Structural asymmetry and the stability of diverse food webs

Untangling the influence of human activities on food-web stability and persistence is complex given the large numbers of species and overwhelming number of interactions within ecosystems. Although biodiversity has been associated with stability, the actual structures and processes that confer stability to diverse food webs remain largely unknown. Here we show that real food webs are structured such that top predators act as couplers of distinct energy channels that differ in both productivity and turnover rate. Our theoretical analysis shows that coupled fast and slow channels convey both local and non-local stability to food webs. Alarmingly, the same human actions that have been implicated in the loss of biodiversity also directly erode the very structures and processes that we show to confer stability on food webs.     

Revision of the Traumatomutilla juvenilis species group (Hymenoptera,Mutillidae)

ABSTRACT

Traumatomutilla duplicata duplicata (Gerstaecker, 1874), T. duplicata feia Casal, 1969, T. bruchi André, 1908, T. cristata (Gerstaecker, 1874), T. aterrima (Gerstaecker, 1874) and T. lorena (Cresson, 1902) are proposed as junior synonyms of Traumatomutilla bivittata (Gerstaecker, 1874). Traumatomutilla immaculiceps André, 1901, T. bivittata rubroguttata André, 1901 and T. estrella (Cresson, 1902) are proposed as junior synonyms of T. juvenilis (Gerstaecker, 1874). Traumatomutilla bispiculata (André, 1907) is proposed as a junior synonym of T. miniata (Gerstaecker, 1874). The previously unknown males of T. guarata Casal, 1969 and T. juvenilis are described and illustrated. All species of the T. juvenilis species group are redescribed and illustrated. A new species, Traumatomutilla juvenindica Bartholomay & Williams sp. nov., is described based on males and females from northern South America. Additionally, identification keys to the species and known colour forms of the T. juvenilis species group are provided.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:3563B9EE-A45B-4939-8436-7A808D4F8996     

(In)consistency of airsea heat flux estimates; ocean heat uptake anomalies and top of atmosphere radiation budgets

This paper introduces the consistency between top of atmosphere （TOA） imbalances and ocean heat uptake, and the inconsistency between ocean heat uptake estimates and flux climatologies, and then gives some recommendations and outlook.     

An analysis of patient register data in the Longitudinal Study - what does it tell us about the quality of the data?

This article uses data for members of the ONS Longitudinal Study (LS) from both Census 2001 enumeration and patient registrations "frozen" on census day 2001 from the National Health Service Central Register (NHSCR) to examine potential sources of difference in area of usual residence.Overall 95.7 per cent of ONS LS members enumerated at census resided in the same area as recorded on the NHSCR data. Where areas differed, or the ONS LS member was not on the NHSCR on census day, subsequent NHSCR records were examined. Records flagged on the NHSCR as ONS LS members in England and Wales on census day but with no census record were also investigated.     

Riser VIV and its numerical simulation

This paper summarizes some of the typical riser vortex-induced vibration (VIV) problems in subsea oil and gas developments,and presents the corresponding computational fluid dynamics (CFD) time domain simulation results to address these problems. First,the CFD time domain simulation approach was applied to analyze the wake field behind a stationary cylinder and a vibrating cylinder. Then a vertical riser VIV response under uniform current was studied. The VIV response time histories revealed some valuable clues that could lead to explanation of the higher harmonics. After that,a vertical riser VIV response under shear current was investigated. A 3 000 ft (1 ft=0.304 8 m) water depth top tensioned riser was sized,and its VIV responses under uniform and shear current were studied. Then this paper continues to discuss one catenary flexible riser VIV response during normal lay. Last,the time domain simulation approach was applied to a partially submerged flexible jumper,to study the jumper VIV behavior,and dynamic motion envelopes. It was demonstrated that the time domain simulation approach is able to disclose details of the flow field,vortex shedding pattern,and riser dynamic behavior,and han-dle different types of risers under different type of currents.     

Accurate whole human genome sequencing using reversible terminator chemistry

DNA sequence information underpins genetic research, enabling discoveries of important biological or medical benefit. Sequencing projects have traditionally used long (400-800 base pair) reads, but the existence of reference sequences for the human and many other genomes makes it possible to develop new, fast approaches to re-sequencing, whereby shorter reads are compared to a reference to identify intraspecies genetic variation. Here we report an approach that generates several billion bases of accurate nucleotide sequence per experiment at low cost. Single molecules of DNA are attached to a flat surface, amplified in situ and used as templates for synthetic sequencing with fluorescent reversible terminator deoxyribonucleotides. Images of the surface are analysed to generate high-quality sequence. We demonstrate application of this approach to human genome sequencing on flow-sorted X chromosomes and then scale the approach to determine the genome sequence of a male Yoruba from Ibadan, Nigeria. We build an accurate consensus sequence from >30x average depth of paired 35-base reads. We characterize four million single-nucleotide polymorphisms and four hundred thousand structural variants, many of which were previously unknown. Our approach is effective for accurate, rapid and economical whole-genome re-sequencing and many other biomedical applications.     

Semi-annual oscillations in Saturn's low-latitude stratospheric temperatures

Observations of oscillations of temperature and wind in planetary atmospheres provide a means of generalizing models for atmospheric dynamics in a diverse set of planets in the Solar System and elsewhere. An equatorial oscillation similar to one in the Earth's atmosphere has been discovered in Jupiter. Here we report the existence of similar oscillations in Saturn's atmosphere, from an analysis of over two decades of spatially resolved observations of its 7.8-microm methane and 12.2-microm ethane stratospheric emissions, where we compare zonal-mean stratospheric brightness temperatures at planetographic latitudes of 3.6 degrees and 15.5 degrees in both the northern and the southern hemispheres. These results support the interpretation of vertical and meridional variability of temperatures in Saturn's stratosphere as a manifestation of a wave phenomenon similar to that on the Earth and in Jupiter. The period of this oscillation is 14.8 +/- 1.2 terrestrial years, roughly half of Saturn's year, suggesting the influence of seasonal forcing, as is the case with the Earth's semi-annual oscillation.     

A DEA-TOPSIS method for multiple criteria decision analysis in emergency management

A hybrid approach of DEA (data envelopment analysis) and TOPSIS (technique for order performance (preference) by similarity to ideal solution) is proposed for multiple criteria decision analysis in emergency management. Two DEA-based optimization models are constructed to facilitate identifying parameter information regarding criterion weights and quantifying qualitative criteria in TOPSIS. An emergency management case study utilizing data from the Emergency Management Australia (EMA) Disasters Database is provided to demonstrate the feasibility of the proposed analysis procedure.     

中国竹类真菌资源和多样性(英文)

本文作者对中国竹类真菌的研究历史、多样性、生活史、地理分布、寄主选择性、组织选择性和竹类真菌的演替作了文献综述。至今中国大陆已经报道了 189种包括 75属竹类真菌 ;此外在香港还报道了 79种包括 58属的竹类真菌。这些竹类真菌大多数是子囊菌 ,其次为担子菌和半知菌。柄锈科 (Pucciniaceae)种类多样性最丰富 ,有 2 0种 ;次之为黑痣菌科 (Phyllachoraceae)有 15种 ,炭角菌科 (Xylariaceae)有 9种 ,煤炱科 (Capnodiaceae)有 8种。