4 research outputs found
Leaf morphological and anatomical variations of paper birch populations along environmental gradients across Canada
No full textLeaf morphology and anatomy have been found to vary considerably among tree
species, and leaf characteristics have widely been used for analyzing plant growth and
resource use strategies because of their structural adaptation to withstand environments.
Considering the changing climate projections, early-successional, broad niched species
like paper birch (Betula papyrifera Marsh.) are expected to increase dominance due to a
zonal shift of natural vegetation and/or open gaps within the current vegetation zones.
Hence, it is important to understand factors such as leaf characteristics that enable these
pioneer species to inhabit a wide geographic range and their increasing dominance.
Paper birch is a pioneer tree species in North America that inhabits wide climatic
and geographic gradients; in addition, the species has developed different leaf
morphology and anatomy that have allowed paper birch to adapt to diverse habitats. This
study examines how the leaf characteristics of paper birch vary under uniform and
stressed environments. The major objectives were (a) to investigate leaf characteristics
variations in paper birch populations grown in uniform environmental conditions as in a
greenhouse and a common garden; (b) to correlate between leaf characteristics and paper
birch’s environment of origins; (c) to investigate leaf characteristic variations in paper
birch populations grown under different carbon dioxide concentrations [CO2] and soil
water levels to determine the relationship between leaf characteristics and individual or
interacting effects of [CO2], water levels and populations; and (d) to analyze the
relationship within and between leaf morphology and anatomy of the birch populations.
The study found significant differences among paper birch populations in leaf
morphological characteristics under a uniform environment at the greenhouse and the
common garden. The leaf characteristic variations in the uniform environment may be
related to the different genotypes of the birch inhabiting a wide environmental gradient.
In paper birch populations grown in the common garden, significant differences in
stomatal density, stomatal area, pore area and guard cell width were identified. As
expected, the birch populations in greenhouse and common garden environments
showed significant correlations of leaf characteristics, namely specific leaf area (SLA),
leaf maximum width index and petiole area to latitude, longitude, elevation, temperature,
precipitation and aridity index of origin. Correlation between leaf characteristics of
paper birch in the greenhouse showed that populations originated in limited precipitation
(during growing season) had low hair density on leaf adaxial surface, with larger leaf
width and petiole area. Birch populations grown in the common garden revealed that
populations originated in higher mean annual precipitation had less hair density on leaf
adaxial surface with smaller leaf area and higher stomatal density. Relationships within
the leaf characteristics revealed significant correlations within and between leaf morphology and anatomy as populations with larger leaf area had larger petiole area and
less adaxial hair density in greenhouse. The larger petiole in larger leaf reflects the need
for mechanical strengthening to support, whereas inverse relationship between leaf area
and hair density possibly showed a strategy of the birch to balance water loss. In
common garden, the birch populations with larger leaf area had larger specific leaf area
and higher adaxial hair density but low stomatal density. All these features in paper
birch populations provide a structural basis for reducing water loss through leaves and
increasing water use efficiency. There was no consistency in leaf characteristics when
the paper birch populations were grown in uniform environments as in the greenhouse
and the common garden.
Analysis of the leaf characteristics in the birch showed significant differences due
to the interaction and/or main effects of [CO2], water levels and populations. Paper birch
had decreased leaf area and increased stomatal density under elevated [CO2] which might
have reduced stomatal conductance and increased water-use efficiency. Under low soil
water level, paper birch populations studied had smaller stomatal area, pore area and
guard cell width. Contrasting with the expectation neither stomatal area was larger nor
stomatal density increased under low water level. A trade-off between stomatal area and
density in this study showed that stomatal area per unit leaf area remained the same.
Hence, smaller stomatal area and guard cell width under low water level must have
improved [CO2
] diffusion and decreased water loss compared to larger stomatal area and
guard cell width.
The results of this study confirmed significant genotypic difference in leaf
characteristics of paper birch populations irrespective of a uniform growing
environment. The characteristics, namely leaf area, maximum width, SLA, stomatal
density and stomatal area, appear related to the environment of origin; however, these
relationships were not consistent in the birch populations grown in the greenhouse and
common garden. Paper birch populations acclimated to the uniform environments;
differences in leaf area, stomatal density and stomatal area in paper birch populations
under different [CO2] and soil water levels prove the birch’s ability to acclimate to
environmental changes. Lastly, integration of leaf morphology and anatomy enhanced
paper birch’s ability to balance between [CO2] gain and water loss
Foraging innovation in an artificial environment: a case of little egret luring prey goldfish through beak dipping: supplementary material
No full textBehavioural innovations play an important role
in animal ecology and evolution. We report a case of little egret using its
beak dips as a tool to lure and catch prey goldfish in an artificial
environment designed to test predator-prey behavioural foraging games. The
egret mimicked the food pellets falling into the pool from a mechanical feeder
that fed the goldfish at regular intervals. The falling pellets created ripples
in the water that acted as a cue for the prey goldfish to come out of the cover
and feed on the floating pellets. The egret learned this phenomenon through
time and used its beak dips to create ripples and attract the prey outside. The
egret preferably used the location of the feeder in the pool to carry out its
beak dipping attempts and maximize its fish capture success. The egret
attempted this behaviour more in the largest cover that provided the best
refuge to the prey goldfish. The egret beak dipping attempts to lure the prey
goldfish out of the cover declined through experimental time as well as with
increasing prey kills. As the beak dipping behaviour did not result in a
high capture rate of fish, the egret subsequently reduced
its attempts through time. This case study illustrates that foraging
innovations can occur through learning in laboratory conditions containing a
novel but artificial environment
Asiakasrullien arkkikatkot Anjalan paperitehtaalla
No full textTämän työn aiheena oli selvittää syyt, jotka aiheuttavat asiakasrullien arkkikatkoja Anjalan paperitehtaalla. Kun syyt oli saatu selville, piti alkaa miettimään keinoja, joilla arkkikatkojen määrää saadaan vähennettyä. Työ rajattiin siten, että eri muuttujien osalta keskityttiin kuljetinjärjestelmään, rullarakenteisiin, rullien dimensioihin sekä olosuhteisiin tehdassalissa.
Yhtenä tutkimusmenetelmänä tässä työssä käytettiin tilastointia, jonka avulla pyrittiin selvittämään, mikä vaikutus eri paperilajeilla ja rulladimensioilla on arkkikatkojen määrään. Toinen tärkeä tutkimusmetodi oli visuaalinen seuranta, joka tarkoitti rullien seurantaa kuljetinjärjestelmällä. Tarkoituksena oli ymmärtää, onko kuljetinjärjestelmän varrella sellaisia paikkoja, joissa rullien pintoja rikkoutuu erityisen paljon. Lisäksi työssä tutkittiin ilmankosteuden ja rullarakenteen vaikutusta arkkikatkojen syntyyn.
Tämän työn tekeminen oli vaihtelevaa ja itse tekeminen jakautui pääosin neljän eri tutkimusmenetelmän mukaan. Suurin osa ajankäytöstä meni tilastointiin, taulukoiden tekemiseen sekä visuaaliseen seurantaan. Rullarakenteiseen ja kuljetinjärjestelmien toimintaan liittyvät tutkimukset suoritettiin lähinnä muiden toimesta, mutta tutkimuksien tuloksia käytettiin osana tätä työtä. Ilmankosteusmittaukset suoritin itse.
Tilastoinnin perusteella saatiin selville, että korkeat ja kapeat rullat aiheuttavat eniten ongelmia Anjalassa. Paperilaaduista eniten rullien arkkikatkoja ilmeni ExoPress-sanomalehtipaperilla. Tilastoista kävi myös ilmi, että mitä enemmän paperia on kalanteroitu, sitä herkempää se on pinnan rikkoutumiselle. Ilmankosteuksien osalta voitiin päätellä, että varsinkin talvisaikaan vallitseva alhainen ilmankosteus tehdassalissa kasvattaa ongelmien määrää. Myös kuljetinjärjestelmästä löytyi heikkouksia. Etenkin pituusleikkuri 5:n kuljettimilla olevat ylimenokohdat rasittavat rullien pintaa. Myös pituusleikkuri 3:n edessä olevien pysäytinläppien huomattiin rikkovan rullia. Rullarakenteella todettiin olevan melko vähäinen merkitys rullien arkkikatkojen syntyyn.
Työssä esiteltävien tutkimusten perusteella voidaan sanoa, että rullien arkkikatko-ongelmat syntyvät monien eri muuttujien yhteisvaikutuksesta. Ongelmia on hyvin vaikea poistaa kokonaan, koska Anjalassa leikattavien paperirullien dimensiot vaihtelevat jatkuvasti. Tärkeimmät keinot arkkikatkojen vähentämiseen ovat kuljetinjärjestelmän tasojen linjaus ja nopeuksien säätö, pituusleikkureiden parametrien viritys sekä lisäkostutinlaitteiden käyttö tehdassalissa.The subject of this thesis was to investigate the causes of sheet rupture of reels in Anjala Mill. Once the causes were found it was time to start thinking about ways to avoid the sheet rupture. The subject was limited to conveyor belts, reelstructure, reel dimensions and humidity at the mill.
Several investigation methods were used in this report. The first method was making statistics. Another important method was visual tracking of reels which meant monitoring the conveyor system. The aim was to understand if the conveyor system had places which cause significant amount of damage to the reels. Also the humidity and reel structure were taken into consideration.
Making this work was full of variety and it was divided into four different research methods. Making the statistics and visual monitoring took the biggest amount of time. Investigations of the reel structure and conveyor systems were carried out mainly by others but the study results were used as part of this work. Humidity measurements were made by author.
On the basis of statistics it was discovered that the high and narrow reels caused the biggest amount of problems in Anjala Mill. The most problem causing paper type was ExoPress-newspaper. Also the low level of humidity increases the amount of sheet rupture problems. The conveyor system had also weaknesses. Especially winder 5 reels have to take serious stress at the overlapping points. Reel structure was found a relatively minor factor in the area of sheet rupture problems.
Based on the results in this study it is possible to say that sheet rupture problems are caused by more than one reason. It is almost impossible to remove the problem completely due to the fact that the dimensions of the reels are changing constantly. The best ways to reduce the problems are adjusting the levels and speeds of the conveyor systems, tuning up the winders and using of the additional humidifier inside the mill
Author's personal copy Medication safety messages for patients via the web portal: The MedCheck intervention
No full texti n t e r n a t i o n a l j o u r n a l o f m e d i c a l i n f o r m a t i c s 7 7 ( 2 0 0 8 ) [161][162][163][164][165][166][167][168] j o u r n a l h o m e p a g e : w w w . i n t l . e l s e v i e r h e a l t h . c o m / j o u r n a l s / i j m i Accordingly, the goal of this study was to learn whether electronic medication safety messages directed to patients can improve communication about medications and identify ADEs. Design: We studied adult patients enrolled in a patient Internet portal at three primary care practices affiliated with a teaching hospital. MedCheck, a medication safety application, sent patients a secure electronic message 10 days after they received a new or changed prescription. MedCheck asked if the patient had filled the prescription or experienced medication-related problems, and then forwarded the patient's response to their primary care physician. Measurements: We selected a stratified random sample of 267 subjects from 1821 patients who received and opened a MedCheck message from April 2001 to June 2002. We reviewed subjects' medical records for three months following their first MedCheck message. We analyzed patient and clinician response rates and times, examined patient-clinician communication about medications, and identified ADEs. Results: Patients opened 79% of MedCheck messages and responded to 12%; 77% responded within 1 day. Patients often identified problems filling their prescriptions (48%), problems with drug effectiveness (12%), and medication symptoms (10%). Clinicians responded to 68% of patients' messages; 93% answered within 1 week. Clinicians often supplied or requested information (19%), or made multiple recommendations (15%). Patients experienced 21 total ADEs; they reported 17 electronically. Conclusion: Patients and physicians responded promptly to patient-directed electronic medication messages, identifying and addressing medication-related problems including ADEs
