51 research outputs found

    Edge-Related Loss of Tree Phylogenetic Diversity in the Severely Fragmented Brazilian Atlantic Forest

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    Deforestation and forest fragmentation are known major causes of nonrandom extinction, but there is no information about their impact on the phylogenetic diversity of the remaining species assemblages. Using a large vegetation dataset from an old hyper-fragmented landscape in the Brazilian Atlantic rainforest we assess whether the local extirpation of tree species and functional impoverishment of tree assemblages reduce the phylogenetic diversity of the remaining tree assemblages. We detected a significant loss of tree phylogenetic diversity in forest edges, but not in core areas of small (<80 ha) forest fragments. This was attributed to a reduction of 11% in the average phylogenetic distance between any two randomly chosen individuals from forest edges; an increase of 17% in the average phylogenetic distance to closest non-conspecific relative for each individual in forest edges; and to the potential manifestation of late edge effects in the core areas of small forest remnants. We found no evidence supporting fragmentation-induced phylogenetic clustering or evenness. This could be explained by the low phylogenetic conservatism of key life-history traits corresponding to vulnerable species. Edge effects must be reduced to effectively protect tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest

    Localization and broadband follow-up of the gravitational-wave transient GW150914

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    A gravitational-wave transient was identified in data recorded by the Advanced LIGO detectors on 2015 September 14. The event candidate, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the gravitational wave data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network Circulars, giving an overview of the participating facilities, the gravitational wave sky localization coverage, the timeline and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the electromagnetic data and results of the electromagnetic follow-up campaign will be disseminated in the papers of the individual teams

    Formation of filamentous carbon through dissociation of chromium carbide under hydrothermal conditions

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    Synthesis of filamentous carbon through the decomposition of chromium carbide was studied employing hydrothermal technique in the pressure and temperature range of 100–200 MPa and 350–800 °C respectively. It was found that chromium carbide dissociates into chromium oxide in the presence of water at temperature <400 °C. But, the formation of free elemental carbon as filamentous particles was noticed in the presence of organic compounds at temperatures above 600 °C. The organic compounds are known to dissociate to C–O–H supercritical fluids under hydrothermal condition. The supercritical fluids generated by the dissociation of organic compounds have great influence on the decomposition of chromium carbide. The scanning electron microscopic (SEM) studies of the experimental run products show that the fibrous or filamentous form of carbon was found with a few spherical shaped carbons, in the chromium carbide—organic compound runs. These carbon particles were solid curved filaments with a mean diameter of 50–100 nm. Micro Raman spectroscopic studies show that the filaments have sp 2 -hybridized carbon atoms

    High-yield Synthesis of Multiwalled Carbon Nanotube by Mechanothermal Method

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    <p>Abstract</p> <p>This study reports on the mechanothermal synthesis of multiwalled carbon nanotube (MWCNTs) from elemental graphite powder. Initially, high ultra-active graphite powder can be obtained by mechanical milling under argon atmosphere. Finally, the mechanical activation product is heat-treated at 1350&#176;C for 2&#8211;4 h under argon gas flow. After heat-treatment, active graphite powders were successfully changed into MWCNTs with high purity. The XRD analyses showed that in the duration 150 h of milling, all the raw materials were changed to the desired materials. From the broadening of the diffraction lines in the XRD patterns, it was concluded that the graphite crystallites were nanosized, and raising the milling duration resulted in the fineness of the particles and the increase of the strain. The structure and morphology of MWCNTs were investigated using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The yield of MWCNTs was estimated through SEM and TEM observations of the as-prepared samples was to be about 90%. Indeed, mechanothermal method is of interest for fundamental understanding and improvement of commercial synthesis of carbon nanotubes (CNTs). As a matter of fact, the method of mechanothermal guarantees the production of MWCNTs suitable for different applications.</p

    Nuorten päihteiden käyttö ja vanhempien saama tuki

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    Nuorten päihteiden käyttö on lisääntynyt viime vuosina. Nuoret eivät yleensä ole päihteistä riippuvaisia, mutta satunnainenkin kokeilu ja käyttö ovat haitallisia. Päihteiden käyttö voi olla yksittäinen ongelma, mutta myös osa suurempaa ongelmakokonaisuutta. Tämän vuoksi nuoren tilannetta tulee tarkastella kokonaisvaltaisesti. Päihteiden käyttöä ei aina huomata, ja sen ilmeneminen voi olla sokki läheisille. Päihteiden käyttö on ongelma käyttäjälle, mutta voi sairastuttaa myös läheiset. Läheiset, usein nuorten vanhemmat, tarvitsevat myös tukea ja neuvoa tilanteessa. Vanhempien oma asenne ja päihdekäyttäytyminen sekä nuoren asioista perillä oleminen ovat tärkeitä ehkäiseviä tekijöitä nuoren päihteiden käytölle. Myös nuoren oma asenne päihteisiin sekä sosiaaliset suhteet ja onnistumisen kokemukset ovat päihteiltä suojaavia tekijöitä. Tämä opinnäytetyö on tehty kokoamalla kattavasti teoriatietoa päihteistä, niiden käytöstä ja haitoista. Etelä-Karjalan sosiaali- ja terveyspiirin (Eksoten) internet-sivuilta selvitettiin, mistä ja miten voi hakea apua ja neuvoja läheisen päihteiden käytön ongelmiin. Lisäksi tehtiin kysely päihdenuorten vanhemmille. Kyselyllä selvitettiin päihdenuorten vanhempien omaa kokemusta saamastaan tuesta sosiaali- ja terveysalan ammattilaisilta. Tulokset analysoitiin empiirisesti. Tulosten mukaan osa vanhemmista on tyyty-väisiä saamaansa tukeen, osa taas kokee, ettei ole saanut tarpeeksi tukea ja tietoa. Päihdepalvelujen parempi ja määrällisesti laajempi saatavuus on kyse-lyyn vastanneiden vanhempien toiveissa. Tästä voidaan päätellä, että päih-denuorten vanhemmat otetaan huomioon ja tukea on tarjolla, mutta kaikkia tuki ei tavoita. Jatkotutkimuksessa voisi selvittää millaiseksi päihdenuoret kokevat saamansa hoidon. Lisäksi voisi selvittää miten sosiaali- ja terveysalan ammattilaiset koke-vat voivansa vaikuttaa nuorten päihdekäyttäytymiseen ja miten sosiaali- ja ter-veysalan ammattilaiset voisivat ottaa päihdenuorten vanhemmat paremmin huomioon. Kirjallisen nuorten päihdeasioita käsittelevän oppaan tekeminen ja jakaminen vanhemmille voisi olla hyödyllinen.Intoxicant use and abuse in young people has increased in recent years. Young people are generally not dependent on intoxicants, but occasional experimentation and use are harmful. Intoxicant use can be a single problem or part of a larger set of problems. Because of this, the situation of the young people should be considered from a broad perspective. Intoxicant use is not always noticed and its appearance may be a shock to those close to the user. Intoxicant use is a problem in the user, but can cause problems for families and friends, as well. Closely related, commonly parents, also need support and counsel in these situations. Parent's own attitudes and customs to use intoxicants, and knowing well issues about young people are important preventive factors for young people's intoxicant use. Also young people's attitude to intoxicant use and social affairs and experience of success are protective factors for intoxicant use. This thesis has been done by collecting comprehensive information on theory of intoxicant consumption and drawbacks of them. With the help of South Karelia District of Social and Health Service's websites, information about where and how to get help and advice for those close to young people with problems was found. In addition to this has been done an inquiry to parents of young people who use intoxicants. By the inquiry, the parents own experiences of having support from professionals in social and health care were examined. The results were analyzed empirically. According to the results, a proportion of parents are satisfied for support they have got, whereas part of parents find that they have not had enough support and information. The parents hope for better and wider availability of services for intoxicant users. Parents of young intoxicant abusers were taken into ac-count, and support services are available, but they do not reach all who need them. For further study, the opinions of the young people, and also of the health professionals about care of intoxicant abusers would be of interest
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