Usability study and pilot validation of a computer-based emotion recognition test for older adults with Alzheimer's disease and amnestic mild cognitive impairment.

OBJECTIVES: This study aimed to carry out a pilot validation of Affect-GRADIOR, a computer-based emotion recognition test, with older adults. The study evaluated its usability, reliability and validity for the screening of people with Alzheimer´s disease (AD) and amnestic mild cognitive impairment (aMCI). METHODS: The test was administered to 212 participants (76.37 ± 6.20 years) classified into three groups (healthy controls, n = 69; AD, n = 84; and aMCI, n = 59) on the basis of detailed neurological, neuropsychological, laboratory and neuro-imaging evidence. Data on usability were collected by means of a questionnaire and automated evaluation. RESULTS: The validated test comprised 53 stimuli and 7 practice items (one per emotion). Participants reported that Affect-GRADIOR was accessible and user-friendly. It had high internal consistency (ordinal Cronbach's α = 0.96). Test-retest reliability correlations were significant and robust (r = 0.840, p < 0.001). Exploratory factor analysis supported a seven-factor model of the emotions assessed (neutral expression, happiness, surprise, disgust, sadness, anger and fear). Receiver operating characteristic curve analyses suggested that the test discriminated healthy older adults from AD and aMCI cases. Correct answer score improved MMSE predictive power from 0.547 to 0.560 (Cox & Snell R2, p = 0.012), and Affect-GRADIOR speed of processing score improved MMSE predictive power from 0.547 to 0.563 (Cox & Snell R2, p = 0.010). CONCLUSIONS: Affect-GRADIOR is a valid instrument for the assessment of the facial recognition of emotions in older adults with and without cognitive impairment.

ELECTRONIC DEVICES FOR COGNITIVE IMPAIRMENT SCREENING: A SYSTEMATIC LITERATURE REVIEW.

OBJECTIVES: The reduction in cognitive decline depends on timely diagnosis. The aim of this systematic review was to analyze the current available information and communication technologies-based instruments for cognitive decline early screening and detection in terms of usability, validity, and reliability. METHODS: Electronic searches identified 1,785 articles of which thirty-four met the inclusion criteria and were grouped according to their main purpose into test batteries, measures of isolated tasks, behavioral measures, and diagnostic tools. RESULTS: Thirty one instruments were analyzed. Fifty-two percent were personal computer based, 26 percent tablet, 13 percent laptop, and 1 was mobile phone based. The most common input method was touchscreen (48 percent). The instruments were validated with a total of 4,307 participants: 2,146 were healthy older adults (M = 73.59; SD = 5.12), 1,104 had dementia (M = 74.65; SD = 3.98) and 1,057 mild cognitive impairment (M = 74.84; SD = 4.46). Only 6 percent were administered at home, 19 percent reported outcomes about usability, and 22 percent about understandability. The methodological quality of the studies was good, the weakest methodological area being usability. Most of the instruments obtained acceptable values of specificity and sensitivity. CONCLUSIONS: It is necessary to create home delivered instruments and to include usability studies in their design. Involvement of people with cognitive decline in all phases of the development process is of great importance to obtain valuable and user-friendly products. It would be advisable for researchers to make an effort to provide cutoff points for their instruments.

Computer-based cognitive interventions for people living with dementia: a systematic literature review and meta-analysis.

OBJECTIVES: To estimate the efficacy of computer-based cognitive interventions for improving cognition in people with dementia (PWD). METHOD: Online literature databases were searched for relevant studies. Interventions were categorised as follows: cognitive recreation, cognitive rehabilitation, cognitive stimulation or cognitive training. A systematic review, quality assessment and meta-analyses were conducted. RESULTS: Twelve studies were identified. Their methodological quality was acceptable according to Downs & Black criteria, the weakest methodological area being the external validity. The meta-analyses indicated cognitive interventions lead to beneficial effects on cognition in PWD (SMD 0.69; 95% CI = 1.02-0.37; P < 0.0001; I(2) = 29%), [corrected] depression (SMD 0.47; 95% CI = 0.16-0.78; P = 0.003; I(2) = 0%) and anxiety (SMD 0.55; 95% CI = 0.07-1.04; P < 0.03; I(2) = 42%). [corrected]. They benefited significantly more from the computer-based cognitive interventions than from the non-computer-based interventions in cognition (SMD 0.48; 95% CI = 0.09-0.87; [corrected] P = 0.02; I(2) = 2%). CONCLUSION: Computer-based cognitive interventions have moderate effects in cognition and [corrected] anxiety and small effects in depression in PWD. No significant effects were found on activities of daily living. They led to superior results compared to non-computer-based interventions in cognition. Further research is needed on cognitive recreation and cognitive stimulation. There is also a need for longer term [corrected] follow-up to examine the potential retention of treatment effects, and for the design of specific outcome measures.

Interference of heavy metals on the photosynthetic response from a Cr(VI)-resistant Dictyosphaerium chlorelloides strain.

The successful selection of a particular type of bioelement and its association to the appropriate transducer determines the specificity of a biosensor. Therefore, from a strain of chloroficea Dictyosphaerium chlorelloides, modified in laboratory to tolerate high Cr(VI) concentrations, the possible interferences of other heavy metals on photosynthetic activity were studied. After exposing wild type and Cr(VI)-resistant cells to increasing Ag(+1), Co(+2), Hg(+2), Cr(+3), Cu(+2), Zn(+2), Fe(+3) and Cd(+2) concentrations, both photosynthetic quantum yields was compared. Photosynthetic electron transport rates were measured with a TOXY-PAM chlorophyll fluorometer, non-linear regression analysis of each of the toxicity tests was done, and means of both groups were compared using unpaired t test. The results show no significant differences between both cell types when they were exposed to Ag(+1), Co(+2), Hg(+2), Cr(+3), Cu(+2), Fe(+3) and Cd(+2) metal ions, and extremely significant differences (p < 0.0001) to Zn(+2) exposures. These results demonstrate the suitability of this Cr(VI)-resistant type D. chlorelloides strain as a suitable bioelement to be coupled to a biosensor based on dual-head microalgae strategy to detect and quantify Cr(VI) in water courses and waste water treatment plants. However, some disturbance may be expected, especially when certain analyte species such as zinc are present in water samples tested. The analysis of binary mixtures between Zn(+2) and other heavy metals showed a slight antagonistic phenomenon in all cases, which should not alter the potential Zn(+2) interference in the Cr(+6) detection process.

Morphological and physiological changes exhibited by a Cd-resistant Dictyosphaerium chlorelloides strain and its cadmium removal capacity.

Changes induced on freshwater microalga Dictyosphaerium chlorelloides (Dc(wt)) acclimated in the laboratory until their survival in culture media enriched with cadmium 100 µM have been studied. Cadmium removal by living cells of this Cd-resistant (Dc(CdR100)) strain was tested in cultures exposed to 100 µM Cd during 30 days. Cell dimensions were measured under light microscopy, and cell growth was studied. Photosynthetic yield (ΦPSII) was analyzed and the photosynthetic oxygen development and respiration response was obtained. Results show that Dc(CdR100) strain exhibited significant cell morphology changes in comparison to Dc(wt) cells, which affected both surface area and cell biovolume. Malthusian fitness analysis showed that Dc(CdR100) strain living in Cd-enriched culture had developed a lower capacity of nearly 50% growth, and its photosynthetic oxygen development and respiration response were significantly reduced in both light and dark photosynthetic phases. Dc(CdR100) strain showed a very high capacity to remove cadmium from the aquatic environment (over 90%), although most of the removed heavy metal (≈70%) is adhered to the cell wall. These specific characteristics of Dc(CdR100) cells suggest the possibility of using this strain in conjunction with Dc(wt) strain as bioelements into a dual-head biosensor, and in bioremediation processes on freshwater polluted with Cd.

Gender differences in cadmium and cotinine levels in prepubertal children.

Susceptibility to environmental stressors has been described for fetal and early childhood development. However, the possible susceptibility of the prepubertal period, characterized by the orchestration of the organism towards sexual maturation and adulthood has been poorly investigated and exposure data are scarce. In the current study levels of cadmium (Cd), cotinine and creatinine in urine were analyzed in a subsample 216 children from 12 European countries within the DEMOCOPHES project. The children were divided into six age-sex groups: boys (6-8 years, 9-10 years and 11 years old), and girls (6-7 years, 8-9 years, 10-11 years). The number of subjects per group was between 23 and 53. The cut off values were set at 0.1 µg/L for Cd, and 0.8 µg/L for cotinine defined according to the highest limit of quantification. The levels of Cd and cotinine were adjusted for creatinine level. In the total subsample group, the median level of Cd was 0.180 µg/L (range 0.10-0.69 µg/L), and for cotinine the median wet weight value was 1.50 µg/L (range 0.80-39.91 µg/L). There was no significant difference in creatinine and cotinine levels between genders and age groups. There was a significant correlation between levels of cadmium and creatinine in all children of both genders. This shows that even at such low levels the possible effect of cadmium on kidney function was present and measurable. An increase in Cd levels was evident with age. Cadmium levels were significantly different between 6-7 year old girls, 11 year old boys and 10-11 year old girls. As there was a balanced distribution in the number of subjects from countries included in the study, bias due to data clustering was not probable. The impact of low Cd levels on kidney function and gender differences in Cd levels needs further investigation.

The potential role of leptin in the vascular remodeling associated with obesity.

BACKGROUND/OBJECTIVES: Extracellular matrix (ECM) participates in the vascular remodeling associated with obesity. We investigated the effects of leptin on the production of ECM components in primary cultured vascular smooth muscle cells (VSMCs) and whether leptin could be a mediator of obesity-induced vascular remodeling. METHODS: T he effects of leptin (100 ng ml(-1)) on ECM components and superoxide anion production (O(2)(.-)) were evaluated in presence or absence of the antioxidant melatonin (10(-)(3) mmol l(-1)) or the inhibitor of phosphatidylinositol 3'-kinase (PI3K), LY294002 (2 × 10(-)(4) mmol l(-1)) in VSMCs from adult rats in order to explore the role of both oxidative stress and the participation of PI3K/Akt pathway in the effects of leptin. ECM components and O(2)(.-) were quantified in the aortic media of male Wistar rats fed a high-fat diet (HFD; 33.5% fat), or a standard diet (CT; 3.5% fat) for 6 weeks. RESULTS: In VSMCs, leptin enhanced gene and protein levels of collagen I, fibronectin, transforming growth factor (TGF)-ß and connective tissue growth factor (CTGF) but did not change those of collagen III and galectin-3. Leptin also increased O(2)(.-) and Akt phosphorylation in VSMCs. These effects were prevented by the presence of either melatonin or LY294002, except O(2)(.-) production in the case of PI3K inhibition. The increase in body weight in HFD rats was accompanied by aorta thickening due to an increase in media area. The aortic fibrosis observed in HFD rats was associated with high levels of leptin, collagen type I, fibronectin, TGF-ß, CTGF, phosphorylated Akt and O(2)(.-). Aortic leptin levels were positively correlated with total collagen, collagen I, TGF-ß and CTGF levels. No differences were observed in the levels of collagen III, elastin or galectin-3 between both the groups. CONCLUSIONS: Leptin could participate in the vascular remodeling and stiffness associated with obesity by ECM production in VSMCs through the activation of oxidative stress-PI3K/Akt pathway and the production of the profibrotic factors TGF-ß and CTGF.

Visual form-processing deficits: a global clinical classification.

INTRODUCTION: Patients who have difficulties recognising visual form stimuli are usually labelled as having visual agnosia. However, recent studies let us identify different clinical manifestations corresponding to discrete diagnostic entities which reflect a variety of deficits along the continuum of cortical visual processing. DEVELOPMENT: We reviewed different clinical cases published in medical literature as well as proposals for classifying deficits in order to provide a global perspective of the subject. Here, we present the main findings on the neuroanatomical basis of visual form processing and discuss the criteria for evaluating processing which may be abnormal. We also include an inclusive diagram of visual form processing deficits which represents the different clinical cases described in the literature. Lastly, we propose a boosted decision tree to serve as a guide in the process of diagnosing such cases. CONCLUSIONS: Although the medical community largely agrees on which cortical areas and neuronal circuits are involved in visual processing, future studies making use of new functional neuroimaging techniques will provide more in-depth information. A well-structured and exhaustive assessment of the different stages of visual processing, designed with a global view of the deficit in mind, will give a better idea of the prognosis and serve as a basis for planning personalised psychostimulation and rehabilitation strategies.

Prevalence of urinary tract cancer in the Spanish cohort of the IDENTIFY study.

INTRODUCTION: Malignant tumors of the urinary tract are associated with high morbidity and mortality, and their prevalence can vary worldwide. Recently, the IDENTIFY study has published results on the prevalence of urinary tract cancer at a global level. This study evaluates the prevalence of cancer within the Spanish cohort of the IDENTIFY study to determine whether the published results can be extrapolated to our population. PATIENTS AND METHODS: An analysis of the data from the Spanish cohort of patients in the IDENTIFY study was performed. This is a prospective cohort of patients referred to secondary care with suspected cancer, predominantly due to hematuria. Patients were recruited between December 2017 and December 2018. RESULTS: A total of 706 patients from 9 Spanish centers were analyzed. Of these, 277 (39.2%) were diagnosed with cancer: 259 (36.7%) bladder cancer, 10 (1.4%) upper tract urothelial carcinoma, 9 (1.2%) renal cancer and 5 (0.7%) prostate cancer. Increasing age (OR 1.05 (95% CI 1.03-1.06; P < 0.001)), visible hematuria (VH) OR 2.19 (95% CI 1.13-4.24; P = 0.02)) and smoking (ex-smokers: OR 2.11(95% CI 1.30-3.40; P = 0.002); smokers: OR 2.36 (95% CI 1.40-3.95; P = 0.001)) were associated with higher probability of bladder cancer. CONCLUSION: This study highlights the risk of bladder cancer in patients with VH and smoking habits. Bladder cancer presented the highest prevalence; higher than the prevalence reported in previous series and presented in the IDENTIFY study. Future work should evaluate other associated factors that allow us to create cancer prediction models to improve the detection of cancer in our patients.

Solid-phase extraction of nitrophenols in water by using a combination of carbon nanotubes with an ionic liquid coupled in-line to CE.

This paper describes the combined use of carbon nanotubes and an ionic liquid directly coupled in-line to commercial CE equipment for sample treatment. The extraction unit operates as a spin column to preconcentrate the analytes. The extraction unit is inserted into the sample vial. The elution is performed in-line, placing the vial on the carrousel of the CE equipment. The joint use of carbon nanotubes and ionic liquids as sorbent is based on the high adsorption capacity of these materials, which makes them highly suitable for microextraction purposes. The LOQ of analytes were within the range of 0.65-0.83 µg/L with a RSD of less than 7%. The values of recovery range between 90 and 112%. The absolute recovery obtained from samples containing 1 µg/L of analytes was 38%.

Graphene nanoparticles as pseudostationary phase for the electrokinetic separation of nonsteroidal anti-inflammatory drugs.

The exceptional properties of graphene (G) were exploited here to facilitate capillary electrokinetic separations. Two types of commercially available G consisting of nanoparticles containing-one to three and-four to six G sheets, respectively, were compared for this purpose. Both proved effective in separating the arylpropyl derivatives of nonsteroidal anti-inflammatory drugs. The highest resolution and shortest migration times were obtained with G containing high amount of single and double G nanosheets. G affords higher resolution than other types of nanoparticles; stable suspensions can be easily prepared and used as BGE without the need of adding an additional surfactant. This results in a high reproducibility in migration times and stability in background noise. The LOD and LOQ obtained by using G nanoparticles as pseudostationary phases spanned the range 0.29-1.18 mg/L and 0.95-3.95 mg/L, respectively, and the RSD was less than 4.7% in all instances.

Microextraction by packed sorbents combined with surface-enhanced Raman spectroscopy for determination of musk ketone in river water.

Microextraction by packed sorbents (MEPS) combined with Surface-enhanced Raman spectroscopy (SERS) was investigated, and applied to the determination of musk ketone (MK) in river water samples. The full MEPS-SERS method includes analyte enrichment by MEPS preconcentration with C18 sorbent followed by SERS detection supported by silver nanoparticles. An eluent drop containing the analyte is deposited directly from the MEPS syringe on a CaF2 glass plate. When the drop has dried, a specific volume of silver nanoparticles solution is added on it before each SERS measurement. Several experimental variables were studied in depth; under the optimum experimental conditions MK can be extracted from a 500 µL sample with recoveries in the range 47-63 %. The limit of detection was 0.02 mg L(-1) and the relative standard deviation 15.2 % (n = 4). Although not investigated in this work, the proposed method might be suitable for in-situ monitoring, because of the portability of the Raman spectrometer used.

Influence of pH on the survival of Dictyosphaerium chlorelloides populations living in aquatic environments highly contaminated with chromium.

The accommodation of photosynthetic organisms to adverse conditions, such as pH changes in the aquatic environment, and their response to aquatic pollutants is essential to develop future biosensors. The present study reports the ability of both Cr(VI)-sensitive and tolerant Dyctiosphaerium chlorelloides strains to live in aqueous solutions highly contaminated with hexavalent chromium under varying ranges of pH, by the determination of chromium toxic effects on these strains. Studies of cell growth, photosynthetic quantum yield and gross photosynthesis rate show that both D. chlorelloides strains are able to survive in alkaline and moderately acidified (pH 4.25) aquatic environments. Below this pH value cell populations from both strains exposed for short periods of time to Cr(VI) showed alterations in the three parameters studied. There were no significant differences comparing the response of both strains at pH change in the culture medium. However, Cr(VI)-tolerant strain exhibits a better fit to maintain cell growth than Cr(VI)-sensitive strain when both were subjected to pH 4.25 in the culture medium. The absence of significant differences in photosynthetic activity results for both strains suggests that the lower sensitivity exhibited by Cr(VI)-tolerant strain would be due to cellular morphological changes rather than changes in cellular activity.

Adverse effects of iron-based nanoparticles on freshwater phytoplankton Scenedesmus armatus and Microcystis aeruginosa strains.

Zero-valent nano-iron particles (nZVI) are increasingly present in freshwater aquatic environments due to their numerous applications in environmental remediation. However, despite the broad benefits associated with the use and development of nZVI nanoparticles, the potential risks of introducing them into the aquatic environment need to be considered. Special attention should be focused on primary producer organisms, the basal trophic level, whose impact affects the rest of the food web. Although there are numerous acute studies on the acute effects of these nanoparticles on photosynthetic primary producers, few studies focus on long-term exposures. The present study aimed at assessing the effects of nZVI on growth rate, photosynthesis activity, and reactive oxygen activity (ROS) on the freshwater green algae Scenedesmus armatus and the cyanobacteria Microcystis aeruginosa. Moreover, microcystin production was also evaluated. These parameters were assessed on both organisms singly exposed to 72 h-effective nZVI concentration for 10% maximal response for 28 days. The results showed that the cell growth rate of S. armatus was initially significantly altered and progressively reached control-like values at 28 days post-exposure, while M. aeruginosa did not show any significant difference concerning control values at any time. In both strains dark respiration (R) increased, unlike net photosynthesis (Pn), while gross photosynthesis (Pg) only slightly increased at 7 days of exposure and then became equal to control values at 28 days of exposure. The nZVI nanoparticles generated ROS progressively during the 28 days of exposure in both strains, although their formation was significantly higher on green algae than on cyanobacteria. These data can provide additional information to further investigate the potential risks of nZVI and ultimately help decision-makers make better informed decisions regarding the use of nZVI for environmental remediation.

Sequencing paired tumor DNA and white blood cells improves circulating tumor DNA tracking and detects pathogenic germline variants in localized colon cancer.

BACKGROUND: In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting a higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study, we assess the potential value of adding white blood cells (WBCs) to tumor tissue sequencing to enhance the accuracy of sequencing results. PATIENTS AND METHODS: A total of 148 patients diagnosed with localized CC were prospectively recruited at the Hospital Clínico Universitario in Valencia (Spain). Employing a custom 29-gene panel, sequencing was conducted on tumor tissue, plasma and corresponding WBCs. Droplet digital PCR and amplicon-based NGS were performed on plasma samples post-surgery to track MRD. Oncogenic somatic variants were identified by annotating with COSMIC, OncoKB and an internal repository of pathogenic mutations database. A variant prioritization analysis, mainly characterized by the match of oncogenic mutations with the evidence levels defined in OncoKB, was carried out to select specific targeted therapies. RESULTS: Utilizing paired tumor and WBCs sequencing, we identified somatic mutations in all patients (100%) within our cohort, compared to 89% using only tumor tissue. Consequently, the top 10 most frequently mutated genes for plasma monitoring were altered. The sequencing of WBCs identified 9% of patients with pathogenic mutations in the germline, with APC and TP53 being the most frequently mutated genes. Additionally, mutations in genes related to clonal hematopoiesis of indeterminate potential were detected in 27% of the cohort, with TP53, KRAS, and KMT2C being the most frequently altered genes. There were no observed differences in the sensitivity of monitoring MRD using ddPCR or amplicon-based NGS (p = 1). Ultimately, 41% of the patients harbored potentially targetable alterations at diagnosis. CONCLUSION: The germline testing method not only enhanced sequencing results and raised the proportion of patients eligible for plasma monitoring, but also uncovered the existence of pathogenic germline variations, thereby aiding in the identification of patients at a higher risk of hereditary cancer syndromes.

The effects of adiponectin and leptin on human endothelial cell proliferation: a live-cell study.

The effect of adiponectin and leptin on the proliferation of the human microvascular endothelial cell line (HMEC-1) was studied in the absence or presence of fetal bovine serum (FBS). The participation of extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase/Akt (PI-3K/Akt) pathways in this effect were evaluated. We studied the effect of both adipokines on the motility, mitosis, proliferation and cell death processes of HMEC-1 cells using live-cell imaging techniques. Adiponectin but not leptin further increased the proliferative effect induced by FBS on HMEC-1. This effect seems to be the consequence of an increase in the mitotic index in adiponectin-treated cells when compared to untreated ones. The presence of either the mitogen-activated protein kinase (MAPK) inhibitor (PD98059), or PI-3K inhibitor (LY294002), reduced the effect of adiponectin in a dose-dependent manner. Neither adipokine was able to affect HMEC-1 proliferation in FBS-free conditions. Duration of mitosis, cell motility and the cell death process were similar in all conditions. These data suggest that adiponectin and leptin exert different effects on endothelial cell function. Adiponectin was able to potentiate proliferation of HMEC-1. This effect involves the activation of both PI3-K/Akt and ERK/MAPK pathways. However, it seems to exert minimal effects on HMEC-1 function in the case of leptin.

(CdSe/ZnS QDs)-ionic liquid-based headspace single drop microextraction for the fluorimetric determination of trimethylamine in fish.

Here, we propose the use of ionic liquid-modified QDs for the combination of ionic liquid-based headspace single drop microextraction technique (IL-HS-SDME) and QD-based fluorimetric detection. In that way, we exploit the advantages of ILs as extractant solvent and the use of QDs as fluorescence detection probe. After in situ generation of volatile trimethylamine (TMA) from fish samples, the analyte was extracted and preconcentrated directly onto a (QD)IL microdrop by HS-SDME. Then, TMA was quantified through the enhancing effect produced on the initial fluorescence of the (QD)IL dispersion. The working conditions for the (QD)IL-HS-SDME procedure were: 20 µL microdrop of (QD)IL exposed for 2 min to the headspace of a 5 mL aqueous sample (0.2 g of fish in 10 M NaOH) placed in a 10 mL vial with stirring and thermostatted at 50-60 °C. For the detection, the microdrop was transferred to a microcuvette with 300 µL of acetonitrile and the fluorescence was recorded (λ(em) = 570 nm, λ(exc) = 400 nm). Under the selected conditions, the analytical response was linear over the range from 0.05 to 0.25 mg L(-1) (R(2) = 0.997) with a detection limit of 0.014 mg L(-1) (0.35 µg TMA per gram of fish) and the relative standard deviation was 3.5% (n = 5). The proposed method was applied to the determination of TMA in hake fish samples with satisfactory results.

Importance of strain type to predict the toxicological risk associated with Microcystis aeruginosa blooms: comparison of Microtox(®) analysis and immunoassay.

The occurrence of toxic cyanobacterial blooms in aquatic environments, associated with human health problems and animal deaths, has increased the need for rapid, reliable and sensitive methods to determine the toxicity of microcystin produced by cyanobacteria. An in vitro Microtox(®) system and a commercially available microcystin ELISA were used to screen out the potential risk associated with selected Microcystis aeruginosa strains (Ma1D-Ma8D). Results showed the existence of three differentiated groups in the selected M. aeruginosa strains. Strains Ma7D and Ma6D were determined to be very toxic, strains Ma2D, Ma1D and Ma5D as moderately toxic and strains Ma8D, Ma4D and MA3D as non-toxic. These results agreed with the microcystin concentration values obtained by immunoassay. Although the data obtained by other authors clearly show that Microtox(®) is not sensitive to microcystins, our results suggested that this bioluminescence assay may prove useful in the preliminary screening of cyanobacterial blooms for microcystin-based toxicity. Additionally, the combination of immunodetection and toxicity-based Microtox(®) provides a useful addition to the methods already available for detection of cyanobacterial toxins.

Prediction of the impact induced by Cd in binary interactions with other divalent metals on wild-type and Cd-resistant strains of Dictyosphaerium chlorelloides.

The metals present in freshwater have a toxic profile with bioaccumulation and are biomagnified along the aquatic food chain. The metals induce high sensitivity in most aquatic organisms, while others, such as some microalgae species, evolve towards resistance. Therefore, this research predicted through the Combination Index method the binary interaction exposed to divalent metals by inhibiting population growth in a Cd-resistant strain (DcRCd100) compared to the wild-type strain (Dc1Mwt) of Dictyosphaerium chlorelloides and evaluate the specific resistance level obtained by DcRCd100 to Cd relative to other divalent metals.The results showed that DcRCd100 presents resistance compared to Dc1Mwt in individual exposure in the order of Fe2+ > Ni2+ > Cd2+ > Co2+ > Zn2+ > Cu2+ > Hg2+ with 50% inhibitory concentration at 72 h of exposure (IC50(72)) values 1253, 644.4, 423, 162.7, 141.3, 35.1, and 9.9 µM, respectively. It induces cross-resistance with high antagonistic rates (Combination Index (CI); CI > > 1) in the Cd/Zn and Cd/Cu. Cd/Ni, its initial response, is antagonistic, and it ends in an additive (CI = 1). DcRCd100 showed a lower resistance in Co, and Cd/Fe resistance was reduced individually. The interaction with Hg increased its resistance ten times more than individually.This research highlights the use of the CI as a highly efficient prediction method of the binary metal interactions in wild-type and Cd-resistant strains of D. chlorelloides. It may have the potential for metal accumulation, allowing the development of new methods of bioremediation of metals in effluents, and to monitor the concentration of metals in wastewater, its relative availability, transport, and mechanisms on resistant strains of microalgae.

The complete chloroplast genome of 'biasong' (Citrus micrantha Wester), a native species from the Southern Philippines.

'Biasong' (Citrus micrantha), native to the Southern Philippine Islands, is an important cultivated fruit tree but has no published plastome sequence. We assembled and characterized the C. micrantha chloroplast genome from accession in the germplasm collection of the Institute of Crop Science, University of the Philippines Los Baños. The complete chloroplast (cp) genome sequence is 159,928-bp long with 128 coding genes comprising 83 mRNA genes, 37 tRNA genes, and eight rRNA genes. Out of the mRNA genes, 45 genes code for photosynthesis, 30 genes code for self-replication, and five genes code for other functions. A phylogenetic analysis of the assembled genome, along with 24 Citrus species and three other Rutaceae species, identified Citrus aurantiifolia as its closest relative with available complete cpDNA sequence.