Relationship Between the Reaction Time and EEG Parameters During Judgments on the Correspondence of Delayed or Simultaneously Presented Images of Two Models

This study examined how judging whether the poses of two figures are the same in tasks with delayed and simultaneous image presentation affects the participants’ reaction times and electroencephalograms (EEGs). Eighteen university students performed a delayed task, in which an image of a doll was first presented for 3 sec followed by a second image of the doll, and a simultaneous task, in which images of two dolls were presented on the left and right sides of the monitor at the same time. The dolls were shown from the front and rear angles. The participants were instructed to judge whether the images were the same as accurately and quickly as possible, and the reaction times were recorded. EEG signals were recorded from Fp1, Fp2, F3, F4, C3, C4, P3, and P4. The reaction times in the delayed task were found to be shorter then those in the simultaneous task, and that these times for the 0° condition were shorter than for the 180° condition. The amplitudes of EEG responses at Fp1 and Fp2 were larger than those at other electrodes, and the responses in the right hemisphere during the 180° condition and the delayed task within the α1 frequency band were smaller than the responses at other electrodes. These results indicate that cerebral activity in the frontal region of the right hemisphere is associated with the judgment of correspondence or non-correspondence in spatial compatibility tasks.     

Determination of the rotational dynamics and pH dependence of the hydrogen exchange rates of the arginine guanidino group using NMR spectroscopy

Summary An improved version of the constant-time HSQC experiment is presented that gives uniform sensitivity over the complete ¹³C bandwidth in ¹³C−¹H correlation experiments without creating artifacts in the methyl and aromatic regions of the spectra. The improvement is achieved by replacing the refocussing ¹³C 180° pulse in the evolution time by a combination of a full-power (22 kHz) hyperbolic secant 180° pulse that inverts and refocusses the entire ¹³C window, immediately followed by a selective 180° pulse on the CO region. Further improvement in signal-to-noise in the aromatic and methyl regions, although less spectacular, is obtained by replacing the other two 180° ¹³C pulses in the INEPT parts of the pulse sequence by full-power hyperbolic secant pulses. Results of simulations and experimental data are presented that demonstrate the excellent performance of the hyperbolic secant pulse for broadband inversion and show that refocussing of transverse magnetization occurs over the same bandwidth, albeit with a ¹³C signal phase that depends quadratically on offset. A further modification, in which one of the selective pulses on the CO region is omitted, is also presented. Implications for other 2D and 3D experiments performed at high fields, where uniform ¹³C inversion and refocussing is desirable, are discussed.     

Effects of spray-drying and storage on astaxanthin content of <Emphasis Type="Italic">Haematococcus pluvialis</Emphasis> biomass

The main objective of this study was to evaluate the stability of astaxanthin after drying and storage at different conditions during a 9-week period. Recovery of astaxanthin was evaluated by extracting pigments from the dried powders and analysing extracts by HPLC. The powders obtained were stored under different conditions of temperature and oxygen level and the effects on the degradation of astaxanthin were examined. Under the experimental conditions conducted in this study, the drying temperature that yielded the highest content of astaxanthin was 220°C, as the inlet, and 120°C, as the outlet temperature of the drying chamber. The best results were obtained for biomass dried at 180/110°C and stored at −21°C under nitrogen, with astaxanthin degradation lower than 10% after 9 weeks of storage. A reasonable preservation of astaxanthin can be achieved by conditions 180/80°C, −21°C nitrogen, 180/110°C, 21°C nitrogen, and 220/80°C, 21°C vacuum: the ratio of astaxanthin degradation is equal or inferior to 40%. In order to prevent astaxanthin degradation of Haematococcus pluvialis biomass, it is recommended the storage of the spray dried carotenized cells (180/110oC) under nitrogen and −21°C.     

Temperature and calcium ions affect aggregation of mesenchymal stem cells in phosphate buffered saline

Bone marrow-derived mesenchymal stem cells (MSC) are being extensively studied as potential therapeutic agents for various diseases and have demonstrated tremendous promise to date. To reduce immunological and inflammatory reaction upon delivery of MSC in situ, the cells are often suspended in protein-free and nutrient-poor buffered saline solution at high titers and kept on ice (0 °C) until completion of the transplantation procedure. This study investigated the effects of suspending MSC (5 × 10⁶ cells/mL) in phosphate buffered saline (PBS) with and without calcium, over a time course of 90 and 180 min, at temperatures of 0 and 37 °C. The results at 0 °C showed a small but significant decrease in cell viability within calcium-free PBS after 180 min, whereas no significant changes in cell viability were observed with PBS containing calcium. Additionally, it was observed that significant aggregation of MSC into cellular clumps occurred when incubated in PBS at 0 °C, with a higher degree of aggregation occurring under calcium-free conditions. By contrast at 37 °C, there was a more pronounced decrease in cell viability after 90 and 180 min, but lesser aggregation of MSC both in the presence and absence of calcium. The aggregation of MSC into cellular clumps could pose an embolic hazard if delivered into the arterial vasculature in cardiac applications, can clog-up injection or infusion catheters utilized for cell delivery during surgery, and can also possibly reduce the overall efficacy of transplantation therapy.     

A Laboratory study on the visual and chemical orientation of the gastropod Nerita Fulgurans Gmelin, 1791

Behavioural responses of the gastropod Nerita fulgurans Gmelin, 1791 to flat black rectangles and intraspecific mucus trails were measured in a circular arena. Snails were tested in water either in the presence or absence of chemicals generated from a predator gastropod, Chicoreus brevifrons (Lamarck, 1822). The test hypothesis was that this snail has different behavioural responses as result of visual and chemical cue integration. Nerita fulgurans has the capacity to orient to solid targets subtending angles larger than 10° and follow its own mucus trails. In water conditioned by the predator C . brevifrons, snails exhibited an avoidance response when 10°, 20° and 45° sectors were presented, demonstrating an integration of chemical and visual information. The simultaneous presentation of two orienting cues (black sectors and mucus trails) was tested to determine the nature of the interaction. When the two cues were oriented in the same direction there was no effect. When the two cues were presented from directions 180° apart a preference for visual cues over mucus trail cues was evident when the visual angle of the visual cue subtended angles greater than 90°. This result demonstrates a hierarchical usage of the orienting references.     

A theoretical estimate of the energy barriers between stable conformations of the proline dimer.

Semi-empirical energy calculations for an internal Pro-Pro dimer are presented that take into account the nature of the flexibility of the proline ring due to its puckering. Calculations show that three stable conformations are available for the dimer: the cis (ω = 0°, ψ = 160°); the trans (ω = 180°, ψ = 160°, also referred to as trans′); and the cis′ (ω = 180°, ψ = ?40°) conformations. The best conformational pathways between these stable conformations are determined. Calculations also show that the barrier for cis′–trans′ conversion is of the same order of magnitude as that for cis–trans conversion.     

Benzyladenine and low temperature promote phase transition from juvenile to vegetative adult in bulblets of Lilium?×?formolongi ‘White Aga’ cultured in vitro

Scales excised from lily bulblets were cultured on MS medium supplemented with 0.044 or 4.4 μM BA in the dark for 180 days. The culture period was divided into stage 1 (day 0–30), stage 2 (day 31–90) and stage 3 (day 91–180). The scales were cultured at 25°C in stage 1, 25°C or 8°C in stage 2, and 25°C in stage 3. When the scales were cultured on medium with 4.4 μM BA at 25°C for 180 days, bulblets with and without an elongated stem were produced. The percentage of bulblets with elongated stems greatly increased when the scales had been cultured at 8°C in stage 2. On medium with 0.044 μM BA, only bulblets without elongated stems were produced. The diameter of shoot primodia significantly enlarged in bulblets produced on medium with 4.4 μM BA at 8°C in stage 2 and no such enlargement occurred under the other conditions. Nearly square parenchyma cells were observed in the non-elongated shoot primodia in the former bulblets but not in the latter. These cells changed into longitudinally rectangular ones in the internode of elongated stems. Procambium was arranged almost parallel to the shoot axis in the stem of bulblets in the medium with 4.4 μM BA, but not in the medium with 0.044 μM BA.     

Flow cytometric analysis from fish samples stored at low,ultra-low and cryogenic temperatures

Flow cytometry is a valuable tool in biomedical and animal sciences. However, equipment used for such analysis presents limitations at field conditions, suggesting then preservation procedures for future analysis at laboratory conditions. In this study, freezing at low (−20 °C), ultra-low (−80 °C) and cryogenic temperatures (−196 °C, i.e. liquid nitrogen) were used as preservation procedures of fish tissue. Samples were maintained in 0.9% NaCl or lysing solution, and stored at the temperatures above for 0 (fresh control), 60, 120 and 180 days of storage. After storage, the samples were thawed and proceeded to flow cytometric analysis. Storage at low temperatures (−20 °C), both in lysing and 0.9% NaCl, exhibited poor results when analyzed after 60, 120 and 180 days, showing noisy peaks, deviation in the DNA content and absence of peaks. Ultralow (−80 °C) and cryogenic (−196 °C) temperatures, both in lysing solution and 0.9% NaCl, showed good results and high quality of histograms. Both storage procedures gave similar histograms and DNA content in comparison with control group (fresh) even after 60, 120 and 180 days of storage, exhibiting the main peak at 2C content from diploid cells and a secondary peak at 4C derived from dividing cells. In conclusion, samples may be stored for 180 days at −80 °C and −196 °C in both, 0.9% NaCl or lysing solution. As cryogenic temperatures in liquid nitrogen permits indefinite storage, this procedure should be used for long-term preservation.     

Combined effect of temperature and light intensity on growth and extracellular polymeric substance production by the cyanobacterium Arthrospira platensis

The effects of light intensity and temperature on Arthrospira platensis growth and production of extracellular polymeric substances (EPS) in batch culture were evaluated using a three-level, full-factorial design and response surface methodology. Three levels were tested for each parameter (temperature: 30, 35, 40°C; light intensity: 50, 115, 180 μmol photons m⁻² s⁻¹). Both growth and EPS production are influenced mainly by the temperature factor but the interaction term temperature*light intensity also had a significant effect. In addition, conditions optimising EPS production are different from those optimising growth. The highest growth rate (0.414 ± 0.003 day⁻¹) was found at the lowest temperature (30°C) and highest light intensity (180 μmol photons m⁻² s⁻¹) tested, no optima were detectable within the given test range. Obviously, optima for growth must be at a temperature lower than 30°C and a light intensity higher than 180 μmol photons m⁻² s⁻¹. For EPS production, light intensity had a positive linear effect (optimum obviously higher than 180 μmol photons m⁻² s⁻¹), but for the temperature parameter a maximum effect was detectable at 35°C.     

Sharper angle,higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes

IntroductionCutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles.Material and methods13 males and 16 females performed cuts at different angles (45°, 90°, 135° and 180°) at maximum speed. 3D kinematics and kinetics were collected. To determine differences across cutting angles (45°, 90°, 135° and 180°) and sex (female, male), a 4 × 2 repeated measures ANOVA was conducted followed by post hoc comparisons (Bonferroni) with alpha level set at α ≤ 0.05 a priori.ResultsAt all cutting angles, males showed greater knee flexion angles than females (p < 0.01). Also, where males performed all cutting angles with no differences in the amount of knee flexion −42.53° ± 8.95°, females decreased their knee flexion angle from −40.6° ± 7.2° when cutting at 45° to −36.81° ± 9.10° when cutting at 90°, 135° and 180° (p < 0.01). Knee flexion moment decreased for both sexes when cutting towards sharper angles (p < 0.05). At 90°, 135° and 180°, males showed greater knee valgus moments than females. For both sexes, knee valgus moment increased towards the sharper cutting angles and then stabilized compared to the 45° cutting angle (p < 0.01). Both females and males showed smaller vGRF when cutting to sharper angles (p < 0.01).ConclusionIt can be concluded that different cutting angles demand different knee kinematics and kinetics. Sharper cutting angles place the knee more at risk. However, females and males handle this differently, which has implications for injury prevention.     

Protocell-like Microspheres from Thermal Polyaspartic Acid

One of the most prominent amino acids to appear in monomer-generating origin-of-life experiments is aspartic acid. Hugo Schiff found in 1897 that aspartic acid polymerizes when heated to form polyaspartylimide which hydrolyzes in basic aqueous solution to form thermal polyaspartic acid which is a branched polypeptide. We recently reported at the ISSOL 2005 Conference that commercially made thermal polyaspartic acid forms microspheres when heated in boiling water and allowed to cool. In a new experiment we heated aspartic acid at 180°C for up to 100 h to form thermal polyaspartylimide which when heated in boiling water without addition of base hydrolyzed to form thermal polyaspartic acid which upon cooling formed microspheres. Thermal polyaspartic acid microspheres appear protocell-like in the sense of being prebiotically plausible lattices or containers that could eventually have been filled with just the right additions of primordial proteins, nucleic acids, lipids, and metabolites so as to constitute protocells capable of undergoing further chemical and biological evolution. Thermal polyaspartic acid microspheres are extremely simple models of protocells that are more amenable to precise quantitative experimental investigation than the proteinoid microspheres of Sidney W. Fox. We present here scanning electron microscope images of such thermal polyaspartic acid microspheres. Figure 1 shows thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×. Figure 2 shows thermal polyaspartic acid microspheres from the same sample at a magnification of 7,000×. The thermal polyaspartic acid microspheres have a diameter of approximately 1 μm These images were viewed with a Hitachi S2460N scanning electron microscope at 20 kV acceleration voltage. Figure 1 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 3,500×.

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Figure 2 Thermal polyaspartic acid microspheres from l-aspartic acid heated at 180°C for 50 h, at a magnification of 7,000×.

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Presented at: National Workshop on Astrobiology: Search for Life in the Solar System, Capri, Italy, 26 to 28 October, 2005.     

X-pinch-based neutron source

Results are presented from experimental studies of the parameters of an X-pinch-based neutron source made of 70- to 80-μm-diameter deuterated polyethylene fibers. At currents of up to 1.7 MA and a current rise time of ～150 ns, hot plasma spots were observed in the fiber crossing region. The formation of hot spots was accompanied by the generation of short soft X-ray pulses with a duration of 2–4 ns, as well as by neutron emission. The neutron energy was measured using the time-of-flight technique in four directions, at 0°, 90°, 180°, and 270° with respect to the load axis. The mean energy of the neutrons emitted along the axis towards the anode and cathode was found to be 2.0 ± 0.2 and 2.6 ± 0.1 MeV, respectively, and that of neutrons emitted in two opposite directions along the radius, 2.5 ± 0.1 and 2.4 ± 0.1 MeV. The maximum neutron yield at a current amplitude of 1.6 MA was of 10¹⁰ neutrons per shot.     

Production of mouse fetuses using spermatozoa exposed temporarily to high temperature or continuously to room temperature after freeze-drying in Na+-free/K+-rich EGTA buffer

Present study aimed to determine to what extent freeze-dried spermatozoa were able to withstand high-temperature conditions: transient increase in storage temperature and long-term exposure to room temperature. Mouse spermatozoa were freeze-dried in EGTA/Tris-HCl buffered solution alkalinized using KOH (K-ETBS, pH 7.7), and then stored for up to 7 months at 4 °C or 25 °C. After 2 months’ storage, some of the 4°C-stored spermatozoa were exposed to 40 °C for 1 week or 1 month, then again stored at 4 °C for the remaining storage period. Following storage, rehydrated spermatozoa were injected into mouse oocytes. The resulting zygotes were assessed for chromosome damage, in vitro development up to the blastocyst stage, and post-implantation development to normal fetuses on day 18 of gestation. In storage at 4 °C, one-week exposure to 40 °C had no adverse effect on the chromosome integrity and developmental competence compared to non-exposure to 40 °C (continuous storage at 4 °C). In contrast, one-month exposure to 40 °C caused an increasing level of chromosome damage (36%, P < 0.05) and reduced frequencies of blastocysts (54%, P < 0.05) and normal fetuses (36%, P < 0.05) compared to the frequencies obtained by continuous storage at 4 °C (15%, 82% and 52%, respectively). Storage at 25 °C resulted in accumulation of chromosome damage (27%, P < 0.05), leading to decreased blastocyst formation (63%, P < 0.05). But, the frequency of normal fetus (44%) was not significantly different from that obtained by continuous storage at 4 °C. Consequently, mouse spermatozoa freeze-dried in K-ETBS withstood temporary exposure to 40 °C for 1 week. Chromosome damage accumulated in spermatozoa during storage at 25 °C.     

Unique genomic sequences in human chromosome 16p are conserved in the great apes

In humans, acute myelomonocytic leukemia (AMML) with abnormal bone marrow eosinophilia is diagnosed by the presence of a pericentric inversion in chromosome 16, involving breakpoints p13;q23 [i.e., inv(16)(p13;q23)]. A pericentric inversion involves breaks that have occurred on the p and q arms and the segment in between is rotated 180° and reattaches. The recent development of a “human micro-coatasome” painting probe for 16p contains unique DNA sequences that fluorescently label only the short arm of chromosome 16, which facilitates the identification of such inversions and represents an ideal tool for analyzing the “divergence/convergence” of the equivalent human chromosome 16 (PTR 18, GGO 17 and PPY 19) in the great apes, chimpanzee, gorilla and orangutan. When the probe is used on the type of pericentric inversion characteristic of AMML, signals are observed on the proximal portions (the regions closest to the centromere) of the long and short arms of chromosome 16. The probe hybridized to only the short arm of all three ape chromosomes and signals were not observed on the long arms, suggesting that a pericentric inversion similar to that seen in AMML has not occurred in any of these great apes. Received: 4 July 1996 / Accepted: 18 September 1996     

Identification and characterization of fermentation inhibitors formed during hydrothermal treatment and following SSF of wheat straw

A pilot plant for hydrothermal treatment of wheat straw was compared in reactor systems of two steps (first, 80°C; second, 190–205°C) and of three steps (first, 80°C; second, 170–180°C; third, 195°C). Fermentation (SSF) with Sacharomyces cerevisiae of the pretreated fibers and hydrolysate from the two-step system gave higher ethanol yield (64–75%) than that obtained from the three-step system (61–65%), due to higher enzymatic cellulose convertibility. At the optimal conditions (two steps, 195°C for 6 min), 69% of available C6-sugar could be fermented into ethanol with a high hemicellulose recovery (65%). The concentration of furfural obtained during the pretreatment process increased versus temperature from 50 mg/l at 190°C to 1,200 mg/l at 205°C as a result of xylose degradation. S. cerevisiae detoxified the hydrolysates by degradation of several toxic compounds such as 90–99% furfural and 80–100% phenolic aldehydes, which extended the lag phase to 5 h. Acetic acid concentration increased by 0.2–1 g/l during enzymatic hydrolysis and 0–3.4 g/l during fermentation due to hydrolysis of acetyl groups and minor xylose degradation. Formic acid concentration increased by 0.5–1.5 g/l probably due to degradation of furfural. Phenolic aldehydes were oxidized to the corresponding acids during fermentation reducing the inhibition level.     

Effect of heat stress on development in vitro and in vivo and on synthesis of heat shock proteins in porcine embryos

The present study was conducted (1) to examine the effect of an acute increase in ambient temperature on the development of porcine day 6 embryos in culture and after transfer to recipient gilts, and (2) to analyze intracellular production of heat shock proteins (hsps). The viability of porcine day 6 embryos following a temporary acute elevation in ambient temperature (at 42°–45.5°C and for 10–180 min) was examined. Synthesis of 70 kDa hsp (hsp 70) and 90 kDa hsp (hsp90) was determined by SDS-PAGE and Western blot analysis in porcine day 6 embryos subjected to heat stresses. Nonheat-stressed embryos were considered as control. Significantly higher numbers of viable nuclei were observed in treatment groups of 42°C-10 min (236.6 ± 71.4; P < 0.05) and 43°C-30 min (276.8 ± 89.4; P < 0.005) compared to control (173.9 ± 53.9). The 42°C-180 min group (158.0 ± 27.1 μm) had a greater increase in diameter after 24 hr in culture following heat stress compared to control (82.5 ± 47.3 μm), while heat stress with 43°C for ≧60 min, 44°–44.5°C for ≧30 min, or 45°-45.5°C for ≧10 min impaired their survival, as assessed by differences in number of viable nuclei. The embryos subjected to heat stresses under the conditions of 42°C-180 min, 43°C-10 min, 43°C-30 min, 44°C-10 min, or 45°C-10 min developed to normal piglets after transfer to recipient gilts. Overall pregnancy rate was 75% (6/8), and farrowing rate 62.5% (5/8). Of heat-stressed embryos transferred, 59% (36/61) developed to normal piglets. Heat-stress conditions of 42°C for 180 min, 43°C for 30 min, 44°C for 10 min, and 45°C for 10 min were determined as critical with respect to the in vitro and in vivo survival of porcine embryos. Porcine day 6 embryos constitutively synthesized hsp70 even without heat stress, while hsp90 was detected only at trace level. Neither hsp70 nor hsp90 levels increased in the embryos subjected to heat stresses. In conclusion, porcine day 6 embryos could continue to develop in vivo or during in vitro culture after exposure to acute and temporary rise in temperature. However, no increase of hsp70 and hsp90 was observed in the heat-stressed porcine embryos, while hsp70 was detected in the nonheat-stressed porcine embryos. The precise mechanism of the thermotolerance was unclear. © 1996 Wiley-Liss, Inc.     

Distortions of length perception

A combined influence of stimulus orientation and structure on the judgement of length was tested in psychophysiological experiments. The subjects adjusted the test part of a stimulus to be equal in length to the reference part. The orientation of the parts of the stimulus varied in the experiments. The stimuli (three dots or the Oppel-Kundt figure, which had ten dots within the filled part) were generated on the monitor. In the Oppel-Kundt figure, the filled part was considered as a reference and the empty part as a test. In sessions of the experiments, values of errors were measured as functions of the size and orientation of the stimulus. The reference part length varied within 14–150 min arc range, and the orientation was fixed in 0°, 90°, 180° or 270° positions. The orientation of the test part varied from 0° to 360° in 7° steps. We assume, that the experiments with the three-dot stimuli yielded pure characteristics of visual field anisotropy, while those with the Oppel-Kundt figure showed the combined effect of both the components (anisotropy and spatial filtering). The data demonstrated independence of the two factors from each other in a simultaneous manifestation. The characteristics of a pure Oppel-Kundt illusion have been found to be in close correspondence with the predictions of the model of spatial filtering. Received: 1 July 1998 / Accepted in revised form: 4 November 1998     

Cold storage of the egg parasitoids Trissolcus basalis (Wollaston) and Telenomus podisi Ashmead (Hymenoptera: Scelionidae)

Adults of Trissolcus basalis and Telenomus podisi were stored either at 15 or 18 °C after their immature development had been completed at 18 or 25 °C. Longevity of the parasitoids in the storage temperatures was evaluated, as well as fecundity and longevity following their return to 25 °C after different periods in reproductive diapause. Temperature during immature development influenced female longevity and highest mean longevity was obtained for females that developed to the adult stage at 25 °C and then were stored at 15 °C (ca. 13 months for T. basalis and 10 months for Te. podisi). For adults of T. basalis that developed at 25 °C, storage periods of 120 or 180 days at 15 or 18 °C did not affect fecundity. The fecundity of T. basalis females that developed at 18 °C and were stored for 120 days at 15 or 18 °C was not affected; however, after remaining for 180 days, fecundity was reduced in ca. 30 and 50%, respectively. Storage of Te. podisi adults at 15 or 18 °C significantly reduced fecundity. It is concluded that adults of T. basalis can be stored in the adult stage at 15 or 18 °C between two soybean crop seasons for mass production purposes, aiming the biological control of stink bugs.     

Knee flexor strength and bicep femoris electromyographical activity is lower in previously strained hamstrings

The aim of this study was to determine if athletes with a history of hamstring strain injury display lower levels of surface EMG (sEMG) activity and median power frequency in the previously injured hamstring muscle during maximal voluntary contractions. Recreational athletes were recruited, 13 with a history of unilateral hamstring strain injury and 15 without prior injury. All athletes undertook isokinetic dynamometry testing of the knee flexors and sEMG assessment of the biceps femoris long head (BF) and medial hamstrings (MHs) during concentric and eccentric contractions at ±180 and ±60° s^?1. The knee flexors on the previously injured limb were weaker at all contraction speeds compared to the uninjured limb (+180° s^?1 p = 0.0036; +60° s^?1 p = 0.0013; ?60° s^?1 p = 0.0007; ?180° s^?1 p = 0.0007) whilst sEMG activity was only lower in the BF during eccentric contractions (?60° s^?1 p = 0.0025; ?180° s^?1 p = 0.0003). There were no between limb differences in MH sEMG activity or median power frequency from either BF or MH in the injured group. The uninjured group showed no between limb differences in any of the tested variables. Secondary analysis comparing the between limb difference in the injured and the uninjured groups, confirmed that previously injured hamstrings were mostly weaker (+180° s^?1 p = 0.2208; +60° s^?1 p = 0.0379; ?60° ^?1 p = 0.0312; ?180° s^?1 p = 0.0110) and that deficits in sEMG were confined to the BF during eccentric contractions (?60° s^?1 p = 0.0542; ?180° s^?1 p = 0.0473). Previously injured hamstrings were weaker and BF sEMG activity was lower than the contralateral uninjured hamstring. This has implications for hamstring strain injury prevention and rehabilitation which should consider altered neural function following hamstring strain injury.