1,207 research outputs found

    Modelling multivariate failure time data using additive risk frailty model

    Get PDF
    Ph.DDOCTOR OF PHILOSOPH

    A new dabco-templated metal sulfate: 1,4-diazo­niabicyclo­[2.2.2]octane hexa­aqua­cadmium bis­(sulfate)

    Get PDF
    The title double mol­ecular salt, (C6H14N2)[Cd(H2O)6](SO4)2, is an isostructure of its Mn and Co analogues. The CdII atom adopts a near-regular CdO6 octa­hedral coordination geometry. The crystal structure can be described as an alternation of cationic and anionic layers along [010], and numerous O—H⋯O and N—H⋯O hydrogen bonds are observed. No thermal anomalies corresponding to possible phase transitions were observed in DSC (differential scanning calorimetry) measurements and the 93 K structure is almost the same as the room-temperature structure

    Dynamic feedbacks among tree functional traits, termite populations and deadwood turnover

    Get PDF
    Changes in the composition of plant functional traits may affect ecosystem processes through influencing trophic interactions. Bottom-up control by plant species through food availability to animals may vary with time. However, such dynamics and their consequences for deadwood turnover are poorly known for detrital food webs. We introduce a dynamic conceptual model of the feedback of tree functional traits, (deadwood-feeding) termite populations and deadwood decomposition. We hypothesized that tree functional diversity (in terms of a wood resource economic spectrum [WES]) supports the sustenance of termite populations via complementary food supplied through time, as deadwood varies in traits both initially across species and because of different decomposition rates. Simultaneously, driven by this temporal dynamics of food quality, the consumption of deadwood by termites should hypothetically sustain deadwood turnover in a functionally diverse forest over time. We tested our hypothesis through an 18-month termite-exclusion decomposition experiment by incubating coarse (i.e. 5 cm diameter) deadwood of 34 woody species in two subtropical forests in East China. One site still sustained a healthy population of pangolins as the keystone termite predator, whereas another had lost its pangolins due to hunting and illegal wildlife trade. The results supported our hypothesis: in the first 12 months, termites amplified the positive linear relationship between % wood mass loss and initial wood quality (WES). In contrast, between 12 and 18 months, termite-mediated consumption, and associated wood mass loss, showed a humpback relation with the initial WES. This shift in termite preference of deadwood species along the WES reflects complementary food availability to termites through time. Synthesis. Our findings imply that tree functional composition, with variation in deadwood quality through decomposition time, can help to sustain termite populations and thereby forest carbon turnover. Future studies need to test whether and how our conceptual model may apply to other detrital systems and food webs. In general, food web research would benefit from a stronger focus on temporal patterns for better understanding the interactions of basal resource functional traits and consumers on ecosystem functions

    Cross-Dataset Person Re-Identification via Unsupervised Pose Disentanglement and Adaptation

    Full text link
    Person re-identification (re-ID) aims at recognizing the same person from images taken across different cameras. To address this challenging task, existing re-ID models typically rely on a large amount of labeled training data, which is not practical for real-world applications. To alleviate this limitation, researchers now targets at cross-dataset re-ID which focuses on generalizing the discriminative ability to the unlabeled target domain when given a labeled source domain dataset. To achieve this goal, our proposed Pose Disentanglement and Adaptation Network (PDA-Net) aims at learning deep image representation with pose and domain information properly disentangled. With the learned cross-domain pose invariant feature space, our proposed PDA-Net is able to perform pose disentanglement across domains without supervision in identities, and the resulting features can be applied to cross-dataset re-ID. Both of our qualitative and quantitative results on two benchmark datasets confirm the effectiveness of our approach and its superiority over the state-of-the-art cross-dataset Re-ID approaches.Comment: Accepted to ICCV 201
    corecore