bluuebunny/crossref_metadata_2025 huggingface dataset:
Alternative splicing produces high levels of noncoding isoforms of bHLH transcription factors during development
Authors: Kanadia Rahul N. , Cepko Constance L.
Published: January 2010

During development, multiple cell types within a tissue often arise from a common pool of progenitor cells (PCs). PCs typically expand in number, while simultaneously producing post-mitotic cells (PMCs). This balance is partly regulated by transcription factors that are expressed within PCs, such as the basic helix–loop–helix (bHLH) gene mouse atonal homolog 7 (Math5), which is expressed in retinal PCs. Here we report that alternative splicing (AS) of Math5 serves as another layer of regulation of Math5 activity. Specifically, Math5, a single exon gene, is alternatively spliced such that the major isoform lacks the entire coding sequence. Similarly, neurogenin 3 (Ngn3), a Math5 paralog expressed in pancreatic PCs, is also alternatively spliced such that the major isoform fails to code for Ngn3 protein. The consequence of reducing the abundance of protein-coding isoforms is likely crucial, as we found that introduction of coding isoforms leads to a reduction in cycling PCs. Thus, AS can limit the number of PCs expressing key regulatory proteins that control PC expansion versus PMC production.
IL-4 induces cathepsin protease activity in tumor-associated macrophages to promote cancer growth and invasion
Authors: Gocheva Vasilena , Wang Hao-Wei , Gadea Bedrick B. , Shree Tanaya , Hunter Karen E. , Garfall Alfred L. , Berman Tara , Joyce Johanna A.
Published: January 2010

Innate immune cells can constitute a substantial proportion of the cells within the tumor microenvironment and have been associated with tumor malignancy in patients and animal models of cancer; however, the mechanisms by which they modulate cancer progression are incompletely understood. Here, we show that high levels of cathepsin protease activity are induced in the majority of macrophages in the microenvironment of pancreatic islet cancers, mammary tumors, and lung metastases during malignant progression. We further show that tumor-associated macrophage (TAM)-supplied cathepsins B and S are critical for promoting pancreatic tumor growth, angiogenesis, and invasion in vivo, and markedly enhance the invasiveness of cancer cells in culture. Finally, we demonstrate that interleukin-4 (IL-4) is responsible for inducing cathepsin activity in macrophages in vitro and in vivo. Together, these data establish IL-4 as an important regulator, and cathepsin proteases as critical mediators, of the cancer-promoting functions of TAMs.
Characterization of the Rice PHO1 Gene Family Reveals a Key Role for OsPHO1;2 in Phosphate Homeostasis and the Evolution of a Distinct Clade in Dicotyledons
Authors: Secco David , Baumann Arnaud , Poirier Yves
Published: January 2010

Phosphate homeostasis was studied in a monocotyledonous model plant through the characterization of the PHO1 gene family in rice (Oryza sativa). Bioinformatics and phylogenetic analysis showed that the rice genome has three PHO1 homologs, which cluster with the Arabidopsis (Arabidopsis thaliana) AtPHO1 and AtPHO1;H1, the only two genes known to be involved in root-to-shoot transfer of phosphate. In contrast to the Arabidopsis PHO1 gene family, all three rice PHO1 genes have a cis-natural antisense transcript located at the 5 ′ end of the genes. Strand-specific quantitative reverse transcription-PCR analyses revealed distinct patterns of expression for sense and antisense transcripts for all three genes, both at the level of tissue expression and in response to nutrient stress. The most abundantly expressed gene was OsPHO1;2 in the roots, for both sense and antisense transcripts. However, while the OsPHO1;2 sense transcript was relatively stable under various nutrient deficiencies, the antisense transcript was highly induced by inorganic phosphate (Pi) deficiency. Characterization of Ospho1;1 and Ospho1;2 insertion mutants revealed that only Ospho1;2 mutants had defects in Pi homeostasis, namely strong reduction in Pi transfer from root to shoot, which was accompanied by low-shoot and high-root Pi. Our data identify OsPHO1;2 as playing a key role in the transfer of Pi from roots to shoots in rice, and indicate that this gene could be regulated by its cis-natural antisense transcripts. Furthermore, phylogenetic analysis of PHO1 homologs in monocotyledons and dicotyledons revealed the emergence of a distinct clade of PHO1 genes in dicotyledons, which include members having roles other than long-distance Pi transport.
Comparison of Developmental and Stress-Induced Nodule Senescence in Medicago truncatula
Authors: Pérez Guerra Juan Carlos , Coussens Griet , De Keyser Annick , De Rycke Riet , De Bodt Stefanie , Van De Velde Willem , Goormachtig Sofie , Holsters Marcelle
Published: January 2010

Mature indeterminate Medicago truncatula nodules are zonated with an apical meristem, an infection zone, a fixation zone with nitrogen-fixing bacteroids, and a “developmental” senescence zone that follows nodule growth with a conical front originating in the center of the fixation zone. In nitrogen-fixing cells, senescence is initiated coincidently with the expression of a family of conserved cysteine proteases that might be involved in the degradation of symbiotic structures. Environmental stress, such as prolonged dark treatment, interferes with nodule functioning and triggers a fast and global nodule senescence. Developmental and dark stress-induced senescence have several different structural and expression features, suggesting at least partly divergent underlying molecular mechanisms.
Arabidopsis Auxin Mutants Are Compromised in Systemic Acquired Resistance and Exhibit Aberrant Accumulation of Various Indolic Compounds
Authors: Truman William M. , Bennett Mark H. , Turnbull Colin G.N. , Grant Murray R.
Published: January 2010

Systemic acquired resistance is a widespread phenomenon in the plant kingdom that confers heightened and often enduring immunity to a range of diverse pathogens. Systemic immunity develops through activation of plant disease resistance protein signaling networks following local infection with an incompatible pathogen. The accumulation of the phytohormone salicylic acid in systemically responding tissues occurs within days after a local immunizing infection and is essential for systemic resistance. However, our knowledge of the signaling components underpinning signal perception and the establishment of systemic immunity are rudimentary. Previously, we showed that an early and transient increase in jasmonic acid in distal responding tissues was central to effective establishment of systemic immunity. Based upon predicted transcriptional networks induced in naive Arabidopsis (Arabidopsis thaliana) leaves following avirulent Pseudomonas syringae challenge, we show that a variety of auxin mutants compromise the establishment of systemic immunity. Linking together transcriptional and targeted metabolite studies, our data provide compelling evidence for a role of indole-derived compounds, but not auxin itself, in the establishment and maintenance of systemic immunity.
Bifurcation and Enhancement of Autonomous-Nonautonomous Retrotransposon Partnership through LTR Swapping in Soybean
Authors: Du Jianchang , Tian Zhixi , Bowen Nathan J. , Schmutz Jeremy , Shoemaker Randy C. , Ma Jianxin
Published: January 2010

Long terminal repeat (LTR) retrotransposons, the most abundant genomic components in flowering plants, are classifiable into autonomous and nonautonomous elements based on their structural completeness and transposition capacity. It has been proposed that selection is the major force for maintaining sequence (e.g., LTR) conservation between nonautonomous elements and their autonomous counterparts. Here, we report the structural, evolutionary, and expression characterization of a giant retrovirus-like soybean (Glycine max) LTR retrotransposon family, SNARE. This family contains two autonomous subfamilies, SAREA and SAREB, that appear to have evolved independently since the soybean genome tetraploidization event ∼13 million years ago, and a nonautonomous subfamily, SNRE, that originated from SAREA. Unexpectedly, a subset of the SNRE elements, which amplified from a single founding SNRE element within the last ∼3 million years, have been dramatically homogenized with either SAREA or SAREB primarily in the LTR regions and bifurcated into distinct subgroups corresponding to the two autonomous subfamilies. We uncovered evidence of region-specific swapping of nonautonomous elements with autonomous elements that primarily generated various nonautonomous recombinants with LTR sequences from autonomous elements of different evolutionary lineages, thus revealing a molecular mechanism for the enhancement of preexisting partnership and the establishment of new partnership between autonomous and nonautonomous elements.
Jasmonate and ppHsystemin Regulate Key Malonylation Steps in the Biosynthesis of 17-Hydroxygeranyllinalool Diterpene Glycosides, an Abundant and Effective Direct Defense against Herbivores inNicotiana attenuata
Authors: Heiling Sven , Schuman Meredith C. , Schoettner Matthias , Mukerjee Purba , Berger Beatrice , Schneider Bernd , Jassbi Amir R. , Baldwin Ian T.
Published: January 2010

We identified 11 17-hydroxygeranyllinalool diterpene glycosides (HGL-DTGs) that occur in concentrations equivalent to starch (mg/g fresh mass) in aboveground tissues of coyote tobacco (Nicotiana attenuata) and differ in their sugar moieties and malonyl sugar esters (0-2). Concentrations of HGL-DTGs, particularly malonylated compounds, are highest in young and reproductive tissues. Within a tissue, herbivore elicitation changes concentrations and biosynthetic kinetics of individual compounds. Using stably transformed N. attenuata plants silenced in jasmonate production and perception, or production of N. attenuata Hyp-rich glycopeptide systemin precursor by RNA interference, we identified malonylation as the key biosynthetic step regulated by herbivory and jasmonate signaling. We stably silenced N. attenuata geranylgeranyl diphosphate synthase (ggpps) to reduce precursors for the HGL-DTG skeleton, resulting in reduced total HGL-DTGs and greater vulnerability to native herbivores in the field. Larvae of the specialist tobacco hornworm (Manduca sexta) grew up to 10 times as large on ggpps silenced plants, and silenced plants suffered significantly more damage from herbivores in N. attenuata's native habitat than did wild-type plants. We propose that high concentrations of HGL-DTGs effectively defend valuable tissues against herbivores and that malonylation may play an important role in regulating the distribution and storage of HGL-DTGs in plants.
Inquiry and feedback: using action learning for transformational change
Authors: Dunton Diane L.
Published: January 2010

Purpose

The purpose of this paper is to share with business professionals a method for solving problems using action learning and inquiry. The outcome will be uncovering the root problem, build teams and leaders and transform how the organization addresses problems.

Design/methology/approach

The paper describes action learning, explains the process used and presents three examples of groups that have used the action learning technique.

Findings

In using action learning to focus on the real problem, organizations can be more effective, build teams and create change. Meetings are more productive, leaders emerge and results are achieved.

Practical implications

This is an approach that can be used with any size organization or group to address problems. Extensive training is not required. Once the concept is understood, the technique can be used throughout as a way to build teams and how change is viewed and problems are solved.

Originality/value

The paper provides a problem‐solving method using action learning and inquiry.
The impact of executive coaching on self‐efficacy related to management soft‐skills
Authors: Baron Louis , Morin Lucie
Published: January 2010

Purpose

Executive coaching has become an increasingly common method to skill development. However, few rigorous empirical studies have tested its capacity to generate outcomes. The purpose of this paper is to investigate the links between executive coaching and self‐efficacy in regard to supervisory coaching behaviors.

Design/methodology/approach

The paper reports on a pretest‐posttest study of a leadership development program using three training methods: classroom seminars, action learning groups, and executive coaching. Data are collected in a large international manufacturing company from 73 first‐ and second‐level managers over an eight‐month period.

Findings

Results indicate that, after controlling for pre‐training self‐efficacy and other training methods, the number of coaching sessions has a positive and significant relationship with post‐training self‐efficacy. Results also show that utility judgment, affective organizational commitment, and work‐environment support have each a positive and significant relationship with post‐training self‐efficacy.

Practical implications

The paper first suggests that an organization that wishes to improve its return on investment with regard to coaching should implement a program with multiple sessions spread over a period of several months. This paper also suggests that organizations should consider coaching from a systemic point of view, that is, taking into account not only the design but also individual and situational variables.

Originality/value

This paper contributes to the scientific literature by investigating, with a solid methodological design, the capacity of executive coaching to increase self‐efficacy related to management skills.
Purchasing power parity over a century
Authors: Hyrina Yevheniya , Serletis Apostolos
Published: January 2010

Purpose

The purpose of this paper is to revisit the evidence for purchasing power parity (PPP) using long, low‐frequency data (over 100 years) for 23 organization for economic co‐operation and development (OECD) countries against each of four different base currencies – the Deutsch mark, the Japanese yen, the British pound, and the US dollar.

Design/methodology/approach

The paper uses standard unit root tests and level and trend stationarity tests, and also investigates the robustness of the results to alternative testing methodologies from statistical physics, such as Lo's modified rescaled range statistic and the Hurst exponent.

Findings

The results indicate that the theory of PPP does not hold.

Originality/value

Motivated by the mixed results from previous research on the validity of the theory of PPP, the robustness of standard unit root and stationarity tests to alternative testing methodologies are investigated. In particular, the paper uses two tests from statistical physics – Lo's modified R/S statistic and the Hurst exponent.
Exploring the contribution of workplace learning to an HRD strategy in the Scottish legal profession
Authors: Watson Sandra , Harmel‐Law Amanda
Published: January 2010

Purpose

The purpose of this paper is to explore the relevance of human resource development (HRD) for law firms in the UK. It examines how the characteristics of legal professional practice in the UK, including the partnership structure, long established methods of targeting solicitors and the law society, may act as barriers to the implementation of HRD.

Design/methodology/approach

The paper uses an exploratory case study research approach to investigate characteristics and issues influencing the adoption of HRD in a Scottish legal firm. Primary data are collected via semi‐structured interviews with a cross‐section of representatives.

Findings

Despite recognition of the importance of learning, the characteristic elements of law firms, including the partnership structure; the pervasiveness of time‐billed targets in the solicitor community; and HR's profile and acceptance among the solicitor community, remain as barriers to the applicability of HRD. The research also exposes variability on the level and scope of development opportunities, an emphasis on technical skills development, and a lack of solicitors' self‐managed learning ability.

Research limitations/implications

While the research findings provide a useful insight into the barriers to HRD in one legal firm, this does not allow for any generalisations being drawn from the study.

Practical implications

The paper explores the suitability of workplace learning to support legal professional development.

Originality/value

There is a dearth of research into HRD in legal practices in the UK. The paper contributes to the contextual influences that limit the applicability of HRD to legal professional practices.
Sales training: effects of spaced practice on training transfer
Authors: Kauffeld Simone , Lehmann‐Willenbrock Nale
Published: January 2010

Purpose

The benefits of spaced training over massed training practice are well established in the laboratory setting. In a field study design with sales trainings, the purpose of this paper is to investigate the effects of spaced compared with massed practice on transfer quantity and quality, sales competence, and key figures.

Design/methodology/approach

Spaced and massed training are compared using behavioral and outcome criteria. A quasi‐experimental follow‐up research design with a sample of 64 bank employees (n=32 in each training group) is used.

Findings

Spaced rather than massed training practice resulted in greater transfer quality, higher self‐reports of sales competence, and improved key figures. Spaced training did not surpass massed training in terms of transfer quantity.

Research limitations/implications

The present study is the first to demonstrate positive effects of technical training on job involvement, and of coaching on job satisfaction. In sum, validity of several developmental interventions is highlighted.

Practical implications

Organizations designing and implementing various developmental interventions should pay attention to the relative effectiveness of these interventions on various organizational‐relevant outcome criteria.

Originality/value

An innovative approach to imply spaced practice in real sales training is presented. The effects of spaced practice on training transfer are investigated in the field.
Solution of 3D singular electrostatics problems using adaptive hp‐FEM
Authors: Kus Pavel , Solin Pavel , Dolezel Ivo
Published: January 2010

Purpose

This paper seeks to describe the solution of a simple electrostatic problem using an adaptive hp‐FEM and to show the benefits of this approach. Numerical experiments are presented to demonstrate its superiority.

Design/methodology/approach

Adaptive hp‐FEM is used. In contrast with standard FEM, the automatic adaptivity procedure can choose from a variety of refinement candidates. An element with over estimated error can be refined in space, or its polynomial degree can be increased. Arbitrary level hanging nodes are allowed, so that no unnecessary refinements are performed in order to keep a mesh regular.

Findings

Numerical solution of a singular electrostatic problem is presented. From the comparison it can be seen that the hp‐FEM outperforms both the standard linear and quadratic elements significantly. The accuracy of an hp‐FEM solution would be hard to attain by standard means due to the limited capacity of the computer memory.

Originality/value

The paper describes results obtained from an original and innovative implementation of the adaptive hp‐FEM.
Deriving value from inter‐organizational learning collaborations
Authors: van Winkelen Christine
Published: January 2010

Purpose

This paper aims to develop the understanding of how organizations can derive more value from participating in inter‐organizational learning collaborations.

Design/methodology/approach

The collaboration is viewed as one “level” within an extended organizational learning system and both feedback processes between levels and the dynamics within the collaboration itself are explored. Seven learning‐based inter‐organizational learning collaborations are studied using a qualitative exploratory research design. An extensive literature review is used to design the semi‐structured interviews undertaken with participants in the collaborations, as well as the convenor of each.

Findings

Multiple forms of value are evident (individual capacity building, operational value, affirmation, reputation and relationship building and learning about how to collaborate more effectively), though subject specific organizational capability building is rarely achieved. Two main factors seemed to influence this: individuals not translating the implications of the learning, and the organizations not transferring and amplify that learning. Building capability required a visible long‐term commitment by leaders to the collaboration.

Research limitations/implications

Confirmatory research is needed to refine the proposed framework of actions to develop the organizational capability to derive value from participating in this kind of collaboration.

Practical implications

A coherent set of actions is proposed for organizations wishing to build the capability to derive more value from participating in inter‐organizational learning collaborations. Recommendations are also generated for those wishing to convene a collaboration.

Originality/value

The contribution is the development of the concept of the organizational capability to participate effectively in inter‐organizational learning collaborations, and the identification of a coherent set of actions required to develop this capability.
Effects of the polarity of high‐electric field stressing on power VDMOSFETs parameters
Authors: El Bitar R. , Salloum G. , Nsouli B.
Published: January 2010

Purpose

The purpose of this paper is to study the effects of positive and negative bias stressing on switching performance of power VDMOSFETs used in communication systems.

Design/methodology/approach

A positive and a negative high‐field stress are applied on the gate oxide of MOS devices and electrical characterization is performed after each period of stress, a comparison is presented.

Findings

Compared results between the two types of stress show that certain doses of stress can increase the device speed. The underlying changes of the threshold voltage under these two types of stress are referred to as the variation of the gate oxide‐trapped charge and interface trap densities.

Originality/value

This paper presents new and original experiments run over a number of metal‐oxide semiconductor field effect transistor devices to compare the effects of the direction of the applied field on the degradation and the reliability of these structures.
Organisational Development through OD‐WIT — Rewards — An Integrated Approach
Authors: Dar‐El Ezey M. , Harel Gedaliahu H.
Published: January 2010

This article describes a new approach to organisational development — one which integrates a management development programme with a worker development programme. The latter uses the Work Improvement Team (WIT) as its vehicle. Aspects of WIT functions, organisation and maintenance are discussed. The article stresses the how aspect of the development methodology and illustrates the process with studies made in two medium‐sized manufacturing plants.
Advances in understanding the pathogenesis of primary familial and congenital polycythaemia
Authors: Huang Lily J. , Shen Yu‐Min , Bulut Gamze B.
Published: January 2010

Primary familial and congenital polycythemia (PFCP) is an autosomal‐dominant proliferative disorder characterized by erythrocytosis and hypersensitivity of erythroid progenitors to erythropoietin (Epo). Several lines of evidence suggest a causal role of truncated erythropoietin receptor (EpoR) in this disease. In this review, we discuss PFCP in the context of erythrocytosis and EpoR signalling. We focus on recent studies describing mechanisms underlying Epo‐dependent EpoR down‐regulation. One mechanism depends on internalization mediated through the p85 regulatory subunit of the Phosphoinositide 3‐Kinase, and the other utilizes ubiquitin‐based proteasomal degradation. Truncated PFCP EpoRs are not properly down‐regulated upon stimulation, underscoring the importance of these mechanisms in the pathogenesis of PFCP.
Providing context to the global code of practice for recreational fisheries
Authors: ARLINGHAUS R. , COOKE S. J. , COWX I. G.
Published: January 2010

Abstract  An in‐depth explanation of selected content of the European Inland Fisheries Advisory Commission’s ‘Code of Practice for Recreational Fisheries’ (CoP) is presented. The focus is on core areas that were intensely debated in the drafting the CoP. These include definition of recreational fishing, recreational fishing practices, fish welfare, recreational fisheries management and research. It is anticipated that the CoP for recreational fisheries promotes best practice and management principles for sustainable recreational fisheries, within the recreational fisheries sector and ancillary industries/sectors regionally, nationally, and ultimately globally. To be viable, the CoP for recreational fisheries must be adopted by the international community complementing the Code of Conduct for Responsible Fisheries of the Food and Agriculture Organization of the United Nations.
Caribbean octocorals record changing carbon and nitrogen sources from 1862 to 2005
Authors: BAKER DAVID M. , WEBSTER KIRBY L. , KIM KIHO
Published: January 2010

During the last century, the global biogeochemical cycles of carbon (C) and nitrogen (N) have been drastically altered by human activities. A century of land‐clearing and biomass burning, followed by fossil fuel combustion have increased the concentration of atmospheric CO2 by approximately 20%, and since the mid‐1900s, the use of agricultural fertilizers has been the primary driver of an approximate 90% increase in bioavailable N. Geochemical records obtained through stable isotope analysis of terrestrial and marine biota effectively illustrate rising anthropogenic C inputs. However, there are fewer records of anthropogenic N, despite the enormous magnitude of change and the known negative effects of N on ecosystem health. We used stable isotope values from independent octocorals (gorgonians) sampled across the Western Atlantic over the last 143 years to document human perturbations of the marine C and N pools. Here, we demonstrate that in sea plumes δ13C values and in both sea plumes and sea fans δ15N values declined significantly from 1862 to 2005. Sea plume δ13C values were negatively correlated with increasing atmospheric CO2 concentrations and corroborate known rates of change resulting from global fossil fuel combustion, known as the Suess effect. We suggest that widespread input of agricultural fertilizers to near‐shore coastal waters is the dominant driver for the decreasing δ15N trend, though multiple anthropogenic sources are likely affecting this trend. Given the interest in using δ15N as an indicator for N pollution in aquatic systems, we highlight the risk of underestimating contributions of pollutants as a result of source mixing as demonstrated by a simple isotope‐mixing model. We conclude that signals of major human‐induced perturbations of the C and N pools are detectable in specimens collected over wide geographic scales, and that archived materials are invaluable for establishing baselines against which we can assess environmental change.
Male parentage in dependent‐lineage populations of the harvester ant Pogonomyrmex barbatus
Authors: SUNI SEVAN S. , GIGNOUX CHRISTOPHER , GORDON DEBORAH M.
Published: January 2010

We investigated the extent to which workers reproduce in a dependent‐lineage population of the monogynous harvester ant Pogonomyrmex barbatus. Dependent‐lineage populations contain two interbreeding, yet genetically distinct mitochondrial lineages, each associated with specific alleles at nuclear loci. Workers develop from matings between lineages, and queens develop from matings within lineages, so queens must mate with males of both lineages to produce daughter queens and workers. Males develop from unfertilized eggs and are haploid. Worker production of males could lead to male‐mediated gene flow between the lineages if worker‐produced males were reproductively capable. This could result in the loss of the dependent‐lineage system, because its persistence depends on the maintenance of allelic differences between the lineages. To investigate the extent of worker reproduction in P. barbatus, we genotyped 19–20 males and workers from seven colonies, at seven microsatellite loci, and 1239 additional males at two microsatellite loci. Our methods were powerful enough to detect worker reproduction if workers produced more than 0.39% of males in the population. We detected no worker‐produced males; all males appeared to be produced by queens. Thus, worker reproduction is sufficiently infrequent to have little impact on the dependent‐lineage system. These results are consistent with predictions based on inclusive fitness theory because the effective queen mating frequency calculated from worker genotypes was 4.26, which is sufficiently high for workers to police those that attempt to reproduce.
Co‐limitation of photosynthetic capacity by nitrogen and phosphorus in West Africa woodlands
Authors: DOMINGUES TOMAS FERREIRA , MEIR PATRICK , FELDPAUSCH TED R. , SAIZ GUSTAVO , VEENENDAAL ELMAR M. , SCHRODT FRANZISKA , BIRD MICHAEL , DJAGBLETEY GLORIA , HIEN FIDELE , COMPAORE HALIDOU , DIALLO ADAMA , GRACE JOHN , LLOYD JON
Published: January 2010

Photosynthetic leaf traits were determined for savanna and forest ecosystems in West Africa, spanning a large range in precipitation. Standardized major axis fits revealed important differences between our data and reported global relationships. Especially for sites in the drier areas, plants showed higher photosynthetic rates for a given N or P when compared with relationships from the global data set. The best multiple regression for the pooled data set estimated Vcmax and Jmax from NDW and S. However, the best regression for different vegetation types varied, suggesting that the scaling of photosynthesis with leaf traits changed with vegetation types. A new model is presented representing independent constraints by N and P on photosynthesis, which can be evaluated with or without interactions with S. It assumes that limitation of photosynthesis will result from the least abundant nutrient, thereby being less sensitive to the allocation of the non‐limiting nutrient to non‐photosynthetic pools. The model predicts an optimum proportionality for N and P, which is distinct for Vcmax and Jmax and inversely proportional to S. Initial tests showed the model to predict Vcmax and Jmax successfully for other tropical forests characterized by a range of different foliar N and P concentrations.
Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63
Authors: Waanders E , Venselaar H , Te Morsche RHM , De Koning DB , Kamath PS , Torres VE , Somlo S , Drenth JPH
Published: January 2010

Waanders E, Venselaar H, te Morsche RHM, de Koning DB, Kamath PS, Torres VE, Somlo S, Drenth JPH. Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63.

Polycystic liver disease (PCLD) is characterized by intralobular bile duct cysts in the liver. It is caused by mutations in PRKCSH, encoding hepatocystin, and SEC63, encoding Sec63p. The main goals of this study were to screen for novel mutations and to analyze mutations for effects on protein structure and function. We screened 464 subjects including 76 probands by direct sequencing or conformation‐sensitive capillary electrophoresis. We analyzed the effects of all known and novel mutations using a combination of splice site recognition, evolutionary conservation, secondary and tertiary structure predictions, PolyPhen, and pMut and sift. We identified a total of 26 novel mutations in PRKCSH (n = 14) and SEC63 (n = 12), including four splice site mutations, eight insertions/ deletions, six non‐sense mutations, and eight missense mutations. Out of 48 PCLD mutations, 13 were predicted to affect splicing. Most mutations were located in highly conserved regions and homology modeling for two domains of Sec63p showed severe effects of the residue substitutions. In conclusion, we identified 26 novel mutations associated with PCLD and we provide in silico analysis in order to delineate the role of these mutations.
Effects of classroom education on knowledge and attitudes regarding organ donation in ethnically diverse urban high schools
Authors: Cárdenas Vicky , Thornton John D. , Wong Kristine A. , Spigner Clarence , Allen Margaret D.
Published: January 2010

Cárdenas V, Thornton JD, Wong KA, Spigner C, Allen MD. Effects of classroom education on knowledge and attitudes regarding organ donation in ethnically diverse urban high schools.  Clin Transplant 2010: 24: 784–793. © 2010 John Wiley & Sons A/S.

Abstract:  School‐based health education is a promising approach for improving organ donation rates, but little is known about its efficacy among ethnically diverse youth. The impact of a classroom intervention was examined in a multicultural high school population where students’ ethnicities were 45% African American, 30% Asian American, and 33% Caucasian (allowing for multiracial choices). A baseline survey was administered to all health classes within two wk prior to intervention. On the intervention day, classes randomly assigned to the intervention group received an educational session, followed by a second survey; in control classes, the second survey was taken before the educational session. At baseline, non‐Caucasian ethnicity and male gender were each associated with lower levels of willingness to donate. Following the intervention, students in the intervention group demonstrated a significant increase in knowledge scores (p < 0.001), as well as positive movement of opinion regarding willingness to donate (p < 0.0001). Most importantly, the positive changes in opinion occurred independently of ethnicity and gender, in spite of these both being negative predictors of opinion at baseline. These results demonstrate that even a single classroom exposure can impact knowledge levels, correct misinformation, and effect opinion change on organ donation among an ethnically diverse adolescent population.
NOTES ON NEW BOOKS
Authors: Magill C. P. , Chambers W. Walker
Published: January 2010

Allemugnes et Allemanas.

Hier ist dus Wort. Gedichte.

Neue Gedichte. Mit einem Nachwort von Gerhart Pohle.

The Archipelago. By Friedrich Holderlin. The text with notes and a new translation by J. B. Leishman. With an introduction by Friedrich Gundolftranslated by J. B. Leishman and Elisabeth Gundolf:

Family Strife in Habsburg.

A Faithful Servant of His Master

Medea. By Franz Grillparzer

The Guest‐Friend and The Argonauts.

Franz Grillparzer. Der Innere Orden. Ein Brevier, Herausgegeben uon Christoph Meyer.

The Stattire of Thomas Mtitin. An Anthology of Criticism.

Nietzsche

Hotbeins Dance of Death.

Steirische LandbatiJi bel.

New Theatres for Old.

Das Wirtshazrs ZUY Verlorenert Zeit.

Vormittug. Erinnertingen eittes Verlegers.

Kiinig Haber. Erzuhlzrg.

Das Neue Buch: Katalog der Neuerscheinungen 1945‐47
Diagenesis of the Amposta offshore oil reservoir (Amposta Marino C2 well, Lower Cretaceous, Valencia Trough, Spain)
Authors: PLAYÀ E. , TRAVÉ A. , CAJA M. A. , SALAS R. , MARTÍN‐MARTÍN J. D.
Published: January 2010

Samples from the Amposta Marino C2 well (Amposta oil field) have been investigated in order to understand the origin of fractures and porosity and to reconstruct the fluid flow history of the basin prior, during and after oil migration. Three main types of fracture systems and four types of calcite cements have been identified. Fracture types A and B are totally filled by calcite cement 1 (CC1) and 2 (CC2), respectively; fracture type A corresponds to pre‐Alpine structures, while type B is attributed to fractures developed during the Alpine compression (late Eocene‐early Oligocene). The oxygen, carbon and strontium isotope compositions of CC2 are close to those of the host‐rock, suggesting a high degree of fluid‐rock interaction, and therefore a relatively closed palaeohydrogeological system. Fracture type C, developed during the Neogene extension and enlarged by subaerial exposure, tend to be filled with reddish (CS3r) and greenish (CS3g) microspar calcite sediment and blocky calcite cement type 4 (CC4), and postdated by kaolinite, pyrite, barite and oil. The CS3 generation records lower oxygen and carbon isotopic compositions and higher 87Sr/86Sr ratios than the host‐limestones. These CS3 karstic infillings recrystallized early within evolved‐meteoric waters having very little interaction with the host‐rock. Blocky calcite cement type 4 (CC4 generation) has the lowest oxygen isotope ratio and the most radiogenic 87Sr/86Sr values, indicating low fluid‐rock interaction. The increasingly open palaeohydrogeological system was dominated by migration of hot brines with elevated oxygen isotope ratios into the buried karstic system. The main oil emplacement in the Amposta reservoir occurred after the CC4 event, closely related to the Neogene extensional fractures. Corrosion of CC4 (blocky calcite cement type 4) occurred prior to (or during) petroleum charge, possibly related to kaolinite precipitation from relatively acidic fluids. Barite and pyrite precipitation occurred after this corrosion. The sulphur source associated with the late precipitation of pyrite was likely related to isotopically light sulphur expelled, e.g. as sulphide, from the petroleum source rock (Ascla Fm).

Geofluids (2010) 10, 314–333
Partial reduction of BACE1 improves synaptic plasticity, recent and remote memories in Alzheimer’s disease transgenic mice
Authors: Kimura Ryoichi , Devi Latha , Ohno Masuo
Published: January 2010

J. Neurochem. (2010) 10.1111/j.1471‐4159.2010.06608.x

β‐Site amyloid precursor protein cleaving enzyme 1 (BACE1) initiates amyloid‐β (Aβ) generation that is central to the pathophysiology of Alzheimer’s disease (AD). Therefore, lowering Aβ levels by BACE1 manipulations represents a key therapeutic strategy, but it remains unclear whether partial inhibition of BACE1, as expected for AD treatments, can improve memory deficits. In this study, we used heterozygous BACE1 gene knockout (BACE1+/−) mice to evaluate the effects of partial BACE1 suppression on different types of synaptic and cognitive dysfunctions in Alzheimer’s transgenic mice (5XFAD model). We found that ∼50% BACE1 reductions rescued deficits of 5XFAD mice not only in hippocampus‐dependent memories as tested by contextual fear conditioning and spontaneous alternation Y‐maze paradigms but also in cortex‐dependent remote memory stabilization during 30 days after contextual conditioning. Furthermore, 5XFAD‐associated impairments in long‐term potentiation (a synaptic model of learning and memory) and declines in synaptic plasticity/learning‐related brain‐derived neurotrophic factor‐tyrosine kinase B signaling pathways were prevented in BACE1+/−·5XFAD mice. Finally, these improvements were related with reduced levels of β‐secretase‐cleaved C‐terminal fragment (C99), Aβ peptides and plaque burden in relevant brain regions of BACE1+/−·5XFAD mice. Therefore, our findings provide compelling evidence for beneficial effects of partially BACE1‐inhibiting approaches on multiple forms of functional defects associated with AD.
Serine/threonine kinase akt activation regulates the activity of retinal serine/threonine phosphatases, PHLPP and PHLPPL
Authors: Kanan Yogita , Matsumoto Hiroyuki , Song Hongman , Sokolov Maxim , Anderson Robert E. , Rajala Raju V. S.
Published: January 2010

J. Neurochem. (2010) 113, 477–488.

In our previous studies, we have shown that insulin receptor (IR) activation leads to the activation of phosphoinositide 3‐kinase (PI3K) and Akt activation in rod photoreceptors. This pathway is functionally important for photoreceptor survival as deletion of IR and one of the isoforms of Akt (Akt2) resulted in stress‐induced photoreceptor degeneration. However, the molecular mechanism of this degeneration is not known. Akt signaling is known to be regulated by the serine/threonine phosphatases, PH domain and leucine‐rich repeat protein phosphatases (PHLPP) and PHLPP‐like (PHLPPL). In this study, we characterized these two phosphatases in the retina and examined the role of IR, PI3K, and Akt signaling on the activity of PHLPP and PHLPPL. Most of the studies published on PHLPP and PHLPPL are directed toward Akt dephosphorylation; however, there are no studies available to date on how the enzyme activities of these phosphatases are regulated. We made a novel finding in this study that both PHLPP and PHLPPL activities were significantly decreased in the presence of insulin ex vivo. The insulin‐induced decrease of phosphatase activities were PI3K‐dependent as pre‐treatment of ex vivo retinal cultures with LY294002 significantly reversed the insulin‐induced inhibition. It has been shown previously that PHLPP and PHLPPL regulate the dephosphorylation of Akt isoforms, and our results demonstrate for the first time that retinal PHLPP and PHLPPL activities are under the control of the IR‐activated PI3K/Akt pathway.
Inhibitory effect of anticholinergics on the contraction of isolated caprine urinary bladder detrusor muscle
Authors: George N. , Shiny P. J. , Miriam J. , Nancy C. A. , Dhanasekar K. R. , Peedicayil J.
Published: January 2010

1. This study investigated whether four anticholinergics which are not clinically used for relaxing the urinary bladder detrusor muscle inhibit the contraction of isolated caprine (goat) detrusor muscle: cyclopentolate (100 nm), homatropine (5 μm), ipratropium (500 nm) and valethamate (1 μm).

2. The effects of these anticholinergics were compared with tolterodine (3 μm), an anticholinergic clinically used for relaxing the detrusor muscle. The inhibitory effect of each of these five anticholinergics was studied on six strips of caprine detrusor muscle made to contract with 100 μm acetylcholine (ACh) by determining the percent inhibition of height of contraction and the area under the contractile curve (AUC).

3. It was found that all five anticholinergics inhibited the ACh‐induced contraction of the caprine detrusor and that this inhibition was reversed by raising the concentration of ACh. Hence, these four anticholinergics, like tolterodine, may be useful in managing clinical conditions that require relaxation of the detrusor muscle.
Seeding Method Influences Warm‐Season Grass Abundance and Distribution but not Local Diversity in Grassland Restoration
Authors: Yurkonis Kathryn A. , Wilsey Brian J. , Moloney Kirk A. , Drobney Pauline , Larson Diane L.
Published: January 2010

Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat‐scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine‐scale seed distribution. However, native warm‐season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine‐scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands.
Cedar Infestation Impacts Avian Communities along the Niobrara River Valley, Nebraska
Authors: Frost January S. , Powell Larkin A.
Published: January 2010

Habitat modification has the potential to cause changes in structure and composition of bird communities. Our goal was to determine the response of Songbird community composition to eastern red cedar (Juniperus virginiana) removal in The Nature Conservancy's Niobrara Valley Preserve, Nebraska. We used point counts to survey birds in the riparian matrix of grassland and forest habitats. More than 60 species were recorded on surveys during 2004–2005. We also use the program PRESENCE to determine the response of five species to various habitat components, including cedar density: House Wren (Troglodytes aedon), Spotted Towhee (Pipilo maculates), Ovenbird (Seiurus aurocapillus), Red‐eyed Vireo (Vireo olivaceus), and Indigo Bunting (Passerina cyanea). Species richness estimates were highest in open and mixed habitat patches. Local populations of Ovenbirds and Red‐eyed Vireos responded positively to cedar density, whereas House Wren numbers declined as cedar density increased. Cedar abundance explained the most variation in bird community similarity between survey points; species richness increased as cedar density decreased. Habitat structure and composition drove variation in community composition and population abundance at fine, local scales within the Preserve. Fine‐scale management to remove cedar from local areas should increase diversity of avian species by maintaining a matrix of habitat types. Cedar removal at any scale will affect the composition of bird communities, and we encourage a structured approach to management decisions.
Salvage Logging Versus the Use of Burnt Wood as a Nurse Object to Promote Post‐Fire Tree Seedling Establishment
Authors: Castro Jorge , Allen Craig D. , Molina‐Morales Mercedes , Marañón‐Jiménez Sara , Sánchez‐Miranda Ángela , Zamora Regino
Published: January 2010

Intense debate surrounds the effects of post‐fire salvage logging (SL) versus nonintervention policies on forest regeneration, but scant support is available from experimental studies. We analyze the effect of three post‐fire management treatments on the recruitment of a serotinous pine (Pinus pinaster) at a Mediterranean mountain. Treatments were applied 7 months after the fire and differ in the degree of intervention, ranging from “no intervention” (NI, all trees left standing) to “partial cut plus lopping” (PCL, felling most of the trees, cutting the main branches, and leaving all the biomass in situ without mastication), and “SL” (felling and piling the logs, and masticating the woody debris). Seedling survival after 3 years was the highest in PCL (47.3% versus 38.7% in SL). This was associated with the amelioration of microclimatic conditions under the scattered branches, which reduced radiation and soil temperature while increasing soil moisture. Seedling density after 2 years was approximately 5.5 times higher in PCL than in SL, as in SL a large fraction of seedlings was lost as a consequence of mechanized mastication. The NI treatment showed the lowest seedling survival (17.3%). Nevertheless, seedling density was similar to SL. Seedling growth scarcely differed among treatments. Our results show that branches left onsite acted as nurse objects that improved key microclimatic conditions for seedling recruitment. This creates a facilitative interaction ideal for seedling establishment in moisture‐deficient ecosystems, as it provides the benefit of a shading overstory but without underground competition.