The impact of exercise on depression: how moving makes your brain and body feel better.

PURPOSE: This study aimed to comprehensively explore and elucidate the intricate relationship between exercise and depression, and focused on the physiological mechanisms by which exercise influences the brain and body to alleviate depression symptoms. By accumulating the current research findings and neurobiological insights, this study aimed to provide a deeper understanding of the therapeutic potential of exercise in the management and treatment of depression. METHODS: We conducted a systematic review of the scientific literature by selecting relevant studies published up to October 2023. The search included randomized controlled trials, observational studies, and review articles. Keywords such as "exercise," "depression," "neurobiology," "endocrinology," and "physiological mechanisms" were used to identify pertinent sources. RESULTS: Inflammation has been linked to depression and exercise has been shown to modulate the immune system. Regular exercise can (1) reduce the levels of pro-inflammatory cytokines, potentially alleviating depressive symptoms associated with inflammation; (2) help in regulating circadian rhythms that are often disrupted in individuals with depression; and (3) improve sleep patterns, thus regulating mood and energy levels. CONCLUSION: The mechanisms by which exercise reduces depression levels are multifaceted and include both physiological and psychological factors. Exercise can increase the production of endorphins, which are neurotransmitters associated with a positive mood and feelings of well-being. Exercise improves sleep, reduces stress and anxiety, and enhances self-esteem and social support. The implications of exercise as a treatment for depression are significant because depression is a common and debilitating mental health condition. Exercise is a low-cost, accessible, and effective treatment option that can be implemented in various settings such as primary care, mental health clinics, and community-based programs. Exercise can also be used as an adjunctive treatment along with medication and psychotherapy, which can enhance treatment outcomes.

Physical exercise-intervention can be valuable therapy for COVID-19 confinement and post-COVID-19 periods.

PURPOSE: The COVID-19 pandemic and its transition into an endemic phase have profoundly impacted physical health, well-being, mental health, education, and various aspects of society, including the economy and social networks. Home confinement, social distancing, and physical inactivity have exacerbated numerous health issues, including obesity, diabetes mellitus, hypertension, hyperlipidemia, cardiovascular diseases, depression, and poor sleep quality. A systematic review has revealed significant findings: Regular aerobic programs (such as cycling or walking at an intensity of 60-80% of HR max for 20-60 minutes per session, repeated 2-3 times a week) have proven effective in improving both physical and mental health, as well as immune function. This type of physical activity has been shown to increase immunological markers, including lymphocytes, leukocytes, neutrophils, monocytes, and interleukin-6 (IL-6), while reducing low-grade inflammation. Therefore, in this study we aimed to assess the impact of tailored exercise interventions on the physical and mental health of COVID-19 patients. Based on the results, we can establish exercise intervention strategies to mitigate the negative health consequences during and after the COVID-19 pandemic. METHODS: We conducted a search of the PubMed database from January 2020 to August 2023 using predefined search terms such as "COVID-19 and post-COVID-19," "exercise intervention and immunity," and "mental health." By examining references, we explored the links between exercise interventions and the mental and physical health of COVID-19 patients. RESULTS: A tailored, multifaceted exercise intervention should be developed and implemented to address the existing mental challenges and enhance mental health during both the pandemic and the post-COVID-19 periods. CONCLUSION: Breathing exercises and respiratory support techniques, including yoga, thoracic expansion exercises, airway clearance methods, and breathing control, are likely to be beneficial.

Multidisciplinary integrated optimal design process for optomechanical structures.

This paper presents an integrated design process for optomechanical structures based on multidisciplinary optimization. The proposed integrated optimal design process comprises a finite element analysis by ANSYS Workbench, the MATLAB optomechanical transfer program, an optical analysis by ZEMAX, and the multidisciplinary optimization solver by Isight. In ANSYS Workbench, the deformation of optical surfaces, structures, and responses according to the design requirements is calculated in one project. Then, Zernike polynomial coefficients are calculated from surface deformation data of optical surfaces through a MATLAB optomechanical transfer program. In ZEMAX, the Zernike polynomial coefficients are imported into optical surface models of an optical system; then, optical performance parameters, such as the wavefront error, optical aberration, MTF, and OPD, are calculated. In the Isight environment, automatic iterative computations are performed between these three programs and, as a result, the design dimensions of optomechanical structures are determined, satisfying the design requirements and improving the performance of an optical system. By using this integrated optimal design process, the optimal design and analysis for a complete optomechanical structure, as well as individual structure parts, can be performed successfully. In this paper, the optimal design problem for three parts of a Cassegrain telescope, which consists of a primary mirror with an outer diameter of 156 mm and a secondary mirror with an outer diameter of 46 mm, was taken as an example. By using optimal parts, the image wavefront error of the Cassegrain telescope was decreased from 29.9 to 16.1 nm.

Classification of a 3D Film Pattern Image Using the Optimal Height of the Histogram for Quality Inspection.

A 3D film pattern image was recently developed for marketing purposes, and an inspection method is needed to evaluate the quality of the pattern for mass production. However, due to its recent development, there are limited methods to inspect the 3D film pattern. The good pattern in the 3D film has a clear outline and high contrast, while the bad pattern has a blurry outline and low contrast. Due to these characteristics, it is challenging to examine the quality of the 3D film pattern. In this paper, we propose a simple algorithm that classifies the 3D film pattern as either good or bad by using the height of the histograms. Despite its simplicity, the proposed method can accurately and quickly inspect the 3D film pattern. In the experimental results, the proposed method achieved 99.09% classification accuracy with a computation time of 6.64 s, demonstrating better performance than existing algorithms.

Effects of Red Ginseng Byproducts on Rumen Fermentation, Growth Performance, Blood Metabolites, and mRNA Expression of Heat Shock Proteins in Heat-Stressed Fattening Hanwoo Steers.

The objective of this study was to evaluate the effects of dietary supplementation with red ginseng byproduct (RGB) on rumen fermentation, growth performance, blood metabolites, and mRNA expression of heat shock proteins (HSP) in fattening Hanwoo steers under heat stress. Two experimental total mixed rations (TMR) were prepared: (1) a TMR meeting the requirement of fattening beef having an average daily gain (ADG) 0.8 kg/day (CON) and (2) a TMR that included 2% RGB on a dry matter (DM) basis (GINSENG). In vitro rumen fermentation and in vivo growth experiments were conducted using two experimental diets. A total of 22 Hanwoo steers were distributed to two treatments (CON vs. GINSENG) in a completely randomized block design according to body weight (BW). The experiment was conducted during the summer season for five weeks. The final BW, ADG, DM intake, and feed conversion ratio did not differ between treatments in the growth trial. In the mRNA expression results, only HSP 90 showed an increasing tendency in the GINSENG group. The use of 2%DM RGB did not improve the growth performance or alleviate heat stress in fattening Hanwoo steers during the summer season.

Antagonistically Functionalized Diatom Biosilica for Bio-Triboelectric Generators.

Although biomaterial-based triboelectric nanogenerators (Bio-TENGs) for use in wearable electronics and implantable sensors have been developed, power generation is not suitable for satisfying the basic requirements for practical applications. Here, to greatly enhance output performances of Bio-TENG devices, an antagonistic approach of diatom frustules (DFs) with amine and fluorine chemical functionalizations is reported. The DFs are treated with piranha solution to increase the density of hydroxyl groups and tribo-positive and tribo-negative composite films are designed with antagonistically functionalized DFs. The tribo-positive composites having electron donating functionality consist of aminated DFs and cellulose nanocrystals (CNCs), while the tribo-negative composite is composed of fluorinated DFs and polydimethylsiloxane (PDMS). An antagonistically and chemically functionalized TENG (ACF TENG) with an efficient contact area of 9.6 cm2 under a force of 8 N and a frequency of 5 Hz exhibits an output voltage of 248 V, a short-circuit current of 16.4 µA, and a power density of 2.01 W m-2 , which is 16.6 times higher than a reference (CNC:PDMS) TENG. This study shows a simple antagonistic approach for chemical functionalization as an efficient method to manipulate the tribo-polarity of bio-additives for enhancing power generation of Bio-TENGs.

Diatom Bio-Silica and Cellulose Nanofibril for Bio-Triboelectric Nanogenerators and Self-Powered Breath Monitoring Masks.

The application of biodegradable and biocompatible materials to triboelectric nanogenerators (TENGs) for harvesting energy from motions of the human body has been attracting significant research interest. Herein, we report diatom bio-silica as a biomaterial additive to enhance the output performance of cellulose nanofibril (CNF)-based TENGs. Diatom frustules (DFs), which are tribopositive bio-silica having hierarchically porous three-dimensional structures and high surface area, have hydrogen bonds with CNFs, resulting in enhanced electron-donating capability and a more roughened surface of the DF-CNF composite film. Hence, DFs were applied to form a tribopositive composite film with CNFs. The DF-CNF biocomposite film is mechanically strong, electron-rich, low-cost, and frictionally rough. The DF-CNF TENG showed an output voltage of 388 V and time-averaged power of 85.5 mW/m2 in the contact-separation mode with an efficient contact area of 4.9 cm2, and the generated power was sufficient for instantaneous illumination of 102 light-emitting diodes. In addition, a cytotoxicity study and biocompatibility tests on rabbit skin suggested that the DF-CNF composite was biologically safe. Moreover, a practical application of the DF-CNF TENG was examined with a self-powered smart mask for human breathing monitoring. This study not only suggests high output performance of biomaterial-based TENGs but also presents the diverse advantages of the DFs in human body-related applications such as self-powered health monitoring masks, skin-attachable power generators, and tactile feedback systems.

The co-injection of antioxidants with foot-and-mouth disease vaccination altered growth performance and blood parameters of finishing Holstein steers.

OBJECTIVE: This study was conducted to evaluate whether the co-injection of antioxidants together with foot-and-mouth disease (FMD) vaccination has the potential to attenuate the negative effects caused by vaccination in Holstein finishing steers. METHODS: A total of 36 finishing Holstein steers (body weight [BW]: 608±45.6 kg, 17 months old) were randomly allocated to one of three treatments: i) control (CON, only FMD vaccination without any co-injection), ii) co-injection of commercial non-steroidal anti-inflammatory drugs (NSAID) with FMD vaccination at a ratio of 10:1 (NSAID vol/FMD vaccine vol) as a positive control (PCON), iii) co-injection of commercial mixture of vitamin E and selenium with FMD vaccination (VITESEL) (1 mL of FMD vaccine+1 mL of antioxidants per 90 kg of BW). Changes in growth performance and blood parameters because of treatments were determined. RESULTS: No significant difference in BW, average daily gain, and dry matter intake of the steers was observed among the treatments. The FMD vaccination significantly increased white blood cells (WBC), neutrophils, platelets, and mean platelet volume (p<0.01) in blood analysis. The count of lymphocyte tended to increase after vaccination (p = 0.08). In blood analysis, steers in VITESEL tended to have higher numbers of WBC, neutrophils, and platelets compared to that of other treatments (p = 0.09, 0.06, and 0.09, respectively). Eosinophils in VITESEL were higher than those in PCON (p<0.01). Among blood metabolites, blood urea nitrogen and aspartate transaminase were significantly increased, but cholesterol, alanine transferase, inorganic phosphorus, Mg, and albumin were decreased after FMD vaccination (p<0.01). CONCLUSION: The use of antioxidants in FMD vaccination did not attenuate growth disturbance because of FMD vaccination. The metabolic changes induced by vaccination were not controlled by the administration of antioxidants. The protective function of antioxidants was effective mainly on the cell counts of leukocytes.

An Electroactive and Transparent Haptic Interface Utilizing Soft Elastomer Actuators with Silver Nanowire Electrodes.

An electroactive and transparent haptic interface having a rectangular void pattern creates tunable surface textures by controlling the wavelength and amplitude of independent void-lines. To make an active tactile surface, the transparent haptic interface employs a silver nanowire (AgNW) electrode to be compliant with the deformed elastomer surface. Here, the dielectric elastomer is newly blended with polydimethylsiloxane and Ecoflex prepolymer to simultaneously control the mechanical stiffness and transparency. The relative resistance of the AgNW electrode on a single void line is nearly unchanged under bending test, confirming the high stretchability and conductivity of the nanowire-networked electrode. The optical transparencies are 92-85%, depending on the ratio of the Ecoflex solution. Transparency values decreas by 7 and 16% after coating with AgNWs at densities of 30 and 140 mg m-2 , respectively. Using EP31, the void line is deformed by 90 µm under a field intensity of 13.0 V µm-1 . The haptic surface is successfully controlled by applying voltage, which produces four different surface textures, from relatively smooth to rough feeling, depending on the distance between deformed void lines. This haptic interface can be applied to diverse display systems as an external add-on screen and will help to realize programmable surface textures in the future.

Electrochemical Synthesis of Ammonia from Water and Nitrogen: A Lithium-Mediated Approach Using Lithium-Ion Conducting Glass Ceramics.

Lithium-mediated reduction of dinitrogen is a promising method to evade electron-stealing hydrogen evolution, a critical challenge which limits faradaic efficiency (FE) and thus hinders the success of traditional protic-solvent-based ammonia electro-synthesis. A viable implementation of the lithium-mediated pathway using lithium-ion conducting glass ceramics involves i) lithium deposition, ii) nitridation, and iii) ammonia formation. Ammonia was successfully synthesized from molecular nitrogen and water, yielding a maximum FE of 52.3 %. With an ammonia synthesis rate comparable to previously reported approaches, the fairly high FE demonstrates the possibility of using this nitrogen fixation strategy as a substitute for firmly established, yet exceedingly complicated and expensive technology, and in so doing represents a next-generation energy storage system.

Comparison of models for estimating methane emission factor for enteric fermentation of growing-finishing Hanwoo steers.

The methodology provided by the Intergovernmental Panel on Climate Change (IPCC) guidelines is widely used for estimating enteric methane (CH4) production by cattle. No attempt other than the default values in the IPCC Tier 1 has been made for estimating CH4 emission from Hanwoo, a dominant beef species in Korea raised in a unique feeding system. The objective of this study was to compare models for estimating the CH4 emission factor (MEF; kg CH4/head/year) for enteric fermentation in Hanwoo steers. The MEF was estimated based on Korea- and Hanwoo-specific data obtained from the literature using several models. The models include the IPCC Tier 1 (T1), the IPCC Tier 2 method (T2), the IPCC Tier 2 methodology with actual dry matter intake (T2DMI), and the Japanese Tier 3 method (JT3). The JT3 was included due to the similarity in the beef cattle production system between the two countries. Estimated MEF using T2 were 43.4, 33.9, and 36.2 kg CH4/head/year for the growing, finishing, and overall period, respectively. The overall MEF estimated using T2 was 23 % lower than the estimate by T1 (47.0 kg CH4/head/year). There were significant differences in the estimated MEF for enteric fermentation of Hanwoo steers among the methods (P < 0.05). The overall MEF estimated by JT3 was 69.1 kg CH4/head/year, which was significantly higher than the estimates by T2 (36.2 kg) and T2DMI (33.5 kg). The JT3 estimated the highest values in all periods possibly due to overestimation of the conversion ratio of feed energy to CH4. No significant difference was found in the overall MEF of Hanwoo steers between T2 and T2DMI. However, T2DMI estimated 8 % higher and 14 % lower MEF than T2 for the growing and finishing period, respectively, mainly because the T2 significantly over-predicts the gross energy intake of Hanwoo steers at the high level of intake. The IPCC default methods have limitations in their use for a feeding systems in non-western countries, and thus development of a country-specific methodology and parameter estimates for enteric CH4 production is required for Hanwoo and other cattle production systems.

Molecular cloning and transcription expression of 3-dehydroecdysone 3α-reductase (3de 3α-reductase) in the different tissues and the developing stage from the silkworm, Bombyx mori L.

Molting in insects is regulated by molting hormones (ecdysteroids), which are also crucial to insect growth, development, and reproduction etc. The decreased ecdysteroid in titre results from enhanced ecdysteroid inactivation reactions including the formation of 3-epiecdyson under ecdysone oxidase and 3-dehydroecdysone 3α-reductase (3DE 3α-reductase). In this paper, we cloned and characterized 3-dehydroecdysone 3α-reductase (3DE 3α-reductase) in different tissues and developing stage of the silkworm, Bombyx mori L. The B. mori 3DE 3α-reductase cDNA contains an ORF 783 bp and the deduced protein sequence containing 260 amino acid residues. Analysis showed the deduced 3DE 3α-reductase belongs to SDR family, which has the NAD(P)-binding domain. Using the Escherichia coli, a high level expression of a fusion polypeptide band of approx. 33 kDa was observed. High transcription of 3DE 3α-reductase was mainly presented in the midgut and hemolymph in the third day of fifth instar larvae in silkworm. The expression of 3DE 3α-reductase at different stages of larval showed that the activity in the early instar was high, and then reduced in late instar. This is parallel to the changes of molting hormone titer in larval. 3DE 3α-reductase is key enzyme in inactivation path of ecdysteroid. The data elucidate the regulation of 3DE 3α-reductase in ecdyteroid titer of its targeting organs and the relationship between the enzyme and metamorphosis.

Expression and functions of dopa decarboxylase in the silkworm, Bombyx mori was regulated by molting hormone.

Insect molting is an important developmental process of metamorphosis, which is initiated by molting hormone. Molting includes the activation of dermal cells, epidermal cells separation, molting fluid secretion, the formation of new epidermis and old epidermis shed and other series of continuous processes. Polyphenol oxidases, dopa decarboxylase and acetyltransferase are necessary enzymes for this process. Traditionally, the dopa decarboxylase (BmDdc) was considered as an enzyme for epidermal layer's tanning and melanization. This work suggested that dopa decarboxylase is one set of the key enzymes in molting, which closely related with the regulation of ecdysone at the time of biological molting processes. The data showed that the expression peak of dopa decarboxylase in silkworm is higher during molting stage, and decreases after molting. The significant increase in the ecdysone levels of haemolymph was also observed in the artificially fed silkworm larvae with ecdysone hormone. Consistently, the dopa decarboxylase expression was significantly elevated compared to the control. BmDdc RNAi induced dopa decarboxylase expression obviously declined in the silkworm larvae, and caused the pupae appeared no pupation or incomplete pupation. BmDdc was mainly expressed and stored in the peripheral plasma area near the nucleus in BmN cells. In larval, BmDdc was mainly located in the brain and epidermis, which is consisted with its function in sclerotization and melanization. Overall, the results described that the dopa decarboxylase expression is regulated by the molting hormone, and is a necessary enzyme for the silkworm molting.

Functional robustness of a polycyclic aromatic hydrocarbon metabolic network examined in a nidA aromatic ring-hydroxylating oxygenase mutant of Mycobacterium vanbaalenii PYR-1.

In this study, we obtained over 4,000 transposon mutants of Mycobacterium vanbaalenii PYR-1 and analyzed one of the mutants, 8F7, which appeared to lose its ability to degrade pyrene while still being able to degrade fluoranthene. This mutant was identified to be defective in nidA, encoding an aromatic ring-hydroxylating oxygenase (RHO), known to be involved in the initial oxidation step of pyrene degradation. When cultured with pyrene as a sole source of polycyclic aromatic hydrocarbon (PAH), high-pressure liquid chromatography analysis revealed that the nidA mutant showed a significant decrease in the rate of pyrene degradation compared to the wild-type PYR-1, although pyrene was still being degraded. However, when incubated with PAH mixtures including pyrene, phenanthrene, and fluoranthene, the pyrene degradation rate of the mutant was higher than that of the mutant previously incubated with pyrene as a sole source of PAH. There was no significant difference between wild-type PYR-1 and the mutant in the rates of phenanthrene and fluoranthene degradation. From the whole-cell proteome analysis of mutant 8F7 induced by pyrene, we identified expression of a number of RHO enzymes which are suspected to be responsible for pyrene degradation in the nidA mutant, which had no expression of NidA. Taken together, results in this study provide direct evidence for the in vivo functional role of nidA in pyrene degradation at the level of the ring-cleavage-process (RCP) functional module but also for the robustness of the PAH metabolic network (MN) to such a genetic perturbation.

The influence of contrasts on directional and spatial frequency tuning in visual cortex areas 17/18 of the cat.

PURPOSE: The purpose of this study was to investigate the effects of contrast display exposure on neuronal directional and spatial frequency tuning. Neuronal responses were recorded from ninety-four neurons in cortical areas 17 and 18 in two adult cats. METHODS: A multi-channel microelectrode was implanted in cortical areas 17 and 18 of two paralyzed and anaesthetized cats. Various drifting sinusoidal grating contrast displays were presented to one of the cats' eyes in the visual field. Contour plots based on the neuronal responses to the drifting sinusoidal grating displays using various contrasts (i.e., 0.4, 0.7, and 1.0) and velocities (i.e., 4.6, 13.9, 23.1, 32.3, 41.5, 50.8, and 60.0 deg/sec) were plotted as a function of the spatial frequency and the direction associated with each velocity and contrast used. RESULTS: Five parameters were extracted from these contour plots: 1) optimum response, 2) preferred direction, 3) optimum spatial frequency, 4) directional tuning width, and 5) spatial frequency bandwidth. To determine the optimal velocity, each parameter was plotted against each of the specific display contrasts used, and a 'best fit' line was established. Response amplitudes were dependent on the type of contrast utilized; however, the spatial frequency and directional tuning properties were stable for the cortical neurons assessed. CONCLUSIONS: The results of the presentation of different contrasts on neuronal directional and spatial frequency tuning are consistent with behavioral results when medium and high contrast displays are used.

Scale-invariant pattern recognition using a combined Mellin radial harmonic function and the bidimensional empirical mode decomposition.

A novel scale and shift invariant pattern recognition method is proposed to improve the discrimination capability and noise robustness by combining the bidimensional empirical mode decomposition with the Mellin radial harmonic decomposition. The flatness of its peak intensity response versus scale change is improved. This property is important, since we can detect a large range of scaled patterns (from 0.2 to 1) using a global threshold. Within this range, the correlation peak intensity is relatively uniform with a variance below 20%. This proposed filter has been tested experimentally to confirm the result from numerical simulation for cases both with and without input white noise.

Facile synthesis of highly ordered mesoporous silver using cubic mesoporous silica template with controlled surface hydrophobicity.

Highly ordered mesoporous silver, which exhibits well-defined mesopores, high surface area and pore volume, has been successfully obtained using a cubic mesoporous silica, KIT-6, with controlled surface hydrophobicity as the hard template.

Analysis of the CO2 and NH3 reaction in an aqueous solution by 2D IR COS: formation of bicarbonate and carbamate.

The two-dimensional (2D) infrared correlation spectra obtained from the reaction time- and concentration-dependent IR spectra elucidates the reaction of CO2 and NH3 in an aqueous solution for CO2 absorption. In the synchronous 2D correlation spectra, the interrelation of the proton with carbamate and bicarbonate indicates that the pH level affected the formation reactions of the two products. Furthermore, the interrelation of carbamate with bicarbonate confirmed the conversion of carbamate into bicarbonate with the release of protons (or the decrease of the pH). From the experimental results including the asynchronous 2D correlation spectra, the reaction of the CO2 and aqueous ammonia proceeded through the following steps: formation of carbamate, formation of bicarbonate, release of protons, and conversion of carbamate into bicarbonate. The analysis of the formation of carbamate and bicarbonate by 2D infrared correlation spectroscopy provides useful information on the reaction mechanism of CO2 and NH3 in aqueous solutions.

Influence of additives including amine and hydroxyl groups on aqueous ammonia absorbent for CO2 capture.

Aqueous ammonia absorbent (10 wt %) was modified with four kinds of additives (1 wt %) including amine and hydroxyl groups, i.e., 2-amino-2-methyl-1-propanol (AMP), 2-amino-2-methyl-1,3-propandiol (AMPD), 2-amino-2-ethyl-1,3-propandiol (AEPD), and tri(hydroxymethyl) aminomethane (THAM), for CO(2) capture. The loss of ammonia by vaporization was reduced by additives, whereas the removal efficiency of CO(2) was slightly improved. These results were attributed to the interactions between ammonia and additives or absorbents and CO(2) via hydrogen bonding, as verified by FT-IR spectra and computational calculation. Molecular structures as well as binding energies were obtained from the geometries of (ammonia + additives) and (ammonia + additives + CO(2)) at the optimized state. These experimental and theoretical findings demonstrate that additives including amine and hydroxyl group are suitable for modifying aqueous ammonia absorbent for CO(2) removal.

Responses in extrastriate cortex to optic flow during simulated turns.

An observer locomoting along a straight path sees a pattern of optic flow in which images move approximately radially outward from his heading point. If the observer turns, the optic flow field changes markedly because each object's image now has a component of horizontal motion added to its "optic flow" motion. We tested the responses of 326 cells in the cat's extrastriate area LS (lateral suprasylvian visual area) to movies simulating the optic flow seen during locomotion in a straight line, and during various simulated turns to the left and right. About 60% of 326 cells tested responded to optic flow simulating turns. Of most interest was a subset of cells, 15% of the total, that had "turn-selective" responses. They responded significantly better to turns in a particular direction (usually to the contralateral side) than to turns in the opposite direction or to optic flow simulating straight-ahead locomotion. For each cell, we generated a display of fronto-parallel motion with a direction and speed that matched the image motion in the preferred turn movie, as seen at the receptive-field center. Most turn-selective cells responded significantly better to their preferred turn movie than to this fronto-parallel stimulus. We examined the role of cells' selectivity for stimulus direction, speed, and acceleration in determining cell preference for particular turns. Direction preference played some role for most cells, but about a third of the cells preferred turn movies that did not reflect their direction selectivity. Other factors, including the presence of opposing motion, only rarely appeared to determine cell preferences for particular turn movies.