Human stem-progenitor cells from neonatal cord blood have greater hematopoietic expansion capacity than those from mobilized adult blood

OBJECTIVE: In this study we compared the hematopoietic capacity of CD34+ cell preparations from neonatal cord blood (CB) vs adult mobilized peripheral blood (PBSC) before and after ex vivo culture. METHODS: CD34+ cell preparations purified from CB or PBSC were cultured in serum-free medium containing FKT: FLT-3 ligand (FL), KIT ligand (KL), and thrombopoietin (TPO). RESULTS: After 1-4 weeks ex vivo culture, CB CD34+ cell preparations had greatly increased numbers of total cells, CD34+ cells, and colony-forming cells (CFC). In contrast, ex vivo-cultured PBSC CD34+ cell preparations generated far less in vitro assessed hematopoietic capacity. Nonobese diabetic severe combined immunodeficient mouse (NOD/SCID) engrafting potential (SEP) was maintained in ex vivo-cultured CB CD34+ cell preparations, whereas ex vivo-cultured PBSC lost SEP. CB CD34+ cells continued to proliferate throughout 3 weeks ex vivo, whereas after 1 week, no additional cell divisions were detected in PBSC CD34+ cells. After 3 weeks in culture, the average CB CD34+ cell had divided more than 5 times, as compared to only 2 times for the average PBSC CD34+ cell. CONCLUSION: CB CD34+ cell preparations generated massively increased in vitro assessed hematopoietic capacity and maintained SEP during 1- to 4-week ex vivo cultures. In contrast, ex vivo-cultured PBSC CD34+ cell preparations generated far less in vitro assessed hematopoietic capacity and decreased SEP. The differences in the in vitro proliferative indices of membrane dye-labeled CD34+ cells from CB vs PBSC correlated with these functional differences.     

Predicting spatial similarity of freshwater fish biodiversity

A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississippi–Missouri river system. Encapsulating immigration, emigration, and stochastic noise, and without resorting to species abundance data, the model is able to reproduce the observed probability distribution of the Jaccard similarity index at any given distance. In addition to providing an excellent agreement with the empirical data, this approach accounts for heterogeneities of different subbasins, suggesting a strong dependence of biodiversity similarity on their respective climates. Strikingly, the model can also predict the actual probability distribution of the Jaccard similarity index for any distance when considering just a relatively small sample. The proposed framework supports the notion that simplified macroecological models are capable of predicting fundamental patterns—a theme at the heart of modern community ecology.     

The revisit of 2004 tsunami in Thailand: characteristics of wounds

The name, tsunami that was unknown to most Thai people, had hit west southern coast of Thailand on 26 December 2004. Following the disaster, prices have been paid and many lessons have been learnt. The current report provides a historical background of the incident, which was reviewed by documents, brief discussion and observation. Data of the patients from three hospitals involved in the management were collected and reviewed. Some of the illustrations were from the operating rooms of Takuapa, Surat Thani and Songklanagarind hospitals. There were totally 2311 patients. Of these, 45% were males and 40% were multinationals. Nearly 40% suffered from salted water aspiration, while 2% developed complication associated with near drowning. The most common orthopaedic-related injury were minor [559 patients (24%)] and major wounds [586 (25%)]. Around 7% sustained fracture dislocation. Lower extremity fractures were more common. The characteristics of wounds associated with the tsunami were severe contamination, multiple sites and organ involvement. Another characteristic was the early development and spreading of infection. The lessons proposed by the study are that minor wound should be left open, small penetrating wound should be thoroughly explored and observed and lacerated wounds need emergency dressing, debridement and subsequent cleansing procedures. Re-evaluation and closed surveillance of the seriously injured patients are mandatory to eliminate the complicated infection and life-threatening conditions. Medical record of any disastrous event should be completed by health care professionals. The model and reporting system should be internationalised.     

Effect of infrastructure design on commons dilemmas in social?ecological system dynamics

The use of shared infrastructure to direct natural processes for the benefit of humans has been a central feature of human social organization for millennia. Today, more than ever, people interact with one another and the environment through shared human-made infrastructure (the Internet, transportation, the energy grid, etc.). However, there has been relatively little work on how the design characteristics of shared infrastructure affect the dynamics of social−ecological systems (SESs) and the capacity of groups to solve social dilemmas associated with its provision. Developing such understanding is especially important in the context of global change where design criteria must consider how specific aspects of infrastructure affect the capacity of SESs to maintain vital functions in the face of shocks. Using small-scale irrigated agriculture (the most ancient and ubiquitous example of public infrastructure systems) as a model system, we show that two design features related to scale and the structure of benefit flows can induce fundamental changes in qualitative behavior, i.e., regime shifts. By relating the required maintenance threshold (a design feature related to infrastructure scale) to the incentives facing users under different regimes, our work also provides some general guidance on determinants of robustness of SESs under globalization-related stresses.Many modern social−ecological systems (SESs) depend heavily on shared infrastructure. How such critical infrastructure mediates social and human−environment interactions is thus central to many pressing sustainability challenges in contemporary SESs (1). For example, the robustness of urban systems to natural hazards often depends on engineered structures such as levees, roads, or buildings. Similarly, global food security depends on irrigation infrastructure through which farmers obtain water. In infrastructure-mediated SESs, the very presence and the design features of infrastructure fundamentally shape the dynamics of coupled social and natural processes (2). A major puzzle for sustainability in this era of global change rests on a deep understanding of interactions among social, natural, and built components and the effects of such interactions on the robustness of SESs to unexpected shocks. How can the design of infrastructure affect the capacity of SESs to maintain vital functions in the face of shocks? What are design criteria for infrastructure for more robust SESs? This study examines these questions using a simple model of a community irrigation system—a classic case of a SES in which shared infrastructure is the key interface between social and natural processes.Community (or farmer-managed) irrigation systems are widespread in Asia and, even today, serve a significant portion of the total irrigated area (3). These systems provide an excellent testing ground for exploring how infrastructure affects SESs. Farmers need a reliable supply of water to produce food and typically divert water from its source through weirs, headgates, and canals. Two strong empirical regularities emerge from a long-term comparative case analysis of robustness of such systems. First is the critical importance of infrastructure maintenance and the collective action problems associated with it (4). A study of 50 irrigation systems in Nepal found that farmer-managed systems typically have cruder infrastructure than agency-managed systems in the form of temporary headworks and unlined canals that demand greater mobilization of collective labor or investment each year to maintain functionality (5). Farmers thus face a threshold public good dilemma. Second is the challenge of fair water distribution, which can be undermined by upstream−downstream asymmetry stemming from the canal layout (an asymmetric commons dilemma) (4,6). Because community irrigation systems contain the key basic features of most SESs, they are, for our study of SES sustainability, a model system in a similar sense to fruit fly as a model organism in evolutionary biology (7).Small-scale irrigation infrastructure, critical for the food security of the bulk of the world’s poorest people, is in dire need of maintenance. This is especially true in South Asia, where much of this infrastructure built in the 1960s and 1970s has deteriorated rapidly, posing a major threat to food security in the region (8). Although a lack of funding is often identified as the reason for the deterioration, studies have shown that reasons for underprovision of shared infrastructure are numerous, and funding is not the predominant problem (9). Rather, the subtle interplay between social, technological, economic, and natural processes strongly influences the capacity of groups to overcome the collective action problem that maintenance poses in farmer-managed systems. Here, we focus on this interplay by characterizing the structure of incentives that users face under different infrastructure design conditions and tracing the dynamics that follow. Our focus on the interactions between the infrastructure design and the incentives facing user groups opens doors to alternative ways of thinking about solutions to the maintenance problem, beyond the budgetary considerations. This problem is highly relevant to current discussions on global food security. Nearly 90% of farms worldwide are operated by smallholder farmers who cultivate less than 2 ha of land (10). A significant proportion of these smallholders practice irrigated agriculture, which consumes roughly 70% of global developed water supplies and produces nearly 40% of global agricultural output (11). It is imperative to understand how these smallholders can continue to maintain cooperation and, with it, critical infrastructure in the face of climate- and globalization-related shocks.We address the question of how infrastructure design affects SES sustainability in two stages. First, we explore the effects of design variations on long-term system behavior in our model system. We examine two types of distribution infrastructure, one with and one without upstream−downstream asymmetry, and different threshold characteristics of infrastructure maintenance. Second, we evaluate how these design variations influence the robustness of system function to an economic shock. Our model results suggest that infrastructure design features can generate the potential for regime shifts, i.e., fundamental changes in qualitative system behavior. Three different SES regimes (sustainable, sustained but unequal, and collapsed) emerged, expanded, or shrunk as we varied infrastructure design features. We also observed that infrastructure design can influence the sensitivity of system performance to socioeconomic shocks such as an increase in the attractiveness of alternative livelihood opportunities. Before presenting the details of the model and analysis, it is important to clarify that our goal is not to accurately model the dynamics of a particular irrigation system. Rather, we studied stylized model SES to better understand the mechanisms that may underlie empirical regularities observed in field settings and behavioral studies, and to explore system dynamics under different design conditions.What emerges from our analysis is the need to ensure that the role of shared infrastructure is properly accounted for in studies of SESs. This can be achieved by conceptualizing “ecologies” in SESs more broadly to include both built and natural elements, as in industrial ecology (12), or simply thinking in terms of coupled infrastructure systems (CIS) of which SESs are special cases where natural infrastructure plays a key role (2). This broader view, built on earlier conceptualizations of the role of hard infrastructure (13) and soft infrastructure in SES governance (14), helps us consider the links among social, natural, and built elements more explicitly.     

Late effects in survivors of childhood acute lymphoblastic leukemia: a study from Thai Pediatric Oncology Group

Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk of long-term late effects. Therefore, systematic screenings of the late complications are essential. The objective of this study was to determine the prevalence of late effects of Thai children and adolescents after completion of ALL therapy. We performed a cross-sectional study for evaluation of the late effects in ALL survivors who came for follow-up at 10 pediatric oncology centers in Thailand. We evaluated the treatment-related late complications of children and adolescents who had finished ALL treatment for at least 2 years. Demographic data, treatment modalities, and late effects were recorded and analyzed. There were 258 survivors with a median age of 12.2 years (range 3.6–23.3 years). The median follow-up time was 7.2 years (range 2–17.5 years). Forty-seven percent (122 cases) suffered from at least one late effect. Overweight/obesity was the most common late effect. Radiation of central nervous system was a significant risk factor for overweight/obesity (OR 1.97, 95% CI 1.02–3.81) and educational problems (OR 4.3, 95% CI 1.32–14.02). Our data have demonstrated a significant prevalence of late effects after childhood ALL therapy. A long-term follow-up program for survivors of childhood cancer is therefore needed in our country.