bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel method for imaging internal growth patterns in marine mollusks: A fluorescence case study on the aragonitic shell of the marine bivalve Arctica islandica (Linnaeus)
Authors: Wanamaker Alan D. , Baker Andy , Butler Paul G. , Richardson Christopher A. , Scourse James D. , Ridgway Iain , Reynolds David J.
Published: April 2011

In this article, we explore the use of fluorescence spectroscopy to image growth patterns in the marine bivalve Arctica islandica (L.). The method presented here does not require any chemical treatment of the polished shell section and yields results comparable to acetate peels of acid‐etched shell sections and Mutveitreated shell sections. Further, our results indicate that the annual growth lines in A. islandica fluoresce in the blue light spectrum (450–490 nm), thus an ultraviolet source (mercury lamp) is not required. The reflected light entering the digital camera was filtered (510–540 nm) and later enhanced to emphasize the annual growth patterns. The fluorescence of annual growth lines was consistent among the four animals used in this study. Additionally, we measured growth increments in the umbo section of one A. islandica shell using both the traditional acetate method and fluorescence imaging. The two sets of measurements were highly correlated (r = 0.97; P < 0.0001). We suggest that the fluorescence imaging method presented here is a viable option for increment identification and measurement in this key marine archive. It is likely that the methods demonstrated here for A. islandica can easily be used/modified for other bivalve (mollusk) taxa. Fluorescence microscopy permits rapid analysis of shell growth patterns with minimal pretreatment and offers an objective method of determination of annual growth increments and lines.
Detection and characterization of benthic filamentous algal stands (Cladophora sp.) on rocky substrata using a high‐frequency echosounder
Authors: Depew David C. , Stevens Andrew W. , Smith Ralph E.H. , Hecky Robert E.
Published: April 2011

A high‐frequency echosounder was used to detect and characterize percent cover and stand height of the benthic filamentous green alga Cladophora sp. on rocky substratum of the Laurentian Great Lakes. Comparisons between in situ observations and estimates of the algal stand characteristics (percent cover, stand height) derived from the acoustic data show good agreement for algal stands that exceeded the height threshold for detection by acoustics (~7.5 cm). Backscatter intensity and volume scattering strength were unable to provide any predictive power for estimating algal biomass. A comparative analysis between the only current commercial software (EcoSAV™) and an alternate method using a graphical user interface (GUI) written in MATLAB® confirmed previous findings that EcoSAV functions poorly in conditions where the substrate is uneven and bottom depth changes rapidly. The GUI method uses a signal processing algorithm similar to that of EcoSAV but bases bottom depth classification and algal stand height classification on adjustable thresholds that can be visualized by a trained analyst. This study documents the successful characterization of nuisance quantities of filamentous algae on hard substrate using an acoustic system and demonstrates the potential to significantly increase the efficiency of collecting information on the distribution of nuisance macroalgae. This study also highlights the need for further development of more flexible classification algorithms that can be used in a variety of aquatic ecosystems.
Rapid and precise δ13C measurement of dissolved inorganic carbon in natural waters using liquid chromatography coupled to an isotope‐ratio mass spectrometer
Authors: Brandes Jay A.
Published: April 2011

The measurement of the carbon isotopic composition (δ13C) of dissolved inorganic carbon (DIC) in natural systems has provided a tool for examining a variety of processes, from net primary production to anthropogenic signatures of CO2 uptake in the oceans. Over the past decade, new δ13C‐DIC methods have steadily decreased the sample analysis time and volumes for this measurement. The development of a new interface capable of inline acidification and extraction of CO2 from a liquid stream (LC‐Isolink™; Thermo Electron) provides break‐throughs in sample size, ease of sample handling, and speed of analyses. Typical sample size injections of 25 µL provide precision and accuracy of 0.04‰, comparable to that obtained by off‐line extractions/dual inlet analyses on much larger samples. Single‐sample injection runs can be accomplished within 4 min, whereas sample preparation is limited to filtration to remove particulates. Thus combined runs of 200 samples over a 20‐h period are possible. Highest‐precision triplicate injection analyses of single samples require 11 min. Manually injected marine sample sizes of 2.5 µL provide nearly the same precision and accuracy as the larger loop sizes. For maximum precision, care must be taken to match sample and standard sizes to correct for linearity effects. Over wider concentration ranges typically found within estuarine systems, the overall precision of the method decreases to 0.06‰ with such correction.
Novel method to concurrently sample the planktobenthos and benthos
Authors: Przeslawski R. , McArthur M. A.
Published: April 2011

The planktobenthos is an important area with unique environmental conditions that represents the immediate link between the benthos and the water column, yet it has never been deliberately sampled concurrently with the benthos. We have developed a new sampling method to allow concurrent collection of benthic and planktobenthic specimens. The Mounted Assembly for Planktobenthic Sampling (MAPS) uses a novel trilayered net with a seafloor‐triggered opening and closing mechanism attached to an epibenthic sled. The MAPS was deployed on the Carnarvon Shelf off Western Australia and was successful at separately sampling both benthic and planktobenthic fauna. A wide variety of epibenthic and infaunal animals were collected from the sled, and planktobenthic animals such as mysids were identified from all three nets. The trilayered net was particularly effective at collecting a broad range of planktobenthic organisms, including smaller fragile larvae and adults that may have otherwise been destroyed during collection in a single net or grab. The number of species in planktobenthic and benthic samples was correlated, although the strength and significance of this relationship varied among taxonomic groups, suggesting that rich benthic assemblages are linked to rich planktobenthic assemblages. Importantly, the MAPS is a value‐adding method, collecting two sample sets for the cost of one, and can be modified for use on a wide variety of benthic sleds to target a range of organisms. The concurrent collection of planktobenthic and benthic biota will contribute to a range of research areas, including larval ecology, nutrient cycling, and surrogacy research for habitat mapping.
The information needs of music therapists: challenges of assessment in the clinical setting
Authors: Richardson Allison , Giustini Dean
Published: April 2011

Objective  This paper explores various methods that librarians can use to evaluate and meet the information needs of clinical music therapists (MTs). Methods  A survey of the literature of music therapy (MT) found many empirical studies of MT but none describing how MTs commonly express and satisfy their information needs. As a means of assessing their information needs, we first examine the basic features of MT practice and then compare MTs' information needs with the well-documented needs of nurses. Results  We believe that MTs and nurses exhibit similar basic information needs, such as access to (i) colleagues and experts; (ii) current information in print, electronic, and alternate formats; (iii) reference and ILL assistance from librarians; and (iv) library training to search databases and catalogues. Conclusions  Librarians should collaborate with MTs to identify their specific information needs. To begin, library services can be built by allocating relatively few resources. To evaluate what is required in evidence-based MT, librarians and MT associations should administer a national needs-assessment survey or questionnaire.
Preparing entry-level practitioners for evidence-based practice
Authors: Villeneuve Michelle , Maranda Suzanne
Published: April 2011

The authors report on a collaborative instructional method used to prepare entry-level practitioners with strategies for systematically employing an evidence-based practice process as an approach to clinical inquiry, while acknowledging the students' shortage of clinical experience and knowledge of critical appraisal. Challenges to evidence-based practice can be categorized as difficulties in obtaining evidence, analyzing evidence, and transferring evidence into practice decisions. For student occupational therapists, additional challenges are encountered as they seek to fill gaps in their knowledge about client-centred occupational therapy (OT) practice, acquire necessary background information regarding clinical conditions, and formulate a clinical question. Students need to develop literature search skills and learn effective strategies to locate appropriate information to answer the clinical question. This paper will encourage OT faculty to begin a dialogue with librarian colleagues at their institution to develop an evidence-based approach to the teaching of both the clinical inquiry and the literature search process.
Consumer health information on the Internet: an evaluation report on the Nova Scotia Health Network
Authors: Amirault Mardi , Cobbett Shelley , Doherty Andrea , Hartigan-Rogers Jackie , LeBlanc Adele , Muise-Davis Martha , Newell Joanne
Published: April 2011

The Nova Scotia Health Network (NSHN) is a province-wide, Web-based consumer health information service provided through the cooperative efforts of various organizations, including public libraries, health sciences libraries, the Nova Scotia Provincial Library, and Dalhousie University. The primary intent of the NSHN was to build on existing community resources to provide a quality source of local and general health information. Objective – The purpose was to evaluate the NSHN from the perspective of its users in relation to the ease of use of the site and the usability of the information and content. Methods – A descriptive design was chosen to address the study objectives. Results – Study participants were those users of the NSHN site who agreed to complete and submit an online survey between June 2002 and June 2003. The majority of study respondents were white, middle-aged, English-speaking females, who resided in rural Nova Scotia. They were mostly able to find the information they wanted with little effort and in a reasonable time frame. One in four participants indicated that the information had been used to help them change their lifestyle, whereas one in three reported that they had shared the information with their health care provider. The content found on the site was very highly rated, with more than 90% reporting that the information was easy to understand, useful, and of high quality. Conclusion – The data obtained in this study was positive and encouraging. Sixty-six percent rated the site as a 4 or 5 (with 5 being the best rating) when compared with other health information sites they had visited. Individuals who visited the NSHN site in the past used the acquired information to change health care practices and (or) seek further treatment.
Ensuring access to consumer health information pamphlets at Capital Health
Authors: Logan Penny , King Eleanor
Published: April 2011

Program objective – The objective of the program was to create a catalogue of patient education pamphlets and provide a stable in-house platform for the database that is sustainable with current staff resources. Rationale – Capital Health has an excellent selection of more than 1000 pamphlets specifically for patients. These pamphlets need to be accessible from the Internet, and they need to be housed on a Capital Health Web page. Main components – The main components were cataloguing the content, designing a user-friendly Web page, ensuring ongoing cataloguing is sustainable, and educating users. Setting – Capital Health, Halifax, Nova Scotia. Participants – Eleanor King, Patient Education Coordinator, Capital Health; Myrna Lawson, Library Technician; Penny Logan, Manager Library Services; Pearl Murphy, Web Coordinator; Boyd Sharpe, Systems Analyst; Deb Cameron, Graphic Designer. Program – The program was to ensure Web access to patient pamphlets. Results – 679 patient pamphlets were catalogued and presented on a user-friendly Web page in a searchable database that is controlled in-house and that can easily be kept up-to-date with current staff and systems. Conclusion – Library software and expertise can be used for more than just a catalogue of books and journals. By using already-available software and expertise, maintaining the pamphlets database can be accommodated without additional expense.
The Ontario Medical Library Association 1887–1907
Authors: Crawford David S
Published: April 2011

In the 19th century it was difficult for the growing number of medical practitioners in North America to access current medical literature. Various ways were suggested to solve this problem; one of them was the creation of physician-run medical library associations. After other failed attempts, Ontario physicians formed the Ontario Medical Library Association (OMLA) in 1887. In 1907 the OMLA became the nucleus of the Academy of Medicine, Toronto.
The value of membership: The CHLA / ABSC 2008 membership survey
Authors: Kharouba Dianne , Powelson Susan , Slater Linda
Published: April 2011

In January 2008, the Canadian Health Libraries Association / Association des bibliothèques de la santé du Canada (CHLA / ABSC) Board of Directors sent a survey to its membership seeking answers to these key questions: What do members value? Why do members join CHLA? The response rate was 42% or 124 of the Association’s personal members. Key results are reported here. The full results, including the comments, are on the Association’s Web site at http://www.chla-absc.ca/.
Examination of the Clinical Queries and Systematic Review “hedges” in EMBASE and MEDLINE
Authors: Bradley Susan M.
Published: April 2011

Introduction – This investigation sought to determine whether the methodological search filters in place as Clinical Queries limits in OvidSP EMBASE and OvidSP MEDLINE had been modified from those written by Haynes et al. and whether the translations of these in PubMed and EBSCO MEDLINE were reliable. The translated National Library of Medicine (NLM) Systematic Reviews hedges in place in OvidSP MEDLINE and EBSCO MEDLINE were also examined. Methods – Search queries were run using the Clinical Queries and Systematic Reviews hedges incorporated into OvidSP EMBASE, OvidSP MEDLINE, PubMed, and EBSCO MEDLINE to determine the reliability of these limits in comparison with the published hedge search strings. Results – Five of the OvidSP EMBASE Clinical Queries hedges produced results that were different from the published search strings. Three of the EBSCO MEDLINE and five of the PubMed translated Clinical Queries hedges yielded markedly different results (>10% difference) than those obtained using the OvidSP MEDLINE hedge counterparts. The OvidSP MEDLINE Systematic Reviews subject subset hedge was found to have a major error, which has been corrected. Discussion – Translations of hedges to appropriate syntax for other database platforms may result in significantly different search results. The platform searched should ideally be the one for which the hedges were written and tested. Regardless, the hedges in place may not be the same as the published hedge search strings. Quality control testing is needed to ensure that the hedges in place as limits are the same as those that have been published.
Declining populations of coastal birds in Great Britain: victims of sea-level rise and climate change?
Authors: Norris K , Atkinson P W
Published: April 2011

Is sea-level rise and (or) climate change responsible for current declines in important coastal bird populations in Great Britain, and how might these processes affect bird populations in future? We review the current status of coastal bird populations in Britain and identify two important species, Common Redshank (Tringa totanus) and Twite (Carduelis flavirostris), whose populations are currently declining. We then review the evidence relating to the causes of these declines. There is evidence that habitat loss, driven by sea-level rise and climate change (e.g., an increase in wind and wave energy reaching the coast due to an increase in the frequency of storms), could have contributed to the decline in Twite. Common Redshank numbers are declining because of changes in grazing management, not sea-level rise. Populations that are currently stable or increasing, such as wintering waders and wildfowl, might in future experience declines in abundance because there is a link between climate, food supply, and bird abundance. There are insufficient reliable data at present to allow us to predict future changes with any confidence. Sea-level rise and climate change are currently important issues facing coastal zone management in Great Britain, and these issues may become even more pressing in future. But, in addition to these environmental processes, coastal bird populations are affected by a range of other anthropogenic factors. Conservationists, therefore, need to identify important bird populations that are (or could be in future) detrimentally affected by any of these activities rather than focusing exclusively on single issues such as sea-level rise. Allowing the sea to breach existing sea defences, thereby creating new saltmarsh, provides a way forward but is not without its practical and political difficulties.Key words: coastal birds, sea-level rise, climate change, population decline, habitat loss, saltmarsh.
Gap dynamics of forest trees: A review with particular attention to boreal forests
Authors: McCarthy J
Published: April 2011

Small-scale gap disturbance in forests is reviewed. Caused by the death of individual or multiple trees with subsequent fall from the canopy, gaps have been extensively studied in temperate deciduous and tropical forests for the past 20 years. This review considers much of this research with a view to assessing the importance of gap disturbance in boreal forests. Because of the ubiquity of large-scale, stand-initiating disturbances such as landscape-level fires, epidemic insect outbreaks, and periodic extensive windthrow events, gap processes in boreal forests have received little attention. Research in the Scandinavian and Russian boreal forest, as well as in high-altitude boreal "outliers" found in Japan and the United States, is showing that gap disturbance determines forest structure and processes to a greater extent than previously assumed. Boreal forests dominated by the shade-tolerant fir (Abies)  spruce (Picea) complex are particularly well-adapted to the development of long-term, old-growth continuity in the absence of large-scale disturbance. Key words: gap dynamics, disturbance, boreal forests, temperate forests, tropical forests, silviculture.
The effects of UV-B radiation and endocrine-disrupting chemicals (EDCs) on the biology of amphibians
Authors: Crump D
Published: April 2011

Statistical meta-analysis of large and diverse data sets has indicated that amphibians have been declining worldwide since the 1960s. Exposure to UV-B radiation (280320 nm) and endocrine-disrupting chemicals (EDCs) have been considered as possible hypotheses to explain the observed declines. Equivocal conclusions have been reached with respect to the effects of UV-B on amphibian populations. Field and laboratory studies employing both ecologically relevant and enhanced UV-B levels have been conducted using a variety of amphibian species and reports differ with respect to the most sensitive developmental stage and the ultimate implications. UV-B radiation has also been shown to interact with other stressors (e.g., pesticides, polycyclic aromatic hydrocarbons, low pH) resulting in decreased survivorship for several amphibian species. Limited evidence of reproductive toxicity of xenobiotics in amphibians exist; however, early exposure to EDCs could cause abnormal development of the amphibian reproductive system, inhibit vital hormone messages that drive metamorphosis, and ultimately contribute to the decline of some amphibian populations. The available evidence suggests that more than one agent is contributing to amphibian population declines and the following review narrows the focus to address the existing data on the effects of UV-B, alone and in combination with other stressors, and EDCs on amphibian survivorship and development. Key words: amphibians, UV-B radiation, endocrine-disrupting chemicals, declines, review.
In situ immobilization of metals in contaminated or naturally metal-rich soils
Authors: Singh B R , Oste L
Published: April 2011

The chemical behaviour of metals is primarily governed by their retention and release reactions of solute with the soil matrix. Liming increased the soil pH, resulting in increased adsorption of Zn, Cu, and Cd in soils, which in consequence decreased the concentration of easily soluble Cd fraction in the soils and the uptake of this metal by wheat (Triticum aestivum) and carrots (Daucus carota). Metal adsorption also depended on the presence of clay and organic matter, and thus the soils having highest amounts of clay (e.g., alum shale) and (or) organic matter (e.g., peat soil) showed the highest adsorption for these metals. Among the materials (Fe and Mn oxides and aluminosilicates) having high binding capacity for metals, the immobilizing capacity of birnessite (MnO2) was higher than that of other materials. Addition of synthetic zeolites significantly reduced the metal uptake by plants. Application of zeolite to a soil resulted in increased dissolved organic carbon (DOC) concentration in the leachate, which in consequence increased the leaching of Cd and Zn. Addition of beringite (an aluminosilicate) to a Zn-contaminated soil resulted in increased shoot length and leaf area of bean (Phaseolus vulgaris) and a significant reduction in Zn concentration in leaves (from 350 to 146 mg kg-1). Cadmium concentration in ryegrass and the concentrations of diethylenetriaminepentaacetic acid (DTPA)- extractable Cd, Cu, Ni, and Zn in the soil decreased significantly (P < 0.05) with increasing amounts of organic matter (peat soil and cow manure) added to soils. These effects were assumed to be related to immobilization of metals due to formation of insoluble metal--organic complexes and increased cation exchange capacity (CEC). An overview of the results showed that the products tested (lime, Fe/Mn-containing compounds, aluminosilicates, and organic matter products) can reduce the solubility and the plant uptake of metals but their immobilizing capacity is limited (sometimes through their side effects). Key words: aluminosilicates, contaminated soils, in situ immobilization, leaching, metal oxides, organic matter, plant uptake.
Global budget of trace metal sources
Authors: Pacyna Jozef M. , Scholtz M. Trevor , (Arthur) Li Y.-F.
Published: April 2011

Global emission inventories, being the key information for the global budgets of trace metals, have become available only recently. The latest information on emissions and sources of trace metals on a global scale is presented in this paper. As the global assessments are prepared on the basis of estimates of regional emissions, these latter data are also reviewed here. A comparison of the worldwide atmospheric emissions from natural and anthropogenic sources suggests that various human activities are the dominant source of many trace metals, including As, Cd, Pb, and Zn. A comparison of the atmospheric and aquatic emissions indicates that, for most of the trace metals, the annual anthropogenic inputs into water exceed the quantities emitted to the atmosphere. However, the largest quantities of trace metals are discharged to the terrestrial environment. So far, the Pb budget seems to be the most accurate owing to a large body of information available on this element. The largest emissions of Pb were estimated for gasoline combustion, contributing about two thirds of the total emissions to the atmosphere. Emissions from nonferrous metal production contributed about one quarter. Emissions from the European and Asian sources contributed each about one third of the global emissions, followed by emissions from sources in North America. A spatial distribution of the global Pb emissions is presented within a 1 × 1° grid system.Key words: trace metals, lead, global emission, emission map.
Effects of forest fragmentation on neotropical fauna: current research and data availability
Authors: Offerman Holly L. , Dale Virginia H. , Pearson Scott M. , O'Neill Robert V. , Bierregaard Jr. Richard O.
Published: April 2011

Tropical deforestation often produces landscapes characterized by isolated patches of forest habitat surrounded by pasture, agriculture, or regrowth vegetation. Both the size and the distribution of these forest patches may influence the long-term persistence of faunal species. There is, therefore, a pressing need to understand faunal responses to patterns of forest fragmentation in tropical systems. The Biological Dynamics of Forest Fragments Project (BDFFP) provides a wealth of autecological information and spatially explicit data describing habitat use and movement of fauna between Amazonian forest fragments. Using data from the BDFFP and other studies in the Amazon Basin, this paper reviews the information available on tropical insects, frogs, birds, primates, and other mammals that can be used to identify and classify species most at risk for extirpation in fragmented forests.Key words: Amazonia, habitat fragmentation, rainforest, fauna, Biological Dynamics of Forest Fragmentation Project.
Environmental significance of elevated natural levels of arsenic
Authors: Azcue José M.
Published: April 2011

Globally, arsenic introduced into the biosphere by human activities has greatly surpassed arsenic from natural sources, the supply of the element from these two sources being approximately 60 and 40%, respectively. However, numerous regions of the world have elevated concentrations of arsenic from natural sources. Arsenopyrite may contain up to 6000 μg∙g−1 of arsenic and the weathering of such geological materials can increase the levels of arsenic in groundwater. Long-term consumption of groundwater containing elevated concentrations of arsenic has caused natural chronic arsenic intoxication in local populations in Taiwan, Mexico, Chile, Argentina, and other countries. An endemic disease commonly called blackfoot disease, which is also caused by arsenic in drinking water, was documented in Taiwan in 1963. For more than 80 years local populations had consumed well water with arsenic concentrations as high as 1829 μg∙L−1. The widespread geographical distribution of minerals with high arsenic content suggests that many new regions with natural arsenic contamination will be identified in the near future.Key words: arsenic, natural, cycling, chronic, contamination.
The use ofDaphniain studies of metal pollution of aquatic systems
Authors: Tomasiks Piotr , Warren D. Michael
Published: April 2011

Daphniidae (Crustacea, Anomopoda) have often been utilized in toxicological studies and environmental monitoring of aquatic systems for a number of reasons, such as their sensitivity to toxins and their ease of culture, and because they are such important members of the zooplankton in so many lakes. The extensive literature on the use of Daphnia as a bioindicator of environmental pollution with metal ions is critically reviewed. A summary of the data on the toxicity of metal ions in Daphnia is presented. These studies have lead to attempts to standardize the use of the bioindicator, as well as the monitoring of procedures. There have also been efforts to derive a relationship between toxicity data and the actual properties of toxins. Such a relationship would be beneficial for predicting the power of toxicity. To date, however, the efforts to establish this relationship have not been satisfactory. This compilation of metal toxicity data and the presentation of the attempts to establish such relationships was carried out in anticipation that it would be useful in future studies that might lead to a universal theory of the effect of metal ion toxicity on aquatic organisms.Key words: aquatic toxicology, bioindicators, Daphniidae, metal ion toxicity.
Nickel: a review of occurrence, uses, emissions, and concentration in the environment in Finland
Authors: Mukherjee Arun B
Published: April 2011

This survey represents a review of current knowledge concerning nickel and its compounds in the Finnish environment. Nickel, a naturally occurring element, is ubiquitous in the environment, especially in the divalent state. It was identified in the middle of the 18th century and its extraction process developed in the middle of the 19th century. In Finland, primary nickel production takes place by the direct high-grade nickel matte flash smelting process. Domestic production of nickel increased from 16 900 t in 1990 to 35 285 t in 1997. As a result of its versatile properties, more than 300 000 end-use applications of nickel have been reported. Its major use in Finland is in the production of stainless steel. In 1996 the release of nickel from industrial sources in Finland was as follows: 47 t to the atmosphere, 19 t to the aquatic environment, and 150 t to landfills and soils. The highest emissions stemmed from fuel-fired utility boilers. Nickel emissions to the atmosphere from the Harjavalta nickel smelter decreased from 7 t in 1993 to 1.2 t in 1996 as a result of technological developments and better gas cleaning equipment. In this study, nickel in the air, stream waters, soils, and lake and river sediments have been examined. It is noted that the background concentration of nickel in the air is about 0.5 ng·m-3, and nickel in stream water varies from 0.14 to 4.0 µg·L-1. There was no significant change of nickel concentration in arable lands between 1974 and 1987. In addition, nickel concentrations in terrestrial and aquatic species in Finland have been touched upon.Key words: nickel, occurrence, emissions, uses, Finnish environment.
Oxidative stress and antioxidative defense with an emphasis on plants antioxidants
Authors: Vichnevetskaia Klara D , Roy D N
Published: April 2011

Increased levels of active oxygen species or free radicals can create an oxidative stress. Concentration of free radicals in living cells increases as a result of exposure to environmental stresses that lead to aging, carcinogenesis, and immunodeficiencies in animals, and membrane leakage, senescence, chlorophyll destruction, and decreased photosynthesis in plants. The antioxidative system of higher plants consists of enzymes, low molecular weight compounds (among them peptides, vitamins, flavonoids, phenolic acids, alkaloids, etc.), and integrated detoxification chains. Enzymatic defense in plants include enzymes capable of removing, neutralizing, or scavenging oxy-intermediates. Catalases and superoxide dismutases are the most efficient antioxidant enzymes. Free radicals cause cell damage by a lipid peroxidation mechanism, which results in a blockade of natural antioxidant systems. Application of synthetic antioxidants can assist in coping with oxidative stress. There are very few publications on effects of synthetic antioxidants on plant growth and physiology. One of the examples of such synthetic antioxidant is 2-methyl-4-dimethylaminomethyl-5-hydroxybenzimidazole (Ambiol), which substantially promoted growth of agricultural and forestry plant species. Ambiol also demonstrated antitranspirant properties, increasing drought tolerance of conifers and agricultural species. The response of plants to Ambiol is under high genetic control. The identification of genes responsible for the reaction of plants to Ambiol may lead to attempts in genetic engineering of organisms with increased tolerance to oxidative stress. It seems impossible to find a universal scavenger trapping all free radicals active in the organism. However, analysis of the structureactivity relationships in antioxidants can contribute to the search for effective antioxidants.Key words: oxidative stress, lipid peroxidation, free radicals, natural and synthetic antioxidants, Ambiol.
The European bison as seed dispersers: the effect on the species composition of a disturbed pine forest community
Authors: Jaroszewicz Bogdan , Pirożnikow Ewa , Sagehorn Ruth
Published: April 2011

We studied the process of change in plant species composition in a pine–spruce forest influenced by endozoochorous seed dispersal by the European bison Bison bonasus L. The intensity of endozoochory was 3.4 times higher in the open tree stand than in the surrounding undisturbed forest (t = –3.0836, df = 50, P = 0.003). Over 1578 individuals/ramets belonging to 23 vascular plant taxa developed on 114 bison dung piles. The process of colonization included two plant species that have never before been recorded in the studied forest community. Seven out of 14 species transferred by bison were small-seeded herbaceous plants without morphological adaptations for long-distance dispersal. The majority of plant species recorded on the bison dung (55.9%) occur in deciduous forests. In contrast, over 50% of the plants surrounding bison faeces represented species of coniferous forests. The PCA analysis revealed the existence of two distinct groups of plant species: within bison faeces and on random systematic samples. The Jaccard coefficient of species composition similarity between them was 0.28. Our results demonstrate that the European bison is an effective vector of plant propagules between plant communities. This fact could have great importance for the restoration of degraded habitats, and could also introduce the risk of invasion by alien species.
Leaf habit, phenology, and longevity of 11 forest understory plant species in Algonquin State Forest, northwest Connecticut, USA
Authors: Tessier Jack T.
Published: April 2011

Many functional attributes of plant species are predicated on their leaf habit. To fully understand the way that plant species coexist and respond to future conditions, it is important to have a thorough understanding of the leaf habit, phenology, and longevity of common forest plant species. I quantified these traits in 11 forest understory species in the Algonquin State Forest of northwestern Connecticut, USA, by labeling and monitoring individual leaves of three replicates of each species over a period of 3 years. While clear patterns exist within the evergreen, wintergreen, seasonalgreen, deciduous, and spring-ephemeral groupings, significant differences exist within and among these groups, including differences in the timing of leafing and senescence, and minimum leaf longevity. Because the impact of local and global disturbance is often predicated on the phenological and life-history traits of species, these differences may be important to the responses that these species have to future disturbance. The size of leaf-supporting structures was positively correlated with leaf longevity across species, supporting a predictive connection between construction costs and leaf longevity. Additionally, the leaf habit of Oxalis acetosella L. at this study site is significantly different from that observed previously in the Catskill Mountains, New York State, USA. These differences may be due to local habitat conditions or genetic predisposition.
The boreal dwarf shrub Vaccinium vitis-idaea retains its capacity for photosynthesis through the winter
Authors: Lundell Robin , Saarinen Timo , Åström Helena , Hänninen Heikki
Published: April 2011

The ability to retain their photosynthetic capacity through the winter may be important for plants in boreal conditions, where the growing season is relatively short and winter temperatures fluctuate from severe freezing up to near 0 °C. The snow cover is an important protector for field-layer plants against both extreme freezing and excessive light, both of which could damage the photosynthetic apparatus. To understand the importance of wintertime photosynthetic activity for evergreen boreal dwarf shrubs, the photosynthesis of Vaccinium vitis-idaea L. was monitored in field conditions for one year. A dynamic model was used to determine the relative effect of temperature on the photosynthetic capacity. Our results show that V. vitis-idaea retains its photosynthetic capacity throughout the winter: its average photosynthetic capacity in winter was almost 25% of the yearly maximum measured. Changes in photosynthetic capacity over the year reflect the changes in air temperature with a certain delay, except in summer. Concentrations of soluble sugars remained high during the winter months, probably as a consequence of CO2 uptake under the snow cover. Our measurements indicated no significant damage to the leaf tissue over the winter, but suggest that photoinhibition may occur immediately after snowmelt.
Variability of nitrogen-fixing Frankia on Alnus species
Authors: Markham John H.
Published: April 2011

Plants maintain mutualistic symbioses with multiple symbiont genotypes that differ in the benefits they provide. To investigate differences in the effect of nitrogen-fixing Frankia on Alnus species, spore-producing (sp+) nodules from Alnus rubra Bong. and Alnus incana subsp. rugosa (Du Roi) Clausen and non-spore-producing (sp–) nodules from Alnus viridis subsp. crispa (Ait.) Turrill, A. rubra, and A. incana subsp. rugosa were collected from each of four different populations and used to inoculate all three Alnus species. As expected, sp+ Frankia produced significantly more nodules on all three species. However, A. crispa, which normally does not have sp+ nodules in the field, was more susceptible to a high level of infection by sp+ Frankia in general, and by any source of sp+ Frankia in particular, whereas A. incana subsp. rugosa, which has the highest abundance of sp+ in the field, was less susceptible to high levels of infection. This suggests that A. incana subsp. rugosa develops resistance to high levels of infection. The infectivity of an sp+ Frankia source on A. viridis subsp. crispa and A. rubra was positively correlated with the proportion of sp+ nodules on the site it was collected from, suggesting that the variation in the abundance of sp+ in the field is caused by sp+ Frankia with different levels of infectivity. There was no effect of Frankia sources on nodule allocation. Plant growth was positively correlated with the specific nodule mass and the specific nodule activity, and negatively correlated with the nodule number per plant. Sp+ Frankia resulted in significantly smaller plants in A. rubra. While there was no overall sp+ type effect on the growth of A. viridis subsp. crispa, the largest plants always resulted when they were inoculated with sp–, and the smallest with sp+ Frankia. Neither spore type nor inoculum source had any effect on the performance of A. rugosa. These results suggest that Alnus species remain susceptible to infection by both Frankia spore types, but are able to modulate the effectiveness of these spore types when they are the common symbionts in the field.
Morphological studies of developingRubusprickles suggest that they are modified glandular trichomes
Authors: Kellogg Allicia A. , Branaman Tatum J. , Jones Nathan M. , Little Coleman Z. , Swanson John-David
Published: April 2011

Prickles are defined as outgrowths of epidermal tissues and can provide a simple developmental system for the study of the control of cell proliferation and growth. Setting the stage for future studies on gene regulation in the genus Rubus (brambles), a detailed analysis and staging series of prickle development in Rubus idaeus subsp. idaeus L.  (red raspberry) is presented and compared with Rubus L. subsp. rubus Watson (blackberry) and Rosa hybrida L. 'Radtko' (rose). Morphological measurements from light and scanning electron micrographs were used to subdivide prickle development into four stages. Our studies indicate that raspberry and rose prickles are modified glandular trichomes continuing to grow and eventually hardening into their final prickle morphologies as outgrowths of epidermal tissue. Although glandular trichomes seem to be involved in blackberry prickle development, our studies indicate that these prickles do not follow the same developmental progression as raspberry, suggesting a potential evolutionary deviation from what is commonly seen in raspberry and rose.
Comparative leaf anatomy of four species of Bromelioideae (Bromeliaceae) occurring in the Atlantic Forest, Brazil
Authors: Pereira Tiago Augusto Rodrigues , de Oliveira Tuane Santos , da Silva Luzimar Campos , Azevedo Aristéa Alves
Published: April 2011

Bromeliaceae, comprising 3172 species, is one of the most important families of the Brazilian Atlantic Forest owing to its high degree of endemism and occurrence in different habitats. The subfamily Bromelioideae is the most representative of Bromeliaceae and the best represented in the state of Minas Gerais, Brazil, with 120 species. The objective of this study is to compare the leaf anatomy of four species found in two areas of the Atlantic Forest: Serra do Brigadeiro State Park, Minas Gerais, Brazil ( Quesnelia strobilispica Wawra and Wittrockia gigantea (Baker) Leme) and a forest fragment located within Bom Sucesso Farm, Viçosa, Minas Gerais, Brazil ( Billbergia euphemiae E. Morren and Bromelia antiacantha Bertol.), relating environmental characteristics to the habit. Leaf samples were studied using light and scanning electron microscopy and histochemical tests with Sudan, phloroglucinol, and ruthenium red stains. Leaves of B. euphemiae and W. gigantea showed several adaptations to the epiphytic habit, including scales on both surfaces, thickened epidermal cell walls, presence of silica bodies, hypodermis with sclerified cells, water-storing tissue (hydrenchyma), and air channels formed by stellate cells in the chlorenchyma. The epiphytic species B. euphemiae and the terrestrial species Q. strobilispica have similar overall structure, including a well-developed parenchyma and extravascular fiber groups. Leaves of the terrestrial species Bromelia antiacantha and the epiphytic species W. gigantea also show structural similarities, such as lack of extravascular fibers and less developed parenchyma. Similar characteristics in species from different habitats may either reflect microclimatic conditions under which these species occur or genetically fixed characteristics.
THE CHLORINATION OF METHANE
Authors: Boswell M. C. , McLaughlin R. R.
Published: April 2011

A small-scale method was first developed in which the degree of chlorination of methane to methyl chloride could be determined by analysis of the resulting gases. The optimum conditions so determined were then applied on a scale which permitted the isolation and measurement of the products. A yield of 80% or better was obtained when using as a catalyst partially-reduced cupric chloride and passing moist nitrogen, methane and chlorine in the ratios of 70:7:1 at 450 °C. It was found that the proportion of chlorine could be more than doubled when 8% of hydrogen was present in the methane. Under such conditions the chlorine was completely utilized and only methyl chloride and hydrogen chloride were formed. The yield of isolated methyl chloride obtained was nearly 80% and this could be increased by operating on a larger scale. The same catalyst was successfully used in the chlorination of methane to carbon tetrachloride. A yield of 90% was obtained, with complete utilization of the chlorine. The chlorination of ethane to ethyl chloride, with a yield of at least 75% was also shown to be possible.
STUDIES IN ISO-UREAS AND ISO-UREIDES: I. SOME NEW ISO-UREAS; SALTS AND ACYL DERIVATIVES
Authors: Basterfield Steward , Powell Edward C.
Published: April 2011

In this investigation a series of new iso-urea ethers has been prepared by the general reaction of addition of alcohols to cyanamide in the presence of dry hydrogen chloride. Where the hydrochlorides of the iso-ureas were difficult to isolate and purify, conversion to the salicylates gave excellent results. The new iso-ureas were further characterized by condensing them with methyl malonate to form iso-urea salts of 2-alkoxy-barbituric acids, from which the acids themselves could be easily liberated by the addition of dilute mineral acid. A few open-chain acyl derivatives were also prepared.
I. REFLECTION OF SOUND ENERGY AND THICKNESS OF PLATE REFLECTOR—ULTRASONIC METHOD
Authors: Boyle R. W. , Froman D. K.
Published: April 2011

The work is an amplification of the method introduced previously by Boyle and Lehmann, and illustrates the application of the theory of monochromatic interference spectroscopy of optics to sound. By experiments with lead, duralumin and paraffin, at different high frequencies, the effects of both high and low reflecting powers are shown, and also the possible influences of harmonics. It is also shown that in travelling through thin discs the velocity of the waves is given more accurately by the bulk modulus of elasticity than by Young's.
CHEMICAL AND PHYSICO-CHEMICAL CHANGES INDUCED IN WHEAT AND WHEAT PRODUCTS BY ELEVATED TEMPERATURES—I
Authors: Geddes W. F.
Published: April 2011

Heat treatments of wheat and wheat products were conducted in an apparatus which made it possible to study independently the influence of time, temperature and moisture content. Straight-grade flour, milled from Western Canadian hard red spring wheat (allowed a limited amount of aging) heat treated for varying times at different temperatures and normal moisture content (13.90%) was used in most of the studies. Baking tests conducted on this flour revealed progressive improvement in baking quality, as determined without bromate, with temperature or time of heating being extended within a certain range. No well defined "region" of improvement was observed. Improvement in baking quality was reflected in a better handling quality of the dough and, in the baked loaf, by a decrease in underfermented characteristics, and by a marked improvement in crumb texture. No significant alteration in loaf volume was observed. Improvement in baking quality induced by heat was not comparable in magnitude to that obtained by the addition of 0.001%, potassium bromate to the baking formula, but induced the same general characteristics in the finished loaf. Baking tests with bromate on heated flour revealed damage to baking quality for all heat treatments. Extension of time or temperature of heating, above the range where improvement was observed, caused pronounced damage to baking quality as determined with or without bromate. The damage caused was reflected in decreased loaf volume, over-fermentation characteristics, and coarse texture. Within the range of damage, the baking quality was found to be approximately a linear function of the temperature for constant time of heating. Heat treatment resulted in a marked decrease in fermentation tolerance. This decrease could not be ascribed to lower diastatic activity, since baking tests after the addition of diastatic malt to the baking formula gave similar results. Increasing the moisture content at which heat treatments were conducted markedly reduced the temperature to which flour could be heated without damage to the baking quality. The safe temperature limit for various moisture contents has been fairly well defined. The limiting moisture content at which damage occurred for a fixed temperature and time of heating was very sharp. Heat treatment of wheats showed somewhat less damage to baking quality of the flour milled therefrom than heat treatment of flour under similar conditions.