Gallstones - approach to medical management

Between 10% and 15% of individuals in the industrialized world have gallstones. The standard treatment is laparoscopic cholecystectomy, making gallstone disease the second most costly digestive disorder in most Western countries. Despite a rapid convalescence, the procedure is not devoid of morbidity or even mortality. Bile duct injury is particularly troublesome, occurring in 0.1% to 0.5% of cases, even in the most experienced hands. Moreover, some 20% of patients continue to suffer from pain (the main indication for treatment) after cholecystectomy. In patients with mild symptoms, surgical treatment has been associated with a higher morbidity than the natural course of the disease. Medical dissolution therapy with bile acids is an alternative for patients with mild-to-moderate symptoms due to cholesterol gallstones. Chenodeoxycholic acid (CDCA, chenodiol) has been largely replaced by the safer and more efficient ursodeoxycholic acid (UDCA). The main drawbacks of UDCA treatment are its low efficacy (approximately 40%), slowness in action, and the possibility of stone recurrence. However, this treatment is extremely safe, and the efficacy and slowness can be somewhat improved by stricter patient selection. Moreover, patient symptoms may respond to this therapy even without complete stone dissolution. New strategies employing more efficient bile acids or related compounds may increase the efficacy of medical dissolution. Furthermore, recent advances in the understanding of biliary lipid secretion and regulation should offer novel opportunities to further improve the prospects of medical treatment of gallstones.     

Contraception for men: a breakthrough new approach

There has not been a new reversible contraceptive for men since the development of the condom, centuries ago. Matzuk et?al. describe a new molecular approach using administration of a small molecule to directly and reversibly inhibit spermatogenesis in mice by blocking the function of a testicular bromodomain without apparent adverse effect on the organism or offspring.     

Nocturnal water storage in plants having Crassulacean acid metabolism

Measurements of water uptake and transpiration, during the dark period of plants having Crassulacean acid metabolism (CAM) allow calculation of leaf-volume changes (V). Nocturnal leaf-volume changes of CAM plants have also been reported in the literature on the basis of waterdisplacement measurements. A third way of estimation is from measurements of turgor changes and cellular water-storage capacity using the pressure probe, cytomorphometry and the Scholander pressure chamber. An extension of the interpretation of results reported in the literature shows that for leaf succulent CAM plants the three different approaches give similar values of V ranging between 2.3 and 10.7% (v/v). It is evident that nocturnal malic-acid accumulation osmotically drives significant water storage in CAM leaf tissue.Abbreviations and symbols C_c water-storage capacity - E transporation (evaporational water loss) - P turgor pressure - U water uptake - V cell volume - cell-wall elastic modulus - osmotic pressure - CAM Crassulacean acid metabolism     

The effects of nocturnal acid breakthrough on Helicobacter pylori eradication

Background. The effects of nocturnal gastric acid breakthrough (NAB) on Helicobacter pylori eradication are still unknown in peptic ulcer patients. The purposes of this study were to compare the effect of lansoprazole 30 mg twice a day (bid) to lansoprazole 60 mg once a day (qd) on the prevalence of NAB, and to determine whether NAB affects the eradication of H. pylori in peptic ulcer patients. Methods. Experiments were carried out in 67 patients with H. pylori‐positive peptic ulcers. They were randomized into two groups, one treated with a combination of lansoprazole 60 mg, clarithromycin 1.0 g, and amoxycillin 2.0 g once a day before breakfast (qd group), and the other, divided doses of the drugs were given before breakfast and dinner (bid group) for 2 weeks. Results. NAB occurred in 31 patients, 55.2% in qd group, and 39.5% in bid group (p = .226). H. pylori eradication was achieved in 61.3% in NAB positive group and 83.3% in NAB negative group (p = .055). The mean duration of NAB for H. pylori eradication group was 99.3 ± 22.7 min, and 293.2 ± 49.8 min for H. pylori persistence group (p < .05). The median intragastric pH of the H. pylori eradication and persistence group was 5.7 ± 0.2 and 4.2 ± 0.4, respectively (p < .05). Conclusions. Neither the morning dose and the divided dose regimen of lansoprazole affected the intragastric acidity and occurrence of the NAB. NAB did not influence H. pylori eradication in peptic ulcer patients, but the duration of NAB and total intragastric median pH were found to influence the H. pylori eradication.     

A new approach to dendrochronological data management

The procedures undertaken during the construction of chronologies often result in large quantities of data, typically in many associated files. The management of these data files, especially maintaining the relationships between processed and raw data, becomes increasingly difficult as a collection grows. To maintain a high level of accountability it is necessary to ensure that any derived or processed data can be replicated by independent researchers. Due primarily to practical limitations, some authors publish only subsets of the processed and/or raw data that constitute a chronology, making the process of independent scientific scrutiny difficult and on occasions impossible. There are associated problems when master chronologies are utilised for the purpose of dating specimens. Maintaining the relationships between chronologies and specimens is extremely important for accountability purposes, especially when errors are detected or revisions required. In these circumstances it is highly desirable to locate all specimens that have been dated with the original chronology to ascertain the implications of changes. This paper describes a new relational database design that addresses these problems and which has been implemented in the Corina dendrochronology application and web service. The new Corina system enables the data and analyses for all chronology building and cross-dating processes to be stored and documented, enabling scrutiny at every stage.     

Menstrual Phase Response to Nocturnal Light

The aims of the study were to test whether nocturnal white light can normalize menstrual cycles in oligomenorrheic women, and whether the phase of the menstrual cycle in which light is given is important for the shortening effect. Twenty-five women with long menstrual cycles (35.9–53.4 days on average) were treated for 1–3 cycles, each of which was preceded and followed by at least two untreated cycles. Treatments were 100 watt bedside lights administered for 5 consecutive nights. They centered at three different phases of the menstrual cycle: 6–7th, 14–17th or 23–25th days of the treated cycle (early, middle or late treatment, respectively). On average, the treatment cycle lengths were modestly, but significantly reduced compared to the duration of baseline cycles (more than 11 %). The difference in the effects of the early, middle and late treatment was not significant. However, if middle or late treatments were administered in the latter half of the interval between the menstrual cycle onset and probable time of ovulation, reductions of the treated cycle length were substantial (more than 20 %, resulting in cycles less than 33 days on average; p &lt; 0.001). Other treatments produced only weak (up to 7 %), if any, cycle reductions. Moreover, we found a strong correlation (p &lt; 0.001) between the duration of baseline cycle and differential effect of middle treatment (compared to early or late treatment). Middle treatments reduced treated cycle duration to the normal range in the subjects with shorter mean baseline cycles (&lt;42 days), while in the subjects with longer duration of baseline cycle the shortening effect was produced by late treatments (p = 0.005 and p = 0.001, respectively). The results support the suggestion that a bedside lamp used on nights prior to ovulation can cause reduction of long menstrual cycles.     

Diels-Alder approach to tetralin-based constrained alpha-amino acid derivatives

Tetralin-based constrained alpha-amino acid derivatives were prepared via [4 + 2]-cycloaddition reaction as a key step. Here sultine is used as a latent diene and 2-acetamidoacrylate serves as a dienophile component.     

可持续林业管理指标的探讨

可持续林业管理指标的探讨曹志平（中国农业大学资环学院生态系,北京１０００９４）钟晓东（国家环保局国际合作司,北京１０００９４）目前,林业管理的方向正在发生变化,即由过去单一的木材生产向可持续的森林生态系统管理转化,从而更好地满足人类的需求。国际社会认...     

A systems approach to unravel complex water management institutions

The study unravels the complexity of water management institutions by analysing the interactive nature of actors and rules to a particular water-related problem, using a systems approach in a hamlet in the Indian Himalayas. The approach builds on the strengths of institutional analysis development framework, but makes amendments to suit complex and adaptive water management institutions. It applies multiple research methods to collect both qualitative and quantitative information at different contextual levels. The information collected is applied in Bayesian belief network model to identify differential rules in influencing water management. Systems perspective in a problem context helped to comprehensively understand the socio-political process of water management by identifying broad array of actors and rules constraining water management, and at the same time identify actors and rules facilitating agents and their agency for a change in the water management process. In this socio-political process, the study reveals human entities – stakeholders, actors and agents – occupy different positions, which they actively shift in a problem context and when agents pursue ‘projects’ by integrating diverse rules and resources to remain adaptive. It is this adaptive and dynamic behaviour that contemporary programmes and policies fail to acknowledge. In this dynamic behaviour of the transformative capacity or power is everywhere, but they are displayed, maintained and upheld, only when agents pursue their ‘project’ by negotiating with other agents. The paper highlights the importance of comprehensive approach, in contrast to simplistic, linear and single package reforms to manage water. Such approach calls for conscious designing of rules and, at the same time, enabling actors to design rules. A conscious designing of rules is required to regulate water distribution, to build the capabilities of the poor, and to be adaptive to institutional and bio-physical crises. It calls for the development of infrastructures to further actors and agent's capabilities to design rules for informed water-related decisions. Such an approach will contribute towards sustainable water resource management.     

Advanced peripheral arteriosclerosis; a physiological approach to management

When peripheral arteriosclerosis progresses to the stage where blood flow through both primary and collateral circulations is impaired seriously, arteriolar relaxants, physical therapeutic, pharmacological and surgical, may aggravate the nutritional deficit. Although tissue viability is maintained precariously, limited activity may be tolerated unless the delicate balance between blood supply and metabolic activity is upset by the vicious circle of rest pain and dependent edema. This vicious circle constitutes an immediate threat to the structural integrity of the limb. Rest pain must be controlled if the delicate balance between blood supply and metabolic activity is to be restored and the threat of amputation mitigated. Intravenous injections of procaine may be of value.     

Biospheric foundations of the ecosystem approach to environmental management

The ecosystem approach to environmental management inter-relates social, economic and environmental factors. Its incorporation into the Great Lakes Water Quality Agreement of 1978 changed the focus of the Agreement from water in a political context to politics in an ecosystem context. Because ecosystems are open and dependent on Biospheric processes for their continued operation, the Biosphere (global ecosystem) emerges as a globally integrating factor in ecosystem management. Influences leading to development of the ecosystem approach in the Great Lakes Basin included: a politically shared resource in jeopardy, pollution, a common drinking water source, common enemies, advances in ecosystem theory, citizen groups, international political institutions, common economic and cultural ties, and a sense of crisis. A rationale is presented for viewing nations as politically defined ecosystems.     

A model management systems approach to manufacturing systems design

Manufacturing systems design involves the solution of a complex series of interrelated problems. This complexity will increase in the future as manufacturing practices change to meet increased global competition. Research within manufacturing systems design has mainly been focused on finding improved models for solving particular problems, or extending existing modeling techniques. This has resulted in numerous modeling tools being available to support manufacturing systems design. However, little research work has been carried out into consolidating the existing theories and models. As a result, a large body of this work has not been applied in industry. Model management has evolved as a research area which investigates methods for storing, modifying, and manipulating models. This article describes a prototype model management system for manufacturing systems design. The objective here is not to develop “another” decision support system for manufacturing design, but to illustrate, through the development of a prototype system, a number of key ideas of how concepts from the area of model management systems can be used to support manufacturing systems design. The prototype model management system utilizes the structured modeling framework and uses an extended version of the structured modeling language. An important aspect of the prototype model management system is the incorporation of the model development task, thus allowing the system to be easily updated and adapted. The prototype system was evaluated using a range of queueing network models for manufacturing systems design.