Combining interactive GIS tools and expert knowledge in validation of tree species models

Poster presented at XIII Congreso Forestal Mundial. FAO, Buenos Aires (Argentina). 18-25 Oct 200

Subtle disorders of the menstrual cycle in subfertile and aging women

Why do some women fail to become pregnant although they have regular menstrual cycles? Why does female fertility decrease with age? In this thesis, several groups of women have been investigated. We examined the growth of ovarian follicles by ultrasound, and we followed the concentrations of some hormones during the cycles of the following groups of women: (1) Women who wished to conceive a pregnancy, but did not succeed to do so after at least one year. (2) Women with an amenorrhea or oligomenorrhea (cycles with a mean length > 6 weeks), who were treated with a drug, clomiphene citrate (CC) to stimulate follicle development and ovulation. (3) Healthy women of an age range (41-46 years) in which fertility is usually greatly diminished. The cycles were compared with those of control groups. We concluded that abnormal cycles occur more often (5% in contrast to almost none) in patients of group (1). In the majority of these cycles, the follicle has a normal growth pattern, but, after the signal that is supposed to induce ovulation, no rupture of the follicle occurs: so-called luteinized unruptured follicle or LUF cycles. It is not certain whether such subtle ovulation disorders (SOD) do occur repeatedly in the cycles of one woman, but this is probably so, because it was found that relatively low progesterone concentrations in blood can predict an SOD in a subsequent cycle. However, diagnosing such disorders is expensive, and makes it necessary for the patient to visit the hospital frequently. After treatment with drugs that are generally used to induce follicle growth and ovulation, many women become pregnant. It is, however, unknown how many of these pregnancies would have been achieved without treatment. Treatment of amenorrheic or oligomenorrheic women with CC is generally assumed to result in less pregnancies (about 40% of the patients) than expected when the ovulation rate (about 80%) is considered. In 12 women from group (2) who showed follicle growth when treated with CC, only one cycle was abnormal showing a LUF. We concluded that SOD are an unlikely cause of the discrepancy between ovulation rate and pregnancy rate during CC treatment. Some, relatively older, women showed a temporary decline of the levels of serum estradiol (the hormone that is produced by growing follicles). The relevance of this finding is still not clear. Cycles of women from group (3) were compared with those of a younger age-group (22-34 years). SOD, as a possible cause of declining fertility with age, did not occur. The cycles of the older women were shorter, due to an earlier start of the development of a dominant follicle (the follicle that is destined to ovulate). The development of such dominant follicles already started during the second half (luteal phase) of the preceding cycle. Until now it has been supposed that the cycles of older women are shorter due to a speeding-up of the growth of a dominant follicle (accelerated growth), instead of such an advanced follicle growth. The earlier start of the development of a dominant follicle possibly occurs during a less favourable hormonal environment, which could be detrimental for the follicle, and for the oocyte it contains

Tree genetic resources at risk in South America: A spatial threat assessment to prioritize populations for conservation

Background Humans threat the populations of tree species by overexploitation, deforestation, land use change, and climate change. We present a novel threat assessment at intraspecific level to support the conservation of genetic resources of 80 socioeconomically viable tree species in South America. In this assessment, we evaluate the threat status of Ecogeographic Range Segments (ERSs). ERSs are groups of populations of a specific species in a certain ecological zone of a particular grid cell of a species’ geographic occupancy. Methods We used species location records to determine the species distributions and species‐specific ERSs. We distinguished eight threat situations to assess the risk of extirpation of the ERSs of all 80 species. These threat situations were determined by large or little tree cover, low or high human pressure, and low or high climate change impact. Available layers of tree cover and threats were used to determine the levels of fragmentation and direct human pressure. Maxent niche modelling with two Global Circulation Models helped determining climate change impact by the 2050s. Results When all 80 species are considered, in total, 59% of the ERSs are threatened by little tree cover or high human pressure. When climate change is also considered, then 71‐73% of the ERSs are threatened. When an increased risk of extirpation of populations outside protected areas is considered, then 84–86% of the ERSs are threatened. Seven species warrant special attention because all their ERSs are threatened across their whole distribution in South America: Balfourondendron riedelianum, Cariniana legalis, Dalbergia nigra, Handroanthus pulcherrimus, Pachira quintana, Prosopis flexuosa, and Prosopis pallida. Conclusions Our results confirm the urgency to set up a regional action plan for the conservation of tree genetic resources in South America. With this threat assessment, we aim to support governments and organizations who are taking up this task

Effectiveness and cost-effectiveness of a nurse-delivered intervention to improve adherence to treatment for HIV : a pragmatic, multicentre, open-label, randomised clinical trial

This trial was funded from public money by the Netherlands Organisation for Health Research and Development (ZonMW; grant number 171002208). Aardex provided support on the development of the study website. We thank all the HIV nurses and physicians from the seven HIV clinics involved in the AIMS study for their input and collaboration (Academic Medical Centre, Slotervaart hospital, and St. Lucas-Andreas hospital, all in Amsterdam; the Leiden University Medical Centre, Leiden; HAGA hospital, The Hague; Erasmus Medical Centre, Rotterdam; and Isala clinic, Zwolle), the study participants, and the Stichting HIV Monitoring (SHM) for their support in accessing the SHM database for identifying patient inclusion criteria and developing the Markov model. Finally, we thank and remember Herman Schaalma (deceased) for his contribution to the study design and grant application.Peer reviewedPostprin

Global strategy for the conservation and use of eggplants

Common eggplant (Solanum melongena L.), also known as brinjal eggplant or aubergine, is a vegetable crop grown for its large soft fruits which are used in cooking. There are also two African eggplant species grown locally: scarlet eggplant (Solanum aethiop icum L.) and gboma eggplant (Solanum macrocarpon L.). According to the statistics of the United Nations Food and Agriculture Organization (FAO), eggplant is grown on 1.8 million hectares (ha) globally, and 90% of eggplant production takes place in Asia. Breeding and research on eggplant is carried out in many coun tries. Numerous germplasm collections of eggplant and its related species exist to provide plant materials for breeding and related research. In the present study, we overview the current status of eggplant germplasm conservation efforts and the use of eggplant diversity with the aim of providing a forward-looking strategy document. To do this, we surveyed the global databases Genesys and WIEWS (World Information and Early Warning System on Plant Genetic Resources for Food and Agriculture) to obtain information about existing eggplant ex situ collections. The most often represented species in these databases is brinjal eggplant with 12,715 acces sions conserved in total. This is followed by scarlet eggplant (886 accessions) and gboma eggplant (209 accessions). Wild relatives of eggplant are conserved in some collections, but some species are not well represented. In total, 109 eggplant collection holders were iden tified through the database searches. The collection holders were asked to complete an online survey on the status of their collections and the challenges that they faced. Responses were received from 32 collec tion holders, 27 of which provided sufficient data for further analyses. Most of the collection holders that responded were governmental organizations or publicly funded institutions. Two respondents were non-governmental organizations (NGOs). Several challenges related to the sustainability of eggplant conservation and use were identified. Shortages of funds and staff were reported as major threats to collection viability and security by many of the collec tion holders. Opportunities for improvement included recruiting new and/or young people interested in eggplant conservation, and increased collaborations across national borders and among institutions. Improved documentation of existing plant materials and increased information sharing were also identi fied as areas for improvement.publishedVersio

Modeling the combined effect of RNA-binding proteins and microRNAs in post-transcriptional regulation

Recent studies show that RNA-binding proteins (RBPs) and microRNAs (miRNAs) function in coordination with each other to control post-transcriptional regulation (PTR). Despite this, the majority of research to date has focused on the regulatory effect of individual RBPs or miRNAs. Here, we mapped both RBP and miRNA binding sites on human 3′UTRs and utilized this collection to better understand PTR. We show that the transcripts that lack competition for HuR binding are destabilized more after HuR depletion. We also confirm this finding for PUM1(2) by measuring genome-wide expression changes following the knockdown of PUM1(2) in HEK293 cells. Next, to find potential cooperative interactions, we identified the pairs of factors whose sites co-localize more often than expected by random chance. Upon examining these results for PUM1(2), we found that transcripts where the sites of PUM1(2) and its interacting miRNA form a stem-loop are more stabilized upon PUM1(2) depletion. Finally, using dinucleotide frequency and counts of regulatory sites as features in a regression model, we achieved an AU-ROC of 0.86 in predicting mRNA half-life in BEAS-2B cells. Altogether, our results suggest that future studies of PTR must consider the combined effects of RBPs and miRNAs, as well as their interactions.No sponso

CD34+ cells home, proliferate, and participate in capillary formation, and in combination with

Objective - Emerging evidence suggests that human blood contains bone marrow (BM)-derived endothelial progenitor cells that contribute to postnatal neovascularization. Clinical trials demonstrated that administration of BM-cells can enhance neovascularization. Most studies, however, used crude cell populations. Identifying the role of different cell populations is important for developing improved cellular therapies. Methods and Results - Effects of the hematopoietic stem cell-containing CD34+ cell population on migration, proliferation, differentiation, stimulation of, and participation in capillary-like tubule formation were assessed in an in vitro 3-dimensional matrix model using human microvascular endothelial cells. During movement over the endothelial monolayer, CD34+ cells remained stuck at sites of capillary tube formation and time- and dose-dependently formed cell clusters. Immunohistochemistry confirmed homing and proliferation of CD34+ cells in and around capillary sprouts. CD34+ cells were transduced with the LNGFR marker gene to allow tracing. LNGFR gene-transduced CD34 + cells integrated in the tubular structures and stained positive for CD31 and UEA-1. CD34+ cells alone stimulated neovascularization by 17%. Coculture with CD34- cells led to 68% enhancement of neovascularization, whereas CD34- cells displayed a variable response by themselves. Cell-cell contact between CD34+ and CD34- cells facilitated endothelial differentiation of CD34+ cells. Conclusions - Our data suggest that administration of CD34+-enriched cell populations may significantly improve neovascularization and point at an important supportive role for (endogenous or exogenous) CD34- cells. © 2005 American Heart Association, Inc. Chemicals / CAS: nitric oxide, 10102-43-9; Antigens, CD34; Biological Marker