Long-term Effects Of Different Types Research Articles

Abstract PO5-11-07: Short- and long-term treatment-related effects on physical health in breast cancer survivors

Abstract Background. Breast cancer (BC) survivors experience greater physical health declines compared to cancer-free women of the same age, which is thought to be caused by their cancer and its treatment. However, the short- and long-term effects of different types of treatment on physical health are not well understood, especially for hormone therapy. Moreover, whether specific aspects of physical health, such as activities of daily living (ADL), are affected by treatment is unknown. Methods. This analysis was conducted in the Cancer Prevention Study 3 (CPS-3), a prospective cohort study with approximately 300,000 participants enrolled between 2006-2013. Participants returned a baseline survey and triennial follow-up surveys beginning in 2015. Incident, non-metastatic, female BC patients were included in this analysis if they returned a survey at least 90 days after their diagnosis through June 30, 2020, the end of follow-up for this analysis. All 2,551 BC patients included in this study had pre- and post-diagnostic surveys and underwent breast surgery if they were diagnosed with invasive disease. They were matched to up to five cancer-free women on age and year of survey returns (N=12,704). Self-reported physical health and ADL were assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Scale instrument. Treatment information was obtained from cancer registries and self-report and included surgery, chemotherapy, radiation and hormonal therapy. Odds Ratios (OR) and 95% confidence intervals (CI) between treatment received and self-reported physical function were estimated using multivariable ordinal logistic regression models at three time points relative to the case’s diagnosis date: before diagnosis, within 90 days to 5 years after diagnosis, and more than 5 years after diagnosis. Results. Median age at diagnosis was 56 years (interquartile range (IQR): 50-62). Approximately 82% of the tumors were hormone-receptor positive. The median times from the three physical health measurements to diagnoses were 1.7 years before diagnosis (IQR: 0.9 – 2.7), 1.7 years (IQR: 0.9 – 2.5) from 90 days to 5 years post-diagnosis and 6.6 years (IQR: 5.5-7.0) for more than 5 years post-diagnosis. There was a significant risk of physical decline within 5 years of diagnosis for women who received chemotherapy or hormonal therapy compared to cancer-free women (Table 1). However, more than 5 years after diagnosis, the risk of physical decline was only observed among those who received chemotherapy. Treatment combinations that included chemotherapy were also associated with a decline in the ability to carry out ADL during the first 5 years. Patients who received hormonal therapy without chemotherapy were comparable to cancer-free women in their ability to carry out ADL during the post-diagnosis period. BC patients who received surgery only or surgery and radiation reported physical health and ADLs similar to cancer-free women within 5 and >5 years after diagnosis. Conclusions. Post-diagnosis physical health decline is time and treatment dependent. Patients receiving chemotherapy have the greatest overall physical health decline and it is long-lasting. Beyond five years from diagnosis, physical health of breast cancer patients who did not receive chemotherapy were similar to cancer-free women. Strategies are needed to help BC patients receiving chemotherapy overcome the long-term physical function limitations of their cancer treatment. Table. Associations between treatment received and physical health and ability to carry out activities of daily living. OR: Odds Ratio; CI: confidence interval; chemo: chemotherapy; radio: radiation therapy; horm: hormonal therapy. *Associations were adjusted for matching factors, which included age and time from diagnosis to measurement of physical health. Citation Format: Clara Bodelon, Matthew Masters, Lauren McCullough, Alpa Patel, Lauren Teras. Short- and long-term treatment-related effects on physical health in breast cancer survivors [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-11-07.

Type of Violence and Ingroup Identity: Evidence From the Spanish Civil War

Wartime violence and authoritarian repression against civilians take various forms. Past research has explored the causes and consequences of violence, but no previous work simultaneously assessed the long-term effects of different types of violence on political identities. This paper contends that indiscriminate attacks can reinforce ingroup identity, whereas the role of civilian agency in selective violence may have a detrimental impact. Equipped with original data capturing municipality-level exposure to both selective and indiscriminate violence during the Spanish civil war (1936–1939) in Biscay (Basque Country), this study examines its legacy on voting behavior (1983–2015). Results indicate that fascist airstrikes increased Basque nationalism while selective violence diminished the popularity of Basque parties. Individual and community-level evidence suggests that airstrikes fostered the intergenerational transmission of political attitudes. Violence can boost national identities, but it can also erode them: it depends on the type.

Epidemiological impact of public health interventions against diabetes in Qatar: mathematical modeling analyses.

To predict the epidemiological impact of specific, and primarily structural public health interventions that address lifestyle, dietary, and commuting behaviors of Qataris as well as subsidies and legislation to reduce type 2 diabetes mellitus (T2DM) burden among Qataris. A deterministic population-based mathematical model was used to investigate the impact of public health interventions on the epidemiology of T2DM among Qataris aged 20-79 years, which is the age range typically used by the International Diabetes Federation for adults. The study evaluated the impact of interventions up to 2050, a three-decade time horizon, to allow for the long-term effects of different types of interventions to materialize. The impact of each intervention was evaluated by comparing the predicted T2DM incidence and prevalence with the intervention to a counterfactual scenario without intervention. The model was parameterized using representative data and stratified by sex, age, T2DM risk factors, T2DM status, and intervention status. All intervention scenarios had an appreciable impact on reducing T2DM incidence and prevalence. A lifestyle management intervention approach, specifically applied to those who are categorized as obese and ≥35 years old, averted 9.5% of new T2DM cases by 2050. An active commuting intervention approach, specifically increasing cycling and walking, averted 8.5% of new T2DM cases by 2050. Enhancing consumption of healthy diets including fruits and vegetables, specifically a workplace intervention involving dietary modifications and an educational intervention, averted 23.2% of new T2DM cases by 2050. A subsidy and legislative intervention approach, implementing subsidies on fruits and vegetables and taxation on sugar-sweetened beverages, averted 7.4% of new T2DM cases by 2050. A least to most optimistic combination of interventions averted 22.8-46.9% of new T2DM cases by 2050, respectively. Implementing a combination of individual-level and structural public health interventions is critical to prevent T2DM onset and to slow the growing T2DM epidemic in Qatar.

The Effects of Online Health Information-Seeking Behavior on Sexually Transmitted Disease in China: Infodemiology Study of the Internet Search Queries.

Sexually transmitted diseases (STDs) are a serious issue worldwide. With the popularity of the internet, online health information-seeking behavior (OHISB) has been widely adopted to improve health and prevent disease. This study aimed to investigate the short-term and long-term effects of different types of OHISBs on STDs, including syphilis, gonorrhea, and AIDS due to HIV, based on the Baidu index. Multisource big data were collected, including case numbers of STDs, search queries based on the Baidu index, provincial total population, male-female ratio, the proportion of the population older than 65 years, gross regional domestic product (GRDP), and health institution number data in 2011-2018 in mainland China. We categorized OHISBs into 4 types: concept, symptoms, treatment, and prevention. Before and after controlling for socioeconomic and medical conditions, we applied multiple linear regression to analyze associations between the Baidu search index (BSI) and Baidu search rate (BSR) and STD case numbers. In addition, we compared the effects of 4 types of OHISBs and performed time lag cross-correlation analyses to investigate the long-term effect of OHISB. The distributions of both STD case numbers and OHISBs presented variability. For case number, syphilis, and gonorrhea, cases were mainly distributed in southeastern and northwestern areas of China, while HIV/AIDS cases were mostly distributed in southwestern areas. For the search query, the eastern region had the highest BSI and BSR, while the western region had the lowest ones. For 4 types of OHISB for 3 diseases, the BSI was positively related to the case number, while the BSR was significantly negatively related to the case number (P<.05). Different categories of OHISB have different effects on STD case numbers. Searches for prevention tended to have a larger impact, while searches for treatment tended to have a smaller impact. Besides, due to the time lag effect, those impacts would increase over time. Our study validated the significant associations between 4 types of OHISBs and STD case numbers, and the impact of OHISBs on STDs became stronger over time. It may provide insights into how to use internet big data to better achieve disease surveillance and prevention goals.

An 18-year field experiment to assess how various types of organic waste used at European regulatory rates sustain crop yields and C, N, P, and K dynamics in a French calcareous soil

Recycling organic waste (OW) in agriculture can improve soil fertility and substitute chemical fertilizers depending on the OW and their treatment. The effects of OW have often been studied in simplified cropping systems to strengthen the observed effects. The objective of this study was thus to evaluate the long-term effects of different types of OW used at European regulatory rates on C storage, crop yields and N, P, and K dynamics. OW has been applied every 2 years at 170 kg N ha-1 since 2001 in the long-term field experiment PROspective in northeastern France on a silty loam calcosol. The 5 types of OW included urban sewage sludge (SLU), green waste and SLU compost (GWS), municipal biowaste compost (BIO), farmyard manure (FYM), and composted FYM (FYMC). The control treatment (CON) did not receive any OW. All treatments were studied after applying (N + ) or not applying (N-) mineral N fertilization at an annual optimal rate. Biowaste digestate was also applied after 2014 in N- treatments. OW application increased crop yield compared with the unfertilized control. Mineral N fertilizer partially substituted by OW allowed crop yield to be sustained compared with mineral fertilizer only, saving 18–54% mineral N fertilizer, 56–80% mineral P fertilizer and 14–76% mineral K fertilizer. No effects on crop grain N, P and K concentrations were found. The efficiency of OW to maintain SOC, total N, Olsen-P and exchangeable K contents in soils greatly varied with the type of OW. Except for SLU, the SOC stocks significantly increased from + 2.9 to + 7.0 t SOC ha-1 for FYMC_N- and BIO_N-, respectively. SLU and digestate had the greatest N fertilizer replacement value (58% and 69%, respectively). N-leaching risk did not increase with OW application in the long term. For a positive ∆P of 100 kg ha-1, Olsen-P increased by 2 mg P kg-1 in the GWS_N- and SLU_N- treatments, whereas Olsen-P decreased in other treatments. A surplus of + 100 kg ha-1∆K raised the exchangeable K stock by 20 and 21 kg K ha-1 in the FYM_N- and FYMC_N- treatments, respectively, whereas exchangeable K decreased in the BIO and GWS treatments. Our results highlight the ability of all tested types of OW to sustain crop yields in the long term when used at EU regulatory rates, while their effects on mineral fertilizer savings, SOC, soil mineral N, Olsen-P, and exchangeable K contents greatly varied according to the considered OW.

Interaction Simulation of Vadose Zone Water and Groundwater in Cele Oasis: Assessment of the Impact of Agricultural Intensification, Northwestern China

Agricultural intensification has boosted land productivity, but it has also created new sustainability issues. As one of the most important human habitations and agricultural farming areas in arid areas, the Cele Oasis has a very developed agricultural system. This paper studies the long-term effects of different types of agricultural intensification strategies on groundwater level fluctuations in the Cele Oasis. A soil water flow (HYDRUS-1D) and aquifer simulation (MODFLOW) coupling model were used to construct the geometric structures of the vadose zone and saturated zone in the Cele Oasis and to analyze the recharge and discharge mechanism of the oasis. The results showed that HYDRUS-1D accurately simulated soil moisture transport in the Cele Oasis, providing reliable data for calibration of the MODFLOW model. The groundwater level simulated by MODFLOW was in good agreement with the observed value. The results of the R2, RMSE, and NSE were ranges of 0.77–0.90, 0.45–0.74 m, and 0.76–0.87, respectively. The errors were acceptable limits. The coupling model predicted the responses of different agricultural types and cropping scenarios to groundwater. Predictions showed that the groundwater level in the Cele Oasis remained stable under the current cropping scenario (100% cropping intensity), and that the groundwater level decreased slightly under the cropping scenario (110% cropping intensity and 130% cropping intensity). When the cropping scenario was at 170% cropping intensity, the groundwater level decreased rapidly, and the maximum drawdown value was 7 m. Therefore, the maximum cropping intensity of the Cele Oasis in the future should be 130% of the current cropping intensity.

The Double-edged Sword Effect of Resource Scarcity on Consumer Behavior: Research Framework and Prospects

Resource scarcity, widespread in the acquisitive modern society, is a subjective feeling of less possession than necessity. Previous studies have suggested that resource scarcity will make individuals focus more on urgent things in the decision-making process, and eventually produce two different outcomes. One is named “tunneling tax”, that is, focusing on urgent things and inhibiting other goals, which eventually leads to adverse consequences. The other is named “focus dividend” that refers to the phenomenon of focusing on and maximizing the use of scarce resources, and ultimately generating favorable results.Will the impact of resource scarcity on consumer behavior also present a double-edged effect? According to the classification of consumption decision-making process model, this paper systematically explicates the double-edged effect of the impact of resource scarcity on consumer behavior. It finds that the double-edged sword effect of resource scarcity on consumer behavior is reflected in the whole process of consumer decision-making. Specifically, before consumption, resource scarcity enables consumers to attain more promotional offers, but it also makes consumers ignore other important information and products. During consumption, resource scarcity causes the high utilization of scarce resources, while it may also lead consumers into a negative cycle of loan. After purchase, resource scarcity increases consumers’ attention on the use value of products, while it may also reduce the utilization of the social value of products.This paper also explores the theories that explain the impact of resource scarcity on consumer behavior, and finds that the attention resource theory, the self-regulation theory and the emotion regulation strategy can explain the double-edged effect of consumer behavior from cognitive, behavioral and emotional levels. By further refining the process of resource scarcity affecting consumer behavior, it is found that resource scarcity can affect consumer behavior through three paths. The first is the “income-increasing” path, where consumers directly obtain scarce resources and easily incur the tunneling tax. The second is the “expenditure-reducing” path, where consumers tend to reduce the consumption of scarce resources, thus using them more efficiently and generating a focus dividend. The third is the “compensatory” path, where consumers tend to pursue other positive feelings. If consumers pursue only happiness, there will be a tunneling tax; if consumers actively pursue other goals than happiness, there will be a focus dividend. The three paths under the guidance of three theoretical foundations can fully explain how resource scarcity affects the double-edged effect of consumer behavior.This paper also sorts out the moderators acting on the three paths from the environmental level or the individual level. Among them, information representation and the type of welfare system at the environmental level and cognitive resources at the individual level will moderate the “income-increasing” path and reduce the generation of tunneling tax. The location of goods will affect the “expenditure-reducing” path, which in turn increases the focus dividend. Resource mutability at the environmental level and the total amount of “slack” at the individual level will moderate the “compensatory” path, directly influencing the choice of consumers on this path.In the end, this paper further provides practical inspiration for consumers, merchants and policy-makers to encourage them to utilize and deal with this effect effectively. Besides, future researches could explore the immediate and long-term effects of different types of resource scarcity on consumer behavior, as well as additional relevant moderators.

Effects of Basketball and Baduanjin Exercise Interventions on Problematic Smartphone Use and Mental Health among College Students: A Randomized Controlled Trial.

Problematic smartphone use (PSU) has become a prevalent issue worldwide. Previous studies suggest that physical exercising may effectively reduce smartphone users' addiction levels. Comparisons and further evaluations on the long-term effects of different types of exercise-based interventions on treating PSU remain to be investigated. Objective. We investigated if group-based basketball and Baduanjin exercise (a type of Qigong) would reduce PSU and improve the mental health of college students and whether such effects would be sustained. A twelve-week experiment was conducted, where 96 eligible Chinese college students with PSU were randomly assigned to two intervention arms (i.e., basketball and Baduanjin exercises) and a control arm. Outcome measures, including PSU (measured by the Mobile Phone Addiction Index in Chinese (MPAI)) and mental health indices for anxiety (measured by Self-Rating Anxiety Scale (SRAS)), loneliness (measured by the short-form of the UCLA Loneliness Scale (UCLA-LS)), inadequacy (measured by the revised Janis and Field's Feelings of Inadequacy Scale (FIS)), and stress (measured by the Chinese version of Perceived Stress Scale (CPSS)) were collected at the baseline, the end of week 12, and the two-month follow-up. A Generalized Estimating Equations (GEE) model for longitudinal data was utilized in analyses. Results. Both exercise interventions demonstrated significant effects on decreasing PSU (basketball: p < 0.01; Baduanjin: p < 0.01), feelings of anxiety (basketball: p < 0.01; Baduanjin: p=0.04), loneliness (basketball: p < 0.01; Baduanjin: p < 0.01), inadequacy (basketball: p < 0.01; Baduanjin: p < 0.01), and perceived stress (basketball: p < 0.01; Baduanjin: p=0.04), at the end of interventions. At two months after interventions, both exercise interventions demonstrated significant effects on decreasing PSU (basketball: p < 0.05; Baduanjin: p < 0.05), feelings of anxiety (basketball: p < 0.01; Baduanjin: p=0.03), loneliness (basketball: p < 0.01; Baduanjin: p < 0.01), and inadequacy (basketball: p < 0.01; Baduanjin: p=0.01), but not for feeling of stress. Furthermore, group-based basketball demonstrated larger improvements for all these significant results on reducing PSU and meanwhile improving their related mental health parameters among college students.

Short- and long-term effects of animal manures and mineral fertilizer on carbon stocks in subtropical soil under no-tillage

Establishing the long-term effects of different types of animal manures on soil organic carbon (SOC) stocks has both agronomic and environmental implications. However, only a few studies have analyzed the effects of the types of animal manure on SOC storage in subsurface soil layers. Furthermore, the effect of animal manure on labile and stable soil organic matter (SOM) fractions has been scarcely reported for subtropical no-till soils. We evaluated the effect of animal manure application in the short and long term (4 and 12 years) on SOC storage at different depths throughout a 0–70 cm soil profile and on the physical fractions of SOM in the 0–20 cm layer of a sandy Alfisol cropped under no-tillage. The study involved five treatments: pig deep-litter (PDL), cattle slurry (CS), pig slurry (PS), mineral fertilizer (MF) and a control without fertilization (CL). The SOC stock in the soil profile (0–70 cm) was influenced by manure application in only the long term, which was due to high SOC accumulation in the surface (0–20 cm) in the short-and long-term. The PDL and CS applications resulted in 16% (8.6 Mg ha−1) and 10% (5.2 Mg ha−1) increases in the SOC stock, respectively, compared with those in the CL, but only PDL resulted in greater SOC stocks than MF. These results are related to the greater C addition and higher SOC retention coefficient with the PDL application (17%) than with the CS (15%) and PS (7%) applications. Most of the manure-induced changes were observed in the silt plus clay-sized heavy fraction (SCHF), with PDL and CS being more efficient at increasing SOC storage as organic-mineral complexes than PS or MF in the 0–20 cm soil layer. However, in the subsurface layer (20–70 cm), manure caused a decrease in SOC compared with that in the CL, resulting in negative SOC storage rates in this layer, which partially or completely neutralized the SOC storage rates observed in the surface layer (0–20 cm). In the long term, this condition resulted in SOC storage rates in the 0–70 cm soil profile of 0.48 Mg ha−1 year−1 for PDL, 0.21 Mg ha−1 year−1 for CS, −0.03 Mg ha−1 year−1 for PS and 0.01 Mg ha−1 year−1 for MF. These results indicate that PDL and CS are suitable alternatives to MF for increasing the SOC stock and that the SOC retention is greater with solid manure than with liquid manure (PDL vs CS and PS) and with CS than with PS. Moreover, the results reveal the importance of monitoring SOC changes in the long term and within deep soil layers to better quantify the effects of successive applications of animal manure on SOC storage potential in subtropical sandy soils under no-tillage.

Child maltreatment and mental health problems in 30-year-old adults: A birth cohort study

Retrospective studies have shown a high association between child abuse and subsequent psychiatric morbidity. Prospective studies are rarer with limited data at 30-year follow-up. This was a prospective record-linkage analysis to examine whether notified and/or substantiated child maltreatment was associated with adverse psychological outcomes in early adulthood when participants were 30 years old. We used data from 2861 young adults who completed the 30-year follow-up phase of the Mater-University of Queensland Study of Pregnancy and its Outcomes, a prospective study commenced in 1981. Exposure to suspected child maltreatment was measured by linkage with state child protection data. The primary outcomes were DSM-IV diagnoses derived from the Composite International Diagnostic Interview-Auto version (CIDI). There were child abuse notifications on 171 participants, of which 103 were substantiated. The most common notifications were for physical abuse (n=96) followed by emotional abuse and neglect (n=80 each). There were 63 notifications of sexual abuse. Of those completing the CIDI at follow-up, 257 participants (9%) reported a depressive disorder, 703 (25%) an anxiety disorder and 138 (5%) PTSD. After adjustment for potential confounders, there were variations in the long-term effects of different types of abuse with physical abuse having a stronger association with depression, and sexual abuse with PTSD. Both emotional abuse and neglect were associated to varying degrees with depression, anxiety and PTSD. Substantiated abuse or multiple forms of abuse had generally the worst outcomes.

Acute, short-, and long-term effects of different types of exercise in central arterial stiffness: a systematic review and meta-analysis.

The independent predictor of cardiovascular mortality, central arterial stiffness (CAS), is modulated by exercise depending on type of exercises, arteries assessed, sample features and time to exposure. Thus, this study aim to determine the endurance, resistance and combined exercise effects on CAS over time in humans. MEDLINE database for studies published between January 1st, 1990 and February 3rd, 2015. Studies measuring the effects of exercise on CAS, measured by aortic pulse wave velocity or carotid arterial compliance measured by ultrasound were included. Two independent reviewers extracted the 56 studies meta-analyzed and allocated among type of exercise and time effects categories: acute (10 minutes to 24 hours post-exercise session effect), short-term (interventional studies testing basal CAS from 1 to 24 weeks of exercise) and long-term (cross-sectional studies comparing trained and untrained individuals). We calculated standard difference in means 95% CIs, applying random or fixed-effects models, according to presence or absence of true heterogeneity, respectively. Endurance exercise reduced CAS in short and long-term analysis (-0.42 [-0.53 to -0.31] and -0.62 [-0.95 to -0.29], respectively), however it did not modify CAS acutely; higher magnitude of reduction occurred in normal weight individuals, with longer duration, higher weekly frequency and continuous (rather than interval) protocols. Resistance exercise increases CAS acutely (0.30 [0.01 to 0.58]) and after long-term (0.47 [0.19 to 0.75]), while short-term resistance exercise did not modify CAS significantly. No significant effect was found for short-term combined exercises and there was not enough number of studies for acute and long-term effects to be meta-analysed. Endurance and resistance exercise have opposite long-term effects, being beneficial and deleterious, respectively, while the combined exercise showed to be innocuous.

Dynamics in research joint ventures and R&D collaborations

We investigate the short- and long-term effects of different types of R&D collaborations on firms, consumers, and the industry. To that end, we consider a differentiated-product market in which firms compete à la Bertrand and invest in process innovation in order to lower the production cost over time. Investments are stochastic and there can be cartelization or competition strategies among firms at the moment of making the decision on the amount to invest in R&D. Our results show that in equilibrium, the long-run welfare is larger under a research joint venture than under other environments. Discounted present value profits increase with the level of the spillover but there are asymmetries that depend on the firms’ asymmetry on marginal costs.

Effects of crop residue management on winter durum wheat productivity in a long term experiment in Southern Italy

A long-term experiment comparing different crop residue (CR) managements was established in 1977 in Foggia (Apulia region, southern Italy). The objective of this study was to investigate the long-term effects of different types of crop residue management on main yield response parameters in a continuous cropping system of winter durum wheat. In order to correctly interpret the results, models accounting for spatial error autocorrelation were used and compared with ordinary least square models. Eight crop residue management treatments, based on burning of wheat straw and stubble or their incorporation with or without N fertilization and irrigation, were compared. The experimental design was a complete randomized block with five replicates. Results indicated that the dynamics of yield, grain protein content and hectolitric weight of winter durum wheat did not show any decline as usually expected when a monoculture is carried out for a long time. In addition, the temporal variability of productivity was more affected by meteorological factors, such as air temperature and rainfall, than CR management treatments. Higher wheat grain yields and hectolitric weights quite frequently occurred after burning of wheat straw compared with straw incorporation without nitrogen fertilization and autumn irrigation and this was attributed to temporary mineral N immobilization in the soil. The rate of 50 kg ha−1 of N seemed to counterbalance this negative effect when good condition of soil moisture occurred in the autumn period, so yielding the same productive level of straw burning treatment.

Dynamics in Research Joint Ventures and R&amp;D Collaborations

We investigate the short- and long-term effects of different types of R&D collaborations on firms, consumers, and the industry. To that end, we consider a differentiated-product market in which firms compete a la Bertrand and invest in process innovation in order to lower the production cost over time. Investments are stochastic and there can be cartelization or competition strategies among firms at the moment of making the decision on the amount to invest in R&D. Our results show that in equilibrium, the long-run welfare is larger under a research joint venture than under other environments. Discounted present value profits increase with the level of the spillover but there are asymmetries that depend on the firms’ asymmetry on marginal costs.

Whole-body potassium and bone mineral density up to 30 years after urinary diversion.

To evaluate the long-term effects of different types of urinary diversion on skeletal bone density and whole-body potassium content in patients with an early correction of base excess (< -2.5). The early correction of base excess (< -2.5) is one of the principles of the treatment of patients undergoing urinary diversion at our institution. In 27 patients with urinary diversion, bone mineral density (assessed by dual-photon absorptiometry), whole-body potassium, electrolyte and creatinine levels were determined, and capillary blood gas analysed. The mean time since surgery was 16.8 years in 16 patients with a rectal reservoir, 20.5 years in six patients with a colonic conduit, 7.8 years in four patients with an ileocaecal pouch and 5 years in one adolescent with an ileal bladder augmentation. Bone mineral density was normal in 25 of the 27 patients; no exact measurement was possible in the remaining two. The whole-body potassium content was reduced in eight of the 27 patients (three with a conduit, two with a rectal reservoir, two with an ileocaecal pouch and one with ileal augmentation). In four of these eight patients the base excess was < -2.5 (-2.7 to -5). Of the other four, two had no regular testing of their base balance and two were obese. The electrolytes were within the normal ranges. None of the patients had hyperchloraemic metabolic acidosis. With early correction of the base excess (< -2.5), there was no decrease in bone mineral density and no hyperchloraemic acidosis. There was no significant difference between the different types of urinary diversion. There seems to be a relationship between low base excess and decreased whole-body potassium.

Comparison among Different Types, Dosages and Duration of Interferon Therapy in Chronic Hepatitis C

In an attempt to determine the best therapeutic protocol for the treatment of chronic hepatitis C with interferon (IFN), we reported our experience comparing the efficacy of IFN at the usual dose and duration, i.e. 3 million units (MU) three times weekly for 6 months, with the immediate and long-term effects of different types, dosages and duration of IFN therapy. 300 patients with chronic hepatitis C were randomly assigned to five groups of 60 subjects each and treated as follows: group A - recombinant IFN alpha (rIFNalpha) 3MU three times weekly for 6 months; group B - rIFNalpha 6MU three times weekly for 6 months; group C - rIFNalpha 3MU 3 times weekly for 12 months; group D - lymphoblastoid IFN (L-IFN) 6MU three times weekly for 6 months; group E - L-IFN 3MU three times weekly for 12 months. The diagnosis of hepatitis was based on clinical, serological and histological data in all patients. A 'biochemical response' was defined as the normalisation of alanine aminotransferase (ALT) values, and a 'complete response' as the normalisation of ALT with disappearance of serum hepatitis C virus (HCV)-RNA. A 'sustained response' was defined as the persistence of ALT normalisation and undetectable viraemia 2 years after the end of treatment. The five groups were homogeneous. The incidence of dropouts was 8%, and IFN treatment was interrupted for adverse effects in 11% of the patients. In group A, 55% of the patients showed a 'biochemical response' and 31% of the subjects demonstrated a 'complete response'. In group B, a 'biochemical response' was observed in 61% and a 'complete response' in 36% of the cases. In group C, 77% of the subjects showed a 'biochemical response', with a 'complete response' seen in 40%. In group D, we observed a 'biochemical response' in 55% of the patients and a 'complete response' in 33%. In group E, 79% of the subjects had a 'biochemical response', and a 'complete response' was seen in 38%. At the end of the treatment-free follow-up the percentage of patients with a sustained response was 24% in group A, 28% in group B, 35% in group C, 27% in group D and 33% in group E. Therefore, a longer period of IFN treatment seems to provide higher percentages of sustained response than the usual 6-month duration, independently of the type of IFN. Moreover, the patients treated with a higher dosage (6MU 3 times weekly) for 6 months showed a slightly better sustained response rate compared with the usual dose. In conclusion, even if the differences among the response rates in the five groups were not statistically significant, we recommend a 12-month regimen, possibly using higher dosages at least in the first 4 to 6 months of treatment.

The human choriocapillaris in organ culture.

4 x 4 mm pieces of human eye walls consisting of the sclera, the choroid and the pigment epithelium were kept in organ culture for 1 month and studied with light and transmission electron microscopy comparing the findings with normal tissue. After 1 month the choriocapillaris still had open vessel lumina lined with flattened endothelial cells containing organelles and vesicles on both inner and outer cell membranes. The endothelial cells lost their fenestrations and polarity in regard to the location of cell nuclei. Otherwise the ultrastructure was similar to that of the choriocapillaris in vitro. This study has shown that choriocapillaris can survive in organ culture for 1 month, and it permits further studies on the behaviour of the choroid under controlled conditions, and on the long-term effects of different types of trauma to the choroid in vitro.

Book reviewsThe Control of Exposure of the Public to Ionizing Radiation in the Event of Accident or Attack. By National Council on Radiation Protection and Measurements, pp. 290, 1982 (NCRP, Bethesda MD, USA), US $20. ISBN 0–913392–58–8

This publication reports the proceedings of a three-day symposium held in April 1982 in the USA, but with international participation, on the topics compendiously indicated in the title. A session was devoted to the short-term and long-term effects of different types of radiation. Then comes an account of methods for lessening radiation exposure, and a section on dosimetry.

Long-term feedback and differential feedback effects in nonmetric multiple-cue probability learning

The purpose of this research was to study the long-term effects of different types of feedback upon learning and performance of individual human organisms and the sensitivity of such subjects to changes in the validity of information in probabilistic judgment tasks. The subject's task consisted of predicting a binary event on the basis of two or three binary cues whose validity changed on each of five successive days. Subjects received one of three different types of informational feedback about their performance - outcome feedback, cue-event validity feedback, or percentage correct feedback. The results indicated, at least for tasks involving additive cues, that adaptation to new cue validities became more rapid on successive days. The different types of feedback tended to produce different response strategies. However, the different strategies had virtually no effect upon overall judgmental accuracy. Further, there was an apparent interaction between task characteristics and feedback type. This result was found to be consistent with the results of other studies utilizing differential feedback in similar tasks.