Managing complexity in a distributed digital library

As the capabilities of distributed digital libraries increase, managing organizational and software complexity becomes a key issue. How can collections and indexes be updated without impacting queries currently in progress? How can the system handle several user-interface clients for the same collections? Computer science professors and lectors from the University of Waikato have developed a software structure that successfully manages this complexity in the New Zealand Digital Library. This digital library has been a success in managing organizational and software complexity. The researchers' primary goal has been to minimize the effort required to keep the system operational and yet continue to expand its offerings

Delivering the Maori-language newspapers on the Internet

Although any collection of historical newspapers provides a particularly rich and valuable record of events and social and political commentary, the content tends to be difficult to access and extremely time-consuming to browse or search. The advent of digital libraries has meant that for electronically stored text, full-text searching is now a tool readily available for researchers, or indeed anyone wishing to have asscess to specific information in text. Text in this form can be readily distributed via CD-ROM or the Internet, with a significant impact on accessibility over traditional microfiche or hard-copy distribution. For the majority of text being generated de nouveau, availability in electronic form is standard, and hence the increasing use of full-text search facilities. However, for legacy text available only in printed form, the provision of these electronic search tools is dependent on the prior electronic capture of digital facsimile images of the printed text, followed by the conversion of these images to electronic text through the process of optical character recognition (OCR). This article describes a project undertaken at the University of Waikato over the period 1999 to 2001 to produce a full-text searchable version of the Niupepa or Maori- language newspaper collection for delivery over the Internet

Characterisation of Ba(OH)(2)-Na2SO4-blast furnace slag cement-like composites for the immobilisation of sulfate bearing nuclear wastes

Soluble sulfate ions in nuclear waste can have detrimental effects on cementitious wasteforms and disposal facilities based on Portland cement. As an alternative, Ba(OH)2–Na2SO4–blast furnace slag composites are studied for immobilisation of sulfate-bearing nuclear wastes. Calcium aluminosilicate hydrate (C–A–S–H) with some barium substitution is the main binder phase, with barium also present in the low solubility salts BaSO4 and BaCO3, along with Ba-substituted calcium sulfoaluminate hydrates, and a hydrotalcite-type layered double hydroxide. This reaction product assemblage indicates that Ba(OH)2 and Na2SO4 act as alkaline activators and control the reaction of the slag in addition to forming insoluble BaSO4, and this restricts sulfate availability for further reaction as long as sufficient Ba(OH)2 is added. An increased content of Ba(OH)2 promotes a higher degree of reaction, and the formation of a highly cross-linked C–A–S–H gel. These Ba(OH)2–Na2SO4–blast furnace slag composite binders could be effective in the immobilisation of sulfate-bearing nuclear wastes

Evidence for B cell exhaustion in chronic graft-versus-host disease

Chronic graft-versus-host disease (cGvHD) remains a major complication of allogeneic hematopoietic stem cell transplantation (HSCT). A number of studies support a role for B cells in the pathogenesis of cGvHD. In this study, we report the presence of an expanded population of CD19+CD21− B cells with features of exhaustion in the peripheral blood of patients with cGvHD. CD21− B cells were significantly increased in patients with active cGvHD compared to patients without cGvHD and healthy controls (median 12.2 versus 2.12 versus 3%, respectively; p < 0.01). Compared with naïve (CD27−CD21+) and classical memory (CD27+CD21+) B cells, CD19+CD21− B cells in cGvHD were CD10 negative, CD27 negative and CD20hi, and exhibited features of exhaustion, including increased expression of multiple inhibitory receptors such as FCRL4, CD22, CD85J, and altered expression of chemokine and adhesion molecules such as CD11c, CXCR3, CCR7, and CD62L. Moreover, CD21− B cells in cGvHD patients were functionally exhausted and displayed poor proliferative response and calcium mobilization in response to B-cell receptor triggering and CD40 ligation. Finally, the frequencies of circulating CD21− B cells correlated with cGvHD severity in patients after HSCT. Our study further characterizes B cells in chronic cGVHD and supports the use of CD21−CD27−CD10− B cell frequencies as a biomarker of disease severity

Nanostructure of cellulose microfibrils in spruce wood

The structure of cellulose microfibrils in wood is not known in detail, despite the abundance of cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the microfibrils of spruce wood cellulose was investigated using a range of spectroscopic methods coupled to small-angle neutron and wide-angle X-ray scattering. The scattering data were consistent with 24-chain microfibrils and favored a “rectangular” model with both hydrophobic and hydrophilic surfaces exposed. Disorder in chain packing and hydrogen bonding was shown to increase outwards from the microfibril center. The extent of disorder blurred the distinction between the I alpha and I beta allomorphs. Chains at the surface were distinct in conformation, with high levels of conformational disorder at C-6, less intramolecular hydrogen bonding and more outward-directed hydrogen bonding. Axial disorder could be explained in terms of twisting of the microfibrils, with implications for their biosynthesis

Eradication of chronic myeloid leukemia stem cells: a novel mathematical model predicts no therapeutic benefit of adding G-CSF to imatinib

Imatinib mesylate induces complete cytogenetic responses in patients with chronic myeloid leukemia (CML), yet many patients have detectable BCR-ABL transcripts in peripheral blood even after prolonged therapy. Bone marrow studies have shown that this residual disease resides within the stem cell compartment. Quiescence of leukemic stem cells has been suggested as a mechanism conferring insensitivity to imatinib, and exposure to the Granulocyte-Colony Stimulating Factor (G-CSF), together with imatinib, has led to a significant reduction in leukemic stem cells in vitro. In this paper, we design a novel mathematical model of stem cell quiescence to investigate the treatment response to imatinib and G-CSF. We find that the addition of G-CSF to an imatinib treatment protocol leads to observable effects only if the majority of leukemic stem cells are quiescent; otherwise it does not modulate the leukemic cell burden. The latter scenario is in agreement with clinical findings in a pilot study administering imatinib continuously or intermittently, with or without G-CSF (GIMI trial). Furthermore, our model predicts that the addition of G-CSF leads to a higher risk of resistance since it increases the production of cycling leukemic stem cells. Although the pilot study did not include enough patients to draw any conclusion with statistical significance, there were more cases of progression in the experimental arms as compared to continuous imatinib. Our results suggest that the additional use of G-CSF may be detrimental to patients in the clinic

Alloreactivity: the Janus-face of hematopoietic stem cell transplantation

Differences in major and minor histocompatibility antigens between donor and recipient trigger powerful graft-versus-host reactions after allogeneic hematopoietic stem cell transplantation (HSCT). The clinical effects of alloreactivity present a Janus-face: detrimental graft-versus-host disease increases non-relapse mortality, beneficial graft-versus-malignancy may cure the recipient. The ultimate consequences on long-term outcome remain a matter of debate. We hypothesized that increasing donor-recipient antigen matching would decrease the negative effects, while preserving antitumor alloreactivity. We analyzed retrospectively a predefined cohort of 32 838 such patients and compared it to 59 692 patients with autologous HSCT as reference group. We found a significant and systematic decrease in non-relapse mortality with decreasing phenotypic and genotypic antigen disparity, paralleled by a stepwise increase in overall and relapse-free survival (Spearman correlation coefficients of cumulative excess event rates at 5 years 0.964; P<0.00; respectively 0.976; P<0.00). We observed this systematic stepwise effect in all main disease and disease-stage categories. The results suggest that detrimental effects of alloreactivity are additive with each step of mismatching; the beneficial effects remain preserved. Hence, if there is a choice, the best match should be donor of choice. The data support an intensified search for predictive genomic and environmental factors of ‘no-graft-versus-host disease’.Leukemia advance online publication, 7 April 2017; doi:10.1038/leu.2017.79