Spontaneous signal generation by an excitable system for cell migration.

Eukaryotic cells exhibit random migration in the absence of extracellular directional cues. This random migration acts as basal motility for various migratory responses such as chemotaxis. The self-organization of random motility requires the internal signals that determine the anterior side of the migrating cell be generated spontaneously from the intrinsic activities of intracellular signaling networks. Recent studies have identified an excitable system as the mechanism of the spontaneous signal generation. Here, we discuss how the excitable system of Ras, a small G protein, regulates signaling networks in Dictyostelium discoideum as a model organism. The excitability produces a domain where an active form of Ras is enriched on the cell membrane without extracellular directional cues, such that Ras serves as the anterior signal. The typical spatiotemporal characteristics are mathematically explained by reaction-diffusion models. These models further enable a quantitative analysis of the dynamics that depends on the internal cellular states and surrounding environments. Downstream of the Ras excitable system, a phosphoinositide metabolic network composed of PI3K, PTEN, PI(3,4,5)P3 and PI(4,5)P2 exhibits bistability to discretize the anterior and posterior regions of the cell membrane. Upstream, a local excitation and global inhibition local excitation global inhibition network, which works for gradient sensing in the presence of chemoattractant gradients, spatiotemporally biases the excitability of Ras for chemotaxis. In parallel with the Ras excitable system, the cGMP signaling pathway constitutes another excitable system of its own periodicity to ensure flexible migratory dynamics. In addition to these intracellular signaling networks, an intercellular signaling network activated by secreted cAMP is coupled with the Ras excitable system for collective cell migration. Finally, we discuss how the excitable system of Ras operates as a platform of information integration by receiving multiple intrinsic and extrinsic signals to ensure spontaneous cellular activity and robust responses in eukaryotic cell migration under natural complex environments.

The cadmium tolerance and bioaccumulation mechanism of Tetratostichococcus sp. P1: insight from transcriptomics analysis.

Cadmium (Cd) has become a severe issue in relatively low concentration and attracts expert attention due to its toxicity, accumulation, and biomagnification in living organisms. Cd does not have a biological role and causes serious health issues. Therefore, Cd pollutants should be reduced and removed from the environment. Microalgae have great potential for Cd absorption for waste treatment since they are more environmentally friendly than existing treatment methods and have strong metal sorption selectivity. This study evaluated the tolerance and ability of the microalga Tetratostichococcus sp. P1 to remove Cd ions under acidic conditions and reveal mechanisms based on transcriptomics analysis. The results showed that Tetratostichococcus sp. P1 had a high Cd tolerance that survived under the presence of Cd up to 100 µM, and IC50, the half-maximal inhibitory concentration value, was 57.0 µM, calculated from the change in growth rate based on the chlorophyll content. Long-term Cd exposure affected the algal morphology and photosynthetic pigments of the alga. Tetratostichococcus sp. P1 removed Cd with a maximum uptake of 1.55 mg g-1 dry weight. Transcriptomic analysis revealed the upregulation of the expression of genes related to metal binding, such as metallothionein. Group A, Group B transporters and glutathione, were also found upregulated. While the downregulation of the genes were related to photosynthesis, mitochondria electron transport, ABC-2 transporter, polysaccharide metabolic process, and cell division. This research is the first study on heavy metal bioremediation using Tetratostichococcus sp. P1 and provides a new potential microalga strain for heavy metal removal in wastewater.[Figure: see text]Abbreviations:BP: Biological process; bZIP: Basic Leucine Zipper; CC: Cellular component; ccc1: Ca (II)-sensitive cross complementary 1; Cd: Cadmium; CDF: Cation diffusion facilitator; Chl: Chlorophyll; CTR: Cu TRansporter families; DAGs: Directed acyclic graphs; DEGs: Differentially expressed genes; DVR: Divinyl chlorophyllide, an 8-vinyl-reductase; FPN: FerroportinN; FTIR: Fourier transform infrared; FTR: Fe TRansporter; GO: Gene Ontology; IC50: Growth half maximal inhibitory concentration; ICP: Inductively coupled plasma; MF: molecular function; NRAMPs: Natural resistance-associated aacrophage proteins; OD: Optical density; RPKM: Reads Per Kilobase of Exon Per Million Reads Mapped; VIT1: Vacuolar iron transporter 1 families; ZIPs: Zrt-, Irt-like proteins.

Bibliometric insights into microalgae cultivation in wastewater: Trends and future prospects for biolipid production and environmental sustainability.

Cultivation of microalgae in wastewater stream has been extensively reported, especially for simultaneous production of biolipid and wastewater treatment process. This study aimed to derive the research trend and focus on biolipid production from microalgae cultivated in wastewater by using bibliometric approach. The search strategy used in Scopus database resulted in 1339 research articles from 1990 to November 2023. Majority of publications (46%) were affiliated to China and India, showing their predominance in this field. Keywords related to the center of attention included biodiesel, biofuel, biomass and nutrient removal. Meanwhile, keyword with recent publication year, indicating the emerging research trends, revolved around the cultivation techniques and application of the system. Co-culture involving more than one microalgae species, bacteria and yeast showed promising results, while addition of nanoparticles was also found to be beneficial. Increasing exploration on the application of microalgae for treatment of saline wastewater was also reported and the carbon fixation mechanism by microalgae has been widely investigated to promote less environmental impact. Future research on these topics were suggested based on the findings of the bibliometric analyses.

Mechanism and kinetic model of microalgal enzymatic hydrolysis for prospective bioethanol conversion.

Tetraselmis chuii is a potential microalgae that is in consideration for producing bioethanol owing to its large content of carbohydrates. The glucose production from T. chuii through an enzymatic process with cellulase and xylanase (pretreatment process) and α-amylase and glucoamylase (saccharification process) was studied. The mechanism of the enzymatic process was developed and the kinetic models were then evaluated. For the pretreatment process, enzymes with 30% concentration reacted at 30 °C for 40 min resulted in 35.9% glucose yield. For the saccharification process, the highest glucose yield of 90.03% was obtained using simultaneous α-amylase (0.0006%) and glucoamylase (0.01%) enzymes at 55 °C and for 40 min. The kinetic models fitted well with the experimental data. The model also revealed that the saccharification process performed better than the pretreatment process with a higher kinetic constant and lower activation energy. The proposed kinetic model plays an important role in implementing processes at a larger scale.

Characteristics of algal-bacterial aerobic granular sludge treating real wastewater: Effects of algal inoculation and alginate-like exopolymers recovery.

Limited information is available on the characteristics of algal-bacterial aerobic granular sludge (AGS) treating real wastewater, especially on its alginate-like exopolymers (ALE) production. In addition, the effect of target microalgae species inoculation on the system performance has not been fully understood. This study aimed to reveal the effect of microalgae inoculation on the characteristics of algal-bacterial AGS and its ALE production potential. Two photo-sequencing batch reactors (PSBR) were employed, namely R1 with activated sludge and R2 with Tetradesmus sp. and activated sludge being inoculated, respectively. Both reactors were fed with locally sourced municipal wastewater and operated for 90 days. Algal-bacterial AGS were successfully cultivated in both reactors. No significant difference was observed between the performances of R1 and R2, reflecting that the inoculation of target microalgae species may not be crucial for the development of algal-bacterial AGS when treating real wastewater. Both reactors achieved an ALE yield of about 70 mg/g of volatile suspended solids (VSS), indicating that a substantial amount of biopolymer can be recovered from wastewater. Interestingly, boron was detected in all the ALE samples, which might contribute to granulation and interspecies quorum sensing. The enrichment of lipids content in ALE from algal-bacterial AGS treating real wastewater reveals its high resource recovery potential. Overall, the algal-bacterial AGS system is a promising biotechnology for simultaneous municipal wastewater treatment and resource (like ALE) recovery.

Algal-bacterial aerobic granular sludge for real municipal wastewater treatment: Performance, microbial community change and feasibility of lipid recovery.

Despite various research works on algal-bacterial aerobic granular sludge for wastewater treatment and resource recovery processes, limited information is available on its application in real wastewater treatment in terms of performance, microbial community variation and resource recovery. This study investigated the performance of algal-bacterial aerobic granular sludge on real low-strength wastewater treatment in addition to the characterization of microbial community and fatty acid compositions for biodiesel production. The results demonstrated 71% COD, 77% NH4+-N and 31% phosphate removal efficiencies, respectively. In addition, all the water parameters successfully met the effluent standard A, imposed by the Department of Environment (DOE) Malaysia. Core microbiome analyses revealed important microbial groups (i.e., Haliangium ochraceum, Burkholderiales and Chitinophagaceae) in bacterial community. Meanwhile the photosynthetic microorganisms, such as Oxyphotobacteria and Trebouxiophyceae dominated the algal-bacterial aerobic granular sludge, suggesting their important roles in granulation and wastewater treatment. Up to 12.51 mg/gSS lipid content was recovered from the granules. In addition, fatty acids composition showed high percetages of C16:0 and C18:0, demonstrating high feasibility to be used for biodiesel production application indicated by the cetane number, iodine value and oxidation stability properties.

Kinetic properties of 137Cs uptake by the cesium-accumulating eustigmatophycean microalga.

Cesium-137 (137Cs) is one of the radioactive substances that was released into the environment as a result of the Fukushima nuclear disaster. Radiocesium exposure is of great concern due to its potential environmental implications. However, research on 137Cs removal using algae is still limited. This is the first report to describe the kinetic properties of 137Cs uptake by Vacuoliviride crystalliferum in the presence and absence of potassium. In this work, we studied the kinetic properties of 137Cs uptake using a freshwater microalga, V. crystalliferum (NIES 2860). We also analyzed the effects of temperature, light, and potassium (K) on the 137Cs uptake. Results showed that V. crystalliferum can remove up to 90% of 157 nM 137Cs within an hour. At 20 °C, the removal increased by up to 96%, compared to less than 10% at 5 °C. However, the removal was inhibited by nearly 90% in the dark compared to the removal in the light, implying that V. crystalliferum cells require energy to accumulate 137Cs. In the inhibition assay, K concentrations ranged from 0 to 500 µM and the inhibitory constant (Ki) for K was determined to be 16.7 µM. While in the uptake assay without potassium (- K), the Michaelis constant (Km) for Cs was 45 nM and increased to 283 nM by the addition of 20 µM potassium (+ K), indicating that V. crystalliferum had a high affinity for 137Cs. In addition, the maximum uptake velocity (Vmax) also increased from 6.75 to 21.10 nmol (mg Chl h)-1, implying the existence of Cs active transport system. In conclusion, V. crystalliferum is capable of removing radioactive 137Cs from the environment and the removal was favorable at both normal temperature and in the light.

Microalgae identification: Future of image processing and digital algorithm.

The identification of microalgae species is an important tool in scientific research and commercial application to prevent harmful algae blooms (HABs) and recognizing potential microalgae strains for the bioaccumulation of valuable bioactive ingredients. The aim of this study is to incorporate rapid, high-accuracy, reliable, low-cost, simple, and state-of-the-art identification methods. Thus, increasing the possibility for the development of potential recognition applications, that could identify toxic-producing and valuable microalgae strains. Recently, deep learning (DL) has brought the study of microalgae species identification to a much higher depth of efficiency and accuracy. In doing so, this review paper emphasizes the significance of microalgae identification, and various forms of machine learning algorithms for image classification, followed by image pre-processing techniques, feature extraction, and selection for further classification accuracy. Future prospects over the challenges and improvements of potential DL classification model development, application in microalgae recognition, and image capturing technologies are discussed accordingly.

Factors associated with spinal instability in low back lumbar diseases with leg pain: Analysis of sagittal translation and segmental angulation.

BACKGROUND: Determining the association between radiographic spinal instability assessment and lower back lumbar diseases with lower limb symptoms can contribute to evidence-based assessment and treatment in clinical practice and rehabilitation. Therefore, radiological evidence of lumbar spine instability assessment, such as sagittal translation (ST) and segmental angulation (SA), is clinically important. OBJECTIVE: To identify factors associated with the assessment of spinal instability in lumbar disc herniation with leg pain and discogenic low back pain using ST and SA. METHODS: We examined 112 patients with lumbar disc herniation with leg pain and 116 with discogenic low back pain at our clinic from 2016 to 2021. Data on age, gender, sports activities, and occupation were collected from medical records. Additionally, ST and SA of L4 and L5 during maximum trunk flexion and extension were measured using radiography. Simple and multiple logistic regression analyses were used for statistical analysis. RESULTS: Simple logistic regression analysis showed that ST and SA (odds ratio [OR]: 1.11; 95% confidence interval [CI]: 1.03-1.19) were associated with lumbar disc herniation. Multiple logistic regression analysis showed that only ST was associated with lumbar disc herniation (OR: 2.29; 95% CI: 1.78-3.00). CONCLUSION: Multiple logistic regression analysis showed that ST was associated with lumbar disc herniation with leg pain and had a stronger association than SA.

Incidence of cervical kyphosis and cervical posterior translation in neck pain associated with radiological evidence of degenerative disc disease.

BACKGROUND: Cervical kyphosis mechanically influences the intervertebral discs, which may lead to neck, shoulder, and scapular pain. OBJECTIVES: To investigate the incidence of cervical kyphosis and posterior displacement of cervical vertebrae (cervical posterior translation index) in patients with radiologically evident degenerative disc disease. DESIGN: Retrospective-cohort study. METHODS: Ninety-five patients with radiologically evident degenerative disc disease were recruited at our clinic from 2015 to 2019. Radiography images were used to analyze the straight-line index in each patient in the upright posture. The straight-line index was calculated by drawing a reference line connecting the posterior inferior edges of C2 to C7 and normalizing the addition of the distances from the posterior inferior edges of C3, C4, C5, and C6 to the reference line, respectively. Straight-line index <0 was defined as cervical kyphosis and ≥0 as cervical lordosis, the cervical kyphosis. In cervical kyphosis group, the distance from the posterior inferior edges of C3, C4, C5, and C6 to the reference line was normalized by the reference line distance to determine posterior displacement. Multiple comparison tests aside from simple and multiple linear regression analysis were performed. RESULTS: The incidence of cervical kyphosis in patients with radiologically evident degenerative disc disease was 60% (57/95 patients). Multiple comparison tests revealed that the cervical posterior translation indexes of C4 and C5 were significantly higher than those of C3, C4, and C6, in cervical kyphosis group. CONCLUSIONS: Cervical kyphosis was present in 60% of patients with radiologically evident degenerative disc disease, with C5 showing the most posterior displacement.

Removal of Microcystis aeruginosa cells using the dead cells of a marine filamentous bacterium, Aureispira sp. CCB-QB1.

Inorganic and synthetic flocculants are widely investigated for removing harmful microalgae, such as Microcystis aeruginosa. However, their toxicity and non-biodegradability are shortcomings. Bioflocculants based on extracellular polysaccharides have attracted much attention as alternative flocculants. However, its high production cost is a limiting factor for applying bioflocculants. Here, we investigate the potential of the dead cells of a marine filamentous bacterium, Aureispira sp. CCB-QB1, as a novel flocculant on M. aeruginosa cells. The removal efficiency of M. aeruginosa cells by the dead cells was measured by mixing and shaking both components in a buffer with 5 mM CaCl2 in different incubation times and concentrations of the dead cells. After that, the minimum effective concentration of CaCl2 was determined. The combination effect of FeCl3 and the dead cells on the removal efficiency was tested. The structure of cell aggregates consisted of the dead cells and M. aeruginosa cells were also observed using a scanning electron microscope. The maximum removal efficiency (75.39%) was reached within 3 min in the presence of CaCl2 when 5 mg/ml of the dead cells (wet cells) were added. The optimal concentration of CaCl2 was 5 mM. The combination of the dead cells and a low concentration of FeCl3 (10 mg/L) with 5 mM of CaCl2 significantly improved the removal efficiency by about 1.2 times (P < 0.05). This result indicates that the combination usage of the dead cells can reduce the use of FeCl3. These results indicated that the dead cells could potentially be a novel biolfocculant to remove M. aeruginosa cells.

Discovering future research trends of aerobic granular sludge using bibliometric approach.

The advantageous characteristics of aerobic granular sludge (AGS) have led to their increasing popularities among academics and industrial players. However, there has been no bibliometric report on current and future research trends of AGS. This study utilized the available reports of AGS in the Scopus database for comprehensive bibliometric analyses using VOSviewer software. A total of 1203 research articles from 1997 to 2020 were analyzed. The dominance of the Netherlands and China were revealed by the high number of publications and citations. Nevertheless, the Netherlands exhibited higher average citation per article at 76.4. A recent process of AGS involving biochar and algal addition were also identified. Meanwhile, the application of AGS for antibiotic containing wastewater as well as possibility of resource recovery were recently reported and was expected to expand in the future. It was suggested that application of AGS would develop further along with the development of sustainable wastewater treatment process.

Improvement and screening of astaxanthin producing mutants of newly isolated Coelastrum sp. using ethyl methane sulfonate induced mutagenesis technique.

Natural astaxanthin is known to be produced by green microalgae, a potent producer of the most powerful antioxidant. To increase the productivity of astaxanthin in microalgae, random mutagenesis has been extensively used to improve the yield of valuable substances. In the presented work, a newly isolated Coelastrum sp. was randomly mutagenized by exposure to ethyl methane sulfonate and further screened using two approaches; an approach for high growth mutant and an approach for high astaxanthin producing mutant with a high-throughput screening method using glufosinate. Among these, mutant G1-C1 that was selected using glufosinate showed the highest of total carotenoids (45.48±1.5 mg/L) and astaxanthin (28.32±2.5 mg/L) production, which was almost 2-fold higher than that of wild type. This study indicates that random mutagenesis via chemical mutation strategy and screening using glufosinate successfully expedited astaxanthin production in a mutated strain of a Coelastrum sp.

Incidence of spinal instability among patients with discogenic low back pain with different backgrounds.

[Purpose] To investigate the incidence of spinal instability among patients with discogenic low back pain and its various effects with respect to the patients' age, gender, sports activity, and occupation. [Participants and Methods] We assessed 65 patients diagnosed with discogenic low back pain at our clinic between May 2016 and May 2020. After measuring segmental angulation using plain radiographs, we divided these patients into two groups: (1) instability group with >10° of segmental angulation or >3 mm of sagittal translation and (2) stability group with <10° of segmental angulation and <3 mm of sagittal translation. Patient data such as age, gender, sports activity, and occupation were collected using their medical records. [Results] The incidence of spinal instability was 57% (37 patients) among the patients with discogenic low back pain. No significant differences in age, gender, sports activity, and occupation were identified between the groups. [Conclusion] The incidence of spinal instability accounted for more than half of the total number of patients. Additionally, age, gender, sports activity, and occupation did not affect the incidence of spinal instability. Our results support the importance of rehabilitation, such as stability training for spinal instability, for patients with discogenic low back pain.

The Area of Impingement in the Throwing Versus Nonthrowing Shoulder of Collegiate Baseball Players: An MRI Study of the Simulated Late-Cocking Phase of Throwing.

BACKGROUND: During shoulder abduction and external rotation, internal impingement can occur when compressive forces between the greater tuberosity and the posterior glenoid rim pinch the undersurface of the rotator cuff. Previous studies on internal impingement have focused on qualitative results such as pathological findings; however, few studies have quantified the area of impingement (AOI) of the rotator cuff muscles between the greater tuberosity and the posterior glenoid rim. PURPOSE: To compare the AOI between the throwing and nonthrowing shoulders of baseball players. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 14 asymptomatic male collegiate baseball players participated in this study. The AOI in both the throwing and the nonthrowing shoulders was calculated using magnetic resonance imaging (MRI) scans. The MRI measurements were collected with the shoulder at 90° of abduction and at 90° and 100° of external rotation. The area, width, and depth of impingement as well as cystic changes in the greater tuberosity and degeneration in the posterior labrum were compared between the throwing and nonthrowing shoulders. RESULTS: The AOI was significantly greater in the throwing shoulders than in the nonthrowing shoulders (90° of external rotation: 32.4 vs 19.1 mm2, respectively; 100° of external rotation, 28.0 vs 15.6 mm2, respectively; P < .001 for both). Compared with the nonthrowing shoulders, there were more positive findings in the throwing shoulders regarding greater tuberosity cystic changes (0 vs 7, respectively; P = .006) and posterior labral degeneration (3 vs 13, respectively; P < .001). CONCLUSION: The AOI and the number of lesions in the greater tuberosity and posterior labrum were greater in throwing shoulders than in nonthrowing shoulders. Therefore, damage to the insertion of the rotator cuff muscles may affect internal impingement. CLINICAL RELEVANCE: Lesions in the greater tuberosity and posterior labrum in throwing shoulders may increase the AOI by expanding the joint gap behind the glenohumeral joint. Impingement of the greater tuberosity and the posterior glenoid rim may lead to rotator cuff tears.

Stabilization of postural sway on a sideward slope using cuboid support insoles.

[Purpose] The purpose of this study was to elucidate whether insoles alter postural sway on a sideward slope rather than on level ground. [Participants and Methods] This study involved 20 flat-footed individuals and 20 normal-footed individuals. The postural sway was determined based on the total length of the locus and the body sway area, which were measured using the Zebris system. The participants were divided into three groups: the BMZ insoles, Superfeet insoles, and no insole groups. These insoles were worn by the participants with their normal shoes worn daily. [Results] The total length of the locus of the BMZ group was significantly lower than those of the Superfeet and no-insole groups. The body sway area did not significantly differ based on the insole condition. [Conclusion] BMZ insoles improve postural sway in both normal-footed and flat-footed individuals on a sideward slope.

Enhancement of astaxanthin accumulation using black light in Coelastrum and Monoraphidium isolated from Malaysia.

Microalgae are important microorganisms which produce potentially valuable compounds. Astaxanthin, a group of xanthophyll carotenoids, is one of the most powerful antioxidants mainly found in microalgae, yeasts, and crustaceans. Environmental stresses such as intense light, drought, high salinity, nutrient depletion, and high temperature can induce the accumulation of astaxanthin. Thus, this research aims to investigate the effect of black light, also known as long-wave ultraviolet radiation or UV-A, as a stressor on the accumulation of astaxanthin as well as to screen the antioxidant property in two tropical green algal strains isolated from Malaysia, Coelastrum sp. and Monoraphidium sp. SP03. Monoraphidium sp. SP03 showed a higher growth rate (0.66 day-1) compared to that of Coelastrum sp. (0.22 day-1). Coelastrum sp. showed significantly higher accumulation of astaxanthin in black light (0.999 g mL culture-1) compared to that in control condition (0.185 g mL-1). Similarly, Monoraphidium sp. SP03 showed higher astaxanthin content in black light (0.476 g mL culture-1) compared to that in control condition (0.363 g mL culture-1). Coelastrum sp. showed higher scavenging activity (30.19%) when cultured in black light condition, indicating a correlation between the antioxidant activity and accumulation of astaxanthin. In this study, black light was shown to possess great potential to enhance the production of astaxanthin in microalgae.

Molecular characterization of multi-drug resistant Escherichia coli isolates from tropical environments in Southeast Asia.

The emergence of antibiotic resistance among multidrug-resistant (MDR) microbes is of growing concern, and threatens public health globally. A total of 129 Escherichia coli isolates were recovered from lowland aqueous environments near hospitals and medical service centers in the vicinity of Kuala Lumpur, Malaysia. Among the eleven antibacterial agents tested, the isolates were highly resistant to trimethoprim-sulfamethoxazole (83.7%) and nalidixic acid (71.3%) and moderately resistant to ampicillin and chloramphenicol (66.7%), tetracycline (65.1%), fosfomycin (57.4%), cefotaxime (57.4%), and ciprofloxacin (57.4%), while low resistance levels were found with aminoglycosides (kanamycin, 22.5%; gentamicin, 21.7%). The presence of relevant resistance determinants was evaluated, and the genotypic resistance determinants were as follows: sulfonamides (sulI, sulII, and sulIII), trimethoprim (dfrA1 and dfrA5), quinolones (qnrS), ß-lactams (ampC and blaCTX-M), chloramphenicol (cmlA1 and cat2), tetracycline (tetA and tetM), fosfomycin (fosA and fosA3), and aminoglycosides (aphA1 and aacC2). Our data suggest that multidrug-resistant E. coli strains are ubiquitous in the aquatic systems of tropical countries and indicate that hospital wastewater may contribute to this phenomenon.

Characterization of Musty Odor-Producing Actinomycetes from Tropics and Effects of Temperature on the Production of Musty Odor Compounds.

Geosmin and 2-methylisoborneol (MIB) outbreaks in tropical water bodies, such as Southeast Asia, by actinomycetes have not yet been elucidated in detail. Six Streptomyces isolates from lowland environments in Malaysia were selected and evaluated for their odor production under different temperatures. The gene responsible for the production of geosmin, geoA, was detected in all isolates, while only two isolates harbored tpc, which is responsible for 2-MIB production. This result suggested that geosmin and 2-MIB synthesis pathway genes already existed in the environment in the Tropics of Southeast Asia. Furthermore, our isolates produced musty odor compounds at 30°C, and differences were observed in musty odor production between various temperatures. This result indicated the potential for odor episodes in water bodies of the tropical countries of Southeast Asia throughout the year due to the mean annual ambient temperature of 27°C in the lowlands.

Effects of friction massage of the popliteal fossa on blood flow velocity of the popliteal vein.

[Purpose] Friction massage (friction) of the popliteal fossa is provided for the purpose of relieving pain related to circulatory disorders by improving venous flow in the lower legs. The purpose of this study is to verify the effects of enhancing the venous flow based on measuring the blood flow velocity of the popliteal vein before and after providing friction to the patients. [Subjects and Methods] Fifteen healthy male university students participated in the study. The Doppler ultrasonography (DU) was used to measure the blood flow velocity of the popliteal vein, in order to verify the effects of enhancing the venous flow by comparing the measured values before and after a friction massage. [Results] The result of comparing the blood flow velocity before and after providing friction showed that there was a significant increase after friction. [Conclusion] This study proved that friction to the popliteal fossa is effectively enhances venous flow by increasing the blood flow velocity in the popliteal vein.