Two-electron lateral quantum-dot molecules in a magnetic field

Laterally coupled quantum dot molecules are studied using exact diagonalization techniques. We examine the two-electron singlet-triplet energy difference as a function of magnetic field strength and investigate the magnetization and vortex formation of two- and four-minima lateral quantum dot molecules. Special attention is paid to the analysis of how the distorted symmetry affects the properties of quantum-dot molecules.Comment: 18 pages, 26 figure

Reproduction and Mortality of Finnish Semi-Domesticated Reindeer in Relation to Density and Management Strategies

We assessed the effects of management strategies during 1960-73 relative to strategies used during 1974-87 on the reproduction and mortality of 56 semi-domesticated herds of Finnish reindeer (Rangifer tarandus tarandus). During 1960-73, reindeer fed exclusively on natural forage growing on their range, and reindeer were harvested mostly as adults. These strategies were modified starting in 1974 to include supplemental feeding in the southern part of the Finnish reindeer range and calf harvesting throughout the range. We found significantly higher calf/female ratios, lower mortality, and less variation in both calf/female ratios and mortality during 1974-87 than during 1960-73. These changes occurred in spite of increased animal density. Coefficients of variation in calf/female ratio and mortality were negatively correlated with the prevalence of mature spruce forests, which are rich in arboreal lichens. Mean calf/female ratio and mortality rate depended on reindeer density only in the southern region during 1960-73. During 1974-87 these did not depend on density in any region. Within herds, calf/female ratio did not depend on density in most cases (98%), while in the later period the relationship between calf production and density was positive in some cases (25%). Mortality depended more often on density during the earlier (46% of herds) than the later (23% of herds) period. Calf harvesting influenced mortality more than supplemental feeding and virtually freed reindeer from density-dependent limitations. Supplemental feeding was used to compensate for deterioration of range resulting from overgrazing and logging of mature forests rich in arboreal lichens.Key words: reproduction, mortality, density dependence, reindeer, Rangifer tarandus, management, FinlandOn a évalué les retombées des stratégies d'aménagement utilisées entre 1960 et 1973 par rapport à celles utilisées de 1974 à 1987 sur la reproduction et la mortalité de 56 troupeaux semi-domestiques de caribous finlandais (Rangifer tarandus tarandus). Au cours de la période allant de 1960 à 1973, les caribous se nourrissaient uniquement de fourrage naturel provenant de leur territoire, et le prélèvement des caribous s'effectuait en majorité sur des animaux adultes. À partir de 1974, ces stratégies ont été modifiées pour inclure un supplément à l'alimentation du caribou finlandais dans la partie sud de son territoire ainsi que le prélèvement de jeunes animaux sur la totalité du territoire. On a trouvé qu'au cours de la période allant de 1974 à 1987, le taux veaux/femelles était considérablement plus élevé, la mortalité était bien moindre et les fluctuations dans le taux veaux/femelles comme dans la mortalité était moindres qu'au cours de la période allant de 1960 à 1973. Ces changements se sont produits en dépit d'une augmentation de la densité des animaux. Les coefficients de variation dans le taux veaux/femelles et la mortalité avaient une corrélation négative avec la prédominance de forêts d'épinettes matures, où abondent les lichens corticicoles. La moyenne du taux veaux/femelles et du taux de mortalité ne dépendait de la densité du caribou que dans la partie méridionale entre 1960 et 1973. Entre 1974 et 1987, ces paramètres n'étaient fonction de la densité dans aucune région. Au sein des troupeaux, le taux veaux/femelles n'était pas fonction de la densité dans la plupart des cas (98 p. cent), alors que dans la deuxième période de l'étude, le rapport entre la production de veaux et la densité était positif dans quelques cas (25 p. cent). La mortalité dépendait plus souvent de la densité au cours de la première période de l'étude (45 p. cent) qu'au cours de la seconde (23 p. cent). Le prélèvement des veaux avait une influence sur la mortalité plus que ne l'avait le supplément à l'alimentation et libérait pratiquement le caribou des restrictions dues à la dépendance de la densité. Le supplément à l'alimentation était utilisé comme compensation à la détérioration du territoire due au surpâturage et à l'exploitation forestière de forêts matures riches en lichens corticicoles.Mots clés: reproduction, mortalité, fonction de la densité, renne, Rangifer tarandus, aménagement, Finland

Effects of insect harassment on weight gain and survival in reindeer calves

Relationships between insect harassment and the weight gain and survival of reindeer calves were studied in two areas in Finland north of the Arctic Circle. The level of insect harassment explained a significant amount of the yearly variation in calf weights determined in autumn or early winter in both areas and directly influenced calf mortality in one of them. The lowest weights and calf percents were experienced in years when a bad winter was followed by a warm summer with severe insect harassment.Råkån vaikutus poronvasojen painonlisåykseen ja eloonjååmiseen.Abstract in Finnish / Tiivistelmd: Rakan (vertaimevat ja porossa loisivat hyonteiset) vaikutusta vasojen painoon ja vasaprosenttiin tutkittiin Alakylan paliskunnassa sekå Kaldoaivi - Paistunturin alueella. Kummallakin alueella rakka selitti huomattavan osan vasojen syyspainojen vuosivaihtelusta ja Kaldoaivi - Paistunturissa se vaikutti suoraan myos vasaprosenttiin. Vasojen painot ja vasaprosentit olivat alhaisimmat vuosina, joina vaikeaa talvea seurasi kuuma, hyonteisille suotuisa kesa.Effekter av insektforstyrrelser på vektøkning og overlevelse av reinkalver.Abstract in Swedish / Sammendrag: Effekter av insektforstyrrelser på vektøkning og overlevelse av reinkalver er studert i to områder av Finland nord for Polarsirkelen. Graden av insektforstyrrelser forklarte en signifikant andel av variasjonene fra år til år i kalvevekter bestemt høst eller tidlig vinter for begge områder. Den virket også direkte inn på kalvedødeligheten i et av områdene. De laveste vekter og kalveprosenter fant man i år der en dårlig vinter ble etterfulgt av en varm sommer med alvorlige insektforstyrrelser

Economic comparison of two methods of supplementary feeding in Finnish reindeer management

The most common methods are (1) supplementary feeding with dry hay (maximally 50 kg per head a season) on natural ranges in mid and late winter, and (2) corral feeding, where the reindeer are fed in small yard-corrals with hay, green silage, lichen, molasses and commercial reindeer feeds for 3-5 months a winter

UNITED STATES ARMY SPECIAL OPERATIONS COMMAND PERFORMANCE MANAGEMENT PRACTICES

The U.S. Army considers people its competitive advantage; however, industrial-age personnel practices still factor into its performance management systems. Just as the Army cannot succeed in fighting future wars with yesterday’s technology, it cannot succeed using antiquated performance management practices in the information age and beyond. With this in mind, we used a mixed research methodology to answer the following question: How can USASOC’s performance management practices be adapted to improve performance and retention of special forces officers? First, we conducted a qualitative comparison of for-profit, nonprofit, and military organizations. Second, we performed quantitative analysis via a SOCOM–sponsored survey of special forces officers. Findings indicate that retention is an output of talent acquisition and talent management systems and is heavily influenced by organizational culture. Moreover, retention issues are symptoms of a larger problem that requires a holistic solution and modernization of performance management practices. We recommend that USASOC adopt a sociotechnical performance management system that incorporates a continuous 360 performance review process, data-driven methodology, and multi-dimensional evaluations to improve performance and retention. Finally, USASOC should extend time in key developmental positions and create specialized career tracks that enable depth of professional development.Major, United States ArmyMajor, United States ArmyMajor, United States ArmyApproved for public release. distribution is unlimite

Sized-related changes in winter condition of male calves in reindeer

Size-related changes in body condition of free-ranging male calves of semi-domesticated reindeer were studied in northern Finland from October 1983 to February 1984. In October-November, back fat depth or muscle fat percent correlated positively with the body size (=back length). In January, the highest means especially for muscle fat percent were found among medium-sized calves. Carcass weight and weight/back length ratio correlated positively with size, excluding February sample, where correlation for carcass weight was non-significant and for weight/back length ratio negative. Weight in the autumn correlated negatively with weight in February. Therefore, normalizing selection for body size (working against small and large phenotypes) is expected to occur in late winter. Small calves may be at greater mortality risk because of lower initial body reserves. Large calves commonly disperse during the rutting season and they may suffer most from increased food competition later in winter. Using of medium-sized calves for breeding might be the safest policy on ranges characterized by short food supply and difficult snow conditions.Koon vaikutus poron urosvasojen talviseen kuntoon.Abstract in Finnish / Tiivistelmä: Koon vaikutusta vapaana laiduntavien poron urosvasojen kuntoon tutkittiin Pohjois-Suomessa loka-helmikuussa talvella 1983-84. Loka-marraskuussa selkärasvan paksuus tai lihaksen rasvaprosentti riippui vasan koosta ( = selän pituus). Tammikuussa sen sijaan lihaksen rasvaprosentti oli korkein keskikokoisilla vasoilla. Ruhopaino sekä ruhopaino/selän pituus oli yleensa riippuvainen koosta. Helmikuussa ruhopainon riippuvuus koosta ei ollut enää tilastollisesti merkitsevä, ja koon ja ruhopainon/selänpituuden välinen korrelaatio oli negatiivinen. Eniten painoa menettivät (%) loka-helmikuun välillä suurikokoisimmat vasat. Havainnot viittaavat siihen, että talvella esiintyvä kuolleisuus on normalisoivaa koon suhteen (karsii pieniä ja suuria fenotyyppejä). Pienten vasojen kuolleisuusriski on suuri alunperinkin vähäisen varastoravinnon vuoksi. Suuret vasat puolestaan erkaantuvat usein emistään jo rykimäaikana, ja joutuvat kärsimään eniten talven mittaan kiristyvästä ravintokilpailusta. Niukoilla laitumilla siitokseen on turvallisinta säästää keskikokoisia vasoja.Sammenhengen mellom størrelse og vinterkondisjon hos hankalver av reinsdyr.Abstract in Norwegian / Sammendrag: Størrelses-relaterte forandringer i kroppskondisjon hos fritt beitende han-kalver av semidomestiserte rein er studert i Nord-Finland fra oktober 1983 til februar 1984. I oktober - november korrelerte tykkelsen av ryggfettet eller muskelfett-prosenten positivt med kroppsstørrelsen (= rygglengden). I januar ble de høyeste middelverdier, særlig for muskelfett-prosenten, funnet hos kalver av middels størrelse. Skrott-vekter og vekt/rygglengde-forholdet korrelerte positivt med kroppsstørrelse bortsett fra februar-prøvene, der korrellasjonen for skrott-vekt var ikke-signifikant og for vekt/rygglengde-forholdet var negativt. Vekt om høsten korrelerte negativt med vekt i februar. Derfor ventes et normaliserende utvalg for kroppsvekt (som arbeider mot små og store fenotyper) å skje på senvinteren. Små kalver er utsatt for større dødsrisiko på grunn av lavere kroppsreserver. Store kalver streifer vanligvis under brunsttiden og kan komme til å lide under økt næringskonkurranse på senvinteren. Bruk av middels store kalver i avlen kan være den sikreste metode på beiter som karakteriseres av dårlige næringstilgang og vanskelige snøforhold

First videos of endemic Zanzibar servaline genet Genetta servalina archeri, African palm civet Nandinia binotata (Mammalia: Carnivora: Viverridae) and other small carnivores on Unguja Island, Tanzania

The faunal diversity of the densely populated island of Unguja, Zanzibar archipelago, Tanzania, includes several endemic mammals. Camera-trapping in Jozani-Chwaka Bay National Park and Kiwengwa–Pongwe Forest Reserve in September 2017 captured the first video footage of the Zanzibar Servaline Genet Genetta servalina archeri, an endemic subspecies first formally described in 1998. Other native small carnivores were also recorded on video for the first time during this survey, including the African Palm Civet Nandinia binotata, which was first documented in print as present in Unguja in 2004. Also camera-trapped in 2017 were the Zanzibar Slender Mongoose Herpestes sanguineus rufescens and the Zanzibar Bushy-tailed Mongoose Bdeogale crassicauda tenuis. Follow-up cameratrapping in Jozani-Chwaka Bay National Park in August 2018 captured additional video of the Zanzibar Servaline Genet and the African Palm Civet. No images were obtained of the African Civet Civettictis civetta, or of the two introduced species—the Banded Mongoose Mungos mungo and the Small Indian Civet Viverricula indica—in either year. As the remaining natural habitat in Zanzibar shrinks in size and becomes fragmented, it is increasingly urgent to document the archipelago’s carnivores and other fauna, so that sound conservation measures can be implemented

Scaling Laws of Stress and Strain in Brittle Fracture

A numerical realization of an elastic beam lattice is used to obtain scaling exponents relevant to the extent of damage within the controlled, catastrophic and total regimes of mode-I brittle fracture. The relative fraction of damage at the onset of catastrophic rupture approaches a fixed value in the continuum limit. This enables disorder in a real material to be quantified through its relationship with random samples generated on the computer.Comment: 4 pages and 6 figure

Lichen ranges, animal densities and production in Finnish reindeer management

In the 1970s, mean lichen biomass ranged by the earmark districts (comprising of 2-9 adjacent herding associations) between 54 kg and 380 kg DM per ha correlating negatively with animal density per lichen ranges (range 1.5 - 14.3 ind. per km2). Biomasses were far below economic carrying capacity of lichen ranges (900 kg DM per ha). The condition of lichen ranges was poorest in the southern half of the area where alternative food to reindeer lichens (Deschampsia flexuosa, arboreal lichens and supplementary feeding) was available. In 1980-86, recruitment (calves per 100 females) was 33% higher than in the 1970's, on an average (65 vs. 49), despite a 90% increase in animal numbers between 1970 and 1986; recruitment has not been dependent on the condition of lichen ranges. The increase in production has been some higher than expected on the basis of animal numbers. The reasons for the increasing trends in animal numbers, recruitment and production remains some unclear, but they may include favorable winter conditions, supplementary feeding, medical treatment against parasites and proper harvesting policy

The effects of stand characteristics on reindeer lichens and range use by semi-domesticated reindeer

The study was carried out in Kuusamo (66°15'N, 29°05'E) and Inari (68°30'N, 28°15'E), northern Finland, where 24 and 22 Scots pine stands were studied respectively. Clear-cutting (logging residue) caused a decline in lichen biomass for some few years, but otherwise the age of the stand had no effect upon lichen biomass. Instead, a positive correlation was found between litter/logging residue and the mean height of lichens; in Kuusamo, logging residue decreased significantly with the age of the stand. Grazing pressure in terms of fecal group density increased with the age of the stand. The preference of old forests came visible also as a lower mean height of lichens, which eliminates the possibility that the preference of old forests is associated only to the use of arboreal lichens. In Inari, grazing pressure sharply increased after the stand had reached the age of 100 years despite scarce litter/logging residue and fair lichen ranges in younger forests; there prevailed a negative correlation between stand density and grazing pressure. It has been suggested that there might be three main reasons for reindeers preferring old forests: 1) hardening of the snow (because of winds) on clear-cut areas, 2) logging residue preventing digging for the food beneath the snow, and 3) poor visibility in young pine stands (Inari) which might increase predation risk