Coarser taxonomic resolutions are informative in revealing fish community abundance trends for the world’s warmest coral reefs

Coral Reefs - The Arabian Gulf is a natural laboratory to examine how subtropical coral reef ecosystems might change in responding to recurring heating events because of uniquely high water...     

Using Insect Electroantennogram Sensors on Autonomous Robots for Olfactory Searches

Robots designed to track chemical leaks in hazardous industrial facilities¹ or explosive traces in landmine fields² face the same problem as insects foraging for food or searching for mates³: the olfactory search is constrained by the physics of turbulent transport⁴. The concentration landscape of wind borne odors is discontinuous and consists of sporadically located patches. A pre-requisite to olfactory search is that intermittent odor patches are detected. Because of its high speed and sensitivity^5-6, the olfactory organ of insects provides a unique opportunity for detection. Insect antennae have been used in the past to detect not only sex pheromones⁷ but also chemicals that are relevant to humans, e.g., volatile compounds emanating from cancer cells⁸ or toxic and illicit substances^9-11. We describe here a protocol for using insect antennae on autonomous robots and present a proof of concept for tracking odor plumes to their source. The global response of olfactory neurons is recorded in situ in the form of electroantennograms (EAGs). Our experimental design, based on a whole insect preparation, allows stable recordings within a working day. In comparison, EAGs on excised antennae have a lifetime of 2 hr. A custom hardware/software interface was developed between the EAG electrodes and a robot. The measurement system resolves individual odor patches up to 10 Hz, which exceeds the time scale of artificial chemical sensors¹². The efficiency of EAG sensors for olfactory searches is further demonstrated in driving the robot toward a source of pheromone. By using identical olfactory stimuli and sensors as in real animals, our robotic platform provides a direct means for testing biological hypotheses about olfactory coding and search strategies¹³. It may also prove beneficial for detecting other odorants of interests by combining EAGs from different insect species in a bioelectronic nose configuration¹⁴ or using nanostructured gas sensors that mimic insect antennae¹⁵.     

Association of VEGF genetic polymorphisms with prostate carcinoma risk and clinical outcome

OBJECTIVES: Vascular endothelial growth factor (VEGF) is a potent stimulus of angiogenesis that has an important role in many human malignancies including prostate carcinoma (PCa). We evaluated the role of the functional VEGF polymorphisms as genetic markers for PCa susceptibility and prognosis. METHODS: The study included 101 patients with PCa and [corrected] 100 age-matched healthy men. The VEGF genotypes -1154G>A were identified by allele-specific polymerase chain reaction (AS-PCR) and the genotypes -634G>C and 936C>T were identified by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). RESULTS: A negative association was found between VEGF -1154AA genotype and PCa risk (OR=0.27; P=0.009). Furthermore, the presence of the VEGF -1154A allele appeared to be associated with a decreased [corrected] risk of higher tumor grade (OR=0.37; P=0.01). A significant increased risk of prostate cancer was associated with the VEGF -634 (GC+CC) combined genotype (OR=1.95; P=0.02). The VEGF -634C allele was associated with the aggressive phenotype of prostate cancer as defined by the high histological grade (OR=3.48; P=0.007). The VEGF -1154A/-634G haplotype was negatively associated with PCa risk (OR=0.48; P=0.005) and high tumor grade compared to low grade (OR=0.37; P=0.02). CONCLUSIONS: Genetic variations in the VEGF may predict not only PCa risk but also tumor aggressiveness.     

Characterization and molecular cloning of thermostable alpha-amylase from Streptomyces sp.To1

Summary A new thermophilic Streptomyces sp. TO1, isolated from Tunisian soil, produced a thermostable alpha-amylase and pullulanase. The gene encoding for the alpha-amylase activity was cloned into the multicopy cloning plasmid pLM1 using S. lividans ZX1 as host strain. The ZX1 / pLM1 strain has the same activity than the initial TO1 strain and about 25 fold higher activity than the ZX1 strain. This alpha-amylase has an optimum of pH and temperature at 6 and 70 °C respectively.     

Vascular endothelial growth factor-induced secretion of fibronectin is ERK dependent

In severe asthma, cytokines and growth factors contribute to the proliferation of smooth muscle cells and blood vessels, and to the increased extracellular matrix deposition that constitutes the process of airway remodeling. Vascular endothelial growth factor (VEGF), which regulates vascular permeability and angiogenesis, also modulates the function of nonendothelial cell types. In this study, we demonstrate that VEGF induces fibronectin secretion by human airway smooth muscle (ASM) cells. In addition, stimulation of ASM with VEGF activates ERK, but not p38MAPK, and fibronectin secretion is ERK dependent. Both ERK activation and fibronectin secretion appear to be mediated through the VEGF receptor flt-1, as evidenced by the effects of the flt-1-specific ligand placenta growth factor. Finally, we demonstrate that ASM cells constitutively secrete VEGF, which is increased in response to PDGF, transforming growth factor-beta, IL-1beta, and PGE(2). We conclude that ASM-derived VEGF, through modulation of the extracellular matrix, may play an important role in airway remodeling seen in asthma.     

Hydroethanolic extract of Psidium guajava leaf for induced osteoarthritis using a guinea pig model

We investigated the therapeutic effects of an extract of Psidium guajava (guava) leaf on experimentally induced osteoarthritis in guinea pig. The left knee of 30 male guinea pigs was anesthetized and the cranial cruciate ligament was severed. The animals were followed for 8 weeks until osteoarthritis was confirmed by radiography and histopathology. Animals were divided randomly into five groups; group 1, the ligament was severed and untreated; group 2, the ligament was severed and treated with piascledine, an extract of soybean and avocado; group 3, the ligament was severed and treated with 200 mg/kg hydroethanolic extract of guava; group 4, the ligament was severed and treated with 400 mg/kg hydroethanolic extract of guava; and group 5, control animals without surgery or extracts. Radiological and histopathological evaluations after 8 weeks showed reduced severity of osteoarthritis in the piascledine treatment group compared to group 1. The guava extract also reduce the severity of osteoarthritis compared to controls. Histopathological examination of treatment and control groups showed that treatment the guava extract improved lesions significantly. Hydroethanolic extracts of guava leaf appears to prevent osteoarthritis by inhibition of free radical formation in the knee joint.     

Integrating Chemical Footprinting Data into RNA Secondary Structure Prediction

Chemical and enzymatic footprinting experiments, such as shape (selective 2′-hydroxyl acylation analyzed by primer extension), yield important information about RNA secondary structure. Indeed, since the -hydroxyl is reactive at flexible (loop) regions, but unreactive at base-paired regions, shape yields quantitative data about which RNA nucleotides are base-paired. Recently, low error rates in secondary structure prediction have been reported for three RNAs of moderate size, by including base stacking pseudo-energy terms derived from shape data into the computation of minimum free energy secondary structure. Here, we describe a novel method, RNAsc (RNA soft constraints), which includes pseudo-energy terms for each nucleotide position, rather than only for base stacking positions. We prove that RNAsc is self-consistent, in the sense that the nucleotide-specific probabilities of being unpaired in the low energy Boltzmann ensemble always become more closely correlated with the input shape data after application of RNAsc. From this mathematical perspective, the secondary structure predicted by RNAsc should be ‘correct’, in as much as the shape data is ‘correct’. We benchmark RNAsc against the previously mentioned method for eight RNAs, for which both shape data and native structures are known, to find the same accuracy in 7 out of 8 cases, and an improvement of 25% in one case. Furthermore, we present what appears to be the first direct comparison of shape data and in-line probing data, by comparing yeast asp-tRNA shape data from the literature with data from in-line probing experiments we have recently performed. With respect to several criteria, we find that shape data appear to be more robust than in-line probing data, at least in the case of asp-tRNA.     

Molecular and morphological evaluation of transgenic Persian walnut plants harboring Fld gene under osmotic stress condition

Molecular Biology Reports - Soil drought stress is a limiting factor of productivity in walnut (Juglans regia L). Ferredoxin (Fd) level decreases under adverse environmental stress. Functional...     

Effects of Sensory Behavioral Tasks on Pain Threshold and Cortical Excitability

Background/Objective

Transcutaneous electrical stimulation has been proven to modulate nervous system activity, leading to changes in pain perception, via the peripheral sensory system, in a bottom up approach. We tested whether different sensory behavioral tasks induce significant effects in pain processing and whether these changes correlate with cortical plasticity.

Methodology/Principal Findings

This randomized parallel designed experiment included forty healthy right-handed males. Three different somatosensory tasks, including learning tasks with and without visual feedback and simple somatosensory input, were tested on pressure pain threshold and motor cortex excitability using transcranial magnetic stimulation (TMS). Sensory tasks induced hand-specific pain modulation effects. They increased pain thresholds of the left hand (which was the target to the sensory tasks) and decreased them in the right hand. TMS showed that somatosensory input decreased cortical excitability, as indexed by reduced MEP amplitudes and increased SICI. Although somatosensory tasks similarly altered pain thresholds and cortical excitability, there was no significant correlation between these variables and only the visual feedback task showed significant somatosensory learning.

Conclusions/Significance

Lack of correlation between cortical excitability and pain thresholds and lack of differential effects across tasks, but significant changes in pain thresholds suggest that analgesic effects of somatosensory tasks are not primarily associated with motor cortical neural mechanisms, thus, suggesting that subcortical neural circuits and/or spinal cord are involved with the observed effects. Identifying the neural mechanisms of somatosensory stimulation on pain may open novel possibilities for combining different targeted therapies for pain control.     

Prompt chlorophyll fluorescence as a tool for crop phenotyping: an example of barley landraces exposed to various abiotic stress factors

The study examined photosynthetic efficiency of two barley landraces (cvs. Arabi Abiad and Arabi Aswad) through a prompt fluorescence technique under influence of 14 different abiotic stress factors. The difference in the behavior of photosynthetic parameters under the same stress factor in–between cv. Arabi Abiad and cv. Arabi Aswad indicated different mechanisms of tolerance and strategies for the conversion of light energy into chemical energy for both the landraces. This study confirmed the suitability of some chlorophyll fluorescence parameters as reliable biomarkers for screening the plants at the level of photosynthetic apparatus.