Entanglement generation resonances in XY chains

We examine the maximum entanglement reached by an initially fully aligned state evolving in an XY Heisenberg spin chain placed in a uniform transverse magnetic field. Both the global entanglement between one qubit and the rest of the chain and the pairwise entanglement between adjacent qubits is analyzed. It is shown that in both cases the maximum is not a monotonous decreasing function of the aligning field, exhibiting instead a resonant behavior for low anisotropies, with pronounced peaks (a total of [n/2] peaks in the global entanglement for an $n$-spin chain), whose width is proportional to the anisotropy and whose height remains finite in the limit of small anisotropy. It is also seen that the maximum pairwise entanglement is not a smooth function of the field even in small finite chains, where it may exhibit narrow peaks above strict plateaus. Explicit analytical results for small chains, as well as general exact results for finite n-spin chains obtained through the Jordan-Wigner mapping, are discussed

Long-term results of NOPHO ALL-92 and ALL-2000 studies of childhood acute lymphoblastic leukemia

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldAnalysis of 2668 children with acute lymphoblastic leukemia (ALL) treated in two successive Nordic clinical trials (Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL-92 and ALL-2000) showed that 75% of all patients are cured by first-line therapy, and 83% are long-term survivors. Improvements in systemic and intrathecal chemotherapy have reduced the use of central nervous system (CNS) irradiation to <10% of the patients and provided a 5-year risk of isolated CNS relapse of 2.6%. Improved risk stratification and chemotherapy have eliminated the previous independent prognostic significance of gender, CNS leukemia and translocation t(1;19)(q23;p13), whereas the post-induction level of minimal residual disease (MRD) has emerged as a new risk grouping feature. Infant leukemia, high leukocyte count, T-lineage immunophenotype, translocation t(4;11)(q21;q23) and hypodiploidy persist to be associated with lower cure rates. To reduce the overall toxicity of the treatment, including the risk of therapy-related second malignant neoplasms, the current NOPHO ALL-2008 protocol does not include CNS irradiation in first remission, the dose of 6-mercaptopurine is reduced for patients with low thiopurine methyltransferase activity, and the protocol restricts the use of hematopoietic stem cell transplantation in first remission to patients without morphological remission after induction therapy or with high levels of MRD after 3 months of therapy

The density of anthropogenic features explains seasonal and behaviour-based functional responses in selection of linear features by a social predator

Anthropogenic linear features facilitate access and travel efficiency for predators, and can influence predator distribution and encounter rates with prey. We used GPS collar data from eight wolf packs and characteristics of seismic lines to investigate whether ease-of-travel or access to areas presumed to be preferred by prey best explained seasonal selection patterns of wolves near seismic lines, and whether the density of anthropogenic features led to functional responses in habitat selection. At a broad scale, wolves showed evidence of habitat-driven functional responses by exhibiting greater selection for areas near low-vegetation height seismic lines in areas with low densities of anthropogenic features. We highlight the importance of considering landscape heterogeneity and habitat characteristics, and the functional response in habitat selection when investigating seasonal behaviour-based selection patterns. Our results support behaviour in line with search for primary prey during summer and fall, and ease-of-travel during spring, while patterns of selection during winter aligned best with ease-of-travel for the less-industrialized foothills landscape, and with search for primary prey in the more-industrialized boreal landscape. These results highlight that time-sensitive restoration actions on anthropogenic features can affect the probability of overlap between predators and threatened prey within different landscapes

Dic(9;20)(p13;q11) in childhood acute lymphoblastic leukaemia is related to low cellular resistance to asparaginase, cytarabine and corticosteroids.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldDic(9;20)(p13;q11) was first described as a nonrandom chromosome abnormality in B-cell precursor acute lymphoblastic leukaemia (BCP ALL) in the mid 1990s,1, 2 and 71 dic(9;20)-positive cases have since then been reported.3, 4, 5 Approximately 90% of these cases were children or adolescents, with dic(9;20) occurring in about 2% of childhood BCP ALL.6 The recent review by Forestier et al.5 describes that dic(9;20)-leukaemias are of B-cell precursor immunophenotype, never have a high hyperdiploid modal number, show a female predominance, and have a significant age incidence peak at 3 years. Most patients are allocated to non-standard risk treatment arms due to high WBC (median 24 109/l) and a relatively high frequency of CNS disease or other extra-medullary leukaemia (EML) at diagnosis. The prognostic implications of dic(9;20) are to a large extent unknown. A relatively large proportion of the relapses reported in the literature have been extra-medullary, and post-relapse treatment including block therapy has been successful in several patients, as illustrated by a p-EFS of 0.62 and a predicted overall survival of 0.82 at 5 years for the 24 Nordic cases.

How Landscape Ecology Informs Global Land-Change Science and Policy

Landscape ecology is a discipline that explicitly considers the influence of time and space on the environmental patterns we observe and the processes that create them. Although many of the topics studied in landscape ecology have public policy implications, three are of particular concern: climate change; land use–land cover change (LULCC); and a particular type of LULCC, urbanization. These processes are interrelated, because LULCC is driven by both human activities (e.g., agricultural expansion and urban sprawl) and climate change (e.g., desertification). Climate change, in turn, will affect the way humans use landscapes. Interactions among these drivers of ecosystem change can have destabilizing and accelerating feedback, with consequences for human societies from local to global scales. These challenges require landscape ecologists to engage policymakers and practitioners in seeking long-term solutions, informed by an understanding of opportunities to mitigate the impacts of anthropogenic drivers on ecosystems and adapt to new ecological realities

Drug metabolizing enzyme activities versus genetic variances for drug of clinical pharmacogenomic relevance

Enzymes are critically important in the transportation, metabolism, and clearance of most therapeutic drugs used in clinical practice today. Many of these enzymes have significant genetic polymorphisms that affect the enzyme's rate kinetics. Regarding drug metabolism, specific polymorphisms to the cytochrome (CYP) P450 enzyme family are linked to phenotypes that describe reaction rates as "ultra", "intermediate", and "poor," as referenced to "extensive" metabolizers that are assigned to wildtype individuals. Activity scores is an alternate designation that provides more genotype-to-phenotype resolution. Understanding the relative change in enzyme activities or rate of clearance of specific drugs relative to an individual's genotypes is an important component in the interpretation of pharmacogenomic data for personalized medicine. Currently, the most relevant drug metabolizing enzymes are CYP 2D6, CYP 2C9, CYP 2C19, thiopurine methyltransferase (TPMT) and UDP-glucuronosyltransferase (UGT). Each of these enzymes is reactive to a host of different drug substrates. Pharmacogenomic tests that are in routine clinical practice include CYP 2C19 for clopidogrel, TPMT for thiopurine drugs, and UDP-1A1 for irinotecan. Other tests where there is considerable data but have not been widely implemented includes CYP 2C9 for warfarin, CYP 2D6 for tamoxifen and codeine, and CYP 2C19 for the proton pump inhibitors

Reliability of Rapid Diagnostic Tests in Diagnosing Pregnancy-Associated Malaria in North-Eastern Tanzania.

Accurate diagnosis and prompt treatment of pregnancy-associated malaria (PAM) are key aspects in averting adverse pregnancy outcomes. Microscopy is the gold standard in malaria diagnosis, but it has limited detection and availability. When used appropriately, rapid diagnostic tests (RDTs) could be an ideal diagnostic complement to microscopy, due to their ease of use and adequate sensitivity in detecting even sub-microscopic infections. Polymerase chain reaction (PCR) is even more sensitive, but it is mainly used for research purposes. The accuracy and reliability of RDTs in diagnosing PAM was evaluated using microscopy and PCR. A cohort of pregnant women in north-eastern Tanzania was followed throughout pregnancy for detection of plasmodial infection using venous and placental blood samples evaluated by histidine rich protein 2 (HRP-2) and parasite lactate dehydrogenase (pLDH) based RDTs (Parascreen™) or HRP-2 only (Paracheck Pf® and ParaHIT®f), microscopy and nested Plasmodium species diagnostic PCR. From a cohort of 924 pregnant women who completed the follow up, complete RDT and microscopy data was available for 5,555 blood samples and of these 442 samples were analysed by PCR. Of the 5,555 blood samples, 49 ((proportion and 95% confidence interval) 0.9% [0.7 -1.1]) samples were positive by microscopy and 91 (1.6% [1.3-2.0]) by RDT. Forty-six (50.5% [40.5 - 60.6]) and 45 (49.5% [39.4 - 59.5]) of the RDT positive samples were positive and negative by microscopy, respectively, whereas nineteen (42.2% [29.0 - 56.7]) of the microscopy negative, but RDT positive, samples were positive by PCR. Three (0.05% [0.02 - 0.2]) samples were positive by microscopy but negative by RDT. 351 of the 5,461 samples negative by both RDT and microscopy were tested by PCR and found negative. There was no statistically significant difference between the performances of the different RDTs. Microscopy underestimated the real burden of malaria during pregnancy and RDTs performed better than microscopy in diagnosing PAM. In areas where intermittent preventive treatment during pregnancy may be abandoned due to low and decreasing malaria risk and instead replaced with active case management, screening with RDT is likely to identify most infections in pregnant women and out-performs microscopy as a diagnostic tool