1,292 research outputs found
Documentation for the spatial analysis system (SPAN) for resource use by animals
Nearest-neighbor analyses have been used with mapped data f or tests of spatial dispersion and association i n plant and animal ecology. This paper full describes a computer software package developed to use Monte
Carlo trials instead of chi-squared distributions for assigning probabilities to observed values of nearest neighbor statistics. The program can factor-out the unique geometry of resources in a sample plot,which can affect locations of animals, thus testing for direct patterns
among the animals independent of their resource patterns. The Kappa statistic for association is a1 o calculated a1though its application has met with limited success. A users manual and the Fortran program language
is included. (80pp.
Simultaneously recorded single-exhalation profiles of ethanol, water vapour and CO2 in humans: impact of pharmacokinetic phases on ethanol airway exchange
The breath alcohol concentration (BrAC) standardized to the alveolar water vapour concentration has been shown to closely predict the arterial blood alcohol (ethanol) concentration (ABAC). However, a transient increase in the ABAC/BrAC ratio has been noted, when alcohol is absorbed from the gastrointestinal tract (absorption phase) and the ABAC rapidly rises. We analysed the plot of simultaneously recorded alcohol, water vapour and CO2 against exhaled volume (volumetric expirogram) for respiratory dead space volume (VD), cumulative gas output and phase III slope within one breath to evaluate whether changes in the BrAC profile could explain this variability. Eight healthy subjects performed exhalations through pre-heated non-restrictive mouthpieces and the concentrations were measured by infrared absorption. In the absorption phase, the respiratory VD of alcohol was transiently increased and the exhaled alcohol was displaced to the latter part of the expirogram. In the post-absorption phase, the respiratory VD for alcohol and water vapour was stable and always less than the respiratory VD for CO2, indicating that the first part of the exhaled alcohol and water originated from the conducting airway. The position of the BrAC profile between water vapour and CO2 in the post-absorptive phase indicates an interaction within the conducting airway, probably including a deposition of alcohol onto the mucosa during exhalation. We conclude that the increase in the ABAC/BrAC ratio during the absorption phase of alcohol coincides with a transient increase in respiratory VD of alcohol and a delay in the appearance of alcohol in the exhaled air as the exhalation proceeds compared with the post-absorption phase
Terrestrial Mollusks of Attu, Aleutian Islands, Alaska
Seven species of land mollusk (2 slugs, 5 snails) were collected on Attu in July 1979. Three are circumboreal species, two are amphi-arctic (Palearctic and Nearctic but not circumboreal), and two are Nearctic. Barring chance survival of mollusks in local refugia, the fauna was assembled overwater since deglaciation, perhaps within the last 10 000 years. Mollusk faunas from Kamchatka to southeastern Alaska all have a Holarctic component. A Palearctic component present on Kamchatka and the Commander Islands is absent from the Aleutians, which have a Nearctic component that diminishes westward. This pattern is similar to that of other soil-dwelling invertebrate groups
Consensus and Confusion in Molluscan Trees: Evaluating Morphological and Molecular Phylogenies
Mollusks are the most morphologically disparate living animal phylum, they have diversified into all habitats, and have a deep fossil record. Monophyly and identity of their eight living classes is undisputed, but relationships between these groups and patterns of their early radiation have remained elusive. Arguments about traditional morphological phylogeny focus on a small number of topological concepts but often without regard to proximity of the individual classes. In contrast, molecular studies have proposed a number of radically different, inherently contradictory, and controversial sister relationships. Here, we assembled a data set of 42 unique published trees describing molluscan interrelationships. We used these data to ask several questions about the state of resolution of molluscan phylogeny compared with a null model of the variation possible in random trees constructed from a monophyletic assemblage of eight terminals. Although 27 different unique trees have been proposed from morphological inference, the majority of these are not statistically different from each other. Within the available molecular topologies, only four studies to date have included the deep sea class Monoplacophora; but 36.4% of all trees are not significantly different. We also present supertrees derived from two data partitions and three methods, including all available molecular molluscan phylogenies, which will form the basis for future hypothesis testing. The supertrees presented here were not constructed to provide yet another hypothesis of molluscan relationships, but rather to algorithmically evaluate the relationships present in the disparate published topologies. Based on the totality of available evidence, certain patterns of relatedness among constituent taxa become clear. The internodal distance is consistently short between a few taxon pairs, particularly supporting the relatedness of Monoplacophora and the chitons, Polyplacophora. Other taxon pairs are rarely or never found in close proximity, such as the vermiform Caudofoveata and Bivalvia. Our results have specific utility for guiding constructive research planning to better test relationships in Mollusca as well as other problematic groups. Taxa with consistently proximate relationships should be the focus of a combined approach in a concerted assessment of potential genetic and anatomical homology, whereas unequivocally distant taxa will make the most constructive choices for exemplar selection in higher level phylogenomic analyses
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Aqueduct Trail Network Development in Metro Boston
The Massachusetts Water Resources Authority (MWRA) and the Metropolitan Area Planning Council (MAPC) are collaborating with associated cities and towns to open up 40 + miles of existing and former aqueduct right-of-ways are available to be permitted for public access for the first time in the western suburbs of Boston. Four aqueducts are being considered for public access.
The first one-mile section along the Weston Aqueduct in Framingham opened to the public in October 2012. By eventually connecting these aqueducts with existing trail systems, we are ultimately creating a 50+ mile continuous greenway network, primarily using existing public land permitted at no cost to municipalities, requiring minimal investment, and creating a maintenance partnership between the MWRA and cities and towns.
The MWRA is working with each of the communities to issue public access permits. Each town will be able to conduct limited improvements to the right-of-way to allow for improved hiking, cycling, and dog-walking activities. A number of schools are adjacent or close to the aqueduct corridors and will provide car-free access for children to walk between school and home. Sections of these aqueduct corridors have been used as informal trails for a number of years. Under the new policy, public access activities will now be authorized and maintenance responsibilities will be split between the MWRA and municipalities.
MAPC is working with each of the communities to connect the disjointed aqueduct segments into a seamless, continuous, connected greenway network. Working through each townâs public process, MAPC is identifying the trail segments that will connect with existing regional rail trails, including the circumferential Bay Circuit Trail around Boston and numerous others. MAPC expects to complete an implementation plan in 2013 that identifies the proposed alignment of the completed aqueduct trail network system
The taxonomist - an endangered race : a practical proposal for its survival
Background: Taxonomy or biological systematics is the basic scientific discipline of biology, postulating hypotheses of identity and relationships, on which all other natural sciences dealing with organisms relies. However, the scientific contributions of taxonomists have been largely neglected when using species names in scientific publications by not citing the authority on which they are based.
Discussion: Consequences of this neglect is reduced recognition of the importance of taxonomy, which in turn results in diminished funding, lower interest from journals in publishing taxonomic research, and a reduced number of young scientists entering the field. This has lead to the so-called taxonomic impediment at a time when biodiversity studies are of critical importance.
Here we emphasize a practical and obvious solution to this dilemma. We propose that whenever a species name is used, the author(s) of the species hypothesis be included and the original literature source cited, including taxonomic revisions and identification literature - nothing more than what is done for every other hypothesis or assumption included in a scientific publication. In addition, we postulate that journals primarily publishing taxonomic studies should be indexed in ISISM.
Summary: The proposal outlined above would make visible the true contribution of taxonomists within the scientific community, and would provide a more accurate assessment for funding agencies impact and importance of taxonomy, and help in the recruitment of young scientists into the field, thus helping to alleviate the taxonomic impediment. In addition, it would also make much of the biological literature more robust by reducing or alleviating taxonomic uncertainty.
Keywords: Taxonomy crisis; taxonomic impediment; impact factor; original species description; citation index; systematic
Stubbtransporter och brÀnslekvalitet hos stubbved
Stump wood is a hot alternative when the heating plants demands more and more forest fuel. The aim with the study has bean to calculate the costs in four different systems for transportations of stump wood, examine if there are any differences in fuel quality for the stump wood in the different systems, analyse if the fuel quality in stump wood is affected with the time it lays by the road side and how much space the stump wood demands on the road side. To calculate the costs for the different systems a system analysis was carried out, where some of the costs were collected through field studies on Holmen Skog stump experiment and other costs were collected from literature and contacts. Data for the fuel quality study was collected from Eons heat plant in Norrköping. Data for the study of how much space stump wood takes along a roadside was collected from field studies.
A system, where stump sections are transported with a lorry from the roadside to the power plant, is the cheapest system if the transport distance is short. A system where the stump wood is crushed at the landing site is the cheapest if the transport distance is a bit longer. A system where the stump wood is taken to a terminal, crushed there and then transported with a chip lorry to the heat plant has a cost just above the system where the stumps is crushed at the landing site. A system with terminal and train is the cheapest system if the transport distance is 250 kilometres.
The study of the stump wood fuel quality revealed that stump wood becomes dryer the longer it is stored at the landing site. No conclusion could be made about how the time at the landing site affected the amount of ash content in stump wood. The study of how much space stump wood takes by the landing place revealed that stump wood needs about 20 meter along the roadside per hectare of harvested stump wood.Stubbved Ă€r ett âhettâ alternativ dĂ„ vĂ€rmeverken skriker efter mer skogsbrĂ€nsle. MĂ„let med
studien var att berÀkna kostnaden i fyra olika system för transport av stubbved och
undersöka om det blev skillnader pĂ„ brĂ€nslekvaliteten i de olika systemen. Ăvriga mĂ„l med
studien var att analysera om brÀnslekvaliteten hos stubbved pÄverkas av tiden vid avlÀgg
och uppskatta hur stor plats stubbved tar vid avlÀgg. För att berÀkna kostnaden pÄ de olika
systemen gjordes en systemanalys dÀr vissa kostnader samlades in med fÀltstudier frÄn
Holmen Skogs stubbförsök, andra frÄn kontakter och litteratur. Uppgifter som anvÀndes för
att utvÀrdera brÀnslekvaliteten samlades in frÄn inmÀtningen vid Eons vÀrmeverk i
Norrköping. Uppgifter till studien av avlÀggsstorlek samlades in genom fÀltstudier.
Ett system dÀr stubbved transporteras med en GROT-bil frÄn avlÀgg direkt till vÀrmeverk
Àr billigast pÄ korta avstÄnd. Ett system dÀr stubbarna krossas vid avlÀgg och dÀrefter körs
med flisbil till vÀrmeverket blir det billigaste alternativet vid lite lÀngre transportavstÄnd.
Ett system dÀr stubbdelarna körs med GROT-bil till en terminal dÀr de krossas för att
dÀrefter köras till vÀrmeverket med flisbil hade en kostnad strax över systemet med
krossning vid avlÀgg. Ett system med terminal och tÄg Àr det billigaste alternativet vid ett
totalt transportavstÄnd pÄ 25 mil.
Studien av brÀnslekvalitet pÄ stubbved visade att stubbveden blev torrare vid lÀngre
lagringstid vid avlÀgg. För askhalten kunde inga slutsatser dras beroende pÄ lagringstid.
FrÄn studien av avlÀggsstorlek framkom att stubbved behöver cirka 20 meter lÀngs en vÀg
frÄn varje stubblyft hektar
Comparisons of Three Different Investigative Interview Techniques With Young Children
After viewing a film of a mother hitting her son, a film not seen by the college student interviewers, children were misinformed about a detail (via exposure to a misleadingquestion) as well as explicitly coached to disclose 3 false details. The children were then interviewed by interviewers who had previously learned 1 of 3 different interviewing procedures: the Yuille Step-Wise Interview developed by J. C. Yuille, R. Hunter,R. Joffe, & J. Zaparniuk (1993); a doll play interview developed by Action for Child Protection Inc. (1994); or the Modified Structured Interview developed for this study. The Modified Structured Interview yielded more âwhereâ information and was better at detecting if coaching had occurred. However, the interviewers were not very good at discriminating suggested versus coached versus correct witnessed information. The authors found that the deeper one digs for memories, the more one uncovers incorrect versus correct items. They concluded that although the Modified Structured Interview was superior tothe techniques currently in use, cautions are necessary
On the proof of Taylor's conjecture in multiply connected domains
In this Letter we extend the proof, by Faraco and Lindberg (2020), of Taylor's conjecture in multiply connected domains to cover arbitrary vector potentials and remove the need to impose restrictions on the magnetic field to ensure gauge invariance of the helicity integral. This extension allows us to treat general magnetic fields in closed domains that are important in laboratory plasmas and brings closure to a conjecture whose resolution has been open for almost 50 years. (C) 2021 Elsevier Ltd. All rights reserved.Peer reviewe
Marine extinction risk shaped by trait-environment interactions over 500 million years
Perhaps the most pressing issue in predicting biotic responses to present and future global change is understanding how environmental factors shape the relationship between ecological traits and extinction risk. The fossil record provides millions of years of insight into how extinction selectivity (i.e., differential extinction risk) is shaped by interactions between ecological traits and environmental conditions. Numerous paleontological studies have examined trait-based extinction selectivity; however, the extent to which these patterns are shaped by environmental conditions is poorly understood due to a lack of quantitative synthesis across studies. We conducted a meta-analysis of published studies on fossil marine bivalves and gastropods that span 458 million years to uncover how global environmental and geochemical changes covary with trait-based extinction selectivity. We focused on geographic range size and life habit (i.e., infaunal vs. epifaunal), two of the most important and commonly examined predictors of extinction selectivity. We used geochemical proxies related to global climate, as well as indicators of ocean acidification, to infer average global environmental conditions. Life-habit selectivity is weakly dependent on environmental conditions, with infaunal species relatively buffered from extinction during warmer climate states. In contrast, the odds of taxa with broad geographic ranges surviving an extinction ( \u3e 2500km for genera, \u3e 500km for species) are on average three times greater than narrow-ranging taxa (estimate of odds ratio: 2.8, 95% confidence interval=2.3-3.5), regardless of the prevailing global environmental conditions. The environmental independence of geographic range size extinction selectivity emphasizes the critical role of geographic range size in setting conservation priorities
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