The role of groundwater in CO2 production and carbon storage in Mediterranean peatlands: An isotope geochemistry approach.

Peatlands are permanent wetlands recognized for ecosystem services such as biodiversity conservation and carbon storage capacity. Little information is available about their response to global change, the reason why most Earth system climate models consider a linear increase in the release of greenhouse gases (GHG), such as CO2, with increasing temperatures. Nevertheless, numerous studies suggest that an increase in the temperature may not imply a decrease in photosynthesis and carbon storage rates if water availability is sufficient, the latter being under the control of local hydrology mechanisms. Mediterranean peatlands well illustrate this fact. Since they are groundwater-dependent, they are hydrologically resilient to the strong seasonality of hydroclimatic conditions, especially during the summer drought. In the present study, we demonstrate that, even if such peatlands release CO2 into the atmosphere, they can maintain a carbon storage capacity. To this end, a geochemical study disentangles the origin and fate of carbon within a Mediterranean peatland at the watershed scale. Field parameters, major ions, dissolved organic and inorganic carbon content and associated δ13C values allow for characterizing the seasonality of hydrochemical mechanisms and carbon input from an alluvial aquifer (where rain, river, shallow, and deep groundwater flows are mixing) to the peatland. The inorganic and organic content of peat soil and δ13C values of total organic matter and CO2 complete the dataset, making it possible to provide arguments in favour of lower organic matter oxidation compared to primary production. Overall, this study highlights the groundwater role in the fluxes of CO2 at the peatland-atmosphere interface, and more broadly the need to understand the interactions between the water and carbon cycles to build better models of the future evolution of the global climate.

Methylcellulose - a versatile printing material that enables biofabrication of tissue equivalents with high shape fidelity.

With the aid of biofabrication, cells can be spatially arranged in three dimensions, which offers the opportunity to guide tissue maturation in a better way compared to traditional tissue engineering approaches. A prominent technique allowing biofabrication of tissue equivalents is extrusion-based 3D (bio)printing, also called 3D (bio)plotting or robocasting, which comprises cells embedded in the biomaterial (bioink) during the fabrication process. First bioprinting studies introduced bioinks allowing either good cell viability or good shape fidelity. Concepts enabling printing of cell-laden constructs with high shape fidelity were developed only rarely. Recent studies showed the great potential of the polysaccharide methylcellulose (mc) as supportive biomaterial that can be utilized in various ways to enable biofabrication and especially extrusion-based bioprinting of bioinks. This minireview highlights the multiple applications of mc for biofabrication: it was successfully used as sacrificial ink to enable 3D shaping of cell sheets or biomaterial inks as well as as internal stabilizing component of various bioinks. Moreover, a brief overview about first bioprinted functional tissue equivalents is given, which have been fabricated by using mc. Based on these studies, future research should consider mc as an auxiliary material for bioinks and biofabricated constructs with high shape fidelity.

Full-scale evaluation of methane production under oxic conditions in a mesotrophic lake.

Oxic lake surface waters are frequently oversaturated with methane (CH4). The contribution to the global CH4 cycle is significant, thus leading to an increasing number of studies and stimulating debates. Here we show, using a mass balance, on a temperate, mesotrophic lake, that ~90% of CH4 emissions to the atmosphere is due to CH4 produced within the oxic surface mixed layer (SML) during the stratified period, while the often observed CH4 maximum at the thermocline represents only a physically driven accumulation. Negligible surface CH4 oxidation suggests that the produced 110 ± 60 nmol CH4 L-1 d-1 efficiently escapes to the atmosphere. Stable carbon isotope ratios indicate that CH4 in the SML is distinct from sedimentary CH4 production, suggesting alternative pathways and precursors. Our approach reveals CH4 production in the epilimnion that is currently overlooked, and that research on possible mechanisms behind the methane paradox should additionally focus on the lake surface layer.

Highly dynamic cellular-level response of symbiotic coral to a sudden increase in environmental nitrogen.

UNLABELLED: Metabolic interactions with endosymbiotic photosynthetic dinoflagellate Symbiodinium spp. are fundamental to reef-building corals (Scleractinia) thriving in nutrient-poor tropical seas. Yet, detailed understanding at the single-cell level of nutrient assimilation, translocation, and utilization within this fundamental symbiosis is lacking. Using pulse-chase (15)N labeling and quantitative ion microprobe isotopic imaging (NanoSIMS; nanoscale secondary-ion mass spectrometry), we visualized these dynamic processes in tissues of the symbiotic coral Pocillopora damicornis at the subcellular level. Assimilation of ammonium, nitrate, and aspartic acid resulted in rapid incorporation of nitrogen into uric acid crystals (after ~45 min), forming temporary N storage sites within the dinoflagellate endosymbionts. Subsequent intracellular remobilization of this metabolite was accompanied by translocation of nitrogenous compounds to the coral host, starting at ~6 h. Within the coral tissue, nitrogen is utilized in specific cellular compartments in all four epithelia, including mucus chambers, Golgi bodies, and vesicles in calicoblastic cells. Our study shows how nitrogen-limited symbiotic corals take advantage of sudden changes in nitrogen availability; this opens new perspectives for functional studies of nutrient storage and remobilization in microbial symbioses in changing reef environments. IMPORTANCE: The methodology applied, combining transmission electron microscopy with nanoscale secondary-ion mass spectrometry (NanoSIMS) imaging of coral tissue labeled with stable isotope tracers, allows quantification and submicrometric localization of metabolic fluxes in an intact symbiosis. This study opens the way for investigations of physiological adaptations of symbiotic systems to nutrient availability and for increasing knowledge of global nitrogen and carbon biogeochemical cycling.

Stable carbon isotope composition of perirenal adipose tissue fatty acids from Engadine sheep grazing either mountain or lowland pasture.

To provide further insights into ruminant lipid digestion and metabolism, and into cis-9,trans-11 18:2 synthesis, 12 growing Engadine lambs grazing either mountain pasture (2,250 m above sea level; n = 6) or lowland pasture (400 m above sea level; n = 6) were studied. Both pastures consisted exclusively of C(3) plants. Before the experiment, all animals grazed a common pasture for 6 wk. Grasses and perirenal adipose tissues of the sheep were analyzed for fatty acids by gas chromatography. Stable C-isotope ratios (δ(13)C values in ‰ vs. the Vienna Pee Dee Belemnite standard) were determined in the composite samples by elemental analysis-isotope ratio mass spectrometry. The δ(13)C of the individual fatty acids were measured by gas chromatography-combustion-isotope ratio mass spectrometry. The δ(13)C value of the entire mountain pasture grass was -27.5‰ (SD 0.31), whereas that of the lowland pasture grass was -30.0‰ (SD 0.07). This difference was reflected in the perirenal adipose tissues of the corresponding sheep (P < 0.05), even though the δ(13)C values were less in the animals than in the grass. The δ(13)C values for cis-9 16:1 and cis-9 18:1 in perirenal fat differed between mountain and lowland lambs (P < 0.05). The 16:0 in the adipose tissue was enriched in (13)C by 5‰ compared with the dietary 16:0, likely as a result of partly endogenous synthesis. The δ(13)C values of cis-9,trans-11 18:2 (cis-9,trans-11 CLA) in the adipose tissue were smaller than those of its dietary precursors, cis-9,cis-12 18:2 and cis-9,cis-12,cis-15 18:3; conversely, the δ(13)C values of trans-11 18:1 were not, suggesting that large proportions of perirenal cis-9,trans-11 18:2 were of endogenous origin and discrimination against (13)C occurred during Δ(9)-desaturation. The same discrimination was indicated by the isotopic shift between 16:0 and cis-9 16:1 in the mountain grazing group. Furthermore, the δ(13)C values of cis-9,trans-11 18:2 were smaller relative to the precursor fatty acids in the mountain lambs compared with the lowland group. This result suggests a reduced extent of biohydrogenation in lambs grazing on mountain grass in comparison with those grazing on lowland grass. This was supported by the smaller cis-9,trans-11 18:2 concentrations in total fatty acids found in the adipose tissues of the lowland lambs (P < 0.001). The results of this study demonstrate that natural differences between δ(13)C values of swards from different pastures and the adipose tissue fatty acids could be used as tracers in studies of lipid metabolism in ruminants.

An investigation in the possible effect of chronic headache on neuropsychological function in aCL-negative patients with SLE.

Controversy exists as to whether patients with migraine may suffer cortical damage. We investigate the possible association between impaired cognitive function and chronic headache in lupus patients. Sixty one patients with systemic lupus erythematosus but without the antiphospholipid (Hughes) syndrome were questioned about headaches and formally assessed for cognitive function. They were also subjected to magnetic resonance imaging (MRI). Twenty one patients denied any significant headaches, 19 reported migrainous headaches and 11 experienced an aura. Eleven patients experienced headaches with features of migraine but did not fulfill the criteria, and seven patients had tension headaches. All patients had stable lupus; there was no difference in the incidence of hypertension, age or previous episodes of neuropsychiatric lupus. Patients with migrainous headaches without aura had marginally shorter duration of disease. There was no difference between the groups with respect to eight different cognitive tests or the ventriculo brain index on MRI. We failed to detect cognitive impairment in lupus patients with chronic headaches including migrainous headaches.

Children with epilepsy and their families: Psychosocial issues

This article commences with the psychological effects of epilepsy on children; followed by the typical emotional problems experienced by parents of children with epilepsy. Subsequently the roles and responsibilities of parents during the various developmental stages of children with epilepsy are discussed. The effect of childhood epilepsy on family life as well as on the siblings is described. Coping strategies that could be helpful to parents of children with epilepsy are briefly discussed. Finally; the importance of a trusting relationship between the family with an epileptic child and their family practitioner is highlighted and recommendations are made in this regard

Headaches in patients with systemic lupus erythematosus: a comparative study.

The incidence and nature of headaches in 85 systemic lupus erythematosus (SLE) patients attending an outpatient clinic were studied and compared to those experienced by 61 nurses. The two groups were similar in age, sex and ethnicity. Test-retest assessment of reliability gave both groups 95% confidence limits of 0.09-0.21. Thirty-two (38%) patients developed migrainous headaches and nine (10%) stress headaches with the onset of lupus. In the control group, four (6%) developed migraine and 40 (66%) developed stress headaches on commencing work. We could not document any association of headaches with flares of systemic disease, the ACA syndrome, Raynaud's phenomenon or increased SLEDAI score. We conclude that migrainous headaches are more common in lupus patients than healthy controls, but in an outpatient setting are not statistically associated with flares of systemic disease.

The application of NMR and MS methods for detection of adulteration of wine, fruit juices, and olive oil. A review.

This review covers two important techniques, high resolution nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), used to characterize food products and detect possible adulteration of wine, fruit juices, and olive oil, all important products of the Mediterranean Basin. Emphasis is placed on the complementary use of SNIF-NMR (site-specific natural isotopic fractionation nuclear magnetic resonance) and IRMS (isotope-ratio mass spectrometry) in association with chemometric methods for detecting the adulteration.

Characterization of cocoa butter and cocoa butter equivalents by bulk and molecular carbon isotope analyses: implications for vegetable fat quantification in chocolate.

The fatty acids from cocoa butters of different origins, varieties, and suppliers and a number of cocoa butter equivalents (Illexao 30-61, Illexao 30-71, Illexao 30-96, Choclin, Coberine, Chocosine-Illipé, Chocosine-Shea, Shokao, Akomax, Akonord, and Ertina) were investigated by bulk stable carbon isotope analysis and compound specific isotope analysis. The interpretation is based on principal component analysis combining the fatty acid concentrations and the bulk and molecular isotopic data. The scatterplot of the two first principal components allowed detection of the addition of vegetable fats to cocoa butters. Enrichment in heavy carbon isotope ((13)C) of the bulk cocoa butter and of the individual fatty acids is related to mixing with other vegetable fats and possibly to thermally or oxidatively induced degradation during processing (e.g., drying and roasting of the cocoa beans or deodorization of the pressed fat) or storage. The feasibility of the analytical approach for authenticity assessment is discussed.

Authentication of vegetable oils by bulk and molecular carbon isotope analyses with emphasis on olive oil and pumpkin seed oil.

The authenticity of vegetable oils consumed in Slovenia and Croatia was investigated by carbon isotope analysis of the individual fatty acids by the use of gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS), and through carbon isotope analysis of the bulk oil. The fatty acids from samples of olive, pumpkin, sunflower, maize, rape, soybean, and sesame oils were separated by alkaline hydrolysis and derivatized to methyl esters for chemical characterization by capillary gas chromatography/mass spectrometry (GC/MS) prior to isotopic analysis. Enrichment in heavy carbon isotope ((13)C) of the bulk oil and of the individual fatty acids are related to (1) a thermally induced degradation during processing (deodorization, steam washing, or bleaching), (2) hydrolytic rancidity (lipolysis) and oxidative rancidity of the vegetable oils during storage, and (3) the potential blend with refined oil or other vegetable oils. The impurity or admixture of different oils may be assessed from the delta(13)C(16:0) vs. delta(13)C(18:1) covariations. The fatty acid compositions of Slovenian and Croatian olive oils are compared with those from the most important Mediterranean producer countries (Spain, Italy, Greece, and France).

Syngnathinema californiense n. gen., n. sp. (Nematoda: Dracunculoidea) from the circulatory system of the bay pipefish Syngnathus leptorhynchus in California.

A new dracunculoid nematode Syngnathinema californiense, n. gen., n. sp., is described from gravid female parasites found inside the heart of wild-caught Bay pipefish Syngnathus leptorhynchus; histologically it was recorded from different sites of the host circulatory system (sinus venosus, atrium, and renal and hepatic veins). The new genus is characterized by the structure of the cephalic end (large oral aperture with a narrow peribuccal ring surrounded by 10 papillae in 2 circles, large circular amphids), division of the esophagus into muscular and glandular portions, location of the well-developed vulva posterior to the esophagus, monodelphic female reproductive organs, and the sharply pointed tail. Because males remain unknown, the genus is provisionally assigned to the Daniconematidae.

A Herpesvirus Associated with Mass Mortality of Juvenile and Adult Koi, a Strain of Common Carp.

A herpesvirus was isolated from adult koi, a strain of common carp Cyprinus carpio, suffering mass mortality in two outbreaks-one in the mid-Atlantic region of the United States and the second in Israel. The principal external signs of dying fish were pale and irregularly colored gills. There were few consistent internal signs in either outbreak. The most prominent microscopic lesions were in the gills, where hyperplasia and necrosis of the epithelium were severe. Other lesions included interstitial nephritis, splenitis, and enteritis. Affected cells often contained nuclei with marginated chromatin and faint intranuclear inclusions. Typical herpesvirus particles were present in branchial epithelial cells, hepatocytes, and among circulating leukocytes. Inoculations of the koi fin (KF-1) cell line with tissue extracts from the gill and kidney-spleen resulted in cytopathic effects characterized by severe vacuolation first detected after 7 d incubation at 20°C. Exposures of adult koi to the herpesvirus as propagated in KF-1 cells by bath or intraperitoneal injections resulted in 80-100% mortality during a 26-d period, and the virus was reisolated from the gill, kidney, liver, spleen, intestine, and brain of dead fish. The viral agents from koi in Israel and the United States appear to be similar if not identical; both could be distinguished from Herpesvirus cyprini by indirect fluorescent antibody tests with rabbit anti-H. cyprini serum. Other factors should be examined but we strongly suspect that this newly recognized koi herpesvirus (KHV) has the potential to be a significant cause of mortality among koi and presumably common carp.

The association between the antiphospholipid antibody syndrome and neuropsychological impairment in SLE.

OBJECTIVE: To examine the relationship between neuropsychological impairment and antiphospholipid antibody syndrome (aPL syndrome) in patients with systemic lupus erythermatosus (SLE). PATIENTS: Sixty-nine patients satisfying ACR criteria were studied. Sixteen patients with the aPL syndrome and 53 patients without the syndrome were subjected to eight neuropsychological tests, a physical examination and serological investigations. No patients with other pathology, known to cause acute or chronic impairment of neuropsychological function, were included. Sixty-five underwent MRI scans. RESULTS: There were no significant differences in age, level of education, incidence of hypertension or disease activity in the two groups. Pearson's correlation coefficients revealed a significant negative correlation with duration of disease in six out of eight tests in the aPL positive group and one out of eight in the aPL negative group. This suggests that aPL syndrome may be involved in the psychological impairment in SLE patients. A larger cohort needs to be studied to confirm this observation.

Stress and coping strategies in spouses of depressed patients.

The relationships between the coping strategies used by spouses of clinically depressed patients and spouses' anxiety, depression, and marital maladjustment were investigated. Fifty spouses of clinically depressed patients completed a biographical questionnaire, the Coping Strategy Indicator (J. H. Amirkhan, 1990, 1994), the Beck Depression Inventory (A. T. Beck, 1967; A. T. Beck, C. H. Ward, M. Mendelson, J. Mock, & J. Erbaugh, 1961), the State-Trait Anxiety Inventory (C. D. Spielberger, R. E. Lushene, B. A. Vagg, & E. Jacobs, 1983), and the Locke-Wallace Marital Adjustment Test (H. J. Locke & K. M. Wallace, 1959, 1987). Anxiety was highly prevalent in the spouses; more than half were depressed, and half showed marital maladjustment. Significant positive correlations were found between an avoidant coping strategy and anxiety as well as depression, and a significant negative correlation was found between an avoidant coping strategy and marital adjustment. These findings indicate the ineffectiveness of an avoidant coping strategy for spouses of clinically depressed patients.

Major depression: a breakdown in sense of coherence?

The relationship between major depression and the salutogenic construct of sense of coherence was investigated. The Sense of Coherence scale and the Beck Depression Inventory were administered to 50 patients diagnosed with major depressive disorder and to 50 control subjects. Significant negative correlations were found between scores on Depression and total scores on the Sense of Coherence scale as well as all three of its subscales (Comprehensibility, Manageability, and Meaningfulness). A significant positive correlation was found between scores on the Sense of Coherence scale and age. Of the three subscales, a low score on Meaningfulness was the best predictor of scores on Depression.

Role of leukocyte-specific LDL receptors on plasma lipoprotein cholesterol and atherosclerosis in mice.

Bone marrow-derived macrophages and lymphocytes express LDL receptors (LDL-R), which allow these cells to take up cholesterol-rich lipoproteins. Although these cells are ubiquitously distributed in the body, it is not known whether they influence plasma cholesterol. Macrophages and T lymphocytes also are found in atherosclerotic lesions, but it is not known whether their LDL-R expression plays a role in atherosclerosis. To address these questions, we subjected LDL-R -/-mice to total body irradiation to eliminate their endogenous bone marrow-derived cells and repopulated them with either LDL-R-expressing wild-type bone marrow (treated mice) or LDL-R -/- bone marrow (control mice). Thus, the only difference between the two groups of mice was the ability of the bone marrow-derived cells to express the LDL-R in the treated mice. Plasma cholesterol levels were similar in the two groups of mice at 8 and 16 weeks after transplantation. Chromatographic separation of the lipoproteins revealed similar lipoprotein cholesterol distributions. Although the extent of lesion area in the aortic valves of the high-fat-diet-fed mice was more severe than that in the chow-fed mice, lesions appeared similar between control and treated mice given either chow or high-fat diet. Abundant LDL-R expression was detected in the lesions of treated mice, whereas the lesions of control mice showed no LDL-R expression, indicating that donor-derived leukocytes had migrated into the lesions of the recipient mice. Thus, bone marrow transplantation can be used as a tool to replace the endogenous bone marrow-derived cells in the artery wall with those of the donor origin.

Influence of macrophage-derived apolipoprotein E on plasma lipoprotein distribution of apolipoprotein A-I in apolipoprotein E-deficient mice.

High density lipoprotein (HDL) cholesterol in apolipoprotein (apo) E-deficient mice is decreased. It has been suggested that apoA-I is lost from HDL in these mice because it must substitute for apoE as a structural protein for the abnormal cholesterol-rich lipoproteins. Therefore, we examined in vivo the influence of selective apoE expression on plasma HDL cholesterol in apoE-deficient mice. Bone marrow transplantation was used to establish macrophage-specific expression of apoE. Bone marrow transplantation normalized plasma triglycerides and significantly reduced total plasma cholesterol, but it did not increase hepatic apoA-I mRNA levels or total plasma apoA-I. Although total plasma apoA-I was not increased, HDL cholesterol measured following chromatographic separation was elevated twofold. Furthermore, plasma apoA-I was recovered from this HDL in animals expressing macrophage apoE. Compared to HDL of wildtype mice, this HDL had a similar chromatographic size distribution, but it lacked apoE and was more negatively charged. These studies indicated that plasma apoA-I distribution and HDL composition are influenced by apoE and that the abnormal apoA-I lipoprotein distribution of apoE-deficient mice can be altered in vivo by macrophage-derived apoE.

Stress and coping amongst South African dentists in private practice.

Stress and coping were investigated in a randomly selected sample of 311 South African dentists of whom 268 were in private practice and 43 were non-private practitioners. Some of the most important findings are the following: Indications were that about 40 per cent of the respondents reported extremely high stress levels, irrespective of type of employment. No significant relationships were found between stress levels and biographical variables. Stressors most often experienced by private practitioners were financial issues and time and scheduling pressures. Other important stressors included patients' unfavourable perceptions of dentists, being perceived as an inflictor of pain, working with children, treating nervous patients, concerns about the future and worrying about the oversupply of dentists. The most stressful stressors were financial issues. Although it was found that time and scheduling pressures were the next most prevalent category of stressors, dentists reported, next to financial issues, problems in dealing with patients as the second most stressful group of stressors. Making decisions about future career directions and limited future options were intense stressors for 47.54 per cent of respondents. Dentists identified rising costs and problems with medical aid schemes as the most prevalent and intense stressors, ones they experienced most difficulty in handling. Stressors which posed few coping problems were staff-related problems, difficulties in keeping to appointment schedules, working under constant time pressures, repetitive nature of the work, feeling isolated and the possibility of a viral contraction. The results indicated that, in general, drug use amongst South African dentists was low. However, fairly high numbers of dentists used analgesics on a regular basis. Substantial numbers of dentists reported marital problems. The prevalence of severe interpersonal problems with the dentists' own children was low. In addition to marital problems, substantial percentages of the sample reported severe problems in other personal relationships and experienced a severe lack of social involvement or outside interests. In the present study 27 (10.23 per cent) of the private practitioners and 2 (4.76 per cent) of the non-private practitioners reported severe suicide ideation.

DSM-III-R classification of psychiatric symptoms in systemic lupus erythematosus.

DSM-III-R criteria applied in the evaluation of 88 systemic lupus erythematosus patients revealed a point prevalence rate of 18.2% for psychiatric disorders, the most common diagnosis being adjustment disorder (11.4%). No patients had disorders compatible with a functional psychosis. Psychiatric morbidity was not associated with increased disease activity, corticosteroid use, brain magnetic resonance imaging abnormalities, or electroencephalogram abnormalities. High scores on a life event scale were associated with psychiatric disorders, suggesting that psychosocial stress is etiologically important. Cognitive testing showed that poor performance on the Stroop Colour-Word Inference Test was associated with psychiatric disorders.