[Effects of a Motivational Interview Intervention on Self-Efficacy, Self-Care Behavior, and Glycemic Control in Type 2 Diabetic Patients].

BACKGROUND: Motivation is an important factor in disease management for diabetic patients. However, motivational strengthening interventions have been inadequately effective in effecting behavior change in this group. PURPOSE: This study was designed to investigate the effect of a motivational interview intervention on self-efficacy, self-care behavior, and blood sugar control in patients with type 2 diabetes. METHODS: The target population comprised patients with type 2 diabetes in two medical wards of a regional hospital in the southern Taiwan. The 112 participants were randomly assigned to the experimental group (n = 56) and control group (n = 56). Over a three month period, the experimental group received 6 motivational interview sessions of 50 minutes each in addition to usual diabetes care, while the control group received usual diabetes care on the ward. Both groups completed the demographic questionnaire, Chinese version of Diabetes Self-Efficacy Scale, Diabetes Self-Care Behavior Scale, glycosylated hemoglobin level pre-test, and 3 months post-test survey. The results were analyzed using SPSS 22.0 for Windows. RESULTS: A total of 55 patients in the experimental group and 52 patients in the control group completed the study. After analysis, significant inter-group differences in self-efficacy and self-care behavior were found between the experimental group and the control group at pre-test and three-month post-test (p < .001). For the experimental group, the three-month post-test score and glycated hemoglobin value were higher than at pre-test. The three-month post-test value was significantly lower (p < .001) than the pre-test value, and the change effect in the experimental group was better than that in the control group. There was a significant difference in the stages of change between pre-test and post-test (χ2 = 43.89, p < .001), and the change effect in the experimental group was better than that in the control group. CONCLUSIONS / IMPLICATIONS FOR PRACTICE: The proposed motivational interview intervention can help patients with type 2 diabetes admitted to medical wards improve their self-efficacy, self-care behavior, and glycated hemoglobin values. In the future, nursing education should improve the teaching of motivational interview skills to allow nurses to conduct effective interviews quickly during treatment, increase their patients' motivation to self-control blood sugar, and enable patients to learn blood sugar control skills before discharge to achieve effective blood sugar control.

Evaluation of cooking effects on otolith stable carbon and oxygen isotope values of teleostean fish Pomadasys kaakan (Cuvier, 1830).

RATIONALE: For years, archaeologists, climatologists, and ecologists have used stable oxygen isotope values (δ13 C, δ18 O) in fish otoliths from archaeological sites to reconstruct the habitats, paleo-temperature, and seasonality of the fish captures. Otoliths from archaeological sites might have been heated when ancient people cooked the fish for food. Therefore, there are debates as to whether the cooking behaviors would cause further isotopic fractionations of the carbonate in the otoliths. METHODS: In this study, we have evaluated the effects of the cooking methods on the otolith δ13 C and δ18 O values by comparing the otoliths of the javelin grunter (Pomadasys kaakan) from the same individuals, with the left otoliths taken out before the different cooking processes. Otolith sections of the fish were then made and several subsamples were milled along the microstructures visible in the otolith pairs, mostly annual check rings, followed by the stable isotope analyses. RESULTS: There were no morphological changes between the cooked and uncooked otoliths. The δ13 C and δ18 O values were highly consistent for the otolith subsamples between the cooked and uncooked pairs, suggesting none or trivial effects of the cooking processes on the isotopic values of the otoliths. In addition, some javelin grunters showed lower δ13 C (-5‰ to -6‰) and δ18 O (-4‰ to -5‰) values deposited in the wide translucent zone of the otoliths, suggesting seasonal migration of the fish to estuaries during the summer. CONCLUSIONS: This study suggests that cooking processes do not change otolith stable isotopic compositions and will therefore allow for future research to use the otolith δ13 C and δ18 O values to better understand the life history and used habitats of the preserved fish remains in the middens.

Vibrio salinus sp. nov., a marine nitrogen-fixing bacterium isolated from the lagoon sediment of an islet inside an atoll in the western Pacific Ocean.

A marine, facultatively anaerobic, nitrogen-fixing bacterium, designated strain DNF-1T, was isolated from the lagoon sediment of Dongsha Island, Taiwan. Cells grown in broth cultures were Gram-negative rods that were motile by means of monotrichous flagella. Cells grown on plate medium produced prosthecae and vesicle-like structures. NaCl was required and optimal growth occurred at about 2-3% NaCl, 25-30 °C and pH 7-8. The strain grew aerobically and was capable of anaerobic growth by fermenting D-glucose or other carbohydrates as substrate. Both the aerobic and anaerobic growth could be achieved with NH4Cl as a sole nitrogen source. When N2 served as the sole nitrogen source only anaerobic growth was observed. Major cellular fatty acids were C14:0, C16:0 and C16:1 ω7c, while major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content was 42.2 mol% based on the genomic DNA data. Phylogenetic analyses based on 16S rRNA genes and the housekeeping genes, gapA, pyrH, recA and gyrB, revealed that the strain formed a distinct lineage at species level in the genus Vibrio of the family Vibrionaceae. These results and those from genomic, chemotaxonomic and physiological studies strongly support the assignment of a novel Vibrio species. The name Vibrio salinus sp. nov. is proposed for the novel species, with DNF-1T (= BCRC 81209T = JCM 33626T) as the type strain. This newly proposed species represents the second example of the genus Vibrio that has been demonstrated to be capable of anaerobic growth by fixing N2 as the sole nitrogen source.

Cascade Vinyl Radical Ipso-Cyclization Reactions and the Formation of α,ß-Unsaturated-ß-aryl-γ-lactams from N-Propargyl Benzamides.

Various N-(2-bromo-allyl) benzamides were used as the starting materials to study vinyl radical cyclization reactions. The vinyl radicals underwent ipso-cyclization, fragmentation, and cyclization reactions to produce ß-aryl-γ-lactams with the carbonyl group remaining intact. To further study this cascade radical reaction, vinyl radicals were generated by the addition of a tributyltin radical to alkyne moieties, followed by radical ipso-cyclization, fragmentation, cyclization, and ß-scission reactions with the production of a series of α,ß-unsaturated-ß-aryl-γ-lactam derivatives. This new type of radical reaction was examined from the substituent effects on both the amino groups and the aryl groups. A bulky tert-butyl substituent on the amino group enhanced the formation of a Z-conformation of the benzamides and facilitated vinyl radical ipso-cyclization reactions. A synthetic method for preparing α,ß-unsaturated-ß-aryl-γ-lactams from N-propargyl benzamides was developed.

Vibrio nitrifigilis sp. nov., a marine nitrogen-fixing bacterium isolated from the lagoon sediment of an islet inside an atoll.

A nitrogen-fixing isolate of facultatively anaerobic, marine bacterium, designated strain NFV-1T, was recovered from the lagoon sediment of Dongsha Island, Taiwan. It was a Gram-negative rod which exhibited motility with monotrichous flagellation in broth cultures. The strain required NaCl for growth and grew optimally at about 25-35 °C, 3% NaCl and pH 7-8. It grew aerobically and could achieve anaerobic growth by fermenting D-glucose or other carbohydrates as substrates. NH4Cl could serve as a sole nitrogen source for growth aerobically and anaerobically, whereas growth with N2 as the sole nitrogen source was observed only under anaerobic conditions. Cellular fatty acids were predominated by C16:1 ω7c, C16:0, and C18:1 ω7c. The major polar lipids consisted of phosphatidylethanolamine and phosphatidylserine. Strain NFV-1T had a DNA G + C content of 42.5 mol%, as evaluated according to the chromosomal DNA sequencing data. Analyses of sequence similarities and phylogeny based on the 16S rRNA genes, together with the housekeeping genes, gyrB, ftsZ, mreB, topA and gapA, indicated that the strain formed a distinct species-level lineage in the genus Vibrio of the family Vibrionaceae. These phylogenetic data and those from genomic and phenotypic characterisations support the establishment of a novel Vibrio species, for which the name Vibrio nitrifigilis sp. nov. (type strain NFV-1T = BCRC 81211T = JCM 33628T) is proposed.

Body Size, Light Intensity, and Nutrient Supply Determine Plankton Stoichiometry in Mixotrophic Plankton Food Webs.

Trophic strategy determines stoichiometry of plankton. In general, heterotrophic zooplankton have lower and more stable C∶N and C∶P ratios than photoautotrophic phytoplankton, whereas mixotrophic protists, which consume prey and photosynthesize, have stoichiometry between zooplankton and phytoplankton. As trophic strategies change with cell size, body size may be a key trait influencing eukaryotic plankton stoichiometry. However, the relationship between body size and stoichiometry remains unclear. Here we measured plankton size-fractionated C∶N ratios under different intensities of light and nutrient supply in subtropical freshwater and marine systems. We found a unimodal body size-C∶N ratio pattern, with a maximum C∶N ratio at ∼50 µm diameter in marine and freshwater systems. Moreover, the variation in C∶N ratios is explained mainly by body size, followed by light intensity and nutrient concentration. To investigate the mechanisms behind this unimodal pattern, we constructed a size-based plankton food web model in which the trophic strategy and C∶N ratio are an emerging result. Our model simulations reproduce the unimodal pattern with a C∶N ratio of photoautotrophs ≤50 µm increasing with body size due to increase of photosynthetic carbon, whereas C∶N ratios of organisms >50 µm decrease with size due to decreasing photoautotrophic but increasing heterotrophic uptake. Based on our field observations and simulation, we extend the classic "light-nutrient" theory that determines plankton C∶N ratio to include body size and trophic strategy dependency. We conclude that body size and size-dependent uptake of resources (light, nutrients, and prey) determine plankton stoichiometry at various light and nutrient supplies.

Toward a standardised protocol for the stable isotope analysis of scleractinian corals.

RATIONALE: The stable isotope analysis of carbon and nitrogen is a powerful tool in many ecological studies, but different sample treatments may affect stable isotope ratios and hamper comparisons among studies. The goal of this study was to determine whether treatments that are commonly used to prepare scleractinian coral samples for stable isotope analysis yield different δ15 N and δ13 C values, and to provide guidelines toward a standardised protocol. METHODS: The animal tissues and Symbiodiniaceae of two symbiotic scleractinian coral species (Stylophora pistillata and Porites lutea) were divided into subsamples to test the effects of the drying method, lipid extraction, acidification treatment and water washing. All the subsamples were analysed for their δ15 N and δ13 C values, using continuous flow elemental analyser/isotope ratio mass spectrometry. RESULTS: The drying method and lipid extraction treatment had no substantial effects on the δ15 N and δ13 C values of Symbiodiniaceae and animal tissues. Acid treatment did cause significant differences in δ13 C values (mean differences ≤0.5‰, with individual samples becoming up to 2.0‰ more negative), whereas no ecologically significant differences were observed in δ15 N values. Animal tissue δ13 C values may vary depending on whether samples are washed or not. CONCLUSIONS: To move towards a standardised protocol in coral research, we recommend using an available drying method (as they are equally acceptable) for the stable isotope analysis of scleractinian corals, examining the need for lipid extraction on a case-by-case basis, performing a direct acidification of Symbiodiniaceae and animal tissues, and avoiding washing animal tissue with distilled water.

Dongshaea marina gen. nov., sp. nov., a facultatively anaerobic marine bacterium that ferments glucose with gas production.

Two isolates of heterotrophic, facultatively anaerobic, marine bacteria, designated DM1 and DM2T, were recovered from a lagoon sediment sample of Dongsha Island, Taiwan. Cells were Gram-reaction-negative rods. Nearly all of the cells were non-motile and non-flagellated during the late exponential to early stationary phase of growth, while a few of the cells exhibited motility with monotrichous flagellation. The two isolates required NaCl for growth and grew optimally at about 30 °C, 2-3 % NaCl and pH 7-8. They grew aerobically and could achieve anaerobic growth by fermenting d-glucose or other carbohydrates with production of acids and the gases, including CO2 and H2. Ubiquinone Q-8 was the only respiratory quinone. Cellular fatty acids were predominated by C16 : 0, C18 : 1ω7c and C16 : 1ω7c. The major polar lipid was phosphatidylethanolamine. Strains DM1 and DM2T had DNA G+C contents of 52.0 and 51.8 mol%, respectively, as determined by HPLC analysis. Phylogenetic analyses based on 16S rRNA gene sequences clearly indicated that the two isolates formed a distinct genus-level lineage in the family Aeromonadaceae of the class Gammaproteobacteria and was an outgroup with respect to a stable supragenic clade comprising species of the genera Oceanimonas, Oceanisphaera and Zobellella. The phylogenetic data and those from chemotaxonomic, physiological and morphological characterizations support the establishment of a novel species and genus inside the family Aeromonadaceae, for which the name Dongshaea marina gen. nov., sp. nov. is proposed. The type strain is DM2T (=BCRC 81069T=JCM 32096T).

Fractionation of otolith nitrogen stable isotopes measured by peroxodisulfate oxidation-bacterial conversion and isotope ratio mass spectrometry.

RATIONALE: Otoliths are usually used to estimate the age of fish and the chemical composition such as nitrogen stable isotope ratios (δ15 N values) may record environmental information and ecological role of the fish. However, the isotopic fractionation of δ15 N values between diets and otoliths has rarely been investigated and remains unclear. METHODS: Nitrogen isotopic fractionation between five different diets (δ15 Ndiet values) and otoliths (δ15 Noto values) were elucidated in tilapia Oreochromis mossambica reared in controlled feeding experiments. The otoliths were dissolved with hydrogen chloride and peroxodisulfate was used to oxidize the total organic materials to nitrate, which was further converted into N2 O gas by denitrification bacteria before the measurement of δ15 Noto values by isotope ratio mass spectrometry. The δ15 N values of muscles, gills, scales and livers of the tilapias were also measured by isotope ratio mass spectrometry. RESULTS: The peroxodisulfate oxidation-bacterial conversion method reduced the minimum mass of the otoliths required for analysis to as low as 2 mg, unlike past methods, which have required masses of 8-155 mg. The δ15 Noto values were not significantly different from the δ15 Ndiet values of the five diets. Furthermore, the somatic growth rate had no effect on the δ15 Noto values. Nevertheless, the δ15 N values of metabolically active tissues were significantly different from each other and higher than the δ15 Ndiet values, due to the deamination of these tissues. CONCLUSIONS: These results suggest that diet was the main source of amino acids for the otolith organic matrix and there was no biochemical transamination during the assimilation of dietary amino acids to otoliths. The δ15 Noto value can be used as a proxy of nitrogen sources of fishes and may have potential application in ecological studies such as the detection of diet shift, migration, trophic levels and environmental changes experienced by the fish population.

Variations in microbial community compositions and processes imposed under contrast geochemical contexts in Sicilian mud volcanoes, Italy.

Terrestrial mud volcanoes represent surface features of channels for subsurface methane transport and, therefore, constitute an important source of methane emission from natural environments. How microbial processes regulate methane emissions in terrestrial mud volcanoes has yet to be fully addressed. This study demonstrated the geochemical characteristics and microbial communities of four mud volcano and seep sites in two geological settings of Sicily, Italy. At sites within the accretionary wedge that exhibited higher methane and sulfate concentrations, the communities were dominated by members capable of catalyzing methane and sulfate metabolisms and organic degradation. In particular, both anaerobic and aerobic methanotrophs were abundant and their abundance distribution coincided with the geochemical transition. In contrast, the sites near Mount Etna were characterized by high fluid salinity, CO2, and low methane and sulfate concentrations, with communities consisting of halophilic organic degraders and sulfur metabolizers, along with a minor presence of aerobic methanotrophs. Substantial variations in community composition and geochemistry across spatial and vertical redox gradients suggest that physicochemical contexts imposed by the geology, fluid path, and source characteristics play a vital role in shaping community composition and cycling of methane, sulfur and organic carbon in Sicily mud volcanoes.

The Temporal Pattern of Repeat Intimate Partner Violence Incidents Among High-Risk Survivors in Taiwan: A Survival Analysis.

Intimate partner violence (IPV) is rarely an isolated incident, with survivors often experiencing repeat violence. Few studies, however, have been conducted to investigate the temporal pattern of IPV revictimization using a validated risk assessment instrument. In Taiwan, service professionals are mandated to report any known IPV incidents using the Taiwan Intimate Partner Violence Danger Assessment (TIPVDA), a validated risk assessment designed to assess the level of lethality faced by IPV survivors. The mandatory reporting policy and the universal use of the TIPVDA provide a unique opportunity to investigate the time course of repeat IPV victimization. This study analyzes high-risk IPV incidents (n = 18,740) reported in Taiwan from 2017 to 2019 using Cox regression analysis. Analysis results suggested three main findings: (a) The time interval between IPV victimizations shortened and the severity of violence increased; (b) the TIPVDA score was consistently associated with repeat victimization, unlike self-assessed dangerousness; (c) specific TIPVDA items, such as IPV history and financial stress, predicted the rate of repeat victimization. Those who reported ever being hurt by their partner during pregnancy, an escalation in physical violence during the past year, their partner threatening to kill them, and their partner being stressed about their financial situation were likely to have a faster rate of reporting the second and third high-risk victimization reports. These findings highlight the importance of using validated risk assessments in practice, not only for predicting reassault, severe reassault, or homicide but also for estimating the timing of revictimization. This can significantly inform intervention strategies and policy decisions.

Investigation of organic contaminants in the blubber of a blue whale (Balaenoptera musculus) first stranded on the coast of Taiwan.

This study presents a comprehensive assessment of persistent organic pollutants (POPs) in the blubber of a stranded blue whale found on the coast of Taiwan. The analysis included polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), Hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The whale exhibited evident signs of emaciation, including low body weight, reduced blubber fat content, and thin blubber thickness. The dominant fatty acid type detected in the blubber was short-chain monounsaturated fatty acids (SC-MUFA), known to aid in thermoregulation. Stable isotope ratios indicated that the blue whale occupied a lower trophic position compared to a fin whale, suggesting its proximity to krill habitats in the Southern Ocean for feeding. The average concentrations of DDTs (1089.2 ± 4.7 ng/g lw; ΣDDT) and PCBs (1057.1 ± 49.8 ng/g lw) in the blubber were almost one order of magnitude higher than PAHs (41.7 ± 10.0 ng/g lw), HCB (70.6 ± 2. ng/g lw), and PBDEs (7.2 ± 1.2 ng/g lw). Pollutant concentrations in this individual blue whale were comparable to levels found in Norway, higher than those found in Chile, and notably lower than those found in Canada and Mexico. Calculating the biomagnification factor (BMF) for the POPs from krill (Euphausia superba) to the blue whale revealed significant bioaccumulation of pollutants in this particular whale. Additional research is imperative to achieve a thorough comprehension of bioaccumulation of POPs and their potential toxicological impacts on whale health.

Anthropogenic nitrogen pollution inferred by stable isotope records of crustose coralline algae.

Since reef ecosystems can offer intricate habitats for various marine organisms, calcified reefs may contain valuable long-term environmental data. This study investigated stable isotopic composition of marine organisms from the Taoyuan and Linshanbi crustose coralline algae (CCA) reef ecosystems to understand sewage pollution. CCA samples from Taoyuan (Palaeo Xin A: ∼1000 years old and Palaeo G: ∼7000 years old) and Linshanbi (Palaeo L: ∼7000 years old and modern CCA) had significantly lower δ15N values (2.5-5.6 ‰) compared to modern CCA from Taoyuan (10.2 ± 1.2 ‰). Intertidal organisms from the Taoyuan CCA reef also showed higher δ15N values than those from Linshanbi CCA reef, indicating anthropogenic stress in both ecosystems. Long-term pollution monitoring and effective strategies to mitigate sewage pollution are recommended for these CCA reef ecosystems.

The methane-oxidizing microbial communities of three maar lakes in tropical monsoon Asia.

Methane-oxidizing bacteria (MOB) is a group of planktonic microorganisms that use methane as their primary source of cellular energy. For tropical lakes in monsoon Asia, there is currently a knowledge gap on MOB community diversity and the factors influencing their abundance. Herewith, we present a preliminary assessment of the MOB communities in three maar lakes in tropical monsoon Asia using Catalyzed Reporter Deposition, Fluorescence In-Situ Hybridization (CARD-FISH), 16S rRNA amplicon sequencing, and pmoA gene sequencing. Correlation analysis between MOB abundances and lakes' physicochemical parameters following seasonal monsoon events were performed to explain observed spatial and temporal patterns in MOB diversity. The CARD-FISH analyses detected the three MOB types (I, II, and NC10) which aligned with the results from 16S rRNA amplicons and pmoA gene sequencing. Among community members based on 16S rRNA genes, Proteobacterial Type I MOB (e.g., Methylococcaceae and Methylomonadaceae), Proteobacterial Type II (Methylocystaceae), Verrucomicrobial (Methylacidiphilaceae), Methylomirabilota/NC10 (Methylomirabilaceae), and archaeal ANME-1a were found to be the dominant methane-oxidizers in three maar lakes. Analysis of microbial diversity and distribution revealed that the community compositions in Lake Yambo vary with the seasons and are more distinct during the stratified period. Temperature, DO, and pH were significantly and inversely linked with type I MOB and Methylomirabilota during stratification. Only MOB type I was influenced by monsoon changes. This research sought to establish a baseline for the diversity and ecology of planktonic MOB in tropical monsoon Asia to better comprehend their contribution to the CH4 cycle in tropical freshwater ecosystems.

Early temperament and physical health in school-age children: Applying a short temperament measure in a population-based cohort.

Temperament has drawn considerable attention in the understanding of behavioural problems and psychopathology across developmental stages. However, less of a focus has been placed on the role of temperament in physical aspects of health. We aimed to examine the relations between early temperament traits and physical health in school-age children. This study used longitudinal data of 18,994 children (52.4% boys) born in 2005 from the Taiwan Birth Cohort Study, in which follow-up surveys were conducted via face-to-face interviews with the child's caregiver. Temperament at 5.5 years of age was assessed using a nine-item measure, and two higher-order temperament traits, surgency and regulation, were derived through confirmatory factor analysis. Physical health outcomes at age 8 included caregiver-rated general health status and medically attended injuries. Multiple logistic regression analysis was applied, with the child's birth outcome, early health status or injury history, health behaviours and family socioeconomic status as control variables. The results indicated that higher levels of surgency and regulation, as early temperament traits, significantly predicted lower odds of caregiver-rated poor health in later years. Higher level of regulation was also associated with lower odds of injury risk. Our findings suggest that assessing early temperament traits could be useful for the promotion and management of physical health in young school-age children.

Responses of a common tropical epiphyte, Asplenium nidus, to changes in water and nutrient availability.

Epiphytes are highly dependent on atmospheric inputs of water and nutrients. Reductions in water availability associated with warming and climate change and continual atmospheric nitrogen (N) deposition can affect plant growth but few studies have evaluated the effects of changes in both water and nutrient availabilities on epiphytes. We experimentally tested whether epiphyte growth is more water- or nutrient-limited, if nutrient limitation was stronger for nitrogen or phosphorus, and whether nutrient limitation interacts with water availability. We applied watering (high and low) and nutrient addition (control, +N, +P, +N+P) treatments to greenhouse-grown Asplenium nidus, a common epiphytic fern found in many tropical and subtropical wet forests. We measured leaf area production and leaf elemental concentrations to assess how A. nidus growth and physiology respond to changes in water and nutrient availabilities. We found that leaf growth of A. nidus was more affected by water availability than nutrient addition and the effect of adding nutrients was not fully realized under low-water availability. Among the different nutrient treatments, +N+P had the greatest effects on A. nidus growth and physiology in both watering treatments. Watering treatment changed leaf elemental concentrations but not their ratios (i.e. C:N and N:P). Nutrient addition altered C:N and N:P ratios and increased the concentration of the added elements in leaves, with more pronounced increases in the high-watering treatment. We conclude that the growth of A. nidus is more water- than nutrient-limited. When nutrient limitation occurs (i.e. under high-water availability), nutrient co-limitation is stronger than limitation by N or P alone. This result taken together with studies of other epiphytes suggests greater water than nutrient limitation is likely widespread among epiphytic plants. The limited effects of nutrient addition in the low-water treatment suggest that the effect of atmospheric N deposition on epiphyte growth will be limited when water availability is low.

Disentangling the impact of anthropogenic and natural processes on the environment in a subtropical subalpine lake catchment in northeastern Taiwan over the past 150 years.

Human activities impose significant changes on sedimentation processes and vegetation cover within lake catchments. However, the needed time for an anthropogenically disturbed natural state to be reversed back to its natural state by environmental protection programs is still ambiguous. Here we employ a multi-proxy approach to delineate major environmental disturbances such as logging and forest fires on the catchment in Cueifong Lake, a subtropical subalpine lake in northeastern Taiwan. X-ray Fluorescence (XRF) core scanning, bulk total organic carbon (TOC), bulk total nitrogen (TN), stable carbon isotope (δ13Corg) analysis, and macro-charcoal counting were utilized to reconstruct changes in the catchment environment based on a sediment core from Cueifong Lake. The results show that the element content changed distinctly around 1975 CE, which coincided with the onset of profound deforestation in the lake vicinity recorded in historical documents and aerial photos. After the cessation of the logging event, the detrital input increased, accompanied by decreasing C/N ratios and increasing δ13Corg values. This suggests that increased terrestrial nutrient input promoted algae growth. After the deforestation phase, our results imply a gradual recovery of elemental composition in the catchment environment. By extrapolating the XRF element records, we suggest that it might take >50 years for the sedimentary regime to reach its pre-logging baseline. In contrast to the depositional system, the C/N and δ13Corg shifted significantly - potentially irreversibly - towards an algae-dominant environment instead of recovering to the pre-logging condition. This could be due to both 1) the changes in the different vegetation species used for reforestation and/or 2) anthropogenically introduced fishes in the 1980s. This study proposes the first assessment of the needed recovery time for subtropical Asian subalpine forests after large-scale logging activity and thus provides an apparent reference for policy decisions on natural resource development and environmental protection.

Microbial methane cycling in a terrestrial mud volcano in eastern Taiwan.

Microbial communities responsible for methane cycling in mud volcanoes onshore are poorly characterized. This study analysed bubbling fluids and cored sediments retrieved from a mud volcano in eastern Taiwan. The pore water profiles revealed that methane concentrations generally increased with depth and changed dramatically at different depth intervals at different sites. The methane concentrations were inversely correlated with Fe(2+)/Mn(2+) concentrations and δ(13)C values of methane, marking iron/manganese-methane transition zones in the sediment cores. Archaeal communities were dominated by ANME-2a members and methylotrophic methanogens, whereas bacterial communities consisted primarily of Proteobacteria, Firmicutes and Bacteroidetes. The 16S rRNA gene copy numbers of ANME-2a and Desulfuromonas/Pelobacter populations varied by two to three orders of magnitude along the profile and exhibited a pattern comparable with those of Fe(2+) and δ(13)C values of methane. These lines of evidence suggest a coupling between anaerobic methanotrophy and metal reduction in the metal-methane transition zones under sulfate-deficient conditions, a metabolic scheme contrasting with that observed in marine cold seeps. Anaerobic methanotrophs proliferate by removing methane produced from in situ methanogenesis and originating from the deep source. Methane finally emitted into the atmosphere is quantitatively and isotopically altered by various microbial processes compartmentalized at different depth intervals.

Geochemical signatures of sedimentary and diagenetic processes in the trace fossil Rosselia from the Pliocene in Taiwan.

Trace fossils are structures left in a substrate as the result of the activities of living organisms. The producer of the spindle-shaped trace fossil Rosselia incorporates fine-grained organic rich material into concentric layers surrounding the central shaft. Because Rosselia is common in stressed shallow marine environments where the preservation potential of organic material is generally poor, these trace fossils may act as natural archives, recording changes in the provenance of organic material. Carbon isotope values of organic carbon preserved in laminae of the studied Rosselia typically lie around - 26‰, suggesting a primary terrestrial source. However, increased levels of S and Ca detected from XRF scanning of the laminae indicate that at least some marine material is incorporated. Examination of a diagenetically altered specimen also demonstrates that both elemental composition and δ13C values can be substantially altered diagenesis. Nevertheless, the long stratigraphic range of Rosselia, from the Cambrian to the Present, and its ubiquitous occurrence in stressed shallow-marine settings make it a potentially powerful tool to reconstruct variations in the input of organic material in settings otherwise devoid of fine-grained organic matter.

Salinity indicators in sediment through the fluvial-to-marine transition (Fraser River, Canada).

Many sediment attributes have been proposed as proxies for determining salinity conditions under which sediment is deposited, and six attributes (Sr/Ba-HAc, Sr/Ba-NH4Ac, δ13Corg, C/N, and the relative abundances and concentrations of dinoflagellate cysts) are compared here. In this paper, sediment attributes from the Fraser River Delta, Canada and surrounding coastal areas are compared by depositional position along the fluvial-to-marine transition, by salinity, and by sedimentological characteristics. Along the fluvial-to-marine transition, most attributes exhibit distinct trends between parts of the river that experience sustained marine water (saltwater) influence over seasonal and tidal timeframes, and parts that experience only freshwater or periodic saltwater influence. No attributes are reliable indicators of depositional position where saltwater incursion is short lived or where water is fresh. Where marine influence is sustained, Sr/Ba-HAc and Sr/Ba-NH4Ac are the most reliable positional indicators along the fluvial-to-marine transition. When compared strictly to salinity, Sr/Ba-HAc, Sr/Ba-NH4Ac, and δ13Corg all correlate predictably except in delta front and prodelta settings. Our data show that all six sediment attributes are heavily impacted by river-derived sedimentation, and it is not appropriate to compare values from strongly river-influenced settings (e.g., deltas) with those from weakly river-influenced settings (e.g., bays and estuaries).