bluuebunny/crossref_metadata_2025 huggingface dataset:
Dendritic Cell–Dependent In Vivo Generation of Autoregulatory T Cells by Antidiabetogenic MHC Class II
Authors: Tsai Sue , Serra Pau , Clemente-Casares Xavier , Slattery Robyn M. , Santamaria Pere
Published: June 2013

Several mechanisms have been proposed to explain how certain MHC class II molecules afford dominant resistance to autoimmune diseases like type 1 diabetes (T1D). However, it remains unclear how protective MHC types can blunt autoreactive T cell responses directed against a diverse repertoire of autoantigenic epitopes presented by disease-promoting MHCs. In this study, we show that expression of I-E on dendritic cells (DCs) of NOD mice promotes the differentiation of MHC promiscuous autoreactive CD4+ clonotypes into antidiabetogenic autoregulatory T cells. We expressed an I-EαkloxP transgene in NOD mice and used cell type–specific I-E ablation to show that I-E–expressing DCs, but not B cells, promote the generation of autoreactive CD4+Foxp3+ regulatory T cells (Tregs) and their accumulation in the pancreas-draining lymph nodes. There, these Tregs suppress the presentation of β cell Ags to naive autoreactive CD4+ and CD8+ T cells restricted by diabetogenic MHC molecules in an I-E–independent manner. Whereas selective removal of I-E on DCs abrogated autoregulatory Treg formation and T1D protection, selective removal of I-E on B cells was inconsequential. These results explain how certain MHC class II molecules can completely suppress antigenically complex autoimmune responses in an Ag-nonspecific manner.
Evidence for the Presence of 1,3-Dimethylamylamine (1,3-DMAA) in Geranium Plant Materials
Authors: Gauthier Thomas D.
Published: June 2013

1,3-Dimethylamylamine (1,3-DMAA) is an aliphatic amine with stimulant properties that are reportedly found naturally only in geranium plants ( Pelargonium graveolens). The presence of 1,3-DMAA in geranium plants was first reported in a paper published in 1996, but some have questioned the identification of 1,3-DMAA in that study. Since then, a number of additional studies have been published, largely reporting the absence of 1,3-DMAA in geranium plants and commercial geranium oils. However, in two recent studies, 1,3-DMAA was detected in geranium plant tissues and a geranium oil sample using a simplified extraction approach on tissues and oil sourced from China. Whether or not 1,3-DMAA is found naturally in plants has significant implications as to how commercial products containing 1,3-DMAA are regulated by the US Food and Drug Administration. In this paper, differences in source materials, extraction procedures, and analytical approaches are reviewed in an attempt to rationalize the apparently conflicting evidence for the presence of 1,3-DMAA in geranium plant materials.
Bevacizumab for the Treatment of Glioblastoma
Authors: Gil-Gil Miguel J. , Mesia Carlos , Rey Montserrat , Bruna Jordi
Published: June 2013

Glioblastoma (GBM) or grade IV glioma is the most common primary brain tumor in adults. Standard treatment median overall survival (OS) is only 14–15 months and less than 10% of patients will survive 5 years after diagnosis. There is no standard treatment in recurrent GBM and OS ranges from 3 to 9 months. GBM is 1 of the most vascularized human tumors and GBM cells produce vascular endothelial growth factor (VEGF). Bevacizumab, a humanized monoclonal antibody against VEGF, has demonstrated activity in vitro and in phase II trials in relapse, as well as in 1 phase III trial as first line therapy. Bevacizumab also improves quality of life for patients suffering GBM. This paper reviews the mechanism of action of bevacizumab, its metabolism and pharmacokinetic profile. It summarizes the clinical studies in recurrent and newly diagnosed GBM, its potential side effects and complications and its place in therapy.
Modeling the radiative effects of desert dust on weather and regional climate
Authors: Spyrou C. , Kallos G. , Mitsakou C. , Athanasiadis P. , Kalogeri C. , Iacono M. J.
Published: June 2013

Abstract. Mineral dust aerosols exert a significant effect on both solar and terrestrial radiation. By absorbing and scattering, the solar radiation aerosols reduce the amount of energy reaching the surface. In addition, aerosols enhance the greenhouse effect by absorbing and emitting outgoing longwave radiation. Desert dust forcing exhibits large regional and temporal variability due to its short lifetime and diverse optical properties, further complicating the quantification of the direct radiative effect (DRE). The complexity of the links and feedbacks of dust on radiative transfer indicate the need for an integrated approach in order to examine these impacts. In order to examine these feedbacks, the SKIRON limited area model has been upgraded to include the RRTMG (Rapid Radiative Transfer Model – GCM) radiative transfer model that takes into consideration the aerosol radiative effects. It was run for a 6 year period. Two sets of simulations were performed, one without the effects of dust and the other including the radiative feedback. The results were first evaluated using aerosol optical depth data to examine the capabilities of the system in describing the desert dust cycle. Then the aerosol feedback on radiative transfer was quantified and the links between dust and radiation were studied. The study has revealed a strong interaction between dust particles and solar and terrestrial radiation, with several implications on the energy budget of the atmosphere. A profound effect is the increased absorption (in the shortwave and longwave) in the lower troposphere and the induced modification of the atmospheric temperature profile. These feedbacks depend strongly on the spatial distribution of dust and have more profound effects where the number of particles is greater, such as near their source.
Multiple daytime nucleation events in semi-clean savannah and industrial environments in South Africa: analysis based on observations
Authors: Hirsikko A. , Vakkari V. , Tiitta P. , Hatakka J. , Kerminen V.-M. , Sundström A.-M. , Beukes J. P. , Manninen H. E. , Kulmala M. , Laakso L.
Published: June 2013

Abstract. Recent studies have shown very high frequencies of atmospheric new particle formation in different environments in South Africa. Our aim here was to investigate the causes for two or three consecutive daytime nucleation events, followed by subsequent particle growth during the same day. We analysed 108 and 31 such days observed in a polluted industrial and moderately polluted rural environments, respectively, in South Africa. The analysis was based on two years of measurements at each site. After rejecting the days having notable changes in the air mass origin or local wind direction, i.e. two major reasons for observed multiple nucleation events, we were able to investigate other factors causing this phenomenon. Clouds were present during, or in between most of the analysed multiple particle formation events. Therefore, some of these events may have been single events, interrupted somehow by the presence of clouds. From further analysis, we propose that the first nucleation and growth event of the day was often associated with the mixing of a residual air layer rich in SO2 (oxidized to sulphuric acid) into the shallow surface-coupled layer. The second nucleation and growth event of the day usually started before midday and was sometimes associated with renewed SO2 emissions from industrial origin. However, it was also evident that vapours other than sulphuric acid were required for the particle growth during both events. This was especially the case when two simultaneously growing particle modes were observed. Based on our analysis, we conclude that the relative contributions of estimated H2SO4 and other vapours on the first and second nucleation and growth events of the day varied from day to day, depending on anthropogenic and natural emissions, as well as atmospheric conditions.
Simple emission metrics for climate impacts
Authors: Aamaas B. , Peters G. P. , Fuglestvedt J. S.
Published: June 2013

Abstract. In the context of climate change, emissions of different species (e.g., carbon dioxide and methane) are not directly comparable since they have different radiative efficiencies and lifetimes. Since comparisons via detailed climate models are computationally expensive and complex, emission metrics were developed to allow a simple and straightforward comparison of the estimated climate impacts of emissions of different species. Emission metrics are not unique and variety of different emission metrics has been proposed, with key choices being the climate impacts and time horizon to use for comparisons. In this paper, we present analytical expressions and describe how to calculate common emission metrics for different species. We include the climate metrics radiative forcing, integrated radiative forcing, temperature change and integrated temperature change in both absolute form and normalised to a reference gas. We consider pulse emissions, sustained emissions and emission scenarios. The species are separated into three types: CO2 which has a complex decay over time, species with a simple exponential decay, and ozone precursors (NOx, CO, VOC) which indirectly effect climate via various chemical interactions. We also discuss deriving Impulse Response Functions, radiative efficiency, regional dependencies, consistency within and between metrics and uncertainties. We perform various applications to highlight key applications of emission metrics, which show that emissions of CO2 are important regardless of what metric and time horizon is used, but that the importance of short lived climate forcers varies greatly depending on the metric choices made. Further, the ranking of countries by emissions changes very little with different metrics despite large differences in metric values, except for the shortest time horizons (GWP20).
The mass distribution of coarse particulate organic matter exported from an alpine headwater stream
Authors: Turowski J. M. , Badoux A. , Bunte K. , Rickli C. , Federspiel N. , Jochner M.
Published: June 2013

Abstract. Coarse particulate organic matter (CPOM) particles span sizes from 1 mm, with masses less than 1 mg, to large logs and whole trees, which may have masses of several hundred kilograms. Different size and mass classes play different roles in stream environments, from being the prime source of energy in stream ecosystems to macroscopically determining channel morphology and local hydraulics. We show that a single scaling exponent can describe the mass distribution of CPOM transported in the Erlenbach, a steep mountain stream in the Swiss Prealps. This exponent takes an average value of −1.8, is independent of discharge and valid for particle masses spanning almost seven orders of magnitude. Together with a rating curve of CPOM transport rates with discharge, we discuss the importance of the scaling exponent for measuring strategies and natural hazard mitigation. Similar to CPOM, the mass distribution of in-stream large woody debris can likewise be described by power law scaling distributions, with exponents varying between −1.8 and −2.0, if all in-stream material is considered, and between −1.4 and −1.8 for material locked in log jams. We expect that scaling exponents are determined by stream type, vegetation, climate, substrate properties, and the connectivity between channels and hillslopes. However, none of the descriptor variables tested here, including drainage area, channel bed slope and forested area, show a strong control on exponent value. The number of streams studied in this paper is too small to make final conclusions.
Platelet-Rich Fibrin as a Biofuel for Tissue Regeneration
Authors: Khiste Sujeet Vinayak , Naik Tari Ritam
Published: June 2013

Wound healing is a staged process which involves the activity of leukocytes and platelets. For this process to work efficiently, the platelets play a vital role. The growth factors present in platelets are important to guide the regenerating cells to the area of healing. Platelet-rich-fibrin (PRF) is one such material that holds on to these growth factors enmeshed in the fibrin network resulting in their sustained release over a period of time that can accelerate the wound healing process. With this knowledge, research has been carried out for a past few years for the clinical application of PRF. Various platelet concentrates have been studied including the platelet-rich-plasma (PRP). However, the short duration of cytokine release and its poor mechanical properties have resulted in the search of a new material with adequate properties for clinical application and ease of preparation. PRF has found a place in the regenerative field owing to its advantages over PRP. This review focuses on the properties and various applications of PRF in the clinical practice.
Aleksei N. Tolstoi and the Enigmatic Engineer: A Case of Vicarious Revisionism
Authors: Maguire Muireann
Published: June 2013

In this article, Muireann Maguire examines the cultural construction of the trope of the engineer-inventor in Russia during the 1920s and 1930s, focusing on the changing representation of this archetype in three science fiction novels by Aleksei Tolstoi: Aelita (1922-23), Soiuzpiati (The Gang of Five, 1925), and Giperboloid inzhenera Garina (Engineer Garin's Death Ray, 1925-26). Tolstoi's fiction portrays engineers as misguided and self-centred at best and as amoral, megalomaniacal, and irredeemably un-Soviet at worst. This increasingly negative portrayal of the engineers in these novels, and in their later redactions and cinema versions, helped to prepare the way for the alienation of engineer and technical specialist within Soviet society, providing cultural justification for Iosif Stalin's show trials and purges of both categories in the 1930s. Tolstoi's alienation of the engineer-inventor, the traditional hero of early Soviet nauchnaia fantastika (science fiction), prefigured the occlusion of science fiction as a mainstream literary genre. As a trained engineer, former aristocrat, and returned émigré whose own status in Soviet Russia was deeply compromised, Tolstoi's literary demonization of engineers effectively purchased his own acceptance within the Stalinist literary hierarchy.
Dancing the Nation in the North Caucasus
Authors: Zhemukhov Sufian , King Charles
Published: June 2013

In the north Caucasus, collective dance has long been an expression of communal identity and a forum for political dissent. In this article Sufian Zhemukhov and Charles King examine the emergence and transformation of a communal dance form known asadyge jegu(roughly, “Circassian festival“) in the Russian republics of Adygeia, Karachaevo-Cherkesia, and Kabardino-Balkaria. They chart the history of the adyge jegu after 2005, elucidate debates over the meaning of authenticity in contemporary Circassian nationalism, and provide a detailed archaeology of the specific decisions that enabled this cultural artifact to get constructed in one way but not another. While attention typically focuses on elite-driven narratives of border security and terrorism, the adyge jegu highlights grassroots debates over the meaning of right behavior, the boundaries of communal identity, and alternatives to Russianness in either itsrusskiiorrossiiskiivarieties.
Population growth and status of the Nushagak Peninsula caribou herd in southwest Alaska following reintroduction, 1988 - 1993
Authors: Hinkes Michael T. , Van Daele Lawrence J.
Published: June 2013

Caribou were reintroduced to the Nushagak Peninsula, Alaska in February 1988, after an absence of over 100 years. The purpose was to reestablish caribou in the area and once again provide hunting to local residents. The Nushagak Peninsula caribou herd (NPCH) has grown rapidly from 146 reintroduced caribou to over 1000 in 6 years at an exponential rate of increase of r = 0.317 or about 38%. The dramatic growth of the herd was attributed to the initial high percentage of females in the herd, high calf production and survival, pristine range, few predators and no hunting. Abundant high quality forage on the Nushagak Peninsula is the probable reason for the enhanced body condition and high natality even among 2-year-olds, and it has most likely contributed to the high calf survival and recruitment. Lack of predators and hunting has allowed calf and adult mortality to remain low. Although the size of the NPCH has grown steadily over the past 6 years, no significant dispersal from the peninsula has occurred. The population density of the NPCH was estimated to be 1.0/km2 in 1993. We believe the herd will continue to grow, and could reach a density of 2.3/km2 by 1998, even with a 10% harvest beginning in 1995. While the current growth of the NPCH makes the réintroduction a success, the increasing density, lack of dispersal and potential for over-grazing, presents managers with hard decisions.
A fire suppression model for forested range of the Beverly and Qamanirjuaq herds of caribou
Authors: Thomas Donald C. , Caribou Management Board The Beverly and Qamanirjuaq
Published: June 2013

A fire suppression model was developed for forested winter range of the Beverly and Qamanirjuaq (formerly Kaminuriak) herds of barren-ground caribou (Rangifer tarandus groenlandicus) in north-central Canada. The model is a balance between total protection, as voiced by some aboriginal people, and a let-burn policy for natural fires advocated by some ecologists. Elements in the model were caribou ecology, lichen recovery after fire, burn history, community priorities for caribou hunting, and fire cycle lengths. The percent ratio of current productive caribou habitat to the goal for that habitat determines whether fire should be suppressed in a specific area. The goals for productive caribou habitat, defined as forests older than 50 years, were scaled by fire cycle length and community priority ranking. Thus, the model is an example of co-management: traditional knowledge combined with science in a joint forum, the Beverly and Qamanirjuaq Caribou Management Board.
Generic preference and in-vivo digestibility of alectorioid arboreal lichens by woodland caribou
Authors: Rominger Eric M. , Robbins Charles T.
Published: June 2013

All caribou exhibited a strong preference (92%) for lichen in the multi-species Bryoria complex (range=87-99%).Preference for Bryoria may be a function of higher protein content, lower tensile strength, or differences in concentrations of secondary plant constituents.
Wild reindeer of the Kamchatka Peninsula - past, present, and future
Authors: Mosolov Vladimir
Published: June 2013

A unique subspecies of wild reindeer (Rangifer tarandus phylarchus Hollister) that is endemic to the Kamchatka Peninsula has been declining in number since the 1950s due to commercial hunting, increasing industrial development and competition with domestic reindeer. The largest remaining herd of wild reindeer occurs in the Kronotsky Reserve in northeastern Kamchatka, and the reserve is now critical to the preservation of this subspecies of reindeer.
Wild reindeer of Yakutia
Authors: Safronov V.M.
Published: June 2013

Three major herds of wild reindeer (Rangifer tarandus tarandus L.), totaling over 200,000 animals, occur in the tundra and taiga of northern Yakutia. These herds have been expanding since the late 1950s and now occupy most of their historic range. In addition, several thousand wild reindeer occupy the New Siberian Islands and adjacent coastal mainland tundra, and there are about 60,000 largely sedentary forest reindeer in mountainous areas of the southern two-thirds of the province. Wild reindeer are commercially hunted throughout the mainland, and the production of wild meat is an important part of the economy of the province and of individual reindeer enterprises which produce both wild and domestic meat.
Proceedings Issue No. 3 - 2nd International Arctic Ungulate Canference
Authors: Haugerud (ed.) Rolf Egil
Published: June 2013

2nd AUC was arranged at the University of Alaska Fairbanks, USA, 13-17 August 1995.
Rangifer population ecology: a Scandinavian perspective
Authors: Reimers Eigil
Published: June 2013

Population ecology is concerned with measuring changes in population size and composition, and identifying the causes of these fluctuations. Important driving variables include animal body size and growth rate, and their relationship to reproduction and mortality. Among wild and domestic reindeer (Rangifer tarandus tarandus), reproductive performance, calving time, calf birth weight and neonatal mortality are strongly correlated to maternal weight. Heavy females enjoy higher pregnancy rates, calve earlier, and give birth to heavier calves which have a higher neonatal survival rate than light females. Most studies indicate that both weaning weight of a calf and mature body weight correlate to its birth weight. Calf body weight and composition influence the rate of attainment of sexual maturity. Females which breed as calves suffer reduced growth and give birth to smaller calves, which suffer higher neonatal mortality and lower rates of postnatal growth. A yet unresolved question is whether reindeer body weight, and hence reproductive performance and neonatal mortality, are more strongly influenced by winter than by summer grazing conditions. This paper reviews population ecology studies on wild and domestic reindeer and promotes the view that body size in Rangifer is determined primarily by grazing conditions during the summer.
Seasonal Patterns in Growth Hormone, Insulin and Insulin-like Growth Factor-1 in Female Muskoxen
Authors: Adamczewski Jan Z. , Tedesco Susan C. , Laarveld Bernhard , Flood Peter F.
Published: June 2013

Over a year, mean serum growth hormone concentrations ranged from 0.5 to 3 ng/ml in tame muskoxen with the lowest values and fewest pulses between October and January. Serum insulin ranged from 0.25 to 0.92 ng/ml, with minima in summer. There were marked seasonal changes in serum insulin-like growth factor-1 in both tame and wild muskoxen but the late summer peak was higher and more distinct in the tame animals with levels reaching 160-250 ng/ml in September.
Seasonal changes in metabolic rates in muskoxen following twenty- four hours of starvation
Authors: Lawler James P. , White Robert G.
Published: June 2013

Timing of seasonal trends in post-prandial energy expenditure (EE) was measured in muskoxen (2 males and 1 female) given a standardized meal followed by a 24-26 h starvation during 10 months over the course of a year. EE was significantly lower in winter than summer. CH4 production (EctM) was reversed with winter highs and summer lows. Ratio of ECH4:EE indicates a change in dietary efficiency but this difference was not associated with a seasonal shift in RQ which was constant. The main increase in EE from winter to summer occurred between April and May and the summer to winter decrease between August and Septembet.
Are arctic ungulates physiologically unique?
Authors: Suttie James M. , Webster James R.
Published: June 2013

Reindeer/caribou (Rangifer tarandus) and muskoxen (Ovibos moschatus) are the arctic ungulates. Few studies have been carried out to directly compare their level of physiological uniqueness with similar species in the same family. The approach adopted in this review has been to compare data within family for physiological parameters including reproduction, nutrition and growth, to attempt to place the adaptations of reindeer/caribou and muskoxen in context. It is concluded that both species have unique adaptations to their environment which are likely to be specific to the Arctic. An hypothesis is advanced that some adaptations are constrained not only by the long intense winters, but also by the need to exploit the brief summers. The review has highlighted considerable gaps in understanding of some key physiological parameters for many species. This incompleteness in some ways mitigated the original goal of the project, but provisional conclusions are presented.
Wild reindeer Rangifer tarandus (L.) in Chukotka
Authors: Chernyavskii Felix B. , Kretchmar Mikhail A.
Published: June 2013

We reviewed historical records of the abundance and distribution of wild reindeer {Rangifer tarandus L.) in Chukotka and studied reindeer numbers, distribution and behavior from 1983 to 1993. There were large numbers of wild reindeer in Chukotka until the end of the eighteenth century, but during the nineteenth century the population declined probably from intensive harvest after the introduction of firearms by the Cossacks. During the nineteenth century herding of domestic reindeer also increased, and reindeer herders continued to hunt wild reindeer intensively. During the 1950s there were only about 8500 wild reindeer in two separate herds in Chukotka. By the late 1970s the wild reindeer population had increased to about 11 000. Ten years later we estimated 16 534 reindeer, and found only one contiguous population. Presently, the population calves and spends the summer in the Anadyr Uplands and migrates west and southwest to spend the winter in forest tundra and northern taiga regions. Predators, primarily wolves and brown bears, kill a significant number of calves. Today, the wild reindeer in Chukotka coexist with 300 000 domestic reindeer. However, current costs of gasoline and helicopters make it prohibitive to herd reindeer in much of central Chukotka, so that wild reindeer have room for expansion. Poaching is a major conservation problem. Poachers shoot wild reindeer from helicopters to obtain velvet antlers. Leaders of domestic reindeer cooperatives encourage poaching by telling people that wild reindeer are in fact just stray domestic reindeer and there is no enforcement of game laws.
Alaska's indigenous muskoxen: a history
Authors: Lent Peter C.
Published: June 2013

Muskoxen (Ovibos moschatus) were widespread in northern and interior Alaska in the late Pleistocene but were never a dominant component of large mammal faunas. After the end of the Pleistocene they were even less common. Most skeletal finds have come from the Arctic Coastal Plain and the foothills of the Brooks Range. Archaeological evidence, mainly from the Point Barrow area, suggests that humans sporadically hunted small numbers of muskoxen over about 1500 years from early Birnirk culture to nineteenth century Thule culture. Skeletal remains found near Kivalina represent the most southerly Holocene record for muskoxen in Alaska. Claims that muskoxen survived into the early nineteenth century farther south in the Selawik - Buckland River region are not substantiated. Remains of muskox found by Beechey's party in Eschscholtz Bay in 1826 were almost certainly of Pleistocene age, not recent. Neither the introduction of firearms nor overwintering whalers played a significant role in the extinction of Alaska's muskoxen. Inuit hunters apparently killed the last muskoxen in northwestern Alaska in the late 1850s. Several accounts suggest that remnant herds survived in the eastern Brooks Range into the 1890s. However, there is no physical evidence or independent confirmation of these reports. Oral traditions regarding muskoxen survived among the Nunamiut and the Chandalar Kutchin. With human help, muskoxen have successfully recolonized their former range from the Seward Peninsula north, across the Arctic Slope and east into the northern Yukon Territory.
Contents table; Proceedings of the 2nd International Arctic Ungulate Conference, Fairbanks, Alaska, 13-17 August, 1995
Authors: Editor Chief
Published: June 2013

With this issue of Rangifer, the proceedings of the Fairbanks meeting are finally accomplished. Conference papers are gathered in the following issues of the journal: 1996, 16 (2): 49-92; 1997, 17 (1): 3-50; 1997, 17 (3): 10-138; 1998, 18 (3-4): 99-154.
Migration - utopia or myopia?
Authors: Osborne Peter
Published: June 2013

Peter Osborne spent a sabbatical in northern America and was surprised that so many scientists and students stated that caribou migration was largely the result of mosquito pressure. He failed however to find any documented evidence of this claim although he was constantly confronted by the well known «facts» that mosquitoes had been observed to drive caribou crazy and even kill juveniles. The issue Osborne wishes to focus is that an experimentally unsubstantiated anthropomorphism appears to have become critical evidence in support of a theory. A recent article in Nature (393, 511-513, 1998) devoted to the uses of 'science in fiction' to stimulate thought and discussion about aspects of academia encouraged him to write the following comment in the form of a parody of ancient Greek dialogues.
What does it mean to put caribou knowledge into an ecosystem context?
Authors: Harrington Fred H.
Published: June 2013

Ecosystems are envisioned as integrated, complex systems with both living and non-living components, that are linked through processes of energy flow and nutrient cycling (Bowen, 1971; Ricklefs, 1979). The ecosystem approach seeks to describe the components of this system, the pathways through which energy and nutrients move, and the processes that govern that movement. The goal is a better understanding of the role or effect of each component (abiotic or biotic) within the system. Theorerically, the more we know, the better we can predict the future behaviour of the ecosystem and therefore manage the system on whatever sustainable basis we deem appropriate. Caribou (Rangifer tarandus) presently inhabit two ecosystems, tundra (arctic and alpine) and taiga (or boreal forest), both characterized by relatively low productivity and diversity (Bowen, 1971; Bliss, 1981; Bonan, 1992a). As increased anthropogenic impacts are expected in these ecosystems through the next century, our ability to ensure the continued survival of caribou requires that we pay increasing attention to the processes that drive these systems. In this endeavour, an awareness of the effects of both spatial and temporal scale, in both ecosystem processes and our research programs to understand those processes, is critical.
Will ecosystem management supply woodland caribou habitat in northwestern Ontario?
Authors: Euler David L.
Published: June 2013

Ecosystem management is emerging as an important concept in managing forests. Although the basic conceptual idea is not new, important defining principles are developing that elucidate some of the specific attributes of ecosystem management. These principles include: the maintenance of all ecosystems in the managed forest, rhe emulation of natural disturbance patterns on rhe landscape and the insurance that structure and function of forested ecosystems are conserved. Forest management has an impact on woodland caribou (Rangifer tarandus caribou), although the presence of wolves (Canis lupus) and moose (Alces alces) in the same northern ecosystems also affects the caribou-forestry interacrion. Specific management for caribou as a featured species has been proposed, based on managing large landscape blocks. Ecosystem management would also produce habitat in a manner that might accomplish the goal of conserving woodland caribou as well as maintaining other important ecosystem functions.
Demographic characteristics of circumpolar caribou populations: ecotypes, ecological constraints, releases, and population dynamics
Authors: Mallory F.F. , Hillis T.L.
Published: June 2013

Data on the status of caribou {Rangifer tarandus) herds throughout the circumpolar region during the last 20 years were obtained from the literature and personal communication with researchers. Information was analysed in relation to ecotype (insular, montane, barren-ground, and woodland/forest), population status (increasing, stable, decreasing), herd size, human impact, and temporal change in number. The data support the conclusions (1) that each ecotype is exposed to different ecological constraints and releases, which influence the demographic characteristics of their populations, (2) that subspecific (genotypic) classification does not explain the demographic characteristics of caribou populations, (3) that insular and montane ecotype populations are relatively stable, (4) that barren-ground ecotype herds are currently experiencing synchronous population growth throughout the circumpolar region and may undergo population cycles, (5) that in North America, the woodland caribou subspecies (genotype) forms the largest barren-ground ecotype herd in the world and is not endangered nor at risk, (6) that populations of woodland/forest ecotypes are declining and threatened throughout the circumpolar region, possibly due to the interaction of human disturbance and predation, and (7) that no relationship exists between herd size and risk of being classified as threatened by researchers.
Development of a preliminary habitat assessment and planning tool for mountain caribou in southeast British Columbia
Authors: Apps Clayton D. , Kinley Trevor A.
Published: June 2013

The Purcell Mountains of southeast British Columbia support a population of mountain caribou near the southernmost extension of their range. This ecotype is dependent upon late-successional forests, largely because such stands provide arboreal lichen for winter forage. Recent provincial forest practices legislation and land-use planning initiatives have provided the impetus for developing an interim caribou habitat assessment model for use as a planning tool. We applied an HSI (habitat suitability index) model developed for a nearby population as a testable hypothesis of caribou habitat selection in the southern Purcells. In a study area of about 6000 km2, 512 radiolocations were obtained for 22 animals from 1993 through 1995. Seasonal selectivity was assessed for the following model variables: elevation, slope, habitat type/current cover type, overstory size class, canopy closure, and age of dominant overstory. Caribou were most selective for stand age, which the model also defined as the greatest determinant of habitat suitability. However, we did not judge overall model output to be an adequate predictor of habitat selection by southern Purcell caribou. Seasonal ratings for each variable were therefore modified to better reflect selection patterns by animals in this study, and subjectively adjusted to ensure that potentially limiting habitat types were rated highly. An evaluation of the adjusted model established its efficacy as an interim decision-support tool. Selection analyses of spatial habitat distribution levels indicated a preference by caribou for landscapes with at least 40% suitable habitat per 250 ha and per 5000 ha. From this, it is apparent that suitable habitat is highly fragmented in this study area.
Caribou in British Columbia: A 1996 status report
Authors: Heard Douglas C. , Vagt Kathryn L.
Published: June 2013

Caribou (Rangifer tarandus) in British Columbia are classified into mountain, northern and boreal ecotypes based on behavioural and ecological characteristics. We recognized 12 mountain caribou herds, 27 northern caribou herds, and an area occupied by low density boreal caribou dispersed in the boreal forests of the northeast portion of the province. Abundance estimates were usually based on attempts at total counts made from the air. Trends were based on repeated population estimates or the difference between recruitment and mortality rates for each herd. In 1996 there were approximately 18 000 caribou in British Columbia; 2300 mountain and 15 600 northern and boreal. These estimates suggest a slight increase in the numbers of both ecotypes over the last 18 years. Fifteen percent of the herds were reportedly increasing, 10% were decreasing, 31% were stable, but for 44% of the herds the trend was unknown. Historically caribou were found throughout 8 of the 14 biogeoclimatic zones in B.C. Caribou are now rarely found in the Sub-Boreal Spruce zone, likely due to increased predation from wolves that increased in response to increasing moose numbers. Ranges of several herds in the Engelmann Spruce — Subalpine Fir and Alpine Tundra zones of south-eastern British Columbia are also reduced relative to historic conditions, probably because of habitat loss, habitat fragmentation, predation and hunting. Forest harvesting represents the greatest threat to caribou habitat and current research focuses on the mitigation of forest harvesting impacts.
Herd size, distribution, harvest, management issues, and research priorities relevant to caribou herds in Alaska
Authors: Valkenburg Patrick
Published: June 2013

There are presently about 960 000 caribou in 32 herds in Alaska, including 4 herds shared with Yukon and Northwest Territories. Since complete population data were last published in the mid-1980s, Alaska's caribou population has doubled in size, largely from increases in the Western Arctic and Mulchatna herds. The number of recognized herds has increased by 6, largely because of increased use of radiotelemetry to inventory small caribou herds in inaccessible areas, and transplanting caribou to unoccupied ranges. About 33 000 caribou are harvested annually in Alaska, mostly from the Western Arctic, Mulchatna, and Nelchina herds. The primary wildlife management problem in Alaska for caribou and other species is the lack of clear management authority among state and federal agencies. Research priorities include work on the influence of short-term and long-term weather trends on nutritional ecology of caribou, and predation mitigation including sterilization, translocation, and diversionary feeding of wolves during the caribou calving period.
Analysis of forest stands used by wintering woodland caribou in Ontario
Authors: Antoniak K. , Cumming H.G.
Published: June 2013

Two summers' field surveys at 9 locations in northwestern Ontario showed that woodland caribou (Rangifer tarandus caribou) wintering areas supported jack pine and black spruce stands with low tree densities (mean 1552 trees/ ha, 39% of a fully stocked stand), low basal areas (mean 14.14 m2/ha), low volumes (mean 116 mVha, 68% of Normal Yield Tables) and short heights (95% of stands 12 m or less). Ecologically, most sights were classed V30. Significantly more lichen (averaging 39% lichen ground cover) was found on plots used by caribou. Three measured areas showed few shrubs, possibly enhancing escape possibilities and reducing browse attractive to moose. An HIS model predicted known locations of caribou winter habitat from FRI data with 76% accuracy. Landsat imagery theme 3 (open conifer) produced 74% accuracy. Combining these methods permitted prediction of all 50 test sites. The low volumes of timber found in caribou wintering areas suggest that setting aside reserves for caribou winter habitat would not sacrifice as much wood product value as might at first appear.
Integrating woodland caribou needs and forestry: perspectives of Alberta's forest industry
Authors: Brown W. Kent
Published: June 2013

Much of Alberta's woodland caribou (Rangifer tarandus caribou) range outside protected areas is subject to commercial forest management. In this paper, I discuss some perspectives of the forest industry regarding caribou-related issues. Six forest companies holding Forest Management Agreements (FMAs) in Alberta were polled. Forest managers were most concerned about 2 aspects of caribou management: reductions of annual allowable cut (AAC) that may be necessary to provide for caribou habitat needs; and management of public access. Perceived information gaps fell into 3 categories: caribou demographics (population size, trends and densities); primary limiting factors of caribou populations (including the influence of human activity); and caribou habitat requirements (including the effects of timber harvest on caribou habitat). Increased costs associated with consideration of caribou have been incurred at the planning and operational levels. However, those costs have been low, primarily because much proposed harvest in caribou ranges has been deferred. Costs are expected to increase substantially in the future as timber from caribou ranges is required to meet harvest objectives. Other issues identified included: the desire for an adaptive management approach to caribou-forestry interactions; the need to incorporate natural-disturbance-regime models into forest planning; consideration of the cumulative effects on caribou of all industrial and recreational activities; and unmanaged harvest by First Nations people. A list of caribou-related projects conducted or supported by forest companies in Alberta during the past 5 years is provided.
Conference report (including non-peer reviewed articles) from the 10th Nordic Conference on Reindeer Research, 13-15 March 1998, Kautokeino, Norway
Authors: Haugerud (Editor) Rolf Egil
Published: June 2013

Nordic Council for Reindeer Research (NOR) arranged the 10th Nordic Reinndeer Research Conference in Kautokeino 13-15 March 1998. The main theme was Reindeer Husbandry in the Nordic countries.
Opening speech of the NOR-conference
Authors: Guhttor Máret
Published: June 2013

The opening speech by the Director of the Sami University College, Máret Guhttor in Norwegian and North Sami, the latter was the language of presentation
Utviklingstrekk - samarbeide over landegrensene
Authors: Sara Ole K.
Published: June 2013

Introductory lecture in Norwegian about cooperation across Nordic borders with primary focus on the Nordic Council for Reindeer Research (NOR) by the former Director of the Norwegian Reindeer Husbandry Administration.
Circumpolar reindrift - Større internasjonalt engasjement i reinforskningen et nødvendig neste skritt
Authors: Turi Johan Mathis
Published: June 2013

Association of World Reindeer Herder's J.M. Turi's lecture on "Circumpolar Reindeer Husbandry - increased international focus on reindeer research a necessary step further" was held in Norwegian.
Kvinnor i modern renskötsel - Historik, status och framtid
Authors: Jonsson Berit Marie Eira
Published: June 2013

Women in Modern Reindeer Husbandry - History, Present Status and Future. Reindeer owner Berit Marie Eira Jonsson's lecture was held in Swedish.
Economical importance of Finnish reindeer industry
Authors: Nieminen Mauri , Kemppainen Jorma
Published: June 2013

Within 15 years favourable weather conditions, antiparasite medication, supplementary feed, modern technology, calf slaughter and other factors all contributed to a vast increase in reindeer, and hence reindeer meat production, so much so that by the early 1990s the total number of reindeer was approaching 430 000, and reindeer meat production exceeded 4 million kg. Due to excess numbers of reindeer, stocks had to be culled. At the same time problems arose with the processing of reindeer meat. As a result, demand slumped and prices plummeted. In a few years the outlook for reindeer management changed drastically. Since then the profession has been marked by uncertainty and change. The number of reindeer is now below the permitted level. In the 1996/97 season, number of living reindeer in herds totalled over 202 000, slaughtered reindeer 80 000 (Fig. 1) and meat production about 2 million kg. Income from slaughtered animals amounted to FIM 58 million.
De enkelte lands reindrift - Norge
Authors: Eira John Henrik
Published: June 2013

The reindeer husbandry in Norway from the view of the chairman of NRL.
Success and failure of reindeer herding in Greenland
Authors: Cuyler Christine
Published: June 2013

Animal husbandry is a recent innovation in Greenland, specifically reindeer husbandry is less than 50 years old. Reindeer husbandry was first established in mid-west Greenland and later in southern Greenland. The Greenland hunter tradition and culture is, however, still dominant in many communities. During the 1980s and 1990s, the incompatibility of these two traditions resulted in the failure of reindeer husbandry in mid-west Greenland. There were neither herding nor seasonal herd movements. Animals remained year round on the winter range, which was destroyed as lichens were trampled every summer. Without seasonal herd movements both sustainable range use and control of the herd were lost. Today, there are just two semi-domestic reindeer herds left, and both are in southern Greenland. One herd is commercially successful, and the other is under development. In mid-west Greenland, semi-domestic reindeer husbandry officially ended in 1998, and a hunt was initiated to remove the remaining population. Possibly, by the year 2000 any animals left in this region will be considered wild caribou.
Quantifying the free living energy exchanges of Arctic ungulates with stable isotopes
Authors: Haggarty Paul
Published: June 2013

When natural diets meet an animal's requirement for energy, other essential nutrients will usually be supplied in amounts at least sufficient for survival. Knowledge of the energy requirements of free ranging species under typical conditions are important in assessing both their nutritional needs and their ecological impact. The doubly labelled water (DLW) method is currently the most promising objective field methodology for estimating free living energy expenditure but expenditure is only equal to the energy requirement when an animal is in energy balance. Reproduction and seasonal cycles of fat deposition and utilization represent significant components of the energy budget of arctic ungulates but the information gained in the course of a typical DLW study may be used to estimate processes such as milk output and fat storage and mobilization in order to predict requirements from expenditure. The DLW method has been exhaustively validated under highly controlled conditions and the introduction of innovations such as faecal sampling for the estimation of body water isotopic enrichment, the availability of appropriate correction factors and stoichiometrics for known sources of error, and iterative calculation of unknown parameters, have produced a methodology suitable for use in truly free ranging species. The few studies carried out so far in arctic ungulates indicate that previous predictions have generally underestimated the true level of expenditure, that there is considerable between animal variation in the level of expenditure and that this is largely determined by physical activity. The disadvantages of the DLW methodology are that it remains expensive and the isotope analysis is technically demanding. Furthermore, although DLW can provide an accurate value for free living energy expenditure, it is often important to have information on the individual components of expenditure, for example the relative contribution of physical activity and thermoregulatory thermogenesis, in order to interpret the values for overall expenditure. For these reasons the most valuable use of the DLW method in the field may be to validate factorial models and other approaches so that they may be used with confidence. Additional important information on the energy exchanges of free ranging animals may be obtained from other stable isotope methodologies. In addition to the use of the isotopes 2H and lsO in the DLW method, natural variations in the abundance of "C and 15N in the arctic environment may be exploited to study diet selection in truly free living arctic ungulates.
Biological rhythms in Arctic vertebrates
Authors: Van Oort B. E.H. , Tyler N. J.C. , Reierth E. , Stokkan K.-A.
Published: June 2013

Many biological processes show regular cyclical fluctuations that persist throughout an organism's life; these range from the transcription of DNA to patterns of behaviour. Persistent, cyclical phenomena of this kind are a fundamental feature of all organisms. They are governed primarily by endogenous rhythms generated by a 'biological clock' situated in the brain. Normally, however, the expression of the clock is modulated to a greater or lesser extent by environmental cues. This paper reviews the physiological control of the temporal organisation of cycles in vertebrates and, in particular, explores their regulation in arctic species like reindeer (Rangifer tarandus L.). We emphasise how exposure to the photoperiodic conditions that characterise polar regions places special demands on timing mechanisms and how arctic species, therefore, are of particular interest for the study of biological rhythms. Thus far, behavioural and physiological studies of these species show that arctic reindeer (and ptarmigan) appear to be truly opportunistic in summer and wintet, seemingly without any active biological clock and that they are, instead, driven directly by photoperiod. This situation, if confirmed, would be unique among vertebrates.