Eco-physiological responses of copepods and pteropods to ocean warming and acidification.

We compare physiological responses of the crustacean copepod Calanus pacificus and pelagic pteropod mollusk Limacina helicina to ocean temperatures and pH by measuring biomarkers of oxidative stress, antioxidant defences, and the activity of the respiratory electron transport system in organisms collected on the 2016 West Coast Ocean Acidification cruise in the California Current System. Copepods and pteropods exhibited strong but divergent responses in the same habitat; copepods had higher oxygen-reactive absorbance capacity, glutathione-S-transferase, and total glutathione content. The ratio between reduced to oxidised glutathione was higher in copepods than in pteropods, indicating lower oxidative stress in copepods. Pteropods showed higher activities of glutathione reductase, catalase, and lipid peroxidation, indicating increased antioxidant defences and oxidative stress. Thus, the antioxidant defence system of the copepods has a greater capacity to respond to oxidative stress, while pteropods already face severe stress and show limited capacity to deal with further changes. The results suggest that copepods have higher adaptive potential, owing to their stronger vertical migration behaviour and efficient glutathione metabolism, whereas pteropods run the risk of oxidative stress and mortality under high CO2 conditions. Our results provide a unique dataset and evidence of stress-inducing mechanisms behind pteropod ocean acidification responses.

Validation of the Mini-TQ in a Dutch-speaking population: a rapid assessment for tinnitus-related distress.

OBJECTIVE: Up to 30% of the adult population experiences tinnitus at some point in life. The aim of the present study was to validate the Mini-Tinnitus Questionnaire (TQ) in a Dutch-speaking population for measuring tinnitus-related distress and compare it with the extended version normally used in clinical practice and research. METHODOLOGY: We assessed 181 patients at the Tinnitus Research Initiative clinic of Antwerp University Hospital. Twelve items from the TQ chosen by Hiller and Goebel based on the optimal combination of high item correlation, reliability, and sensitivity were selected and correlated to the different subscale and global scores of the TQ. Internal consistency was evaluated using Cronbach's alpha coefficient, and the Guttman split-half coefficient was used to confirm reliability. RESULTS: Correlation to the global TQ score was .93, internal consistency was .87, and reliability was .89. This study further revealed that the Mini-TQ correlates better with the different subscales of the TQ in the Dutch-speaking population. The convergence validity was confirmed, ensuring that this new instrument measures distress. In addition, the norms suggested by Hiller and Goebel were verified and established. CONCLUSION: Based on these results, the Mini-TQ is recommended as a valid instrument for evaluating tinnitus-related distress in Dutch-speaking populations for a compact, quick, and economical assessment.

Prey capture of pike Esox lucius larvae in turbid water.

Pike Esox lucius larvae captured fewer calanoid and cyclopoid copepods in turbid than in clear water, whereas no differences were detected in feeding rates on Daphnia longispina. Decreased capture of copepods may lead to lower growth and survival of E. lucius larvae in turbid areas, in particular, if cladocerans are scarce.

Burst transcranial magnetic stimulation: which tinnitus characteristics influence the amount of transient tinnitus suppression?

BACKGROUND: Transcranial Magnetic Stimulation (TMS) is a method capable of temporarily suppressing tinnitus by delivering tonic or burst stimuli. Burst TMS has a high interindividual variability and low effect size. Tinnitus type and laterality, tinnitus-related distress, and tinnitus duration might contribute to this large individual variation. METHODS: The effect of burst TMS on the auditory cortex in 100 male individuals is evaluated with coil placed over the auditory cortex. For unilateral tinnitus, this coil was placed contralaterally to the tinnitus, whilst for bilateral tinnitus the coil was placed over the right auditory cortex. The site of maximal tinnitus suppression is determined using 1-Hz stimulation with five pulses per burst (intensity of the stimulation set at 90% of the motor threshold). When tinnitus suppression is noted, the patients are asked to estimate the decrease in tinnitus in percentage using the numeric rating scale. The procedure is repeated with stimulations at 5, 10 and 20 Hz, each stimulation session consisting of 200 pulses. RESULTS: Results demonstrate that burst stimulation can decrease the perceived tinnitus intensity transiently in 57.83% of the patients. Patients with bilateral tinnitus respond better to burst TMS than patients with unilateral tinnitus and highly distressed patients presenting with unilateral pure tone tinnitus fail to bust TMS. CONCLUSIONS: Burst TMS modulates both unilateral and bilateral tinnitus, both high and low distress and both pure tones and narrow band tinnitus. However, the suppression effect is moderated by tinnitus type and laterality, tinnitus-related distress, and tinnitus duration.

A small modification to a decompressive craniotomy to improve the brain-cranium interface: technical note.

One underlying aspect of a decompressive craniotomy is the brain-cranium interface. Due to the high pressure, the brain has the tendency to mushroom and squeeze the brain tissue at the bony edges of the craniotomy. A small modification to the decompressive craniotomy is described. The inner tabula and part of the diploe are drilled away using a high-speed drill (using either a sharp or a diamond drill) prior to opening the dura while during drilling, the dura is protected with a spatula.

Characterization, standardization and experiences with KONE ISE for Mg2+.

The principles of a fully automated potentiometric determination of ionized magnesium in human blood serum are presented. By incorporating a magnesium selective electrode, into a commercially available six channel electrolyte analyzer (Microlyte 6, KONE Instruments, Finland), determination of the biologically-active, ionized fraction of magnesium has been made possible. In this paper, the analytical performance of the measurement system is presented and determination of ionized magnesium in real patient samples is discussed with special attention to the significance of this new parameter.

Biomechanical analysis of the knee extension exercise.

A mathematical analysis of knee extension and flexion exercise is presented to determine effectiveness in strengthening the quadriceps and hamstring muscles. A quantitative relationship between the quadriceps force and the hamstring force is obtained for several variations of the exercises. The theoretical results are supplemented with experimental studies performed on subjects exercising with the Tekdyne Incentive Dynamometer.

Overprediction and blocking in the McCollough aftereffect.

The Rescorla-Wagner theory (Rescorla & Wagner, 1972) of associative learning offers specific predictions about the associative strength of CS-US pairs when two or more CSs are conditioned to the same US separately and subsequently paired in a compound with the same US. The magnitude of orientation-contingent color aftereffects (AEs) was used as an index of associative strength in this study. The results of experiments using an "overprediction" (Rescorla, 1970) and a "blocking" (Kamin, 1969) paradigm conformed to the predictions of the Rescorla-Wagner theory. In Experiment 1, AEs were established simultaneously for horizontal-vertical and diagonal patterns. When observers subsequently viewed compound induction patterns, AE magnitude was found to be significantly decreased, relative to a condition in which observers did not view such an induction pattern. In Experiment 2, AE magnitude for a given test pattern following inspection of compound induction stimuli was significantly reduced by inspection of the other component prior to viewing the compound induction stimuli. The applicability of associative learning and feature-adaptation models of the McCollough effect is discussed.

Capital intensive hospital technology and illness: an analysis of American state data.

This paper: describes the development of a 'hospital technology index' to measure the level of capital intensive medical technology in each of the 50 U.S. states and the District of Columbia, reports differences between states in scores on this index, and tests the hypothesis that there is a low but significant negative correlation between the level of capital intensive medical technology and the level of illness. The three subscales of the hospital technology index have high alpha coefficients of reliability, are reasonably orthogonal, and there is at least some evidence of construct and discriminant validity for each. The multiple regression analysis suggests that there is either no relation between capital intensive medical technology and the rate of illness or that there is a slight tendency for the illness rate to increase as the level of technology increases. Eight possible explanations for the findings are discussed.