the possibility of bipedalism associated with negligible arboreal displacement, results more from an evolutionary fact than from a real scientific conflict.  相似文献   

4.
During the last years, an international debate about the concept of “Palaeolithic art” has taken place. On one hand, several specialists have critiqued the use of the concept of “art” in naming the images created by Homo sapiens during the Palaeolithic era. They claim that the use of this term implies the projection of a modern category to a world - that of prehistoric humans - which is completely different from our own. On the other hand, some archaeologists consider that the term “Palaeolithic art” does not imply an anachronistic interpretation of prehistoric representations. In presenting the historical context, which has made such a discussion possible, we consider the causes and effects of this controversy. Firstly, we analyze the traditional interpretation, which considered Palaeolithic images as “works of art”. Secondly, we examine the connections, which can be found between the debate about “Palaeolithic art” and certain polemics, which have arisen from the history of art and anthropological frameworks. Thirdly, we consider the arguments utilized by those who are for and those who are against the term “Palaeolithic art”. Finally, we emphasize the importance of this debate to better understand the categories and the concepts, which determine the scientific practice.  相似文献   

5.
Gerald Mayr 《Geobios》2006,39(6):865
A postcranial skeleton of a small bird from the early Oligocene locality Pichovet in Southern France is described and identified as Eocuculus cf. cherpinae Chandler, 1999. It is the second fossil record of Eocuculus which was hitherto known from a postcranial skeleton from the late Eocene of North America only. Although Eocuculus shares some derived similarities with Cuculidae (cuckoos), it distinctly differs in a number of osteological features from crown group members of this taxon. If future, more complete skeletons prove its cuculiform affinities, Eocuculus is a stem lineage representative of this taxon and not within the crown group. Recognition of Eocuculus in the early Oligocene of France provides evidence for the presence of an extinct late Eocene/early Oligocene avian taxon with an intercontinental Northern Hemisphere distribution.  相似文献   

6.
In this article I argue for a kinship anthropology of politics, understood as a focus on the day‐to‐day imbrications of kinship and politics in a given political space, and the implications of that for the construction of political subjects. I describe kinship within shop‐floor‐level trade union delegations of state employees in Argentina in three different ways: first, languages of kinship mobilized to describe political allegiance and dispositions, especially inheritance; second, family connections in recruitment and activism; and, third, practices of kinning as relatedness. The combination of these three kinship modes creates the union as kin group, and enables it to act on the world politically in order to transform it.  相似文献   

7.

Aim

Retrospective study to assess the value of fluorine-18 dihydroxyphenylalanine (18F-Dopa) positron emission tomography (PET)/computed tomography (CT) in the post-surgical follow-up of patients with history of medullary thyroid carcinoma (MTC) and biological suspicion of disease relapse. A review of the literature was also performed.

Patients and methods

Ten patients (23-71 years) with MTC previously treated by surgery were examined by at least one 18F-Dopa PET/CT. All patients presented with elevated serum calcitonin (130-9076 ng/l) and/or CEA (1.2-518 ng/ml) levels. 3D whole body PET/CT was performed 45 and 120 minutes after intravenous injection of 4 MBq/kg of 18F-Dopa. Scintigraphic images were visually interpreted. For quantitative analysis, maximum standardized uptake value (SUVmax) per focus was employed. PET results were compared with histological findings and/or with the results of all other imaging procedures.

Results

Seven patients (70%) had a positive 18F-Dopa PET/CT. Twenty-five focal tracer accumulations were described. Histopathological confirmation of metastatic disease was obtained in four of the seven patients with pathologic 18F-Dopa PET/CT. No scintigraphic abnormalities were evidenced in the three other patients, whose conventional morphological imaging procedures were also negatives. Delayed PET/CT examinations didn’t increase sensitivity. No correlation between 18F-Dopa PET/CT results and both serum calcitonin and CEA levels was achieved.

Conclusion

Our results are in accordance with the existing literature, showing the potential role of 18F-Dopa PET/CT in the clinical management of patients with history of MTC and biological suspicion of relapse during post-surgical follow-up. Prospective studies including larger patient series are necessary to confirm the future place of 18F-Dopa PET/CT in follow-up of MTC.  相似文献   

8.
There are three species of Phoenix (Arecaceae) in the territory of the European Union, P. canariensis, P. dactylifera and P. theophrasti, found in wild-native populations, feral, planted and intermediate states, accounting each for thousands of individuals. The EU Habitats Directive has addressed the conservation of P. theophrasti and P. canariensis under the habitat type 9370, ‘Palm groves of Phoenix,’ but neglected to include the wild-growing populations of P. dactylifera palms in southern Spain. In this paper, we survey the habitats and status of both representative native and naturalized populations of Phoenix, in total 103, through fieldwork, image analysis and review of literature. We underline the significance of feral populations and palms originating from ancient abandoned plantations, existing in protected areas as a reservoir of genetic variation. We conclude that, in order to improve their conservation status by adequate protection and conservation management, the concept of Phoenix palm groves in the Habitats Directive should be redefined to include the western group of P. dactylifera and the various habitats of P. canariensis and P. theophrasti that do not appear in the current definition.  相似文献   

9.
Reactions in water between the di-sodium salt of amino terepthalic acid (C8H3NO4Na2) and a lanthanide chloride lead to a family of 3D-coordination polymers with general chemical formula [Ln(C8H3NO4)(C8H4NO4), O] where Ln = La-Eu (except Pm) and 8 ? n ? 11. All these compounds are isostructural. High quality single crystals of [Ln(C8H3NO4)(C8H4NO4), nH2O] with Ln = La-Sm (except Pm) and 8 ? n ? 11 have been obtained by slow diffusion in agar-agar gels. The crystal structure has been solved for the Nd-containing compound. This compound crystallizes in the cubic system, space group Ia-3 (no. 206) with a = 26.8056(5) Å. The crystal structure can be described as the juxtaposition of large channels with square cross-section.The channels are filled by highly disordered crystallization water molecules. The dehydration of the compounds by freeze-drying is possible and most of the crystallization water molecules can be removed without destruction of the molecular skeleton. The partially dehydrated compounds have general chemical formula [Ln(abdc)(Habdc), 2H2O] with Ln = La-Eu except Pm. The porosity of the Nd-containing compound has been estimated by computational methods to 2170 m2 g−1. This dehydrated compound reversibly binds water when exposed to wet atmosphere restoring the initial hydrated phase.  相似文献   

10.
Xiaofei Yu  Maofa Yang 《ZooKeys》2013,(260):77-83
Two new species of the empoascine leafhopper genus Membranacea Qin & Zhang are reported from China: Membranacea hubeiensis Yu & Yang, sp. n. and Membranacea stenoprocessa Yu & Yang, sp. n.. A key to distinguish all species of the genus is provided.  相似文献   

11.
Human–wildlife interactions are believed to be increasing in urban areas. In Britain, numerous media reports have stated that urban foxes (Vulpes vulpes) are becoming “bolder,” thereby posing a risk to public safety. However, such claims overlook how an individual''s personality might influence urban fox behavior. Personality determines multiple aspects of an animal''s interactions with both conspecifics and its environment, and can have a significant impact on how people perceive wildlife. Furthermore, describing urban foxes as “bold” confounds two different but inter‐related behaviors, both of which influence an animal''s propensity to take risks. Neophobia affects an animal''s reaction to novelty, wariness its reaction to potential threats. Since urban wildlife frequently encounters both novel and threatening stimuli, a highly adaptable species such as the red fox might be predicted to exhibit reduced neophobia and wariness. We investigated how social status influenced both behaviors in Bristol''s fox population. Dominant foxes were significantly more neophobic and warier than subordinates, which adopt a more exploratory and risk‐taking lifestyle to meet their energetic and other needs. We found no seasonal effect on neophobia and wariness, although this may be due to sample size. The presence of conspecifics decreased neophobia for dominants, and wariness for both dominants and subordinates. We highlight the importance of considering animal social status and personality when planning management protocols, since interventions that destabilize fox social groups are likely to increase the number of subordinate foxes in the population, thereby increasing rather than decreasing the number of interactions between humans and urban foxes.  相似文献   

12.

Objective

A meta-analysis was applied to evaluate the associations between tumor necrosis factor-α (TNF-α) −308G>A (rs1800629) polymorphism and type 2 diabetes mellitus (T2DM).

Methods

Hardy-Weinberg equilibrium (HWE) was employed to test genetic equilibrium among the genotypes of the selected literature. Power analysis was performed with the Power and Sample Size Calculation (PS) program. A fixed or random effect model was used on the basis of heterogeneity. Publication bias was quantified and examined with the Begg''s funnel plot test and Egger''s linear regression test. The meta-analysis was performed with Review Manager 5.1 and Stata 11.0.

Results

There were 10 studies including 1425 T2DM patients and 1116 healthy control subjects involved in this meta-analysis. No significant publication bias was found in the studies. The pooled ORs (95% CIs) for TNF-α −308G>A of A vs. G allele and GA+AA vs. GG genotype were 1.63 (1.17–2.25) and 1.47 (1.17–1.85), respectively.

Conclusion

This meta-analysis result suggested that TNF-α −308G>A polymorphism was strongly associated with T2DM risk, and A allele at this locus might be a susceptibility allele for the development of T2DM in Han Chinese population.  相似文献   

13.
Ioan I. Bucur 《Facies》2007,53(3):377-388
A new dasycladalean alga Salpingoporella? popgrigorei n. sp. was identified in P?durea Craiului Mountains (northern Apuseni, Romania) in the Lower Aptian limestone of the Valea Bobdei Member. The new alga was found within the external platform coarse bioclastic facies with fragments of corals, sclerosponges, bivalves (including rudists), gastropods, echinoderms, brachiopods, and bryozoans. The micropaleontological assemblage consists of foraminifera, calcareous algae, rare rivulariacean-type cyanobacteria, and some problematic microfossils. The deposits are Early Bedoulian in age, as clearly indicated by the orbitolinid foraminifera Orbitolinopsis pygmaea, Paracoskinolina sunnilandensis and Palorbitolina lenticularis. Salpingoporella? popgrigorei n. sp. is a medium-sized dasycladalean alga showing funnel-like laterals with an euspondyl arrangement. The laterals consist of two distinctive parts. The proximal part is narrow and flattened. The distal part widens relatively suddenly, and then narrows slightly before the final widening towards the exterior, in the place where the laterals most probably formed an assimilatory cortex. The distinctive features of the new species are represented by the shape of the laterals. The new Salpingoporella best resembles the Upper Hauterivian–Lower Barremian p.p. Salpingoporella genevensis (Conrad), especially due to the quadrangular aspect of the laterals in middle-deep tangential section. However, differences refer to the laterals’ general shape, and to the typical features of the laterals in deep tangential section of Salpingoporella? popgrigorei n. sp.  相似文献   

14.
The action of the environmental toxic Pb2+ on photosynthetic electron transport was studied in thylakoid membranes isolated from spinach leaves. Fluorescence and thermoluminescence techniques were performed in order to determine the mode of Pb2+ action in photosystem II (PSII). The invariance of fluorescence characteristics of chlorophyll a (Chl a) and magnesium tetraphenylporphyrin (MgTPP), a molecule structurally analogous to Chl a, in the presence of Pb2+ confirms that Pb cation does not interact directly with chlorophyll molecules in PSII. The results show that Pb interacts with the water oxidation complex thus perturbing charge recombination between the quinone acceptors of PSII and the S2 state of the Mn4Ca cluster. Electron transfer between the quinone acceptors QA and QB is also greatly retarded in the presence of Pb2+. This is proposed to be owing to a transmembrane modification of the acceptor side of the photosystem.  相似文献   

15.
Chronic back pain (CBP) is a common symptom throughout the world, and those undergoing it often experience a profound degradation of life. Despite extensive research, it remains an elusive symptom. In most cases, CBP is “non-specific,” since bio-mechanisms examined in the clinic do not account for it; another way of saying this is that it is “of obscure origins.” This paper re-directs attention towards origins that are distal and usually out of sight from the vantage point of the clinic. CBP as considered here is non-specific, persists ≥ 3 months, and, additionally, interferes with activities of daily life, such as family interaction or work. A theory proposed in the paper draws upon Durkheim’s Suicide to explain why exposures in the distal social contexts of family and workplace are fundamentally implicated in CBP. The theory is formed out of previously published studies on family and workplace social contexts of CBP and, in effect, provides a theoretical framework with which to review them. After treatment of CBP in the clinic, patients return to family and workplace contexts. Unless exposures in these contexts are addressed, they serve as continually renewing sources of CBP that remain unabated regardless of mechanism-based treatment in the clinic.  相似文献   

16.
The commentary by Schendler and Trexler (2015) strikes us as an intriguing paradox. Schendler and Trexler see responses to the threat of global climate change beginning to move forward in the corporate world, but they fear these corporate initiatives will be a distraction from what is ultimately required. They emphasize the need for “greater government intervention.” An earlier text by Schendler and Toffel (2013) notes, and we agree, that “we're failing to deal with the problem at anywhere near sufficient scale.” But we feel that the article by Schendler and Trexler does not adequately acknowledge the importance of these corporate efforts as elements of initiation and leadership. Schendler and Trexler express the impatience that many of us feel regarding the continued failure of political progress at the national and international levels. But they do not embrace the thoughts attributed to the sixth century B.C. Chinese philosopher Lao Tzu: “A journey of a thousand miles begins with a single step.” They fail to acknowledge that, in democratic governments, there is the need for grass‐roots support in order to develop and implement effective policy. Rather than distractions, individual and corporate efforts are generally necessary prerequisites for implementation of and receptiveness to government action. We agree that society is not dealing with climate change at anything approaching the needed scale and that, ultimately, a meaningful government and international response to climate change is required. The challenge is finding the way forward to achieve this outcome. In a first‐best scenario, the global community would simply negotiate an effective international climate agreement. For more than 35 years, individual countries have collaborated to pursue this first‐best scenario, starting with the first World Climate Conference in 1979 and continuing with the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. But this “top‐down” approach has yielded little success and even less hope, with global carbon dioxide (CO2) emissions increasing by more than 50% since adoption of the UNFCCC in 1992. While countries agree on the need for an international agreement, “there is disagreement on almost every aspect of the climate change problem. Countries approach the problem in different stages of development and from different development paths, and thus with different perspectives” (Cherry et al. 2014, 23).  相似文献   

17.
李巍  张喆 《遗传》2009,31(1)
1.多囊肾的遗传 问:我有家族多囊肾遗传史,自己双肾有囊肿,现在怀孕29周,胎儿彩超双肾大,有回声,医生判定为多囊肾,我如果不要这胎,再怀孕,有不遗传的可能吗?  相似文献   

18.
The preparation of a new tridentate N2O-donor ligand N-(2-pyridylmethyl)-3-methoxysalicylaldiminato (HL) is described, together with the corresponding copper(II) complexes [Cu(L)X] (X = Cl, Br). The compounds were characterized by elemental analysis, spectral, magnetic and crystallographic studies. In both compounds, the local molecular structure of the Cu(II) ion involves a square-planar CuN2OX chromophore, consisting of a deprotonated phenolate oxygen, an imine nitrogen, the pyridine nitrogen and X. In the solid state, π-π stacking interactions are dominantly present, involving the pyridine and phenolate rings of neighboring molecules, which lead to a one-dimensional arrangement with alternating short and long Cu ? Cu distances of [3.720, 4.599 Å] for the bromo complex and of [3.698, 4.696 Å] for the chloro complex. The temperature-dependent magnetic measurements and EPR data of polycrystalline samples, as well as of frozen solutions in CHCl3 show that there is no observable exchange interaction between the Cu ions. The EPR parameters (g, A) agree with a perfect planar geometry, just as found in the X-ray analysis.  相似文献   

19.
The ability of an ecosystem to retain anthropogenic nitrogen (N) deposition is dependent upon plant and soil sinks for N, the strengths of which may be altered by chronic atmospheric N deposition. Sugar maple (Acer saccharum Marsh.), the dominant overstory tree in northern hardwood forests of the Lake States region, has a limited capacity to take up and assimilate NO3. However, it is uncertain whether long-term exposure to NO3 deposition might induce NO3 uptake by this ecologically important overstory tree. Here, we investigate whether 10 years of experimental NO3deposition (30 kg N ha−1 y−1) could induce NO3 uptake and assimilation in overstory sugar maple (approximately 90 years old), which would enable this species to function as a direct sink for atmospheric NO3 deposition. Kinetic parameters for NH4+ and NO3 uptake in fine roots, as well as leaf and root NO3 reductase activity, were measured under conditions of ambient and experimental NO3 deposition in four sugar maple-dominated stands spanning the geographic distribution of northern hardwood forests in the Upper Lake States. Chronic NO3 deposition did not alter the V max or K m for NO3 and NH4+ uptake nor did it influence NO3 reductase activity in leaves and fine roots. Moreover, the mean V max for NH4+ uptake (5.15 μmol 15N g−1 h−1) was eight times greater than the V max for NO3 uptake (0.63 μmol 15N g−1 h−1), indicating a much greater physiological capacity for NH4+ uptake in this species. Additionally, NO3 reductase activity was lower than most values for woody plants previously reported in the literature, further indicating a low physiological potential for NO3 assimilation in sugar maple. Our results demonstrate that chronic NO3 deposition has not induced the physiological capacity for NO3 uptake and assimilation by sugar maple, making this dominant species an unlikely direct sink for anthropogenic NO3 deposition.  相似文献   

20.
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