A new Centaurea L. (Asteraceae) species from Turkey

A new Centaurea L. (Asteraceae) species from Turkey is described and illustrated. Centaurea mersinensis Uysal and Hamzao?lu exists on calcareous slopes in Pinus brutia forests of Ayd?nc?k (Mersin) in southern Anatolia. It belongs to C. sect. Phalolepis (Cass.) DC., and taxonomically its closest relative is C. lycaonica. Diagnostic morphological characters from very similar taxa are provided, and a key is provided that includes related species of sect. Phalolepis from Turkey. The geographical distribution of the new species and relatives of the same section are mapped. The chromosome number of C. mersinensis, 2n = 18, counted in root tips, is also reported and illustrated.     

Vegetation mapping and nature conservation: a case study in Terceira Island (Azores)

In order to emphasize the importance of vegetation mapping for nature conservation purposes a case study in Terceira island (Azores) is presented, in which the importance of the natural vegetation of the eastern slope of Santa Bárbara volcano (which is part of the Site of Community Importance of Santa Bárbara–Pico Alto) is evaluated through the elaboration of its vegetation map. Fourteen (14) different natural vegetation types were identified: grasslands (1 type), peat bogs (2 types), scrubs (2), forests (5), successional vegetation (3) and vegetation of rocky slopes (1). All communities are protected under the Habitat and Species Directive (EC/92/43) and most of them are endemic to the Azores Islands. This fact, together with the significant number of Azorean endemic taxa (18), Macaronesian endemic taxa (5) and species protected under the Habitat and Species Directive (7), gives this area an important conservation value that justifies future protection actions. Vegetation mapping is an important tool for the characterization, evaluation and implementation of managing plans of natural areas of the Azores islands. The use of a floristic-based classification, supported by multivariate analysis and structural data, is an efficient methodology for the construction of these maps. The data collected comprise an important set of information about the distribution and abundance of natural vegetation types and endemic and rare species. This information was not available until now and is indispensable for the elaboration of management plans of Special Zones for Conservation that will be part of the NATURA 2000 network.     

Modeling the impact of immigration on the epidemiology of tuberculosis

This paper presents two new theoretical frameworks to investigate the impact of immigration on the transmission dynamics of tuberculosis. For the basic model, we present new analysis on the existence and stability of equilibria. Then, we use numerical simulations of the model to illustrate the behavior of the system. We apply the model to Canadian reported data on tuberculosis and observe a good agreement between the model prediction and the data. For the extended model, which incorporated the recruitment of the latent and infectious in immigrants to the basic model, we find that the usual threshold condition does not apply and a unique equilibrium exists for all parameter values. This indicates that the disease does not disappear and becomes endemic in host areas. This finding is also supported by numerical simulations with the extended model. Our study suggests that immigrants have a considerable influence on the overall transmission dynamics behavior of tuberculosis.     

Global Stability of Equilibria in a Two-Sex HPV Vaccination Model

Human papillomavirus (HPV) is the primary cause of cervical carcinoma and its precursor lesions, and is associated with a variety of other cancers and diseases. A prophylactic quadrivalent vaccine against oncogenic HPV 16/18 and warts-causing genital HPV 6/11 types is currently available in several countries. Licensure of a bivalent vaccine against oncogenic HPV 16/18 is expected in the near future. This paper presents a two-sex, deterministic model for assessing the potential impact of a prophylactic HPV vaccine with several properties. The model is based on the susceptible-infective-removed (SIR) compartmental structure. Important epidemiological thresholds such as the basic and effective reproduction numbers and a measure of vaccine impact are derived. We find that if the effective reproduction number is greater than unity, there is a locally unstable infection-free equilibrium and a unique, globally asymptotically stable endemic equilibrium. If the effective reproduction number is less than unity, the infection-free equilibrium is globally asymptotically stable, and HPV will be eliminated.     

青冈亚属植物的地理分布

对壳斗科青冈亚属（Quercus subg.Cyclobalanopsis)植物分布区内各地区的分布作了分析和统计。通过分析,认为中国南部、西南部和中南半岛北部,即印度支那植物地区,是青冈亚属植物地理分布的分布区中心。基于其形态、现代分布和地史资料,马来西亚地区分布有许多性状较原始的类群,是青冈亚属原始类的保存中心。青冈亚属植物中有许多地区 特有种,它们的分布区很狭窄,集中分布在加里曼丹、台湾、海南和云南东部部,其产生的原因主要是地理隔离,如海峡、高山等,以及气候和地史的复杂性。青冈亚属植物还存在许多替代现象,如青冈（Q.schottkyana）、赤皮青冈（Ｑ.gilva)和黄毛青冈（Ｑ.delavayi)`、云山青冈（Q.sessifolia)和窄叶青冈（Ｑ.augustinii)为中国－日本分布式和中国－喜马拉雅分布式之间替代。     

Gypsicolous flora, conservation and restoration of quarries in the southeast of the Iberian Peninsula

The southeast of the Iberian Peninsula, more precisely, the province of Almería, has the most important gypsum quarries in Spain. Despite the severe environmental impact of these quarries, so far little attention has been paid to either the effect on the flora, especially on the more restricted endemic taxa, or to the restoration of the habitats after the end of exploitation. It is our view that restoration of gypsum quarries should aim not only at correcting the visual impact of mining on the landscape, but should also attend to the biological impact of the quarrying. Although the cicatrising potential of gypsophytes is already well known, not all the species are able to recolonise worked-out quarries. Using species abundances, all analysis clearly show that artificial rehabilitation results in very altered communities. The preservation of the gypsum flora merits prioritary protective strategies which, at least to some extent, would make gypsum mining and nature conservation compatible.     

Global stability of an SEIS epidemic model with recruitment and a varying total population size

This paper considers an SEIS epidemic model that incorporates constant recruitment, disease-caused death and disease latency. The incidence term is of the bilinear mass-action form. It is shown that the global dynamics is completely determined by the basic reproduction number R(0). If R(0)1, a unique endemic equilibrium is globally stable in the interior of the feasible region and the disease persists at the endemic equilibrium.     

New conservation status for data-deficient endemic mammals of East Africa

Knowing the exact status of several species is unimaginable since the data available is not adequate to determine their category, they are classified as Data Deficient (DD) by the IUCN. Lack of sufficient information impedes the assessment of conservation status for DD species and could lead to missing conservation opportunities for rare mammals under multiple threats. It seems appropriate that available knowledge of each species should be recorded now because the next few decades will see even more human-induced changes. The main objective is to suggest a strategic framework and establishing categories to help overcome the uncertainty regarding the conservation status of endemic mammals of East Africa. Preliminary extinction risk categories were determined based on the IUCN Red List Criterion B particularly of criteria B1 which uses the extent of occurrence. We use quantile regression to model a relationship between the time since species discovery (50 years as a reference) and log-transformed range-size of mammal species (1–20,000 km² area for a threatened category). Mammals that were described more than 50 years ago and have an EOO of less than 20,000 km² are categorized under threatened status. We found a significant positive relationship between time since species discovery and geographic range size of the non-DD mammal species for all quantile levels (p < 0.05) allowed the use of time since species discovery and geographic range size to infer the proper red list category of species. Only 16 endemic mammals currently listed as Data Deficient, should continue to be listed as so (group A). The remaining species should be re-listed as threatened (17 species) and as non-threatened (25 species, groups C and D). Our finding reduced the number of DD species of mammals of East Africa from 32.04% to 8.83%. As of the investigation of the present study, 12 (70.6%) mammals suggested for threatened categories are small-sized shrews and bats. DD species introduce greater uncertainty in estimates of overall extinction risk to the endemics, and by no means are they such species that can be considered low priorities for research. DD mammals may still face high extinction risks and may be more frequently threatened than successfully evaluated mammals. These findings may hopefully contribute to a more efficient allocation of conservation funds and more efficient development of conservation plans using data available for almost all mammalian species.     

广西武鸣县种子植物区系研究

为了解广西武鸣县野生种子植物区系特征, 对其野生种子植物资源进行调查。结果表明,广西武鸣县有野生种子植物2 542种,隶属于184科898属,以被子植物占优势,裸子植物贫乏。从科属组成上看,以大科、单种属和寡种属为主体。科、属和种分布区类型丰富,含典型的热带亚热带成分,兼具温带成分,呈热带至亚热带过渡性质。与邻近地区比较,武鸣县植物多样性比较丰富,植物区系成分与广西横县最相近。因此,武鸣县种子植物多样性丰富、热带性质明显、地理成分多样、起源古老,同时聚集了一些特有植物和珍稀濒危植物,体现出北部湾植物区系的特征。     

东亚特有植物合被韭和长梗合被韭遗传多样性的ISSR分析

合被韭(Allium tubiflorum)和长梗合被韭(A.neriniflorum)是葱属(Allium L.)植物中花被片合生的类群,是东亚特有植物的典型代表,也是研究第四纪气候变化对东亚温带落叶林地变迁影响的理想模式植物。该研究对合被韭16个居群154个个体和长梗合被韭14个居群133个个体采用ISSR分子标记,分析不同居群合被韭和长梗合被韭DNA水平的差异和分化,揭示2个种的遗传多样性水平和遗传结构,探讨片段化生境对居群遗传多样性和遗传分化的影响。结果表明:(1)2个类群在种级水平的遗传变异丰富,合被韭的多态位点百分率(PPB)为98.00%,Nei’s基因多样度指数(H)为0.264 8,Shannon多样性信息指数(Ho)为0.415 3;长梗合被韭PPB为95.56%,H为0.253 9,Ho为0.399 8,但居群水平遗传多样性较低,遗传分化系数(Gst)分别为0.421 8和0.430 1,变异百分率分别为38.95%和39.17%,遗传变异主要存在于居群内部。(2)结合本研究结果和前人的细胞学研究资料,认为合被韭和长梗合被韭的进化驱动力是杂交和多倍化;合被韭和长梗合被韭均以鳞茎兼行无性繁殖,克服了杂交和多倍化带来的育性降低和居群个体数量下降,保存其变异;复杂的遗传背景和多样化的繁育方式极可能是导致居群内遗传分化显著的重要因素。(3)根据已有系统发育资料和本研究UPGMA聚类显示,合被韭和长梗合被韭在种级水平具紧密亲缘关系,互为姊妹类群。研究推测,这两种的分布重叠区域——燕山山脉、太行山脉及邻近地区可能是其祖先分布区,且该区域居群遗传变异最为丰富,因此,燕山山脉、太行山脉及邻近地区可能是合被韭和长梗合被韭的分化中心和遗传多样性中心。