Two new species of Palaeoarthroteles Kovalev and Mostovski (Diptera, Rhagionidae) from the Callovian-Oxfordian (Jurassic) Daohugou biota of China

Two new species of fossil snipe flies (Rhagionidae) from the Daohugou Formation of Chifeng City in Inner Mongolia Autonomous Region (northeastern China) are described as Palaeoarthroteles jurassicus nov. sp. and P. pallidius nov. sp. They are the first record of the genus Palaeoarthroteles Kovalev and Mostovski beyond Siberia, which have implications for stratigraphic correlation of the formations in which they are found.     

Predicting cortisol stress responses in older individuals: influence of serotonin receptor 1A gene (HTR1A) and stressful life events

Considerable variability in the activity of the hypothalamus-pituitary-adrenal (HPA) axis in response to stress has been found in quantitative genetic studies investigating healthy individuals suggesting that at least part of this variance is due to genetic factors. Since the HPA axis is regulated by a neuronal network including amygdala, hippocampus, prefrontal cortex as well as brainstem circuits, the investigation of candidate genes that impact neurotransmitter systems related to these brain regions might further elucidate the genetic underpinnings of the stress response. However, aside from genetic risk factors, past stressful life events might also result in long-term adjustments of HPA axis reactivity. Here, we investigated the effects of the − 1019 G/C polymorphism in the HTR1A gene encoding the serotonin (5-HT) receptor 1A (5-HT_1A) and stressful life events experienced during childhood and adolescence on changes in cortisol levels in response to the Trier Social Stress Test (TSST) in a sample of healthy older adults (N = 97). Regression analyses revealed a significant effect of HTR1A genotype with the G allele being associated with a less pronounced stress response. In addition, an inverse relationship between past stressful life events and cortisol release but no gene × environment interaction was detected. The results further underscore the crucial role of functional serotonergic genetic variation as well as stressful events during critical stages of development on the acute stress response later in life.     

Bio-magnetostratigraphy and environment of the oldest Eurasian hominoid from the Early Miocene of Engelswies (Germany)

The paleobiogeography of hominoids exhibits a puzzling pattern of migrations between and within Africa and Eurasia. A precise dating of hominoid-bearing localities is therefore essential to reveal the timing, direction and possible causes of dispersals. Here, we present a bio-magnetostratigraphic analysis of the section of Engelswies (Southern Germany, Upper Freshwater Molasse, North Alpine Foreland Basin) where the oldest Eurasian hominoid was found. Our paleomagnetic results reveal a very short normal and a reverse magnetic polarity for the entire section. The polarity record is correlated to the Astronomical Tuned Neogene Time Scale using an integrated stratigraphic approach. This approach follows the chronostratigraphic framework for the Upper Freshwater Molasse, which combines magnetostratigraphy with biostratigraphic, lithostratigraphic and ⁴⁰Ar/³⁹Ar dating results. According to this outcome, the reverse polarity of the Engelswies section most likely correlates to magnetochron C5Cr. The origin of the short normal polarity remains enigmatic. The magnetostratigraphic calibration and the evolutionary level of the Engelswies small mammal fauna suggest an age of 17.1-17.0 Ma (Early Karpatian, Early Miocene) for the oldest Eurasian hominoid, and roughly confirm the estimates of Heizmann and Begun (2001). The estimated age suggests that the first hominoids in Eurasia are contemporaneous with Afro-Arabian afropithecins, and dispersal may have been facilitated by intra-Burdigalian (∼18-17 Ma) sea-level low stands and the beginning of the Miocene Climate Optimum. The paleoclimatic and environmental reconstruction of the Engelswies locality indicates a lakeshore environment near dense subtropical rain forest vegetation, where paratropical temperatures (mean annual temperature around 20 °C) and humid conditions (mean annual precipitation > 1.100 mm) prevailed.     

A semiparametric estimator of the bivariate distribution function for censored gap times

Let (T(1), T(2)) be gap times corresponding to two consecutive events, which are observed subject to random right-censoring. In this paper, a semiparametric estimator of the bivariate distribution function of (T(1), T(2)) and, more generally, of a functional E [φ(T(1),T(2))] is proposed. We assume that the probability of censoring for T(2) given the (possibly censored) gap times belongs to a parametric family of binary regression curves. We investigate the conditions under which the introduced estimator is consistent. We explore the finite sample behavior of the estimator and of its bootstrap standard error through simulations. The main conclusion of this paper is that the semiparametric estimator may be much more efficient than purely nonparametric methods. Real data illustration is included.     

广东省蛇类新纪录——越南烙铁头蛇

2009年6月,在广东省信宜市云开山自然保护区调查时采集到越南烙铁头蛇(Ovophis tonkinensis)标本2号,为广东省新纪录,为该种在中国分布的有效性提供了重要的依据.标本保存在华南濒危动物研究所.     

广东省爬行类新纪录——海南棱蜥

2010年6月2日,在广东省韶关市始兴县车八岭国家级自然保护区采集到蜥蜴幼体标本1号,经鉴定为海南棱蜥(Tropidophorus hainanus),为广东省爬行动物新纪录,标本保存在华南濒危动物研究所。     

Isolepis namaquana (Cypereae, Cyperaceae), a new endemic species from the winter rainfall area of South Africa

A new species, Isolepis namaquana Muasya & J.Viljoen, is described and illustrated. It is known from two localities in Namaqualand: near Kamieskroon and at the foot of the Matsikammaberge, where it grows in ephemeral wetlands. The tufted annual species is diagnosed by floral and fruit characters including glume size, bifid stigma and colliculate nutlet surface ornamentation.     

中国鸟类新纪录种——白颈鹳

2011年6月10日在云南省迪庆藏族自治州香格里拉县野外考察中,于纳帕海自然保护区发现一大型涉禽,经查阅文献,确认该物种为中国鸟类新纪录种——白颈鹳(Ciconia episcopus)。     

Disa albomagentea (Orchidaceae), a new species from the Hottentots Holland Mountains in the Cape Floristic Region, South Africa

A new orchid, Disa albomagentea, is described from the Hottentots Holland Mountains in the Western Cape Province of South Africa. It is an obligately fire-dependent species closely related to Disa obtusa (sect. Disella), from which it can be easily distinguished by the larger flowers, i.e. galea 7-9 mm long versus 4-7 mm long, which are patent and bicoloured, i.e. magenta, white and not spotted versus purple brown, white to cream to greenish, and variously purple spotted. It appears to be endemic to seeps and marshes on the high peaks.     

斜口涡虫(原卵黄目,斜口科)的生物学特性

摘要：本文报道了采自广东惠州市东江支流(23°09′00. 31"N,114°22′26.59″E)的中国涡虫一新纪录目原卵黄目(Prolecithophora)斜口涡虫(Plagiostomum sp.)。该虫体长4.51 ～6.00 mm,体被不规则的褐色细网纹,头钝圆,尾圆锥形,体中部圆柱状,眼点4只。该涡虫运动...