Associations between trilobite intraspecific moulting variability and body proportions: Estaingia bilobata from the Cambrian Emu Bay Shale,Australia

Trilobites were notably flexible in the moulting behaviours they employed, producing a variety of moult configurations preserved in the fossil record. Investigations seeking to explain this moulting variability and its potential impacts are few, despite abundant material being available for study. We present the first quantitative study on moulting in a single trilobite species using a dataset of almost 500 moult specimens of Estaingia bilobata from the Cambrian (Series 2, Stage 4) Emu Bay Shale, South Australia. Specimens were categorized by moulting mode (Salter's or Sutural Gape) and their associated configurations, and their body proportions measured from both a museum collection (including a bycatch sample) and a randomly-collected field sample. This enabled analysis of the proportion of E. bilobata specimens displaying the Sutural Gape and Salter's modes of moulting and their different configurations, and tests for association between moulting behaviour and body proportions. The results show a wide range of E. bilobata moulting configurations in all samples, suggesting that configurations represent definable instances in a largely continuous spectrum of variation. Analyses comparing body proportions of specimens showing the two modes of moulting were non-significant, suggesting there is no true association between moulting behaviour and body proportion, except for a single significant result for body length. All results were relatively consistent between the museum and field samples. However, removing accessioned specimens from the museum sample brought results even further in line with the field sample, supporting the need for consideration of museum collection bias in palaeontological analyses.     

A comparison of two methods to assess apparent total tract digestibility of nutrients in dogs

ABSTRACT

The apparent total tract digestibility (ATTD) of nutrients can be assessed by total collection of faeces (TC), which is the reference method, or by the indicator method (IM). Little information is available on proper faecal sampling methodologies for IM in canines to obtain results comparable to TC. The objective of this study was to determine the minimum number of sub-samples required for the IM to make it comparable with TC. A total of 11 adult male dogs were individually housed in metabolism cages. Dogs had access to a grass yard to facilitate defaecation. Faecal sub-samples (1/day) were taken from the daily faecal output to prepare the pooled samples for IM, obtaining cumulative sample combinations of 3 (IM3), 4 (IM4), 5 (IM5), 6 (IM6) and 7 d (IM7). Digestibility of dry matter, gross energy, crude protein and crude fibre was similar between TC and IM5, IM6 and IM7 (p > 0.05). The IM7 presented the greatest statistical similarity with TC. Nevertheless, IM was not a good predictor of crude fibre digestibility. In conclusion, IM can replace the TC method in dogs to evaluate ATTD of several nutritional fractions as long as the composite sample is collected during seven consecutive days. For estimation of fibre digestibility by IM, longer collection periods are probably required.     

A bar code scoring system for behavioral research

A data collection method using lap-top computers and bar codes was developed and used in behavioral research. The studies involved several common sampling methods and a variety of study subjects. Advantages and restrictions of the system are discussed. Overall, we found bar code technology to increase both efficiency and accuracy of behavioral data collection.     

Spat collection studies on pearl oysters Pinctada mazatlanica and Pteria sterna (Bivalvia,Pteriidae) in Bahia de La Paz,South Baja California,Mexico

The present work deals with the temporal and bathymetrical variations of the epifaunal community associated with two species of pearl oysters (Pinctada mazatlanica and Pteria sterna) during a seed collecting season from June to November 1989. A total of 63 items (species, genera and/or families) were recorded; their variations in presence and abundance were followed during three periods (June–July, August–September and October–November). The collectors were examined for different immersion times (2, 4, 6 and 8 weeks) for each period. Community structure was compared through the Brillouin Index, the Morisita Index and the Importance Value.We define the chronology of spatfall for both species of pearl oysters and their bathymetrical distribution. Relationships between these species and the epifaunal community present into the collectors were analysed, searching for possible noxious effects on the survival of juvenile pearl oysters, and identifying index species related with their spatfall. A strategy for starting massive seed collection of both species is established, particularly for P. mazatlanica.     

Variation in Betula pubescens Ehrh. (Betulaceae) in Scotland: its nature and association with environmental factors

A classification, based on climatological, topographical and geological attributes and developed by Bunce, Barr & Whittaker (1981: Annual Report of the Institute of Terrestrial Ecology, U.K. 1980) for stratifying the U.K. into 32 land classes, was used to ensure objectivity when sampling the range of variation within Betula spp. in northern Britain.
Seeds of Betula spp. were collected, wherever possible, from each of ten woodland trees in three geographically distinct locations of each of 12 land classes known to 'carry' Betula species. Trees in a thirteenth land class, restricted to the west of Scotland, were inaccessible.
Seedlings from 170 of 196 trees were attributed to B. pubescens which occurred in all 12 land classes: the remaining 26 trees were identified as B. pendula which is restricted to five land classes in southern and eastern Scotland.
Detailed analyses of plant morphological and phenological features using principal component analyses, cluster analyses and canonical variance analyses showed that leaf size, shape and hairiness were good discriminators of variation, as was the occurrence of fruitbodies of Laccaria proxima , a sheathing (ecto-)mycorrhizal fungus. These discriminators enabled the seedlings to be arranged in a nuniber of distinctive groups: sredlings with drooping branclirs and small laves, chararteristirs of B. pubescens subspecies tortuosa , originating from westerly and wet locations to seedlings with upright branches arid large leaves originating from easterly and dry locations.
Leaf lengths and the increasing frequency of petiolar hairs were related to maximum July trmperaturcs and mcasurrs of oceanicity (at the sites of origin).     

Introducing plants for bee-keeping at any cost? – Assessment of Phacelia tanacetifolia as nectar source plant under xeric Mediterranean conditions

 We assessed nectar and honey potential of Phacelia tanacetifolia, an American plant, under Mediterranean conditions. Its flowering occurred during the major flowering season unless intensely irrigated, whereas duration and flower life span were shorter compared to continental conditions. Mediterranean climate limitations to nectar secretion were assessed on plants grown under natural conditions (xeric) vs. regular irrigation. May flowering xeric plants produced less nectar per flower than the irrigated ones, but had the same nectar potential per surface area. On the contrary, at the cost of intense irrigation, July flowering plants produced much higher nectar per flower and per surface area compared to xeric ones. In all flowering periods and sections honeybees were the most constant and numerous visitors, visiting the flowers mainly for nectar, whereas solitary bees were scarce. Based on our results, we suggest that although the plant may be a good nectar source for honeybees in some cases, we have serious reservations for a generalised use in the Mediterranean. Received September 3, 2002; accepted November 18, 2002 Published online: June 2, 2003     

全球专利微生物菌种近20年的保藏与发放情况分析

本文基于世界知识产权组织（WIPO）公开的“国际保藏单位2001-2019年专利微生物保藏与发放”数据进行统计分析。结果表明：全球专利微生物保藏量呈现稳步增长态势，中国专利菌种保藏量位列全球第一，保藏全球近四成专利菌种（31386株，占比39.86%）；2018年后全球菌种发放量陡增，其中美国是专利菌种发放量最多的国家（24153株，占全球发放量的96.63%），中国专利菌种的发放率处于较低水平（1034株，发放率3.29%）。中国专利菌种“重保藏、轻发放”的现象严重，需要适当提升产业化开发利用水平。     

Collection,particle sizing and detection of airborne viruses

Viruses that affect humans, animals and plants are often dispersed and transmitted through airborne routes of infection. Due to current technological deficiencies, accurate determination of the presence of airborne viruses is challenging. This shortcoming limits our ability to evaluate the actual threat arising from inhalation or other relevant contact with aerosolized viruses. To improve our understanding of the mechanisms of airborne transmission of viruses, air sampling technologies that can detect the presence of aerosolized viruses, effectively collect them and maintain their viability, and determine their distribution in aerosol particles, are needed. The latest developments in sampling and detection methodologies for airborne viruses, their limitations, factors that can affect their performance and current research needs, are discussed in this review. Much more work is needed on the establishment of standard air sampling methods and their performance requirements. Sampling devices that can collect a wide size range of virus-containing aerosols and maintain the viability of the collected viruses are needed. Ideally, the devices would be portable and technology-enabled for on-the-spot detection and rapid identification of the viruses. Broad understanding of the airborne transmission of viruses is of seminal importance for the establishment of better infection control strategies.     

Annotated catalogue of the types of Indo-Burmese non-marine Gastropoda deposited in the Faculty of Tropical Medicine,Mahidol University,Thailand

ABSTRACT

Four decades after its publication, Rolf A.M. Brandt’s 1974 monograph on the non-marine molluscs of Thailand remains the main authority on freshwater and estuarine species for Southeast Asia and includes up to 165 new species of snails and bivalves described by Brandt and colleagues in the same book and preceding publications. All the holotypes are lodged at the Forschungsinstitut und Naturmuseum Senckenberg in Germany, and are largely inaccessible to Thai and other Southeast Asian researchers, who rely heavily on the Brandt collection as a key reference. Paratypes were, however, donated to various other collections, including some in Thailand. We present the first catalogue of 45 paratypes of gastropods of the Brandt collection, described from Thailand, Laos and Cambodia, which are lodged at the Faculty of Tropical Medicine, Mahidol University, Thailand.