Associations between oral hygiene habits,diet, tobacco and alcohol and risk of oral cancer: A case–control study from India

ObjectiveThis study examines the association between the incidence of oral cancer in India and oral hygiene habits, diet, chewing and smoking tobacco, and drinking alcohol. We also assessed the effects of oral hygiene habits with oral cancer risk among chewers versus never chewers.MethodsA hospital-based case–control study was conducted in Pune, India, based on face-to-face interviews, anthropometry, and intra-oral examinations conducted for 187 oral cancer cases and 240 controls.ResultsPoor oral hygiene score was associated with a significant risk of oral cancer (adjusted OR = 6.98; 95%CI 3.72–13.05). When stratified by tobacco-chewing habit, the poor oral hygiene score was a significant risk factor only among ever tobacco chewers (adjusted OR = 14.74; 95%CI 6.49–33.46) compared with never chewers (adjusted OR = 0.71; 95%CI 0.14–3.63). Dental check-ups only at the time of pain by ever-chewers with poor oral hygiene was associated with an elevated risk (adjusted OR = 4.22; 95%CI 2.44–7.29), while consumption of green, yellow, and cruciferous vegetables and citrus fruits was protective. A linear dose–response association was observed between oral cancer and chewing tobacco in terms of age at initiation, duration, and frequency of chewing per day (P < 0.001). Smoking more than 10 bidis/cigarettes per day (adjusted OR = 2.74; 95%CI 1.28–5.89) and for a duration >25 years (adjusted OR = 2.31; 95%CI 1.14–4.71) elevated the risk of oral cancer.ConclusionGood oral hygiene habits – as characterized by healthy gums, brushing more than once daily, use of toothpaste, annual dental check-ups, and a minimal number of missing teeth – can reduce the risk of oral cancer significantly. In addition to refraining from chewing/smoking tobacco, a diet adequate in fruits and vegetables may protect against the disease.     

Hydrophilicity and antigenicity of proteins — A case study of myoglobin and hemoglobin

Hydrophilicity index is used to locate antigenic determinants on two related groups of proteins-myoglobin and hemoglobin. The data on 41 species (including 34 mammals) of myoglobin show that average hydrophilicity for the complete myoglobin molecules as well as the average hydrophilicity for all hydrophilic regions put together seem to remain constant; the variation in the size and location of the antigenic determinants in these species is very small indicating that the antigenic sites are not shifted during evolution. In the case of both the proteins there is a good agreement between the antigenic sites picked up by using hydrophilicity index and the experimentally determined antigenic sites. The data on 56 species of hemoglobin α-chains and 44 species of hemoglobinβ-chains showed that although there are few sites on hemoglobin which have remained invariant during evolution, there is a significant variation in other sites in terms of either a splitting of a site, or a drastic change in the hydrophilicity values and/or a length of the site. Comparison of the hydrophilicity data on these two groups of proteins suggests that hemoglobins which perform a variety of functions as compared to myoglobins are evolving faster than myoglobins supporting the contention of earlier workers.     

An innovative approach of Drinking Water Quality Index—A case study from Southern Tamil Nadu,India

The aim of the present study is to exhaust the limitations of conventional reputed Water Quality Index (WQI) methodologies through the proposed reliable Drinking Water Quality Indexing (DWQI) system. Slight modifications were carried out in the methodology of the DWQI development which were parameter categorization, development of sub-index with regression statistics and aggregation function with Min–Max operator. Twenty-two water quality parameters were selected for quality evaluation. The proposed DWQI was compared with conventional methodologies of arithmetic DWQI and geometric DWQI and evaluated with a case study. A data set of 24 ground water samples collected from Southern Tamil Nadu, India was made to illustrate the application and feasibility of the index.The results of the case study revealed that arithmetic DWQI scores were higher than the proposed and geometric DWQI while geometric DWQI scores were lower than the proposed DWQI scores. All the indices were well correlated (r ≥ +0.98) with each other. The arithmetic DWQI exhibited significant difference (P < 0.001) with other indices but the proposed DWQI scores had insignificant variations (P = 0.40) with geometric DWQI scores. The comparison of different forms of indices showed that the proposed DWQI was the most reliable indexing system than the others which diminished the sensitivity and eclipsing problems of conventional indexing system.     

Subsite mapping of enzymes: Collecting and processing experimental data—a case study of an amylase-malto-oligosaccharide system

Two research groups have independently developed the theory and experimental methodology for quantitatively assessing substrate monomer-subsite binding-energies for depolymerases. When the two approaches are applied to the same enzyme-substrate system they yield surprisingly divergent results. This paper outlines the application of the two approaches to an amylase-maltooligosaccharide system and points out the more important areas of disagreement. We show that by proper data-management, the conflicts between the two laboratories are basically resolved. The complexities of the subsite model demand extensive data-gathering and exacting data-processing and verification that the computed model-parameters can faithfully reproduce the experimental data.     

Declining snake population—why and how: a case study in the Mangrove Swamps of Sundarban, India

Species diversity of reptiles is much higher in Sundarban than in other mangrove ecosystems in India. Presently snakes are declining in Sundarban due to habitat loss caused by tremendous population pressure. Besides, irresponsible killing to avoid snakebite both from poisonous and nonpoisonous varieties is another reason for the gradual declining snake population. According to an intensive household survey in 35 villages in Sundarban, about 22 species (five poisonous and 17 non-poisonous) of snakes have been identified and there appears to have been a general decline in densities. On the contrary, a large number of people are bitten and die from snakebite every year with 0.57 and 0.34 vulnerability and mortality rate per 10,000 people, respectively. The two most commonly observed poisonous species are the common krait, Bungarus caeruleus (51 %) and common cobra, Naja naja (40 %), and that of non-poisonous varieties are the Ptyas mucosus (41 %), Typhlina bramina (34 %), Xenochrophis piscator (12 %), and Amphiesma stolata (10 %). Apart from killing of snakes out of fear; habitat loss, unscientific handling of snakes by snake catchers and charmers, and netting by fisherman contributes to snake mortality to a large extent; 72 % killed snakes are of poisonous varieties, 60 % of which are B. caeruleus, the most venomous snake in Sundarban. This paper is an attempt to highlight some of the important conservation efforts like the introduction of snake firms, alternative employment channels for the snake charmers and catchers, and mass awareness campaign through panchayet (village level governing body) and local NGOs.     

Conservation “identity” and marine protected areas management: A Mediterranean case study

Protection of natural environments sought through management plans varies greatly between countries; characterizing these differences and what motivates them can inform future regional and international conservation efforts. This research builds on previous work addressing the spatial distribution of marine protected areas in the Mediterranean Sea. Particularly, it examines the relationship between a “protection level” (PL) score and a set of variables pertaining to each country's conservation efforts, economic conditions and human impact along the coast using regression analysis. Four sets of models demonstrated country characteristics that correlate with higher protection levels within marine protected areas (MPAs). Certain contextual factors – economic dependence on the marine environment, efforts at terrestrial conservation and greater human impact – were found to be significantly associated with higher PLs among the northern littoral countries of the Mediterranean. Such findings can inform policy makers about where efforts and investments should be directed for marine conservation.     

Environmental risk assessment of heavy metals pollution in aquatic ecosystem—A case study: Sediment of Kor River,Iran

A comprehensive investigation of fractionation and environmental risk of nine heavy metals is carried out for 12 sediment samples collected from Kor River, Iran. For this purpose, the 5-stage sequential extraction method, along with individual contamination factor, global contamination factor, and Environmental Risk Index (ERI), is used. Total concentrations of Cr, Hg, Ni, and Zn were found to be beyond the threshold effect level. The results of fractionation patterns indicate that As, Cr, Ni, Pb, and Zn are mostly associated with Fe-Mn oxide fraction, organic fraction, and residual fraction, while Cd and Mo are predominantly associated with carbonate fraction. Cu and Hg are mostly associated with organic and exchangeable fractions. The results of ERI revealed High to Dangerous risks in 40% of Kor River stations. The applied approach in this study is beneficial to other environmental studies that require analysis of complex data.     

Family history of cancer and the risk of bladder cancer: A case–control study from Italy

BackgroundA family history of bladder cancer has been associated with the risk of bladder cancer, but quantification of the excess risk in different populations is still a relevant issue. Further, the role of a family history of other cancers on the risk of bladder cancer remains unclear.MethodsWe analyzed data from an Italian case–control study, including 690 bladder cancer cases and 665 hospital controls. Odds ratios (ORs) were estimated through unconditional logistic regression models, adjusted for sex, age, study center, year of interview and further for education, smoking and sibling’s number.ResultsThe OR for family history of bladder cancer was 2.13 (95% confidence intervals (95%CIs) 1.02–4.49) from the model with partial adjustment, and 1.99 (95%CI 0.91–4.32) after additional adjustment for smoking and siblings’ number, based on 23 cases (3.3%) and 11 controls (1.7%) with a family history of bladder cancer. The fully adjusted OR was 3.77 when the relative was diagnosed at age below 65 years. Smokers with a family history of bladder cancer had a four-fold increased risk compared to non-smokers without a family history. Bladder cancer risk was significantly increased among subjects with a family history of hemolymphopoietic cancers (OR = 2.97, 95%CI 1.35–6.55). Family history of cancer at other sites showed no significant association with bladder cancer risk.ConclusionThis study confirms an approximately two-fold increased risk of bladder cancer for family history of bladder cancer, and indicates a possible familial clustering of bladder cancer with cancers of the hemolymphopoietic system.     

Body mass index and weight gain after middle adulthood are associated with risk of papillary thyroid cancer: A case–control study

BackgroundIt is unclear whether weight change after middle adulthood influences the risk of thyroid cancer. The aim of this study was to investigate associations between the risk of papillary thyroid cancer (PTC) and body mass index (BMI) and weight change after middle adulthood (age 35).MethodsA matched case–control study based on three hospitals included 516 pairs of cases newly diagnosed with PTC and controls. Current height and weight after defecation in the morning were measured by trained nurses. During measurement, all subjects were requested to wear lightweight clothing and no shoes. Weight at age 35 was self-reported. BMI and weight change were modeled as continuous and categorical variables. Conditional and unconditional logistic regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95%CI) for the association between BMI and weight change after middle adulthood and PTC.ResultsAfter adjustment for covariates, measured BMI at the time of current diagnosis was positively associated with PTC (OR 1.16, 95%CI 1.10–1.21). According to WHO BMI guidelines for Asia-Pacific populations, the OR (95%CI) for PTC risk in obesity was 2.99 (1.92–4.67) compared to normal weight (p-trend <0.001). Moreover, PTC was positively associated with BMI at age 35; the OR (95%CI) for PTC risk per unit increase in BMI was 1.06 (1.02–1.11). Compared to stable weight (changed <0.5 kg/year), weight gain ≥1.0 kg/year after middle adulthood was positively associated with PTC (OR 2.57, 95%CI 1.39–4.76, p-trend <0.001). Compared to maintaining non-overweight status, the PTC risk was significantly increased in those individuals who gained weight and became overweight after middle adulthood (OR 3.82, 95%CI 2.50–5.85).ConclusionThis study showed that high BMI and obesity were positively associated with increased risk of PTC, and weight gain after middle adulthood also could elevate the PTC risk.     

Green tea drinking and risk of pancreatic cancer: A large-scale,population-based case–control study in urban Shanghai

Background: Little is known about the etiology of pancreatic cancer. Epidemiological studies on tea consumption and pancreatic cancer risk have been inconclusive. The purpose of the present study was to investigate the association between green tea drinking and the risk of pancreatic cancer in urban Shanghai, China. Methods: In this population-based case–control study conducted in urban Shanghai, 908 cases of pancreatic cancer and 1067 healthy controls were recruited. Information on tea drinking, including type of tea, amount of tea consumption, temperature of tea, and the duration of regular tea drinking, were collected via interview questionnaire. Results: We examined the association of multiple tea drinking habits with the risk of pancreatic cancer. In women, regular green tea drinking was associated with 32% reduction of pancreatic cancer risk (OR 0.68, 95% CI 0.48–0.96), compared to those who did not drink tea regularly. Increased consumption and longer duration of tea drinking were both associated with reduced pancreatic cancer risk in women. Among regular tea drinkers, lower temperature of tea was associated with reduced risk of pancreatic cancer in both men and women, independent of amount or duration of tea drinking. Conclusions: Habits of green tea drinking, including regular drinking, amount of consumption, persistence of the habit, and tea temperature, may lower pancreatic cancer risk.     

Importance of dose‐response model form in probabilistic risk assessment: A case study of health effects from methylmercury in fish

We compared the effect of uncertainty in dose‐response model form on health risk estimates to the effect of uncertainty and variability in exposure. We used three different dose‐response models to characterize neurological effects in children exposed in utero to methylmercury, and applied these models to calculate risks to a native population exposed to potentially contaminated fish from a reservoir in British Columbia. Uncertainty in model form was explicitly incorporated into the risk estimates. The selection of dose‐response model strongly influenced both mean risk estimates and distributions of risk, and had a much greater impact than altering exposure distributions. We conclude that incorporating uncertainty in dose‐response model form is at least as important as accounting for variability and uncertainty in exposure parameters in probabilistic risk assessment.     

Serum pepsinogen level,atrophic gastritis and the risk of incident pancreatic cancer—A prospective cohort study

Background: Pancreatic cancer is a highly fatal disease without screening tests. Studies have suggested possible etiologic similarities between gastric and pancreatic cancers. Atrophic gastritis, a pre-malignant condition for gastric cancer, is characterized by low serum pepsinogen I (SPGI) level. We hypothesized that low SPGI level may be associated with an increased risk of pancreatic cancer and be a useful biomarker for the disease. Methods: Our analytic cohort included 20,962 participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) who had SPGI level measured. Of these, 1663 (7.9%) subjects had low SPGI levels (<25 μg/l) and were invited for gastroscopy which was completed in 1059 (63.7%) participants. Atrophic gastritis was histologically confirmed in 1006 (95.0%) subjects. We used Cox proportional hazards regression to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for pancreatic cancer. Results: During follow-up of up to 16.3 years (mean = 10.8 years; 226,325 person-years), 227 incident pancreatic cancers were diagnosed. The incidence rates were 9.9, 11.3, and 12.7 per 10,000 person-years of follow-up for participants with normal pepsinogen level (≥25 μg/l), low pepsinogen level and histologically confirmed atrophic gastritis, respectively. Compared to subjects with normal pepsinogen levels, there was no statistically significant increased risk of pancreatic cancer among subjects with low pepsinogen level (adjusted HR = 1.01; 95% CI: 0.63–1.62) or those with histologically confirmed atrophic gastritis (adjusted HR = 1.13; 95% CI: 0.66–1.95). Conclusions: Atrophic gastritis, serological or histological, is not associated with increased risk of pancreatic cancer. These findings do not provide any evidence for potential usefulness of SPGI for pancreatic cancer screening.     

Influenza vaccination,pneumococcal vaccination and risk of acute myocardial infarction: matched case–control study

Background

Previous studies have shown an association between acute myocardial infarction and preceding respiratory infection. Contradictory evidence exists on the influence of influenza vaccination and pneumococcal vaccination in preventing cardiovascular disease. We aimed to investigate the possible association of influenza vaccination and pneumococcal vaccination with acute myocardial infarction.

Methods

We used a matched case–control design with data from the United Kingdom General Practice Research Database. Cases were patients who were at least 40 years of age at diagnosis of first acute myocardial infarction recorded from Nov.1, 2001, to May 31, 2007, and were matched for sex, general practice, age and calendar time (i.e., month corresponding to index date of acute myocardial infarction), with up to four controls each. Data were analyzed using conditional logistic regression, adjusted for vaccination target groups, cardiovascular risk factors, treatment medications and attendances at a general practice.

Results

We included 78 706 patients, of whom 16 012 were cases and 62 694 were matched controls. Influenza vaccination had been received in the previous year by 8472 cases (52.9%) and 32 081 controls (51.2%) and was associated with a 19% reduction in the rate of acute myocardial infarction (adjusted odds ratio [OR] 0.81, 95% confidence interval [CI] 0.77–0.85). Early seasonal influenza vaccination was associated with a lower rate of acute myocardial infarction (adjusted OR 0.79, 95% CI 0.75–0.83) than vaccination after mid-November (adjusted OR 0.88, 95% CI 0.79–0.97). Pneumococcal vaccination was not associated with a reduction in the rate of acute myocardial infarction (adjusted OR 0.96, 95% CI 0.91–1.02).

Interpretation

Influenza vaccination but not pneumococcal vaccination is associated with a reduced rate of first acute myocardial infarction. This association and the potential benefit of early seasonal vaccination need to be considered in future experimental studies.Winter peaks in incidence of acute myocardial infarction have been linked to climate,¹ metabolic factors² and infection.³ Because known risk factors do not fully account for cases of acute myocardial infarction, current interest is focused on the putative link with respiratory infection. Significant increases in acute myocardial infarction occur during peak winter incidence of pneumonia, influenza and influenza-like syndrome,⁴ particularly during years dominated by epidemic rather than nonepidemic influenza A. This association supports the notion that the increase is caused by influenza rather than cold weather.⁵Acute myocardial infarction may increase susceptibility to respiratory illness,⁶ but the association between acute myocardial infarction and respiratory infection occurring within four weeks prior to the acute myocardial infarction^7,8 supports infection as a cause of acute myocardial infarction. Although the exact mechanism is unknown, the favoured hypothesis is that infection triggers plaque rupture.⁹ Although several observational studies, as well as two randomized controlled trials,^10,11 suggest a positive effect of influenza vaccine in preventing acute myocardial infarction, they provide insufficient and conflicting evidence.¹²The aim of this study was to investigate a possible association between influenza or pneumococcal vaccination and acute myocardial infarction.     

Empowerment of coastal communities in cultivation and processing of Kappaphycus alvarezii��a case study at Vizhinjam village, Kerala, India

The Science & Society Division of Department of Science & Technology, Government of India sanctioned a project in 2005 under the Woman Scientist Program (DST WOS-B) with an objective to develop technologies for the cultivation of high-value seaweeds widely used for industrial purposes/human consumption with empowerment of the coastal communities in Kerala. The project was divided into two phases: an experimental/investigational phase and an extension phase. In the experimental phase, pilot-scale culture experiments were conducted to evaluate the possibility and feasibility of the cultivation of the red alga, Kappaphycus alvarezii, in the southwest coast of Kerala. Pilot-scale studies of seaweed culture were conducted in the shallow subtidal waters on the Vizhinjam Harbor area in two bamboo rafts tied with seeds of K. alvarezii (100?±?1.20 g) following accepted culture and growth monitoring procedures. The first harvest was carried out after 45 days and the growth was nearly eight times the initial biomass (826?±?2.80 g). A group of local fishermen were trained in the fabrication of culture rafts, implanting seed material, rearing the seedlings with periodical monitoring, harvesting, and post-harvest technologies like drying, sorting, packing, etc. as part of the pilot-scale study. The pilot-scale efforts showed good scope for the further expansion of the large-scale cultivation of K. alvarezii in the southwest coast of Kerala by imparting training and adopting fishermen families for their additional employment/alternative livelihood. Success in the pilot-scale cultivation led to the second phase of the project, the extension phase, which fulfilled the main objectives of the DST WOS-B programme. Vizhinjam Gramapanchayat (village), where the pilot-scale cultivation was carried out successfully and headed by a woman president, came forward to pool resources of the project to be implemented as a Model Seaweed Cultivation Programme. A training/workshop on ??seaweed farming technology?? was conducted and nearly 60 people were trained. Mangalam purusha sahaya sangham, a registered self-help group (SHG) of Vizhinjam, came forward to start the culture operations at Vizhinjam with technical backup from the DST-WOS-B Programme. Some seaweed entrepreneurs from inside and outside Kerala also came forward with a 100% buyback guarantee for the produce. Nationalised banks like the State Bank of India offered loans to trained SHGs for starting seaweed cultivation at commercial scale.     

Nonuse of bicycle helmets and risk of fatal head injury: a proportional mortality, case�Ccontrol study

Background:

The effectiveness of helmets at preventing cycling fatalities, a leading cause of death among young adults worldwide, is controversial, and safety regulations for cycling vary by jurisdiction. We sought to determine whether nonuse of helmets is associated with an increased risk of fatal head injury.

Methods:

We used a case–control design involving 129 fatalities using data from a coroner’s review of cycling deaths in Ontario, Canada, between 2006 and 2010. We defined cases as cyclists who died as a result of head injuries; we defined controls as cyclists who died as a result of other injuries. The exposure variable was nonuse of a bicycle helmet.

Results:

Not wearing a helmet while cycling was associated with an increased risk of dying as a result of sustaining a head injury (adjusted odds ratio [OR] 3.1, 95% confidence interval [CI] 1.3–7.3). We saw the same relationship when we excluded people younger than 18 years from the analysis (adjusted OR 3.5, 95% CI 1.4–8.5) and when we used a more stringent case definition (i.e., only a head injury with no other substantial injuries; adjusted OR 3.6, 95% CI 1.2–10.2).

Interpretation:

Not wearing a helmet while cycling is associated with an increased risk of sustaining a fatal head injury. Policy changes and educational programs that increase the use of helmets while cycling may prevent deaths.One cyclist dies in Canada each week, and cycling fatalities account for more than 2% of traffic fatalities, a leading cause of death in young adults.¹ Cycling safety regulations vary by jurisdiction, and controversy remains about the effectiveness of safety measures such as helmets. There is strong evidence that helmets prevent nonfatal head injuries,² but very limited evidence exists related to fatal head injuries. A meta-analysis of case–control studies showed a protective effect of helmets against head injuries, but it was based on just 4 case fatalities in which helmets were not worn.³ Another large study involving 1710 cycling collisions found a trend toward a protective effect of helmets, but included only 14 fatalities.⁴ The existing literature leaves open the possibility that helmets prevent nonfatal head injuries, but not fatal ones.We sought to determine whether cycling without a helmet was associated with an increased risk of sustaining a fatal head injury.     

Carcinogen DNA adducts and the risk of colon cancer: case–control study

Colorectal cancer represents 8.5% of all tumours at the King Faisal Specialist Hospital & Research Centre. Environmental and dietary carcinogens such as polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) have long been suspected to play a prominent role in colon cancer aetiology. We designed a case–control study to test the hypothesis of whether or not the presence of DNA adducts can play a role in the aetiology of colon cancer. DNA adducts were measured in 24 cancerous and 20 non-cancerous tissue samples of newly diagnosed colon cancer patients by ³²P-post-labelling technique. Normal tissue from 19 hospital patients served as controls. The mean levels of adducts per 10¹⁰ nucleotides in cancerous and non-cancerous tissue were 151.75±217.27 and 114.81±186.10, respectively; however, only adducts in cancerous tissue were significantly higher than controls (32.78±57.51 per 10¹⁰ nucleotides) with p-values of 0.017. No BPDE-DNA adducts were found. No relationship was found between urinary cotinine as a marker of tobacco smoke and 1-hydroxypyrene as an indicator of an individual's internal dose of PAHs and DNA adducts. In a logistic regression model, only adducts in cancerous tissue were associated with the subsequent risk of colon cancer, with an odds ratio of 3.587 (95% confidence interval 0.833–15.448) after adjustment for age and the duration of living in the current region, but of a borderline significance (p=0.086). Although it is difficult to arrive at a definite conclusion from a small dataset, our preliminary results suggest the potential role of DNA adducts in the colon carcinogenesis process. Additional studies with larger sample sizes are needed to confirm our preliminary finding. It is also important to identify the structural characterization of these unknown DNA adducts in order to have a better understanding of whether or not environmental carcinogens play a role in the aetiology of colon cancer.     

A case–control study on the effect of metabolic gene polymorphisms, nutrition, and their interaction on the risk of non-alcoholic fatty liver disease

The oxidative stress is a key issue in the etiology of non-alcoholic fatty liver disease (NAFLD). The aim of our study was to evaluate the effect of metabolic gene polymorphisms involved in the oxidative stress (GSTT1, GSTM1, SULT1A1, CYP2E1, and 1A1), lifestyle and nutrition aspects, and their interaction, on the risk of NAFLD. We enrolled 294 cases and 359 controls, and collected demographics, anthropometric, lifestyle, and nutrition data. A subgroup of NAFLD provided additional data on nutrients and on physical activity engagement. Each patient provided a blood sample for DNA extraction and genotyping. Clinical and laboratory data were collected from cases. Multivariable analysis shows a significant protective effect of age, gender, and moderate drinking habits on the risk of NAFLD, while an increased risk for greater consumption of fruit and grilled meat or fish. Significant interactions were reported between alcohol consumption, fruit intake, grilled meat and fish, and selected genetic variants. From the subgroup analysis, a moderate/high consumption of fat and/or grilled meat/fish, and a high consumption of white meat increase the risk of NAFLD. Engaging any physical activity at least 1 time/week halves the risk of NAFLD. Besides confirming the beneficial effect of moderate alcohol intake and regular physical activity, and the increased risk associated with high fruit and fat intake, for the first time, we report a detrimental effect of grilled food on NAFLD risk. An effect modification by selected gene variants increases the risk in combination with fruit and grilled food intake.     

Simulation of urban expansion and encroachment using cellular automata and multi-agent system model—A case study of Tianjin metropolitan region,China

The combination model of cellular automata and multi-agent system were used in this paper for simulating spatio-temporal dynamics of urban expansion and its encroachment on other lands at the regional scale. The human system(contain authorities and residents) and their behavior, the landscape system and its behavior as well as the inter actions between them were all simulated in this paper. The behavior of human system is established based on multi-agent system, the authority agent and the resident agent were both regarded as abstract entities. The cellular automata is embedded into the model for simulating the spontaneous urban growth. The impact of neighbor cells were considered so that the expansion of urban lands can be limited near the existed urban lands. Moreover, the rural residential lands have higher probability to convert to urban lands if they were close to the cities or towns. Simulation of urban expansion is undertaken on the time series from 2000 to 2020 for Tianjin metropolitan region, the largest open coastal city in northern China. The results show that Tianjin’s urban lands focus on the epitaxial expansion around the central city accompanied with the growing exurb expansion distributing in multiple districts and counties. The croplands are taken the most area of the land-use types, 1764.03 km² are converted to urban lands, and more than one fourth of the rural residential lands are changed to urban lands in 2000–2020. The urban development and the cropland protection should be both taken into account to minimize the threats on food security and ecological environment.