Associations between annual and seasonal variations in body mass and reproductive success and blood biochemical parameters in semi-domesticated reindeer

The main objective of the study was to follow reproductive performance and blood biochemical parameters associated with fat and carbohydrate metabolism in a herd of free-ranging, semi-domesticated reindeer (Rangifer tarandus tarandus) over a two-year period, with extreme between-year variation in forage availability. The effects of climatic factors on reindeer reproductive performance were investigated by analysing whether time of onset of luteal function in autumn and calf survival were associated with changes in body mass and weather conditions, such as snow depth, precipitation, and temperature. Considerable between-year variation in the onset of luteal activity was found. In 1997, 4.2% of the female reindeer were either cycling or pregnant in the second week of October, whilst in 1998, in the same week, 100% were cycling or pregnant. Although energy balance was important for timing of the onset of luteal activity, delayed conception had no apparent effect on calf survival. The results indicated that maternal body mass (BM) in spring was of primary importance for calf survival, and the productivity of the herd. Since climatic factors influence the availability of forage, and hence female BM, it also has an indirect impact on calf survival. Females with low BM demonstrated greater seasonal variation in BM than heavier females. Plasma concentrations of free fatty acids and β-hydroxy butyric acid responded to changes in forage availability, but the initial condition of the reindeer and their fat reserves also seemed to have a major influence on these parameters.Abstract in Norwegian / Sammendrag:Sammenheng mellom års- og sesongvariasjon i kroppsvekt og henholdsvis reproduksjonssuksess og biokjemiske blodparametre hos tamreinHovedformålet med studien var å følge reproduksjonen og blodparametre knyttet til fett og karbohydratmetabolismen hos en tamreinflokk (Rangifer tarandus tarandus) gjennom en toårs periode med stor årlig variasjon i næringstilgang. Effekten av klima på reinens reproduksjonssuksess ble undersøkt ved å analysere om værdata som snødybde, nedbørsmengde og temperatur og forandringer i vekt hadde innvirkning på igangsetting av lutealfunksjonen hos simlene og på kalvenes overlevingsevne gjennom sommeren. Det ble funnet en betydelig forskjell mellom år når det gjaldt igangsetting av lutealfunksjon. I oktober 1997, var kun 4,2% av simlene drektige eller i lutealfasen av brunstsyklusen mens i den samme uken i 1998 var alle dyrene drektige eller i brunstens lutealfase. Selv om energibalanse var viktig for igangsetting av lutealfunksjonen, hadde forsinkelse i drektighetene ingen innflytelse på kalveoverlevelsen. Resultatene våre indikerte at simlenes vårvekt var av størst betydning for kalveoverlevelsen, og dermed også for produktiviteten til flokken. Siden de til enhver tid gjeldene værforhold påvirket tilgangen av fôr, påvirket dette også simlenes vekt med en indirekte effekt på kalveoverlevelsen. Simler med lav levendevekt viste større sesongvariasjon i vekt enn tyngre simler. Plasmakonsentrasjonen av frie fettsyrer, β-hydroxy-smørsyre forandret seg i takt med beitegrunnlaget, men den initiale kondisjonen og fettreservene hos simlene syntes også å påvirke disse parametrene

Determination of the characteristic directions of lossless linear optical elements

We show that the problem of finding the primary and secondary characteristic directions of a linear lossless optical element can be reformulated in terms of an eigenvalue problem related to the unimodular factor of the transfer matrix of the optical device. This formulation makes any actual computation of the characteristic directions amenable to pre-implemented numerical routines, thereby facilitating the decomposition of the transfer matrix into equivalent linear retarders and rotators according to the related Poincare equivalence theorem. The method is expected to be useful whenever the inverse problem of reconstruction of the internal state of a transparent medium from optical data obtained by tomographical methods is an issue.Comment: Replaced with extended version as published in JM

Combined Quantitative X-ray Diffraction, Scanning Electron Microscopy, and Transmission Electron Microscopy Investigations of Crystal Evolution in CaO–Al2O3–SiO2–TiO2–ZrO2–Nd2O3–Na2O System

Glass-ceramics, with a specific crystalline phase assembly, can combine the advantages of glass and ceramic and avoid their disadvantages. In this study, both cubic-zirconia and zirconolite-based glass-ceramics were obtained by the crystallization of SiO2-CaO-Al2O3-TiO2-ZrO2-Nd2O3-Na2O glass. Results show that all samples underwent a phase transformation from cubic-zirconia to zirconolite when crystallized at 900, 950, and 1000 °C. The size of the cubic-zirconia crystal could be controlled by temperature and dwelling time. Both cubic-zirconia and zirconolite crystals/particles show dendrite shapes, but with different dendrite branching. The dendrite cubic-zirconia showed highly oriented growth. Scanning electron microscopy images show that the branches of the cubic-zirconia crystal had a snowflake-like appearance, while those in zirconolite were composed of many individual crystals. Rietveld quantitative analysis revealed that the maximum amount of zirconolite was ∼19 wt %. A two-stage crystallization method was used to obtain different microstructures of zirconolite-based glass-ceramic. The amount of zirconolite remained approximately 19 wt %, but the individual crystals were smaller and more homogeneously dispersed in the dendrite structure than those obtained from one-stage crystallization. This process-control feature can result in different sizes and morphologies of cubic-zirconia and zirconolite crystals to facilitate the design of glass-ceramic waste forms for nuclear wastes

Flexible modelling of spatial variation in agricultural field trials with the R package INLA

The objective of this paper was to fit different established spatial models for analysing agricultural field trials using the open-source R package INLA. Spatial variation is common in field trials, and accounting for it increases the accuracy of estimated genetic effects. However, this is still hindered by the lack of available software implementations. We compare some established spatial models and show possibilities for flexible modelling with respect to field trial design and joint modelling over multiple years and locations. We use a Bayesian framework and for statistical inference the integrated nested Laplace approximations (INLA) implemented in the R package INLA. The spatial models we use are the well-known independent row and column effects, separable first-order autoregressive ( AR1⊗AR1 ) models and a Gaussian random field (Matérn) model that is approximated via the stochastic partial differential equation approach. The Matérn model can accommodate flexible field trial designs and yields interpretable parameters. We test the models in a simulation study imitating a wheat breeding programme with different levels of spatial variation, with and without genome-wide markers and with combining data over two locations, modelling spatial and genetic effects jointly. The results show comparable predictive performance for both the AR1⊗AR1 and the Matérn models. We also present an example of fitting the models to a real wheat breeding data and simulated tree breeding data with the Nelder wheel design to show the flexibility of the Matérn model and the R package INLA

Portability and networked learning environments

Abstract The portability of educational software is defined as the likelihood of software usage, with or without adaptation, in an educational environment different from that for which it was originally designed and produced. Barriers and research relevant to the portability of electronic learning resources are discussed and organised into a portability-limiting factors model. With the increase in number and scope of networked learning environments, portability issues take on a new dimension. Using electronic (study) books as an example, the portability problem space of networked learning environments is explored

Vulnerability to natural disasters in Serbia: spatial and temporal comparison

The frequency of natural disasters and the extent of their consequences at a global level are constantly increasing. This trend is partially caused by increased population vulnerability, which implies the degree of population vulnerability due to high magnitude natural processes. This paper presents an analysis of vulnerability to natural disaster in Serbia in the second half of the twentieth and the early twenty-first century. Vulnerability changes were traced on the basis of demographic–economic indicators derived from statistical data for local government units (municipalities) provided by the Statistical Office of the Republic of Serbia. Calculations were performed in the geographical information system environment. The results of the study show that spatial and temporal vulnerability variations are causally correlated with changes in the selected components. Significant rise of vulnerability is related to urban areas, while lower values are characteristic for other areas of Serbia; this is primarily a consequence of different population density

Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)

Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species

Microsatellite Support for Active Inbreeding in a Cichlid Fish

In wild animal populations, the degree of inbreeding differs between species and within species between populations. Because mating with kin often results in inbreeding depression, observed inbreeding is usually regarded to be caused by limited outbreeding opportunities due to demographic factors like small population size or population substructuring. However, theory predicts inclusive benefits from mating with kin, and thus part of the observed variation in inbreeding might be due to active inbreeding preferences. Although some recent studies indeed report kin mating preferences, the evidence is still highly ambiguous. Here, we investigate inbreeding in a natural population of the West African cichlid fish Pelvicachromis taeniatus which showed clear kin mating preferences in standardized laboratory experiments but no inbreeding depression. The presented microsatellite analysis reveals that the natural population has, in comparison to two reference populations, a reduced allelic diversity (A = 3) resulting in a low heterozygosity (Ho = 0.167) pointing to a highly inbred population. Furthermore, we found a significant heterozygote deficit not only at population (Fis = 0.116) but also at subpopulation level (Fis = 0.081) suggesting that inbreeding is not only a by-product of population substructuring but possibly a consequence of behavioral kin preferences

Digesta retention time in roe deer Capreolus capreolus, as measured with cerium-, lanthanum- and chromium-mordanted fibre

Studies on particle retention time in ruminants are commonly conducted utilizing chromium (Cr) and/or a lanthanide bound to feeds. Both types of markers have different chemical properties which potentially bias estimates of digesta retention—their combined use is therefore a topic of ongoing discussion. In order to evaluate the suitability of two lanthanides for studies assessing the passage kinetics of different-sized particles, we measured the mean retention time in roe deer with cerium (Ce) and lanthanum (La) labelled to the same particle length and compared it to Cr-mordanted fibre of the same size. We expected a simultaneous excretion of Ce- and La-labelled fibre, but a delayed excretion of Cr-mordanted fibre compared to the other markers. In this study, the mean retention times of Ce- and La-labelled fibre did not differ significantly, and Cr-mordanted fibre was retained on average 5 h longer than Ce and La. Despite the limitation of the small sample size, Ce and La showed the same excretion pattern and can therefore be recommended as mordants in studies assessing passage kinetics of different particle sizes