bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth of self-assembled monolayers on sulfide treated gallium arsenide using predetermined linkage moieties
Authors: Keys Andrea , Barron Andrew R.
Published: August 2006

Hexanethiol (C6H13SH), phenylphosphonic acid [PhP(O)(OH)2], and 3-bromo-benzoic acid (3-BrC6H4CO2H) have been reacted with {100}-GaAs surface which have been pretreated with an acid etch and an ammonium sulfide reactive passivation layer. The chemically reacted surfaces have been characterized by XPS and advancing contact angle measurements. As predicted from simple model compounds, [(tBu)2Ga(µ-X)]2, the thiol and phosphonic acid ligands allow for uniform surface layers, while the carboxylic acid is geometrically unsuited to binding the surface of GaAs. The relative acidity of thiol versus phosphonic acid results in greater coverage for the latter due to a more facile reaction with the sulfide passivated GaAs surface.
Dielectric relaxation studies of formamide-alcohol mixtures using time domain reflectometry
Authors: Ramachandran K. , Dharmalingam K. , Sivagurunathan P. , Prabhakar Undre B. , Khirade P. W. , Mehrotra S. C.
Published: August 2006

Dielectric relaxation studies of formamide-alcohol mixtures have been carried out for different concentrations at 303K. Time domain reflectometry (TDR) in reflection mode has been used to measure the reflection coefficient in the frequency range of 10 MHz to 10 GHz. The bilinear calibration method has been used to obtain dielectric quantities viz., static dielectric constant (ε0) and relaxation time (τ). The Kirkwood correlation factor and excess dielectric properties were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The values of the relaxation time and the Kirkwood correlation factor decrease with increased formamide concentration in alcohol.
Review Article: Cost-effectiveness of healthcare-based interventions aimed at improving physical activity
Authors: Hagberg Lars A. , Lindholm Lars
Published: August 2006

Aim: This article aims to review current knowledge concerning the cost-effectiveness of healthcare-based interventions aimed at improving physical activity. Method: A search was performed for economic evaluations containing the terms ``physical activity'', ``exercise'', or ``fitness''. Cost-effectiveness for the articles found was described based on a model for evaluating interventions intended to promote physical activity. Results: A total of 26 articles were found in the search. Nine of them concern a general population, 7 evaluated older people, and 10 studied disease-specific populations. A preventive perspective is most common, but some have a treatment perspective. Around 20 of the interventions studied were cost-effective according to their authors, but all analyses had some shortcomings in their evaluation methods. Conclusion: This review found many examples of cost-effective interventions. There is a lack of evidence for the cost-effectiveness of interventions aimed at those whose only risk factor for illness is a sedentary lifestyle. There is more evidence, although it is limited, for the cost-effectiveness of interventions aimed at high-risk groups or those who manifest poor health related to physical inactivity. Most of the evidence for cost-effectiveness is for older people and those with heart failure. Promotion of physical activity can be cost-effective with different methods and in different settings, but there remains a lack of evidence for specific methods in specific populations.
Anxiety and the interpretation of ambiguous facial expressions: The influence of contextual cues
Authors: Blanchette Isabelle , Richards Anne , Cross Adele
Published: August 2006

In 3 experiments, we investigate how anxiety influences interpretation of ambiguous facial expressions of emotion. Specifically, we examine whether anxiety modulates the effect of contextual cues on interpretation. Participants saw ambiguous facial expressions. Simultaneously, positive or negative contextual information appeared on the screen. Participants judged whether each expression was positive or negative. We examined the impact of verbal and visual contextual cues on participants’ judgements. We used 3 different anxiety induction procedures and measured levels of trait anxiety (Experiment 2). Results showed that high state anxiety resulted in greater use of contextual information in the interpretation of the facial expressions. Trait anxiety was associated with mood-congruent effects on interpretation, but not greater use of contextual information.
The Sad1-UNC-84 homology domain in Mps3 interacts with Mps2 to connect the spindle pole body with the nuclear envelope
Authors: Jaspersen Sue L. , Martin Adriana E. , Glazko Galina , Giddings Thomas H. , Morgan Garry , Mushegian Arcady , Winey Mark
Published: August 2006

The spindle pole body (SPB) is the sole site of microtubule nucleation in Saccharomyces cerevisiae; yet, details of its assembly are poorly understood. Integral membrane proteins including Mps2 anchor the soluble core SPB in the nuclear envelope. Adjacent to the core SPB is a membrane-associated SPB substructure known as the half-bridge, where SPB duplication and microtubule nucleation during G1 occurs. We found that the half-bridge component Mps3 is the budding yeast member of the SUN protein family (Sad1-UNC-84 homology) and provide evidence that it interacts with the Mps2 C terminus to tether the half-bridge to the core SPB. Mutants in the Mps3 SUN domain or Mps2 C terminus have SPB duplication and karyogamy defects that are consistent with the aberrant half-bridge structures we observe cytologically. The interaction between the Mps3 SUN domain and Mps2 C terminus is the first biochemical link known to connect the half-bridge with the core SPB. Association with Mps3 also defines a novel function for Mps2 during SPB duplication.
Muscle-specific microRNA miR-206 promotes muscle differentiation
Authors: Kim Hak Kyun , Lee Yong Sun , Sivaprasad Umasundari , Malhotra Ankit , Dutta Anindya
Published: August 2006

Three muscle-specific microRNAs, miR-206, -1, and -133, are induced during differentiation of C2C12 myoblasts in vitro. Transfection of miR-206 promotes differentiation despite the presence of serum, whereas inhibition of the microRNA by antisense oligonucleotide inhibits cell cycle withdrawal and differentiation, which are normally induced by serum deprivation. Among the many mRNAs that are down-regulated by miR-206, the p180 subunit of DNA polymerase α and three other genes are shown to be direct targets. Down-regulation of the polymerase inhibits DNA synthesis, an important component of the differentiation program. The direct targets are decreased by mRNA cleavage that is dependent on predicted microRNA target sites. Unlike small interfering RNA–directed cleavage, however, the 5′ ends of the cleavage fragments are distributed and not confined to the target sites, suggesting involvement of exonucleases in the degradation process. In addition, inhibitors of myogenic transcription factors, Id1-3 and MyoR, are decreased upon miR-206 introduction, suggesting the presence of additional mechanisms by which microRNAs enforce the differentiation program.
Sumoylation of the budding yeast kinetochore protein Ndc10 is required for Ndc10 spindle localization and regulation of anaphase spindle elongation
Authors: Montpetit Ben , Hazbun Tony R. , Fields Stanley , Hieter Philip
Published: August 2006

Posttranslational modification by the ubiquitin-like protein SUMO (small ubiquitin-like modifier) is emerging as an important regulator in many cellular processes, including genome integrity. In this study, we show that the kinetochore proteins Ndc10, Bir1, Ndc80, and Cep3, which mediate the attachment of chromosomes to spindle microtubules, are sumoylated substrates in budding yeast. Furthermore, we show that Ndc10, Bir1, and Cep3 but not Ndc80 are desumoylated upon exposure to nocodazole, highlighting the possibility of distinct roles for sumoylation in modulating kinetochore protein function and of a potential link between the sumoylation of kinetochore proteins and mitotic checkpoint function. We find that lysine to arginine mutations that eliminate the sumoylation of Ndc10 cause chromosome instability, mislocalization of Ndc10 from the mitotic spindle, abnormal anaphase spindles, and a loss of Bir1 sumoylation. These data suggest that sumoylation of Ndc10 and other kinetochore proteins play a critical role during the mitotic process.
Restricted epithelial proliferation by lacritin via PKCα-dependent NFAT and mTOR pathways
Authors: Wang Jiahu , Wang Ningning , Xie Jinling , Walton Staci C. , McKown Robert L. , Raab Ronald W. , Ma Peisong , Beck Shannon L. , Coffman George L. , Hussaini Isa M. , Laurie Gordon W.
Published: August 2006

Renewal of nongermative epithelia is poorly understood. The novel mitogen “lacritin” is apically secreted by several nongermative epithelia. We tested 17 different cell types and discovered that lacritin is preferentially mitogenic or prosecretory for those types that normally contact lacritin during its glandular outward flow. Mitogenesis is dependent on lacritin's C-terminal domain, which can form an α-helix with a hydrophobic face, as per VEGF's and PTHLP's respective dimerization or receptor-binding domain. Lacritin targets downstream NFATC1 and mTOR. The use of inhibitors or siRNA suggests that lacritin mitogenic signaling involves Gαi or Gαo–PKCα-PLC–Ca2+–calcineurin–NFATC1 and Gαi or Gαo–PKCα-PLC–phospholipase D (PLD)–mTOR in a bell-shaped, dose-dependent manner requiring the Ca2+ sensor STIM1, but not TRPC1. This pathway suggests the placement of transiently dephosphorylated and perinuclear Golgi–translocated PKCα upstream of both Ca2+ mobilization and PLD activation in a complex with PLCγ2. Outward flow of lacritin from secretory cells through ducts may generate a proliferative/secretory field as a different unit of cellular renewal in nongermative epithelia where luminal structures predominate.
Selective dysregulation of the FcγIIB receptor on memory B cells in SLE
Authors: Mackay Meggan , Stanevsky Anfisa , Wang Tao , Aranow Cynthia , Li Margaret , Koenig Scott , Ravetch Jeffrey V. , Diamond Betty
Published: August 2006

The inappropriate expansion and activation of autoreactive memory B cells and plasmablasts contributes to loss of self-tolerance in systemic lupus erythematosus (SLE). Defects in the inhibitory Fc receptor, FcγRIIB, have been shown to contribute to B cell activation and autoimmunity in several mouse models of SLE. In this paper, we demonstrate that expression of FcγRIIB is routinely up-regulated on memory B cells in the peripheral blood of healthy controls, whereas up-regulation of FcγRIIB is considerably decreased in memory B cells of SLE patients. This directly correlates with decreased FcγRIIB-mediated suppression of B cell receptor–induced calcium (Ca2+) response in those B cells. We also found substantial overrepresentation of African-American patients among those who failed to up-regulate FcγRIIB. These results suggest that the inhibitory receptor, FcγRIIB, may be impaired at a critical checkpoint in SLE in the regulation of memory B cells; thus, FcγRIIB represents a novel target for therapeutic interventions in this disease.
In vivo mature immunological synapses forming SMACs mediate clearance of virally infected astrocytes from the brain
Authors: Barcia Carlos , Thomas Clare E. , Curtin James F. , King Gwendalyn D. , Wawrowsky Kolja , Candolfi Marianela , Xiong Wei-Dong , Liu Chunyan , Kroeger Kurt , Boyer Olivier , Kupiec-Weglinski Jerzy , Klatzmann David , Castro Maria G. , Lowenstein Pedro R.
Published: August 2006

The microanatomy of immune clearance of infected brain cells remains poorly understood. Immunological synapses are essential anatomical structures that channel information exchanges between T cell–antigen-presenting cells (APC) during the priming and effector phases of T cells' function, and during natural killer–target cell interactions. The hallmark of immunological synapses established by T cells is the formation of the supramolecular activation clusters (SMACs), in which adhesion molecules such as leukocyte function-associated antigen 1 segregate to the peripheral domain of the immunological synapse (p-SMAC), which surrounds the T cell receptor–rich or central SMAC (c-SMAC). The inability so far to detect SMAC formation in vivo has cast doubts on its functional relevance. Herein, we demonstrate that the in vivo formation of SMAC at immunological synapses between effector CD8+ T cells and target cells precedes and mediates clearance of virally infected brain astrocytes.
Non-display applications and the next generation of liquid crystal over silicon technology
Authors: Wilkinson T.D , Henderson C , Gil Leyva D , Ghannam R , Crossland W.A
Published: August 2006

The next generation of applications for liquid crystal (LC) over silicon technology will be non-display oriented systems such as adaptive optical interconnects, optical switches and optical image processors. These new non-display applications have a different set of material parameters, which means that existing display-based materials are not entirely optimal. This is particularly the case when the application is driven by phase modulation at high frame rates (more than 1 kHz). An example of such a non-display application is in adaptive optical interconnects. Optical data transmission between printed circuit boards is becoming more and more important as the data rate in electronic systems increases into the gigahertz region. One way of avoiding the data bottlenecks in board to board interconnects is to use optical links to transmit the data. Recent research into free-space optical links has shown that a high level of manufacturing tolerance must be used to maintain the link. However, one way of avoiding these limitations is to use a reconfigurable LC phase hologram as a beam-steering element to compensate for movement between the boards and maintain the optical data path.
Photonics and lasing in liquid crystal materials
Authors: Palffy-Muhoray Peter , Cao Wenyi , Moreira Michele , Taheri Bahman , Munoz Antonio
Published: August 2006

Owing to fundamental reasons of symmetry, liquid crystals are soft materials. This softness allows long length-scales, large susceptibilities and the existence of modulated phases, which respond readily to external fields. Liquid crystals with such phases are tunable, self-assembled, photonic band gap materials; they offer exciting opportunities both in basic science and in technology. Since the density of photon states is suppressed in the stop band and is enhanced at the band edges, these materials may be used as switchable filters or as mirrorless lasers. Disordered periodic liquid crystal structures can show random lasing. We highlight recent advances in this rapidly growing area, and discuss future prospects in emerging liquid crystal materials. Liquid crystal elastomers and orientationally ordered nanoparticle assemblies are of particular interest.
Artificial muscles based on liquid crystal elastomers
Authors: Li Min-Hui , Keller Patrick
Published: August 2006

This paper presents our results on liquid crystal (LC) elastomers as artificial muscle, based on the ideas proposed by de Gennes. In the theoretical model, the material consists of a repeated series of main-chain nematic LC polymer blocks, N, and conventional rubber blocks, R, based on the lamellar phase of a triblock copolymer RNR. The motor for the contraction is the reversible macromolecular shape change of the chain, from stretched to spherical, that occurs at the nematic-to-isotropic phase transition in the main-chain nematic LC polymers.

We first developed a new kind of muscle-like material based on a network of side-on nematic LC homopolymers. Side-on LC polymers were used instead of main-chain LC polymers for synthetic reasons. The first example of these materials was thermo-responsive, with a typical contraction of around 35–45% and a generated force of around 210 kPa. Subsequently, a photo-responsive material was developed, with a fast photochemically induced contraction of around 20%, triggered by UV light.

We then succeeded in preparing a thermo-responsive artificial muscle, RNR, with lamellar structure, using a side-on nematic LC polymer as N block.

Micrometre-sized artificial muscles were also prepared. This paper illustrates the bottom-up design of stimuli-responsive materials, in which the overall material response reflects the individual macromolecular response, using LC polymer as building block.
Optimized ultrasound‐mediated gene transfection in cancer cells
Authors: Feril Loreto B. , Ogawa Ryohei , Tachibana Katsuro , Kondo Takashi
Published: August 2006

Ultrasound‐mediated gene transfection (sonotransfection) is a promising physical method for gene therapy, especially for cancer gene therapy. To investigate the optimal sonotransfection conditions and to determine whether the optimal transfection rate using sonotransfection is comparable to that of electrotransfection or liposome‐mediated transfection, we sonicated different cancer cell lines (U937, HeLa, PC‐3, Meth A and T‐24) using a 1‐MHz unfocused ultrasound at different intensities, pulse repetition frequencies and exposure times. The ideal ultrasound conditions were noted to be at 1.5 Watt/cm2 pulsed at 0.5 Hz with a duty factor of 50%. The results showed that transfection rate increased with the number of pulses, and peaked between 10 and 15 pulses before it started to decline. Using such optimal conditions, we have shown that sonotransfection is superior to electrotransfection and liposome‐mediated transfection at the fixed conditions used in the present study. These findings suggest that sonotransfection could be a better alternative to other non‐viral methods (e.g. electroporation and liposome‐mediated transfection) of gene transfection, particularly in cancer gene therapy. (Cancer Sci 2006; 97: 1111–1114)
Novel tumor marker REG4 detected in serum of patients with resectable pancreatic cancer and feasibility for antibody therapy targeting REG4
Authors: Takehara Akio , Eguchi Hidetoshi , Ohigashi Hiroaki , Ishikawa Osamu , Kasugai Tsutomu , Hosokawa Masayo , Katagiri Toyomasa , Nakamura Yusuke , Nakagawa Hidewaki
Published: August 2006

Pancreatic ductal adenocarcinoma (PDAC) shows the worst mortality rate among common malignancies, with a 5‐year survival rate of only 4%, and the majority of PDAC patients are diagnosed at an advanced stage in which no effective therapy is available at present. Although the proportion of curable cases is still not so high, surgical resection of early stage PDAC is the only way to cure the disease. Hence, establishment of a screening strategy to detect early stage PDAC by novel serological markers is required urgently, and development of novel molecular therapies for PDAC treatment is also eagerly expected. We here report overexpression of REG4, a new member of the regenerating islet‐derived (REG) family, in PDAC cells on the basis of genome‐wide cDNA microarray analysis as well as reverse transcription–polymerase chain reaction and immunohistochemical analysis. We also detected significant elevation of REG4 in the serum of some patients with early‐stage PDAC using our enzyme‐linked immunosorbent assay system, indicating the possibility of REG4 as a new serological marker of PDAC. Furthermore, we found that knockdown of endogenous REG4 expression in PDAC cell lines with small interfering RNA caused a decrease in cell viability. Concordantly, addition of recombinant REG4 to the culture medium enhanced growth of a PDAC cell line in a dose‐dependent manner. A monoclonal antibody against REG4 neutralized its growth‐promoting effects and attenuated significantly the growth of PDAC cells. These findings indicate that REG4 is a promising tumor marker to screen early‐stage PDAC, and also that neutralization of REG4 by the antibody may offer novel potential tools for the treatment of PDAC. (Cancer Sci 2006; 97: 1191–1197)
Deletion and single nucleotide substitution at G:C in the kidney of gpt delta transgenic mice after ferric nitrilotriacetate treatment
Authors: Jiang Li , Zhong Yi , Akatsuka Shinya , Liu Yu‐Ting , Dutta Khokon Kumar , Lee Wen‐Hua , Onuki Janice , Masumura Ken‐ichi , Nohmi Takehiko , Toyokuni Shinya
Published: August 2006

An iron chelate, ferric nitrilotriacetate (Fe‐NTA), induces oxidative renal proximal tubular damage that subsequently leads to a high incidence of renal cell carcinoma in rodents, presenting an intriguing model of free radical‐induced carcinogenesis. In the present study, we used gpt delta transgenic mice, which allow efficient detection of point mutations and deletions in vivo, to evaluate the mutation spectra, in association with the formation of 8‐oxoguanine and acrolein‐modified adenine during the first 3 weeks of carcinogenesis. Immunohistochemical analysis revealed the highest levels of 8‐oxoguanine and acrolein‐modifed adenine in the renal proximal tubules after 1 week of repeated administration. DNA immunoprecipitation and quantitative polymerase chain reaction analysis showed that the relative abundance of 8‐oxoguanine and acrolein‐modified adenine at the gpt reporter gene were increased at the first week in the kidney. Similarly, in both 6‐thioguanine and Spi− selections performed on the renal specimens after Fe‐NTA administration, the mutant frequencies were increased in the Fe‐NTA‐treated mice at the first week. Further analyzes of 79 mutant clones and 93 positive plaques showed a high frequency of G:C pairs as preferred targets for point mutation, notably G:C to C:G transversion‐type mutation followed by deletion, and of large‐size (>1 kilobase) deletions with short homologous sequences in proximity to repeated sequences at the junctions. The results demonstrate that the iron‐based Fenton reaction is mutagenic in vivo in the renal tubular cells and induces characteristic mutations. (Cancer Sci 2006; 97: 1159–1167)
Review article: mode of action and delivery of 5‐aminosalicylic acid – new evidence
Authors: DESREUMAUX P. , GHOSH S.
Published: August 2006

The effectiveness of sulfasalazine depends on the splitting of the diazo bond in the molecule by the action of bacteria in the large bowel, releasing the pharmacologically active moiety, 5‐aminosalicylic acid. The development of pH‐dependent, delayed‐release formulations of 5‐aminosalicylic acid abolished the toxicity associated with the sulfapyridine part of sulfasalazine.

5‐aminosalicylic acid is now believed to act by activating a class of nuclear receptors involved in the control of inflammation, cell proliferation, apoptosis and metabolic function, the γ form of peroxisome proliferator‐activated receptors. These receptors are expressed at particularly high levels in colon epithelial cells, where their expression appears to be at least in part stimulated by gut bacteria. Other drugs known to act via peroxisome proliferator‐activated receptor‐γ, such as rosiglitazone and the selective peroxisome proliferator‐activated receptor‐γ ligand GW1929, can be displaced from their binding sites on the peroxisome proliferator‐activated receptor‐γ molecule by 5‐aminosalicylic acid at concentrations of 5‐aminosalicylic acid that correspond with the concentrations found in the lumen of ulcerative colitis patients taking oral mesalazine.

Genetically engineered heterozygous knockout mice (peroxisome proliferator‐activated receptor‐γ±) are particularly susceptible to colonic inflammation, and inflammation is more severe in these mice, in response to chemicals that induce experimental colonic ulcers. In these experimental models, 5‐aminosalicylic acid is ineffective in peroxisome proliferator‐activated receptor‐γ± mice. This new insight provides a mechanistic foundation for the possibility that long‐term treatment with 5‐aminosalicylic acid can reduce the risk of colorectal cancer in patients with ulcerative colitis.
PI3K/Akt‐dependent Epo‐induced signalling and target genes in human early erythroid progenitor cells
Authors: Sivertsen Einar Andreas , Hystad Marit Elise , Gutzkow Kristine Bjerve , Døsen Guri , Smeland Erlend Bremertun , Blomhoff Heidi Kiil , Myklebust June Helen
Published: August 2006

Erythropoietin (Epo) is the major regulator of differentiation, proliferation and survival of erythroid progenitors, but the Epo‐induced changes in gene expression that lead to these effects are not fully understood. The aim of this study was to examine how Epo, via activation of phosphatidylinositol 3‐kinase (PI3K)/Akt, exerts its role in the development of erythroid progenitors from CD34+ cells, and to identify early Epo target genes in human erythroid progenitors. In CD34+ progenitor cells, Epo alone was able to induce cell cycle progression as demonstrated by upregulation of cyclin D3, E and A leading to hyperphosphorylation of the retinoblastoma protein (RB). These effects were completely counteracted by the PI3K inhibitor LY294002. Furthermore, enforced expression of an activated form of Akt kinase highly augmented Epo‐induced erythropoiesis. Fluorescent‐activated cell sorting (FACS)‐sorted CD34+CD71+CD45RA−GPA− erythroid progenitors stimulated with Epo in the presence or absence of LY294002 were subjected to gene expression profiling. Several novel target genes of Epo were identified, and the majority were regulated in a PI3K‐dependent manner, including KIT (CD117) and CDH1 (E‐cadherin). FACS analysis of Epo‐stimulated erythroid progenitors showed that the increased mRNA expression of KIT and CDH1 was accompanied by an induction of the corresponding proteins CD117 and E‐cadherin.
Gene expression analysis of myeloid and lymphoid lineage markers during mouse haematopoiesis
Authors: Sakhinia E. , Byers R. , Bashein A. , Hoyland J. , Buckle A.‐M. , Brady G.
Published: August 2006

Expression profiling of haematopoietic cells is hampered by the heterogeneous nature of haematopoietic tissues and the absolute rarity of early unrestricted progenitors. To overcome this, the expression profile of lymphoid and myeloid‐associated genes (LEF1, EBF, CD19, Sox‐4, B29, CD45, C‐fms, lysozyme, PU.1 and CD5) were investigated in 40 mouse myeloid haematopoietic precursors covering the entire haematopoietic hierarchy from multipotential to committed single lineages. The lineage‐specific expression seen in single‐cell studies was confirmed by examining fractionated bone marrow, whole tissues and differentiation of the multipotent cell line FDCP (Factor Dependent Cell Paterson) mix. Analysis of the 40 single myeloid precursors failed to detect expression of lymphoid‐associated genes, LEF1, EBF, CD19 and CD5, despite detection in lymphoid cell controls. Surprisingly, the lymphoid‐associated genes, Sox‐4 and B29 were detected in the single myeloid precursors, which was confirmed in bone marrow and a multipotential myeloid cell line. The pattern of Sox‐4 and B29, is consistent with a potential role in the commitment of bipotential granulocytic/macrophage precursors towards the granulocyte or macrophage lineage. In addition to providing baseline values for myeloid and lymphoid lineage markers during mouse haematopoiesis, these results highlight the importance of single‐cell analysis in the study of complex tissues.
Differential gene expression in non‐malignant tumour microenvironment is associated with outcome in follicular lymphoma patients treated with rituximab and CHOP
Authors: Harjunpää Antti , Taskinen Minna , Nykter Matti , Karjalainen‐Lindsberg Marja‐Liisa , Nyman Heidi , Monni Outi , Hemmer Samuli , Yli‐Harja Olli , Hautaniemi Sampsa , Meri Seppo , Leppä Sirpa
Published: August 2006

Rituximab in combination with chemotherapy (immunochemotherapy) is one of the most effective treatments available for follicular lymphoma (FL). This study aimed to determine whether differences in gene expression in FL tissue correlate with outcome in response to rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy (R–CHOP). We divided 24 patients into long‐ [time to treatment failure (TTF) >35 months] and short‐term (TTF <23 months) responders, and analysed the gene expression profiles of lymphoma tissue using oligonucleotide microarrays. We used a supervised learning technique to identify genes correlating with outcome, and confirmed the expression of selected genes with quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Among the transcripts with a high correlation between microarray and qPCR analyses, we identified EPHA1, a tyrosine kinase involved in transepithelial migration, SMAD1, a transcription factor and a mediator of bone morphogenetic protein and transforming growth factor‐β signalling, and MARCO, a scavenger receptor on macrophages. According to Kaplan–Meier estimates, high EPHA1, and low SMAD1 and MARCO expression were associated with better progression‐free survival (PFS). Immunohistochemistry showed that EphA1 was primarily localised in granulocytes. In addition, both EphA1 and Smad1 were expressed in vascular endothelia. However, no difference in vasculature was detected between long‐ and short‐term responders. In a validation set of 40 patients, a trend towards a better PFS was observed among patients with high EphA1 expression. We conclude that gene expression in non‐malignant cells contributes to clinical outcome in R–CHOP‐treated FL patients.
High D‐dimer levels at presentation in patients with venous thromboembolism is a marker of adverse clinical outcomes
Authors: Paneesha S. , Cheyne E. , French K. , Bacchu S. , Borg A. , Rose P.
Published: August 2006

Qualitative d‐dimer results, together with clinical probability scores, are well established in the diagnosis of venous thromboembolism (VTE). The predictive value of quantitative d‐dimer levels for various clinical outcomes in VTE patients is not fully understood. d‐dimer levels obtained at presentation were analysed in 699 (360 men; 339 women) VTE patients for survival and occurrence of malignancy. Patients were followed for a median of 23 months. 17·2% patients had a d‐dimer level >8000 ng FEU/mlat presentation, which was associated with decreased overall survival (OS) (P < 0·001) and event‐free survival (EFS) (P < 0·001). 25·4% patients had malignancy and 4% subsequently developed malignancy following VTE. 29·9% of patients with VTE and malignancy had a d‐dimer level >8 mg/l when compared with 13·4% of patients with VTE without malignancy (P < 0·001). 50% of patients who developed subsequent malignancy following VTE had a presentation d‐dimer >8000 ng FEU/mlas compared with 13·3% of patients with VTE with out malignancy (P = 0·009). In conclusion, d‐dimer >8000 ng FEU/ml at presentation in patients with VTE is a marker of poor OS, EFS and underlying malignancy. Consideration of screening for malignancy is recommended in patients with VTE with a presentation d‐dimer >8000 ng FEU/ml and age >60 years.
Influence of trees on soil organic matter in Mediterranean agroforestry systems: an example from the ‘Espinal’ of central Chile
Authors: Muñoz C. , Zagal E. , Ovalle C.
Published: August 2006

The ‘Espinal’ agroforestry system of the Mediterranean zone of central Chile, which covers an area of 2000 000 ha, is in various stages of degradation due to human activities. The objective of our study was: (i) to determine the effects of the canopy cover of Acacia caven (‘Espino’) on total soil organic carbon (SOC), soil respiration and the labile components of soil organic matter (microbial biomass, and light fraction); and (ii) to determine the influence of ecosystem degradation on total and labile components of SOC. Soils of the study area are classified as fine, mixed, active, mesic Ultic Palexeralfs, typical of the Mediterranean‐type environment. We investigated sites according to the percentage coverage of A. caven canopy: (i) well‐preserved Espinal (WPE), 80–51% cover; (ii) good Espinal (GE), 50–26% cover; (iii) degraded Espinal (DE), 25–11% cover; and (iv) very degraded Espinal (VDE), < 10% cover. In addition, a site under native forest (NF) was included to characterize the original state of the zone. Soil samples were taken under and outside the canopy of A. caven at two depths, 0–5 and 5–10 cm. We conclude that the microbial biomass carbon (Cmic), and total and labile components of SOC are influenced by the presence of the A. caven tree, with greater values under than outside its canopy. Under the tree canopy, to a depth of 10 cm, Cmic was less under all the agroforestry systems than in NF (46 and 30% less for WPE and GE, respectively, and 67 and 57% less for DE and VDE). However, there was no clear trend for less Cmic with increased ecosystem degradation, especially outside the canopy. However, the respiration of microbial communities was affected by ecosystem degradation for both soil depths under the tree canopy, e.g. soil respiration in VDE ecosystems was about 50% greater than that found in WPE ecosystems. Increasing the coverage of the A. caven tree in the semiarid ecosystems of central Chile, e.g. changing from VDE to WPE, would result in an eventual, long‐term (over several centuries) increase in soil organic C of approximately 50%.
Landscape‐scale variation in the seed banks of floodplain wetlands with contrasting hydrology in China
Authors: LIU GUI H. , LI WEI , LI EN H. , YUAN LONG Y. , DAVY ANTHONY J.
Published: August 2006

1. At a local scale, the species composition, diversity and spatial variation of wetland plant communities are determined primarily by spatial and temporal heterogeneity in their environments. Less is known about variation at a landscape‐level. The floodplain of the Changjiang (Yangtze) River in China includes hydrologically connected, subtropical wetlands with different hydrological characteristics.

2. We examined seed‐bank species composition and richness in marshes of two contrasting hydrological types: permanent marshes, fed by local runoff, and lakeshore marshes more closely connected to the regulated river. Lakeshore marshes are flooded annually to depth of approximately 1 m and during flooding they support an alternate, aquatic vegetation type. The soil seed bank in March was a comparative estimator of species diversity. At the beginning of the growing season it included seeds from both phases of alternating vegetation types associated with the annual hydrological cycle.

3. A regional pool of 101 species was detected in the seed banks of six wetlands associated with the river and its tributaries: 56 occurred in permanent marshes and 59 in lakeshore marshes, with only 15 common to both. Species rarefaction curves indicated that more species occurred in permanent than lakeshore marshes at equal numbers of individuals sampled. However, the more heterogeneous lakeshore seed banks were estimated (Chao 2) to have greater total species richness (81) than permanent marsh (60).

4. Analysis using Sørensen's coefficient of similarity and DCA ordination revealed complex variation, with much greater differences between hydrological types than within them, irrespective of geographical distance. The types also differed significantly in the composition of four functional groups of species.

5. Despite the potential for dispersal of propagules via the annually pulsing river system (hydrochory), at a regional and landscape scale, diversity is maintained largely by large‐scale temporal hydrological heterogeneity and smaller scale spatial and topographic heterogeneity.
Urban ecosystems and the North American carbon cycle
Authors: PATAKI D. E. , ALIG R. J. , FUNG A. S. , GOLUBIEWSKI N. E. , KENNEDY C. A. , MCPHERSON E. G. , NOWAK D. J. , POUYAT R. V. , ROMERO LANKAO P.
Published: August 2006

Approximately 75–80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in urban systems models, plausible emissions scenarios from major cities may be generated. Integrated land use and transportation models that simulate energy use and traffic‐related emissions are already in place in many North American cities. To these can be added a growing dataset of carbon gains and losses in vegetation and soils following urbanization, and a number of methods of validating urban carbon balance modeling, including top down atmospheric monitoring and urban ‘metabolic’ studies of whole ecosystem mass and energy flow. Here, we review the state of our understanding of urban areas as whole ecosystems with regard to carbon balance, including both drivers of fossil fuel emissions and carbon cycling in urban plants and soils. Interdisciplinary, whole‐ecosystem studies of the socioeconomic and biophysical factors that influence urban carbon cycles in a range of cities may greatly contribute to improving scenarios of future carbon balance at both continental and global scales.
MOP3, a component of the molecular clock, regulates the development of B cells
Authors: Sun Yimin , Yang Zhihui , Niu Zeqing , Peng Jianxiao , Li Qinghuan , Xiong Wanfen , Langnas Alan N. , Ma Mark Y. , Zhao Yong
Published: August 2006

Differentiation and proliferation of haematopoietic progenitor cells occur in intimate contact with the bone marrow microenvironment which is composed of stromal cells and extracellular matrix proteins. MOP3 (also known as brain and muscle Arnt‐like protein‐1, BMAL1), a master regulator of circadian rhythm, plays important roles in the regulation of cell differentiation and general physical functions. In the present studies, MOP3‐deficient mice had significantly reduced levels of B cells in the peripheral blood, spleen and bone marrow compared MOP3+/– or MOP3+/+ littermates. Flow cytometry analysis showed the levels of pre‐B cells in bone marrow of MOP3–/– mice were similar as that in control mice. Adoptive transfer of MOP3–/– bone marrow cells (BMC) to lethally irradiated BALB/c Rag2–/– recipients, normal T and B cell development was observed, whereas Adoptive transfer of BALB/c BMC to lethally irradiated MOP3–/– recipients, B‐cell development was significantly impaired. These results presented herein with MOP3‐deficient mice reveal the involvement of MOP3 in the development of B cells, but not other immune cells. The effect of MOP3 on the differentiation of pre‐B cells to mature B cells might be mediated by the bone marrow microenvironment. This study also showed a connection between a master regular of circadian rhythm with B‐cell development in mice.
The effect of tapping for frankincense on sexual reproduction in Boswellia papyrifera
Authors: RIJKERS TOON , OGBAZGHI WOLDESELASSIE , WESSEL MARIUS , BONGERS FRANS
Published: August 2006

In the Horn of Africa, frankincense (an aromatic hardened wood resin) is obtained by tapping Boswellia papyrifera. World‐wide, frankincense is of great economic and social importance as an important element of incense and perfumes. The production is declining as a result of poor natural regeneration of the Boswellia woodlands, possibly as a result of the low production of viable seeds. We hypothesize that this is because of the current intensive tapping regime, which might favour allocation of carbohydrates for synthesis of resin at the expense of allocation for generative growth.

Investigations were carried out at sites in different agro‐ecological zones with annually tapped trees and with trees that had not been tapped for several years. Seed viability and germination success were determined for 200 randomly collected seeds in each site. For three stands, the sexual reproduction (number of flowers, fruits and seeds) was determined for different sized trees subjected to three experimental tapping intensities (no, normal and heavy tapping).

At the stand level, non‐tapped trees produced three times as many healthy and filled seeds as tapped trees. Germination success was highest in stands with non‐tapped trees (> 80%) and lowest for those with tapped trees (< 16%).

At the tree level, sexual reproduction decreased with increasing tapping regime irrespective of tree size. Overall, large trees tended to produce slightly heavier seeds than small trees, and seeds from non‐tapped trees were heavier than those from tapped trees. In the stands where tapping was prohibited changes in tapping regimes had the greatest effect on sexual reproduction. Trees subjected to annual tapping always showed the lowest sexual reproduction.

Synthesis and applications. Tapping for frankincense results in limited flower and fruit production, and low production of mainly non‐viable seeds in B. papyrifera. We argue that tapping causes competition for carbohydrates between frankincense production, and fruit and seed setting. Consequently, the current tapping regimes will cause tree exhaustion and eventually a decline in vitality. Tapping may potentially reduce natural regeneration of the species. New tapping regimes are suggested that include periods of time in which tapping is prohibited in order for trees to recover and replenish their stored carbon pool, and a reduction in the number of tapping points per tree. This is important in view of the long‐term sustainability of frankincense production, an internationally highly valued resource.
Assessing the carbon sequestration potential of managed forests: a case study from temperate Australia
Authors: ROXBURGH S. H. , WOOD S. W. , MACKEY B. G. , WOLDENDORP G. , GIBBONS P.
Published: August 2006

The concept of assessing forests for carbon sequestration is well established. Operationally, estimating a forests’ potential to sequester carbon requires comparing its current carbon state with a prediction of its carbon carrying capacity (CCC). Assessment of CCC is, however, problematic. Mathematical models can be used, although traditional modelling techniques, where parameters are estimated from empirical measurements, are usually limited by a lack of field data. For example, estimates of carbon residency times in vegetation and soil are not generally available, nor are they easily measured. Alternative methods are required.

Current carbon stocks in 17 previously logged field sites were measured by field survey. CCC for those sites was then predicted using a terrestrial carbon model, calibrated with measurements from mature, unlogged vegetation of a comparable forest type. Model parameters were estimated using ‘model–data fusion’ methods, where the model is inverted and field measurements of the carbon stocks (the model outputs) are used to calibrate the model parameters. Spatial variation was included through functions defining landscape‐scale effects on plant growth relating to topographic influences on light and soil water availability.

Current above‐ground carbon stocks (living plus litter) varied with management history, averaging 273 ± 30 tC ha−1 (mean ± SE). Model‐predicted CCC was 445 ± 13 tC ha−1, yielding a carbon sequestration potential of 172 ± 31 tC ha−1. Model simulations predicted the recovery of an average site to take 53 years to reach 75% carrying capacity, and 152 years to reach 90% carrying capacity. Extrapolation of these results to 7 Mha of comparable managed forests in the same region suggested a potential carbon sink of 680–895 Mt C.

Synthesis and applications. In this study we have demonstrated that forests recovering from prior logging have the potential to store significant amounts of carbon, with current biomass stocks estimated to be approximately 60% of their predicted carrying capacity, a value similar to those reported for northern temperate forests. Although sequestration activities often focus on the aforestation and reforestation of previously cleared land, our results suggest that, where appropriate, native forest management should also be considered when developing terrestrial carbon management options, and for terrestrial carbon accounting more generally.
Capybara (Hydrochoerus hydrochaeris) distribution in agroecosystems: a cross‐scale habitat analysis
Authors: De Barros Ferraz Katia Maria P. M. , De Barros Ferraz Silvio F. , Moreira José Roberto , Couto Hilton Thadeu Z. , Verdade Luciano M.
Published: August 2006

Aim  The aim of this study was to understand the spatial distribution of capybara (Hydrochoerus hydrochaeris) according to habitat attributes, using a multiscale approach based on fine‐ and broad‐scale variables in agroecosystems.

Location  Piracicaba river basin, south‐eastern Brazil (22°00′–23°30′ S; 45°45′–48°30′ W).

Methods  Potential habitats for capybara were selected in order to evaluate species presence/absence from October 2001 to December 2002. In each site, habitat attributes were sampled in the field (fine scale) and from GIS maps (broad scale) in terms of their presence or absence close to water. The variability of land cover between study sites was described by principal components analysis. Chi‐square tests were calculated for capybara presence/absence and the presence of each habitat attribute. A linear discriminant function analysis was used to describe to what extent the species’ presence could be explained by habitat attributes.

Results  The species presence was predominantly related to flat open areas (slope ranging from 0% to 6%) (χ2 = 37.054, d.f. = 4, P < 0.001), covered by sugar cane or cultivated pasture (χ2 = 84.814, d.f. = 9, P < 0.001). Terrain curvature, water meadows, aquatic vegetation, forest cover and open areas resulted in the best combination of variables, explaining 69.7% of capybara occurrence in the study sites in this river basin.

Main conclusions  Capybaras are widespread in the Piracicaba river basin, except in elevated areas. The spatial distribution of capybara was associated with the main types of land cover in the river basin – sugar cane plantations or pasture – both key food sources for capybara. This probably explains the species’ recent abundance in the region, since an intensive process of landscape alteration has taken place in this region owing to the expansion of agriculture in recent decades. These results may be useful in understanding the relationship between recent landscape modifications and the species’ population expansion in agroecosystems.
ORIGINAL ARTICLE: Elevational parallels of latitudinal variation in the proportion of lianas in woody floras
Authors: Jiménez‐Castillo M. , Wiser S. K. , Lusk C. H.
Published: August 2006

Aim  To determine if elevational variation in the proportion of lianas in woody floras parallels the variation observed on latitudinal gradients. This is to be expected if the poleward decrease in the importance of lianas is related to the vulnerability of their wide vessels to freeze embolism.

Location  Coastal ranges of south‐central Chile (latitude 37°–40° S) and western South Island of New Zealand (41°–43° S).

Methods  The presence of all woody species was recorded in plots of 2500 m2 (Chile) or 100–400 m2 (New Zealand) on four elevational gradients in temperate rain forest. Each species was classified as a tree, shrub or liana. Original data were obtained from 22 plots at two sites in Chile. In New Zealand, two surveys comprising a total of 296 plots were extracted from the National Vegetation Survey data base.

Results  Liana species richness declined more or less monotonically on all four gradients, whereas richness of trees and shrubs showed more varied elevational patterns. The proportion of woody species contributed by the liana life‐form was negatively correlated with elevation on all four gradients, falling from 15 to 35% of the woody flora at c. 200 m a.s.l. to nil well below the tree line. The elevational and latitudinal limits of liana species were marginally significantly correlated in Chile, but not in New Zealand.

Main conclusions  The elevational parallel of the well‐documented decline in liana representation with increasing latitude is consistent with the hypothesis that cold intolerance is a strong control on the global distribution of the liana life‐form.