Chromosome Organization in Meiosis

Our objective is to understand the mechanics of homologous chromosome pairing during meiosis. Aberrant pairing can result in nondisjunction and birth defects in humans. This study used yeast, Saccharomyces cerevisiae, with chromosomally‐integrated arrays of tetO operators that bind TetR repressor proteins fused to GFP to produce a fluorescent signal. In diploid cells, the tetO/TetR‐GFP system allows homologous chromosomes to be identified as two foci (unpaired) or one focus (paired) as they progress through meiosis. We conducted three replicate timecourse experiments, analysing three different stages of meiosis, t=0 hours: pre‐meiotic, t=3 hours: pairing transition, and t=5 hours: synapsis. At each stage, the cells were imaged for 25 minutes, with z‐stacks taken at 30 second intervals. To analyse individual cells, we developed a 4D image analysis pipeline in MATLAB that allowed us to calculate the mean squared change in distance (MSCD), a metric describing the distance between two foci, and analyse deviations from normal diffusive motion

Prostate tumours from an Asian population: examination of bax, bcl-2, p53 and ras and identification of bax as prognostic marker

Molecular studies have suggested that ethnicity may play a significant role in prostate tumorigenesis, but no information exists for groups other than Caucasian or Japanese patients. We examined 62 archival samples of prostate tumours from Asians of non-Japanese origin for the over-expression of p53, for the possible presence of mutated ras genes, for the overexpression of the bcl-2 and bax proteins, as well as directly for the presence of apoptotic cells by the TUNEL methodology. Gene lesions of both ras(0%) and p53 (3%) were rare. While bcl-2 expression was not observed in any sample, bax expression was noted in 76% of samples and was associated with a significantly worse patient prognosis both overall (P< 0.005) and specifically in Chinese patients (P< 0.02). Apoptotic cells were found in 61% of samples, and were significantly associated with the presence of bax expression (P= 0.002), but not patient survival. These results suggest that prostate tumours from non-Japanese Asians are genetically distinct from prostate tumour found in both Japanese and Caucasian patients, and that treatment modalities may need to be tailored for specific population groups. © 2000 Cancer Research Campaig

Auditory stimulation improves motor function and caretaker burden in children with cerebral palsy- A randomized double blind study.

AIM: To investigate the impact of auditory stimulation on motor function in children with cerebral palsy (CP) and disabling hypertonia. METHOD: 9 matched pairs (age: 7y5m, SD 4y1m; 13 boys; gross-motor-functional-classification-scale: median 4; manual-ability-classification-system: median 4) were randomized to receive either auditory stimulation embedded in music (study, n = 9) or music alone (sham, control, n = 9) for at least 10 minutes 4 times a week for 4 weeks. Goal-Attainment-Scale, Care-and-Comfort-Hypertonicity-Questionnaire, Gross-Motor-Function-Measure and Quality-of-Upper-Extremity-Skills-Test (QUEST) were assessed before and 5 months following intervention. RESULT: Children receiving auditory stimulation attained more goals than children who listened to music alone (p = 0.002). Parents reported improved care and comfort in children in the study group compared to a slight deterioration in controls (p = 0.002). Upper extremity skills improved in the study group compared to controls (p = 0.006). Similar gross motor function changes were documented in both groups (p = 0.41). One participant reported increased seizure frequency; no other participants with epilepsy reported increased seizure frequency (n = 6/18) and no other adverse events were reported. INTERPRETATION: Auditory stimulation alleviated hypertonia and improved fine and gross motor functions

Nonintrusive energy meter for nontechnical losses identification

We present in this paper a method and apparatus for nonintrusive measurement of active energy in low-voltage ac installations. In the proposed method, the active power is calculated from the voltage and current waveforms, and the phase shift between them. No voltage amplitude measurement is required since the nominal voltage of the ac installation is considered as the actual voltage. This approach bypasses the main disadvantage of capacitive ac voltage probing: low accuracy in amplitude measurements due to variations on the sensor coupling capacitance. The energy meter that implements the technique is composed of a commercial nonintrusive current sensor (clamp-on current transformer) and a contactless capacitive voltage sensor-designed to measure the voltage phase and waveform. The voltage sensor includes a shield to isolate it from external electric fields, making the energy meter suitable for applications in polyphase systems. The developed energy meter does not require on-site calibration, galvanic contact to the phase conductors, neither electrical circuit opening, allowing for quick, safe, and easy installation on overhead service drop line. Due to these characteristics, it can be used by electricity distribution companies in the preinspection of consumer units suspected of fraud. Experimental results proved that the developed energy meter is insensitive to the characteristics of cables (width and insulation), external electrical fields, as well as to the voltage sensor capacitance variations. The error of the active energy measurement under real condition in a two-phase installation was 1%69411401147COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESnão te

Stereo in-line holographic digital microscope

Biologists use optical microscopes to study plankton in the lab, but their size, complexity and cost makes widespread deployment of microscopes in lakes and oceans challenging. Monitoring the morphology, behavior and distribution of plankton in situ is essential as they are excellent indicators of marine environment health and provide a majority of Earth's oxygen and carbon sequestration. Direct in-line holographic microscopy (DIHM) eliminates many of these obstacles, but image reconstruction is computationally intensive and produces monochromatic images. By using one laser and one white LED, it is possible to obtain the 3D location plankton by triangulation, limiting holographic reconstruction to only the voxels occupied by the plankton, reducing computation by several orders of magnitude. The color information from the white LED assists in the classification of plankton, as phytoplankton contains green-colored chlorophyll. The reconstructed plankton images are rendered in a 3D interactive environment, viewable from a browser, providing the user the experience of observing plankton from inside a drop of water