Estimation of reindeer lichen biomass by image analysis

During consultation procedures between forest owners and the Sámi, data on, e.g., reindeer lichen biomass on the current site is needed. Hitherto, the existing methods of measuring lichen cover and biomass has been either objective methods such as the Point Intercept method, which is time consuming, or some sort of subjective visual estimation, which is faster but less accurate. However, both these methods are sensitive to different observers and/or to different inventories. This paper addresses the further development and evaluation of a photographical inventory method that uses colour distribution in images to estimate lichen biomass. During the autumn of 2011 six different locations, with different grazing pressure and lichen cover, in Norrbotten county were inventoried using both the Point Intercept method and the photographical method, complemented with collection of biomass samples. The sample images were analyzed with respect to lichen and background areas (cover) using WinCAM™. Statistical analyses were used to create equations for estimation of lichen biomass from lichen cover, as well as to compare photographically estimated lichen cover and lichen cover from the Point Intercept method. Results shows that it is possible to estimate lichen biomass from lichen cover analyzed via image analysis. Results also indicate that different equations should be used for different sites depending degree of lichen cover and ground vegetation.Vid samråd mellan skogsägare och renskötande samer krävs bland annat information om mängden renlavsbiomassa i det bestånd som är aktuellt för skogsbruksåtgärder. Hittills har skattning av lavbiomassa skett genom den objektiva Point Intercept-metoden, vilken är tidsödande, eller genom någon form av subjektiv visuell bedömning, vilken är snabbare men har lägre nogrannhet. Båda dessa metoder är dock känsliga för olika förättningsmän och kan även ge skiftande resultat mellan olika inventeringar. Det här arbetet tar upp vidareutvecklingen och utvärderingen av en fotografisk inventeringsmetod baserad på färgskillnader i bilder. Under hösten 2011 genomfördes provtagningar på sex olika platser i Norrbottens län med olika betestryck och täckningsgrad av renlav. Både Point Intercept-metoden och den fotografiska metoden användes under provtagningen, dessutom togs lavbiomassaprover. Bilderna analyserades med avseende på lavtäckningsgrad med hjälp av programvaran WinCAM™. Statistiska analyser användes för att skapa funktioner för skattning av lavbiomassa utifrån lavtäckningsgrad, men även för att jämföra lavtäckningsgrader från både Point Intercept-metoden och den fotografiska metoden. Resultaten visar att det var möjligt att skatta mängden renlavsbiomassa med hjälp av bildanalys, och att biomassafunktioner bör beakta såväl lavtäckningsgrad som betestryck

Polygons on a Rotating Fluid Surface

We report a novel and spectacular instability of a fluid surface in a rotating system. In a flow driven by rotating the bottom plate of a partially filled, stationary cylindrical container, the shape of the free surface can spontaneously break the axial symmetry and assume the form of a polygon rotating rigidly with a speed different from that of the plate. With water we have observed polygons with up to 6 corners. It has been known for many years that such flows are prone to symmetry breaking, but apparently the polygonal surface shapes have never been observed. The creation of rotating internal waves in a similar setup was observed for much lower rotation rates, where the free surface remains essentially flat. We speculate that the instability is caused by the strong azimuthal shear due to the stationary walls and that it is triggered by minute wobbling of the rotating plate. The slight asymmetry induces a tendency for mode-locking between the plate and the polygon, where the polygon rotates by one corner for each complete rotation of the plate

Anticoccidial Vaccination Is Associated with Improved Intestinal Health in Organic Chickens

Simple Summary In recent years, the number of organic chicken farms has increased. Chickens can be infected by single-cell parasites, coccidia, which cause lesions in the lining of the intestine leading to poor growth and sometimes death (coccidiosis). This infection can also lead to overgrowth in the intestine of a bacterium, Clostridium perfringens, that may cause further damage (necrotic enteritis). Prevention is often achieved by adding substances in the feed that will slow down the development of parasites and bacteria, but this is not allowed in organic farming. The aim of this study was to investigate if vaccination against coccidia can prevent these diseases in organic chickens. Vaccinated chickens developed milder gut lesions, had fewer and less damaging C. perfringens, and had similar or higher body weight compared to unvaccinated chickens six weeks after vaccination. No deaths from coccidiosis or necrotic enteritis occurred among vaccinated chickens while some unvaccinated chickens died from these diseases. We conclude that vaccination against coccidia benefits organic chickens. This study provides knowledge supporting further development of the organic chicken industry. The results are also of relevance to the management of coccidiosis and necrotic enteritis in conventional broilers. Eimeria spp. and Clostridium perfringens (CP) are pathogens associated with coccidiosis and necrotic enteritis (NE) in broiler chickens. In this study we evaluated the effect of anticoccidial vaccination on intestinal health in clinically healthy organic Ross 308 chickens. On each of two farms, one unvaccinated flock (A1 and B1) was compared to one vaccinated flock (A2 and B2) until ten weeks of age (WOA). Faecal oocysts were counted weekly, and species were identified by PCR (ITS-1 gene). Lesion scoring, CP quantification and PCR targeting the CP NetB toxin gene were performed at three, four, and six WOA and chickens were weighed. Necropsies were performed on randomly selected chickens to identify coccidiosis/NE. Oocyst shedding peaked at three WOA in all flocks. Later oocyst shedding (E. tenella/E. maxima) in unvaccinated flocks at 5-7 WOA coincided with coccidiosis/NE. Although results differed somewhat between farms, vaccination was associated with lower intestinal lesion scores, reduced caecal CP counts, lower proportions of netB-positive CP, lower body weight at three-four WOA, and similar or slightly increased body weight at six WOA. In conclusion, the intestinal health of organic broilers can benefit from anticoccidial vaccination when oocyst exposure levels are high

Vibration response of long cable-stayed timber footbridge – case study

Timber footbridges with a span larger than 30 meters are sensitive to vibrations and dynamic factors must therefore be taken into considerations in the design. A case study of a cable-stayed footbridge, Älvsbacka Bridge, with a free span of 130 meters, is presented. The dynamic design of the bridge is compared, based on the old Swedish code, BRO 2004 and the Eurocode 5. Simplified force models presented in BRO 2004 and the ISO 10137 international standard are compared. Vertical and lateral accelerations are measured on the bridge with accelerometers attached to the bridge deck. According to the simplified force model, the vertical acceleration limit was met for a group of twenty pedestrians, which was regarded as a reasonable design situation. From the measured accelerations, the damping factor was calculated as 1.2% of critical damping, which is twice the value used in design

The Association of the Antenna System to Photosystem I in Higher Plants COOPERATIVE INTERACTIONS STABILIZE THE SUPRAMOLECULAR COMPLEX AND ENHANCE RED-SHIFTED SPECTRAL FORMS

We report on the association of the antenna system to the reaction center in Photosystem I. Biochemical analysis of mutants depleted in antenna polypeptides showed that the binding of the antenna moiety is strongly cooperative. The minimal building block for the antenna system was shown to be a dimer. Specific protein-protein interactions play an important role in antenna association, and the gap pigments, bound at the interface between core and antenna, are proposed to mediate these interactions Gap pigments have been characterized by comparing the spectra of the Photosystem I to those of the isolated antenna and core components. CD spectroscopy showed that they are involved in pigment-pigment interactions, supporting their relevance in energy transfer from antenna to the reaction center. Moreover, gap pigments contribute to the red-shifted emission forms of Photosystem I antenna. When compared with Photosystem II, the association of peripheral antenna complexes in PSI appears to be more stable, but far less flexible and functional implications are discussed

Planering av tätortsnära rekreationsskogar hos kommuner i Västerbottens län

Det svenska landskapet har under det senaste århundradet förändrats. Detta har lett till att det finns en efterfrågan efter naturupplevelser och rekreationsområden. Sedan den första nationalparken bildades i Sverige, har skyddandet av värdefull natur varit ett uppdrag som utförts av staten. Alltsedan dess har kommunerna fått mer ansvar för natur- och kulturvård. Tidigare studier visar på att det behövs mer kunskap om den samhällsekonomiska potentialen som den tätortsnära skogen har för kommunerna. Naturvårdsverket och Naturskyddsföreningen rapporterade 2010 att det varierar hur kommunerna tar ansvar för att det ska finnas tätortsnära skog. I detta kandidatarbete har en studie utförts som försöker ta reda på hur kommuner i Västerbottens län hanterar den tätortsnära skogen i översiktlig planering och hur den praktiska skötseln genomförs. Genom intervjuer med ansvariga på Umeå kommun och kranskommuner samt analys av policydokument fann vi att kommunerna är medvetna om sitt ansvar att tillhandahålla tätortsnära skog och att det varierar i vilken utsträckning de tar detta ansvar.The Swedish landscape has experienced a transformation the past century. This in turn has led to a public demand for recreational sites and nature experiences. Since the first national park was established in Sweden, the responsibility for protecting land rich in biological values has been a responsibility that has been appointed to the Swedish government. Since then the municipality’s responsibility for such affairs has increased. Previous studies show that there is a need for more knowledge about the socio-economic potential that the urban forests have for the Swedish counties. The Swedish Environmental Protection Agency and the Swedish Society for Nature Conservation both reported in 2010 that the amount of effort that the Swedish municipalities put in to ensure that urban forests exists within its own municipality varied. In this bachelors thesis we have made a study that aims to show how municipalities in Västerbottens County manage their urban forests in the long run and how the everyday managing is implemented. By conducting interviews with the people responsible and hired at Umeå municipality and surrounding municipalities together with studies of the municipalities land-use plans, we found that the municipalities know of their responsibility of providing urban forests and that there is a variation to what extent they do so

Skötselns och ståndortens betydelse för kärnvedsbildningen i tall

Heartwood has always been a desirable part of the tree, due to it’s superior decay qualities com-pared to the sapwood. How the formation of heartwood works has been known for a long time, but which factors that initiates and stimulates the production are poorly understood. This case study presents the results of a study in which silvicultural treatments and site properties had a key position as factors to the formation of heartwood. According to the hypothesis the amount of sapwood is directly controlled by the size of the crown. The amounts of heartwood in four Scots pine stands, including a dense low quality site, a low density high quality site, and two in be-tween, was examined by extraction of core samples. According to the hypothesis dense stands at low quality sites would develop small crowns with a little need of sapwood, and therefore a larger need of heartwood. The results basically showed that dense stands on poor sites had a bigger proportion of heartwood than low density stands on high quality sites, but the widths of the growth rings seems to be an important factor as well. However, the variation in, and especially between, the stands are large, and therefore it is difficult to draw any conclusion. The results are, nevertheless, discussed against existing theories and other field trials that had similar results

Lung fractional moving blood volume in normally grown and growth restricted foetuses.

Objective: To examine foetal lung blood perfusion using power Doppler ultrasound (PDU) and to compare fractional moving blood volume (FMBV) and mean pixel intensity (MPI) estimations in the lungs of normally grown (NG) foetuses and foetuses with intrauterine growth restriction (IUGR) and also to correlate foetal lung FMBV and MPI with respiratory complications after birth. Methods: Lungs of 47 NG and 25 IUGR foetuses after 32 weeks of gestation were examined with PDU. FMBV and MPI were estimated in a defined region in the posterior part of the foetal lung closest to maternal abdominal wall. FMBV and MPI were correlated to foetal weight deviation and gestational age. Perinatal outcome and respiratory complications after birth were recorded in both groups. Results: There were significantly lower FMBV and MPI values in IUGR than in NG foetuses. The overall variation was lower for FMBV than for MPI. There was a slightly higher correlation between FMBV and foetal weight deviation [r = 0·33, 95% confidence intervals (CI) 0·11-0·52] than between MPI and foetal weight deviation (r = 0·26, 95% CI 0·03-0·46). There was no significant correlation between FMBV or MPI and gestational age. No differences between the groups were found in the rate of respiratory complications, and they were not correlated either to the FMBV or MPI. Conclusion: FMBV and MPI, estimated from the PDU signals of foetal lung circulation, showed lower values in third-trimester pregnancies complicated by IUGR. The frequency of neonatal respiratory complications was not increased in cases with low pulmonary FMBV and MPI values

Questionnaire study suggests grave consequences of infectious laryngotracheitis, infectious coryza and mycoplasmosis in small chicken flocks

BackgroundA growing number of people in western countries keep small chicken flocks. In Sweden, respiratory disease is a common necropsy finding in chickens from such flocks. A respiratory real-time polymerase chain reaction (PCR) panel was applied to detect infectious laryngotracheitis virus (ILTV), Avibacterium paragallinarum (A. paragallinarum) and Mycoplasma gallisepticum (M. gallisepticum) in chickens from small flocks which underwent necropsy in 2017-2019 and had respiratory lesions. Owners (N = 100) of PCR-positive flocks were invited to reply to a web-based questionnaire about husbandry, outbreak characteristics and management.ResultsResponse rate was 61.0%. The flocks were from 18 out of Sweden's 21 counties indicating that respiratory infections in small chicken flocks are geographically widespread in Sweden. Among participating flocks, 77.0% were coinfected by 2-3 pathogens; 91.8% tested positive for A. paragallinarum, 57.4% for M. gallisepticum and 50.8% for ILTV. Larger flock size and mixed-species flock structure were associated with PCR detection of M. gallisepticum (P = 0.00 and P = 0.02, respectively). Up to 50% mortality was reported by 63.9% of respondents. Euthanasia of some chickens was carried out in 86.9% of the flocks as a result of the outbreaks. Full clinical recovery was reported by 39.3% of owners suggesting chronic infection is a major challenge in infected flocks. Live birds had been introduced in many flocks prior to outbreaks, which suggested these as an important source of infection. Following the outbreaks, 36.1% replaced their flocks with new birds and 9.8% ceased keeping chickens.ConclusionsThis study highlights the severity of respiratory outbreaks in small non-commercial chicken flocks and points to the need for more research and veterinary assistance to prevent and manage respiratory infections in small chicken flocks

Frequency dependence of speckle in continuous-wave ultrasound with implications for blood perfusion measurements.

Speckle in continuous wave (CW) Doppler has previously been found to cause large variations in detected Doppler power in blood perfusion measurements, where a large number of blood vessels are present in the sample volume. This artifact can be suppressed by using a number of simultaneously transmitted frequencies and averaging the detected signals. To optimize the strategy, statistical properties of speckle in CW ultrasound need to be known. This paper presents analysis of the frequency separation necessary to obtain independent values of the received power for CW ultrasound using a simplified mathematical model for insonation of a static, lossless, statistically homogeneous, weakly scattering medium. Specifically, the autocovariance function for received power is derived, which functionally is the square of the (deterministic) autocorrelation function of the effective sample volumes produced by the transducer pair for varying frequencies, at least if a delta correlated medium is assumed. A marginal broadening of the modeled autocovariance functions is expected for insonation of blood. The theory is applicable to any transducer aperture, but has been experimentally verified here with 5-MHz, 6.35-mm circular transducers using an agar phantom containing small, randomly dispersed glass particles. A similar experimental verification of a transducer used in multiple-frequency blood perfusion measurements shows that the model proposed in this paper is plausible for explaining the decorrelation between different channels in such a measurement