Using sensillum potential analysis to quantify pheromone sensing of the antennal sensilla of Apis florea Fabricius (1787), foragers and guards

Odor perception via the antennal sensilla in most honeybee species is poorly studied. We measured the antennal sensillum potential in response to Apis florea mandibular gland pheromone and showed that it is robust and reliable in forager and guard bees. Mandibular gland pheromone may be involved in signaling alarm or foraging resource depletion. Changes of antennal sensilla placodea potential of A. florea foragers and guards were measured after exposure to three concentrations of the synthetic pheromones, 2-heptanone and (Z)-11-eicosen-1-ol, using a potentiostat connected to an e-corder (ED401) with microelectrodes. The resting sensillum potential of A. florea foragers and guards were ?55.37 ± 3.44 and ?52.85 ± 5.34 mV, respectively. The sensillum potential of bees exposed to 1.0%, 5.0% and 10.0% (Z)-11-eicosen-1-ol were ?23.35 ± 0.98, ?16.78 ± 1.94 and ?24.24 ± 8.20 mV, respectively, in foragers, and ?21.95 ± 3.21, ?21.42 ± 4.73 and ?13.54 ± 4.16 mV, respectively, for guards. Exposure of bees to 1.0%, 5.0% and 10.0% 2-heptanone induced sensillum potentials of ?10.64 ± 2.44, ?44.88 ± 2.41 and ?48.84 ± 4.40 mV, respectively, in foragers and 15.85 ± 9.38, ?25.48 ± 1.43 and ?15.52 ± 6.61 mV, respectively, in guards. The highest sensillum potential was recorded in foragers exposed to 1.0% 2-heptanone. In general, except for the response to 1.0% 2-heptanone, the sensillum potentials of all bees to (Z)-11-eicosen-1-ol were higher than that of 2-heptanone. These results show that A. florea antennal sensilla in foragers and guard bees exhibit a stronger response to (Z)-11-eicosen-1-ol as compared to 2-heptanone. Our results also provide useful comparative data to explore olfactory perception in non-model honey bee species.     

Differences in preovulatory follicle dynamics and timing of preovulatory LH surge affect fertility of maiden sheep reared in semi-arid extensive conditions

In the current study follicular dynamics, pituitary function, ovulatory response and luteal activity of 30 maiden Barbarine sheep were analyzed according to oestrus occurrence and lambing outcome after oestrus synchronisation with cloprostenol. Animals were retrospectively classified in three groups named as O? (n = 7, ewes not displaying oestrus), O+L? (n = 7, ewes showing oestrus but failing to lamb) and O+L+ (n = 16; ewes showing oestrus and lambing thereafter). All the sheep ovulated and daily transrectal ultrasonographies revealed that preovulatory follicles were present at cloprostenol injection in all the animals. In sheep O+L+ and O+L?, 50% and 57% of the ovulatory follicles were the largest follicles at cloprostenol treatment (mean size of 4.1 ± 0.26 mm and 4.3 ± 0.74 mm, respectively). In O? ewes, the same percentage was higher (86%, P < 0.05 when compared to group O+L+; mean size of 4.0 ± 0.46 mm). The number of large follicles and the final diameter of the ovulatory follicles at oestrous tended thereafter to be higher in group O+L+ (1.4 ± 0.1 and 6.4 ± 0.2) than in groups O+L? (1 ± 0.2 and 5.7 ± 0.36) and O? (0.9 ± 0.2 and 5.9 ± 0.5, respectively). Conversely, the number of medium follicles at oestrus detection was higher in the group O+L? (2.1 ± 0.3, P < 0.05) than in the other two groups (1 ± 0.2 and 1 ± 0.3 for O+L+ and O? respectively). Timing of preovulatory LH surge was earlier for ewes O? (24.0 ± 4.75, P < 0.05) than for sheep O+L+ and O+L? (37.9 ± 2.45 h and 38.0 ± 4.75 h, respectively) and 94% of O+L+ ewes had a LH surge between 16 h and 64 h after cloprostenol injection compared to 57% in O+L? and O? groups (P < 0.05). Thus, maiden Barbarine sheep failing to display oestrus or conceive showed alterations in their follicular dynamics and, thereafter, pituitary function and ovulatory response.     

Cation selectivity of the plasma membrane of tobacco protoplasts in the electroporated state

Cation selectivity of the cellular membrane of tobacco culture cells (cell line ‘bright yellow-2’) exposed to pulsed electric fields in the millisecond range was investigated. The whole cell configuration of the patch clamp technique was established on protoplasts prepared from these cells. Ion selectivity of the electroporated membrane was investigated by measuring the reversal potential of currents passing through field-induced pores. To this end the membrane was hyper- or depolarized for 10 ms (prepulse); subsequently the voltage was driven to opposite polarity at a constant rate (+ 40 or ? 40 mV/ms, respectively). The experiment was started by polarizing the membrane to moderately negative or positive voltages (prepulse potential ± 150 mV) that would not induce pore formation. Subsequently, an extended voltage range was scanned in the porated state of the membrane (prepulse potential ± 600 mV). IV curves in the porated and the non-porated state (obtained at the same prepulse polarity) were superimposed to determine the voltage at which both curves intersected (‘Intersection potential’). Using a modified version of the Goldmann–Hodgkin–Katz equation relative permeabilities to Ca^2 + and various monovalent alkali and organic cations were calculated. Pores were found to be fairly cation selective, with a selectivity sequence determined to be Ca^2 + > Li⁺ > Rb⁺ ≈ K⁺ ≈ Na⁺ > TEA⁺ ≈ TBA⁺ > Cl^?. Relative permeability to monovalent cations was inversely related to the ionic diameter. By fitting a formalism suggested by Dwyer at al. (J. Gen. Physiol. 75 (1980), 469–492) the effective average diameter of field induced pores was estimated to be about 1.8 nm. Implications of these results for biotechnology and electroporation theory are discussed.     

Behavioral thermoregulation and critical thermal limits of giant keyhole limpet Megathura crenulata (Sowerby 1825) (Mollusca; Vetigastropoda)

The thermoregulatory behavior of the giant keyhole limpet Megathura crenulata was determined in a horizontal thermal gradient during the day at 18.9 °C and 18.3 °C for the night. The final preferendum determined for giant keyhole limpets was of 18.6±1.2 °C.Limpets' displacement velocity was 10.0±3.9 cm h⁻¹ during the light phase and 8.4±1.6 cm h⁻¹ during the dark phase. The thermotolerance (measured as CTMax at 50%) was determined in a keyhole limpet in three acclimation temperatures 17, 20, and 23 °C. Limpets were subjected to water increasing temperatures at a rate of 1 °C every 30 min, until they detached from the substrate. The critical thermal maximum at 50% was 27.2, 27.9 and 28.3 °C respectively.     

Discriminating the endogenous and exogenous urinary estrogens in human by isotopic ratio mass spectrometry and its potential clinical value

Estrogens were prohibited in the food producing animals by European Union (96/22/EC directive) and added to the Report on Carcinogens in United States since 2002. Due to very low concentration in serum or urine (～pg/mL), the method of control its abuse had not been fully developed.The endogenous estrogens were separated from urines of 18 adult men and women. The exogenous estrogens were chemical reference standards and over the counter preparations. Two patients of dysfunctional uterine bleeding (DUB) administered exogenous estradiol and the urines were collected for 72 h. The urinary estrogens were separated by high-performance liquid chromatography (HPLC) and confirmed. The exogenous and exogenous estrogens were analyzed by gas chromatography combustion isotope ratio mass spectrometry (GC–C–IRMS) to determine the ¹³C/¹²C ratio (δ¹³C‰).The δ¹³C‰ values of reference standard of E1, E2, and E3 were ?29.36 ± 0.72, ?27.98 ± 0.35, ?27.62 ± 0.51, respectively. The δ¹³C‰ values of the endogenous E1, E2, and E3 were ?21.62 ± 1.07, ?22.14 ± 0.98, and ?21.88 ± 1.16, with P < 0.01 (t-test). Two DUB patients’ urinary estradiol δ¹³C‰ values was depleted to ?28.02 ± 0.33 after the administration. The progesterone, 17α-hydroxyprogesterone, pregnanediol, as well as desogestrel and ethinylestradiol from contraceptives were also determined.Stable carbon isotope analysis can distinguish the endogenous and exogenous urinary estrogen in human.     

Synthesis and in vitro study of benzofuran hydrazone derivatives as novel alpha-amylase inhibitor

The α-amylase acts as attractive target to treat type-2 diabetes mellitus. Therefore in discovering a small molecule as α-amylase inhibitor, we have synthesized benzofuran carbohydrazide analogs (1–25), characterized through different spectroscopic techniques such as ¹HNMR and EI-MS. All screened analog shows good α-amylase inhibitory potentials with IC₅₀ value ranging between 1.078 ± 0.19 and 2.926 ± 0.05 µM when compared with acarbose having IC₅₀ = 0.62 ± 0.22 µM. Only nine analogs among the series such as analogs 3, 5, 7, 8, 10, 12, 21, 23 and 24 exhibit good inhibitory potential with IC₅₀ values 1.644 ± 0.128, 1.078 ± 0.19, 1.245 ± 0.25, 1.843 ± 0.19, 1.350 ± 0.24, 1.629 ± 0.015, 1.353 ± 0.232, 1.359 ± 0.119 and 1.488 ± 0.07 µM when compare with standard drug acarbose. All other analogs showed good to moderate α-amylase inhibitory potentials. The SAR study was conducted on the basis of substituent difference at the phenyl ring. The binding interaction between analogs and active site of enzyme was confirmed by docking studies.     

Different effects of ATP on the contractile activity of mice diaphragmatic and skeletal muscles

Apart from acetyl-choline (Ach), adenosine-5′-trisphosphate (ATP) is thought to play a role in neuromuscular function, however little information is available on its cellular physiology. As such, effects of ATP and adenosine on contractility of mice diaphragmatic and skeletal muscles (m. extensor digitorum longa—MEDL) have been investigated in in vitro experiments. Application of carbacholine (CCh) in vitro in different concentrations led to pronounced muscle contractions, varying from 9.15 ± 4.76 to 513.13 ± 15.4 mg and from 44.65 ± 5.01 to 101.46 ± 9.11 mg for diaphragm and MEDL, respectively. Two hundred micromolars of CCh in both muscles caused the contraction with the 65% (diaphragm) to 75% (MEDL) of maximal contraction force—this concentration was thus used in further experiments. It was found that application of ATP (100 μM) increased the force of diaphragmatic contraction caused by CCh (200 μM) from 335.2 ± 51.4 mg (n = 21) in controls to 426.5 ± 47.8 mg (n = 10; P < 0.05), but decreased the contractions of MEDL of CCh from 76.6 ± 6.5 mg (n = 26) in control to 40.2 ± 9.0 mg (n = 8; P < 0.05). Application of adenosine (100 μM) had no effect on CCh-induced contractions of these muscles.Resting membrane potential (MP) measurements using sharp electrodes were done at 10, 20 and 30 min after the application of ATP and adenosine. Diaphragm showed depolarization from 75 ± 0.6 down to 63.2 ± 1.05, 57.2 ± 0.96 and 53.6 ± 1.1 mV after 10, 20 and 30 min of exposition, respectively (20 fibers from 4 muscles each, P < 0.05 in all three cases). Adenosine showed no effect on diaphragmatic MP. Both agents were ineffective in case of MEDL.The effects of ATP in both tissues were abolished by suramin (100 μM), a P2-receptor antagonist, and chelerythrin (50 μM), a specific protein-kinase C (PKC) inhibitor, but were not affected by 1H-[1,2,4]-oxadiazolo-[4,3-α]-quinoxalin-1-one (ODQ, 1 μM), a guanylyl-cyclase inhibitor, or by adenosine-3,5-monophosphothioate (Rp-cAMP, 1 μM), a protein-kinase A (PKA) inhibitor.Besides the action on contractile activity, ATP (100 μM) led to a significant (P < 0.001) depolarization of diaphragm muscle fibers from 74.5 ± 2.3 down to 64 ± 2.1, 58.2 ± 2.2 and 54.3 ± 2.4 mV after 10, 20 and 30 min of incubation, respectively. Incubation of MEDL with the same ATP concentration showed no significant change of MP.Denervation of the muscles for 28 days led to a decrease of CCh-induced contractions of diaphragm down to 171.1 ± 34.5 mg (n = 11, P < 0.05), but increased the contractile force of MEDL up to 723.9 ± 82.3 mg (n = 9, P < 0.01). Application of ATP elevated the contractility of denervated diaphragm caused by CCh up to normal values (311.1 ± 79.7 mg, n = 6, P > 0.05 versus control), but did not significantly affect of contractility of MEDL, which became 848.1 ± 62.7 mg (n = 6).These results show that the effects of ATP on both diaphragmatic and skeletal muscles are mediated through P2Y receptors coupled to chelerytrin-sensitive protein-kinase C.     

Endocrine responses and milk emission characteristics in high yielding Alpine dairy goats under once daily milking management

This study was done to verify if the lack of increase of milk fat content observed in Alpine dairy goats under once daily milking (ODM) compared to twice daily milking (TDM), results from disturbances of animals and/or milk ejection reflex. In this respect, we determined the milk yield and composition in the same 12 multiparous Alpine dairy goats when they were managed first under TDM (period 1: P1) and then under ODM (period 2: P2). Furthermore, oxytocin (OT) and cortisol (CORT) releases and milk emission kinetic of these goats were measured at morning milking 2 and 4 times in P1 and P2, respectively.ODM compared to TDM, caused 18 and 23% reductions, respectively in daily milk yield and milk fat content without milk protein content modification.Although baseline concentration of blood OT was lower under ODM than TDM management (7.0 pg/mL vs 17.8 ± 2.0 pg/mL, respectively), ODM did not modify the total amount of OT released during milking (15,484 pg/mL/32 min vs 18,996 ± 2865.3 pg/mL/32 min, respectively), the peak concentration of OT (57.2 pg/mL vs 73.6 ± 10.5 pg/mL, respectively) or the time to reach it (3.0 min vs 2.0 ± 0.5 min, respectively) by comparison to TDM.ODM compared to TDM, never modified the baseline concentrations of CORT (6.1 ng/mL vs 7.1 ± 1.1 ng/mL, respectively), the total amount of CORT released (11,727 ng/mL/32 min vs 10,073 ± 1522.2 ng/mL/32 min, respectively), the peak concentrations of CORT (16.1 ng/mL vs 15.1 ± 2.1 ng/mL, respectively) and the time to reach it (13.1 min vs 11.0 ± 1.5 min).During ODM, milk flow latency was reduced (−61%) while the mean flow rate was increased (+28%) by comparison to TDM. ODM compared to TDM management, did not modify the maximum flow rate (1.6 L/min vs 1.6 ± 0.2 L/min, respectively) or the time to reach this maximum (103.0 s vs 95.0 ± 10.0 s, respectively). The total milking duration at morning milking was not different (250.0 s vs 221.0 ± 22.0 s, respectively) although the morning milk yield was significantly higher under ODM management (2.63 kg/d vs 1.87 ± 0.1 kg/d, respectively).This results show that milk emission is improved under ODM management in Alpine goats without inhibition or disturbance of neuro-hypophyseal OT release pattern and lack of activation of the hypothalamic–pituitary–adrenal axis and plasma cortisol increase, disproving our initial hypotheses of a disturbance of animals and/or incomplete milk ejection to explain the low fat content of milk under ODM in this breed.     

Electroporation by subnanosecond pulses

Electropermeabilization of cell membranes by micro- and nanosecond-duration stimuli has been studied extensively, whereas effects of picosecond electric pulses (psEP) remain essentially unexplored. We utilized whole-cell patch clamp and Di-8-ANEPPS voltage-sensitive dye measurements to characterize plasma membrane effects of 500 ps stimuli in rat hippocampal neurons (RHN), NG108, and CHO cells. Even a single 500-ps pulse at 190 kV/cm increased membrane conductance and depolarized cells. These effects were augmented by applying brief psEP bursts (5–125 pulses), whereas the rate of pulse delivery (8 Hz–1 kHz) played little role. psEP-treated cells displayed large inward current at negative membrane potentials but modest or no conductance changes at positive potentials. A 1-kHz burst of 25 pulses increased the whole-cell conductance in the range (?100)–(?60) mV to 22–26 nS in RHN and NG108 cells (from 3 and 0.7 nS, respectively), but only to 5 nS in CHO (from 0.3 nS). The conductance increase was reversible within about 2 min. Such pattern of cell permeabilization, with characteristic inward rectification and slow recovery, was similar to earlier reported effects of 60- and 600-ns pulses, pointing to the similarity of structural membrane rearrangements in spite of a different membrane charging mechanism.     

Male and female Popillia quadriguttata (Fabricius) and Protaetia brevitarsis (Lewis) (Coleoptera: Scarabaeidae) response to Japanese beetle floral and pheromone lures

Popillia quadriguttata (Fabricius), and Protaetia brevitarsis (Lewis) adults were captured with Japanese beetle, Popillia japonica Newman, sex attractant and floral lures at Changchun, China during July–August 2012. The floral lure (phenethyl propionate:eugenol:geraniol, 3:7:3) was attractive to male and female P. quadriguttata (AV: 1.2 ± 0.9; 1.1 ± 0.3; total: 2.3 ± 0.8), and was similar in attraction to the combination of the sex attractant (SA) [(R, Z)-5-(1-decenyl) dihydro-2(3H)-furanone] plus the floral lure for male (1.60 ± 0.2), female (1.30 ± 1.1) and total captures (2.9 ± 3.0). However, the SA alone captured only males in much higher numbers than when combined with the floral lure (10.0 ± 6.4). In a separate earlier test, the greatest number of P. quadriguttata males (12.5 ± 3.0), female (12.2 ± 1.5) and total captures (24.7 ± 2.5) was in yellow, laboratory-made, bottle traps. The floral lure also attracted female Pro. brevitarsis (10.0 ± 3.4), while the SA attracted only few male beetles (1.0 ± 0.2). The combination SA + floral lure captured similar females (11.0 ± 2.0) and total (14.2 ± 2.2) Pro. brevitarsis as the floral lure alone. Two butterflies, Colias erate poliographus (Motschulsky) and Pieris rapae (Linnaeus), were also attracted to the floral lure. These studies indicate a potential for replacing pesticides by using the Japanese beetle lures for monitoring and control of several insects in China, and that they would be useful in monitoring and eradication of two potential scarab pests, P. quadriguttata and Pro. brevitaris, in the United States and Europe.     

Neuromuscular and psychological influences on range of motion recovery in anterior cruciate ligament reconstruction patients

To identify distinguishing characteristics for knee surgery patients who experience a protracted recovery process, we sought to determine if there is an association between the neuromuscular stretch reflex and psychological factors of pain perception and anxiety on the range of motion (ROM) recovery rate of post-operative anterior cruciate ligament reconstruction (ACLR) rehabilitation patients. The ACLR participants were categorized into a slow recovery group (SRG: >6 weeks to recover 0–125° knee flexion [n = 10]) and a normal recovery group (NRG: <6 weeks to recovery 0–125° knee flexion [n = 12]). Control participants (n = 22) were age, gender and activity-level matched to the surgical participants. Neuromuscular testing consisted of sagittal plane video kinematics of the Wartenberg Pendulum Test for determining lower limb stiffness indices and electromyography-monitored patellar tendon tap reflex responses. Psychological and health status assessments consisted of the State–Trait Anxiety Inventory and SF-36? Health Survey. Data revealed that neuromuscular reflex profiles, lower limb stiffness indices, pain, anxiety and SF-36? indices of function were not significantly different between the two surgical groups (SRG and NRG). The surgical groups exhibited significantly greater pain (2.67 ± 2.27 SRG, 1.49 ± 1.15 NRG) than the control group (p ? .05). SF-36? indices were significantly lower for the surgical groups for total score (546.55 ± 94.70 SRG, 577.57 ± 125.58 NRG), function 69.00 ± 20.24 SRG, 67.08 ± 19.12 NRG), role physical (53.75 ± 22.85 SRG, 53.12 ± 23.15 NRG), social (76.24 ± 25.31 SRG, 65.62 ± 27.24 NRG), and emotional (82.49 ± 19.81 SRG, 81.38 ± 23.02 NRG) subscales (p ? .05). These results suggest that neuromuscular reflex responses, visual analogue scale (VAS) pain, and anxiety are not distinguishing factors for ROM recovery rate between the SRG and NRG. Decreased SF-36? indices, including pain as it influences function, though clinically relevant factors, were not statistically associated with post-operative ROM recovery rate.     

Comparison of the lipid properties of captive,healthy wild,and pansteatitis-affected wild Nile crocodiles (Crocodylus niloticus)

The results presented describe and compare the fatty acid composition and melting properties of captive, healthy wild, and pansteatitis-affected wild crocodiles (Crocodylus niloticus). Differences in fatty acid composition between intramuscular and adipose fat is noted in captive crocodiles, and the latter differs from wild crocodiles as a result of different diets. Adipose fat of healthy wild crocodiles differs minimally from diseased ones, respectively with 37.3 ± 2.6% vs. 43.2 ± 2.3% monounsaturated fatty acids, and 43.2 ± 2.9% in dead crocodiles, while polyunsaturated fatty acids decrease from 27.3 ± 1.9% to as low as 21.9 ± 3.6% respectively. Of the unsaturated fatty acids 18:2n? 6 decreased from 6.5 ± 2.6% in unaffected crocodiles to 3.5 ± 0.6% in highly affected and 3.2 ± 0.4% in dead crocodiles, and 22:5n?3 from 2.8 ± 0.6% to 1.8 ± 0.3% and 2.2 ± 0.3% respectively. The melting properties as determined by differential scanning calorimetry show that extracted adipose fat is a small degree softer in pansteatitis-affected tissue, specifically in the temperature range 7–36 °C, and does not contribute to the hard texture noted for adipose fat tissue of pansteatitis-affected animals. A high moisture content of 51.0 ± 19.7% of the fat tissue of pansteatitis-affected animals vs.17.1 ± 8.0% of healthy ones, suggests that physiological changes due to interstitial inflammation may contribute to the hard texture.     

Enhancement of pilot scale production of l(+)-lactic acid by fermentation coupled with separation using membrane bioreactor

Traditional batch fermentation leads to a higher energy consumption and lower production capability because of longer culture time. In this work, a pilot scale bioreactor composed of a 3000 L fermentor and external ceramic microfiltration equipment was used to perform cell-recycle fermentation. Repeat feeding medium was also used to relieve the substrate inhibition. In such pilot system, the maximum yield and productivity of l(+)-lactic acid production reached 157.22 ± 3.42 g/L and 8.77 ± 0.15 g/L/h which were 4.23% and 315.64% higher than those of batch fermentation, respectively, when equal amount of sugar was consumed. The cost of l(+)-lactic acid production was successfully reduced about two-thirds by the increase of yield and productivity. 12 rounds of cell-recycle fermentations were successfully achieved in the pilot system. The membrane filtration productivity reached to 61.27 ± 2.74 L/m²/h which increased 172.80%, while the cell damaging rate dropped to 3.88 ± 0.18% which decreased 85.77%, compared with those of the ultrafiltration. Furthermore, the ceramic microfiltration membrane showed advantages in tolerance for the temperature, pressure and acid, compared with the organic ultrafiltration membrane. The experimental results indicated that the method could give a reference for low cost production of l(+)-lactic acid in an industrial scale.     

Phytosynthesis of silver nanoparticles from Jatropha integerrima Jacq. flower extract and their possible applications as antibacterial and antioxidant agent

Jatropha integerrima Jacq. flower extract was used for the synthesis of silver nanoparticles in the current study. Various spectroscopic analyses were used to characterize the synthesized nanoparticles (JIF-AgNPs). The antibacterial efficacy of JIF-AgNPs was studied by well diffusion and microdilution techniques. In addition, the impact of JIF-AgNPs on free radicals was evaluated. On the ultraviolet–visible spectrum, the nanoparticles exhibit the highest absorbance at 422 nm. Based on the Fourier transform infrared spectrum, phenols and amino acids were involved in capping the JIF-AgNPs. Crystalline sphere-shaped nanoparticles with an average size of 50.07 nm and zeta potential of ?19.0 mV were confirmed by X-ray diffraction, transmission electron microscopy, and dynamic light scattering analysis respectively. The JIF-AgNPs exhibit the highest and lowest growth inhibitory activity towards E. coli and B. subtilis. The minimal inhibitory concentration of JIF-AgNPs against E. coli, K. pneumoniae, S. aureus, and B. subtilis were 2.5, 5.0, 5.0, and 7.5 μg/mL, respectively. The JIF-AgNPs exhibited significant radical scavenging activities against DPPH (IC₅₀-32.5 ± 0.06 µg/mL), hydroxyl (IC₅₀-25 ± 0.09 µg/mL), Superoxide (IC₅₀-42.5 ± 0.13 µg/mL), and ABTs (IC₅₀-33.5 ± 0.15 µg/mL). Thus, synthesized nanoparticles were a good alternative to develop an antibacterial and antioxidant agent.     

Voluntary activation of trapezius measured with twitch interpolation

This study investigated the feasibility of measuring voluntary activation of the trapezius muscle with twitch interpolation. Subjects (n = 8) lifted the right shoulder or both shoulders against fixed force transducers. Stimulation of the accessory nerve in the neck was used to evoke maximal twitches in right trapezius. The twitch-like increments in force (superimposed twitches) evoked during different strength voluntary contractions were linearly related to voluntary force (r = ?0.82 to ?0.99). Hence, voluntary activation could be quantified by twitch interpolation with this stimulus. Comparison of unilateral and bilateral MVCs showed that maximal voluntary force was greater in unilateral than bilateral efforts (92.7 ± 2.9% and 82.3 ± 5.8% MVC, respectively) but voluntary activation was similar (88.6 ± 9.6% and 91.7 ± 5.2%). Trapezius is commonly affected in work-related musculoskeletal disorders. Measurement of voluntary activation will be a useful technique to demonstrate whether the reduced maximal voluntary force reported in such disorders is due to muscular or neural factors.     

Effects of abamectin and deltamethrin to the foragers honeybee workers of Apis mellifera jemenatica (Hymenoptera: Apidae) under laboratory conditions

This study aimed at evaluating the toxicity of some insecticides (abamectin and deltamethrin) on the lethal time (LT₅₀) and midgut of foragers honeybee workers of Apis mellifera jemenatica were studied under laboratory conditions. The bees were provided with water, food, natural protein and sugar solution with insecticide (concentration: 2.50 ppm deltamethrin and 0.1 ppm abamectin). The control group was not treated with any kind of insecticides. The mortality was assessed at 1, 2, 4, 6, 12, 24, 48, and 72 hour (h) after insecticides treatment and period to calculate the value of lethal time (LT₅₀). But the samples the histology study of midgut collected after 24 h were conducted by Scanning Electron Microscope. The results showed the effects of insecticides on the current results show that abamectin has an adverse effect on honeybees, there is a clear impact on the lethal time (LT₅₀) was the abamectin faster in the death of honeybee workers compared to deltamethrin. Where have reached to abamectin (LT₅₀ = 21.026) h, deltamethrin (LT₅₀ = 72.011) h. However, abamectin also effects on cytotoxic midgut cells that may cause digestive disorders in the midgut, epithelial tissue is formed during morphological alterations when digestive cells die. The extends into the internal cavity, and at the top, there is epithelial cell striated border that has many holes and curves, abamectin seems to have crushed the layers of muscle. Through the current results can say abamectin most toxicity on honeybees colony health and vitality, especially foragers honeybee workers.     

δ15N and δ13C diet–tissue discrimination factors for large sharks under semi-controlled conditions

Stable isotopes (δ¹⁵N and δ¹³C) are being widely applied in ecological research but there has been a call for ecologists to determine species- and tissue-specific diet discrimination factors (?¹³C and ?¹⁵N) for their study animals. For large sharks stable isotopes may provide an important tool to elucidate aspects of their ecological roles in marine systems, but laboratory based controlled feeding experiments are impractical. By utilizing commercial aquaria, we estimated ?¹⁵N and ?¹³C of muscle, liver, vertebral cartilage and a number of organs of three large sand tiger (Carcharias taurus) and one large lemon shark (Negaprion brevirostris) under a controlled feeding regime. For all sharks mean ± SD for ?¹⁵N and ?¹³C in lipid extracted muscle using lipid extracted prey data were 2.29‰ ± 0.22 and 0.90‰ ± 0.33, respectively. The use of non-lipid extracted muscle and prey resulted in very similar ?¹⁵N and ?¹³C values but mixing of lipid and non-lipid extracted data produced variable estimates. Values of ?¹⁵N and ?¹³C in lipid extracted liver and prey were 1.50‰ ± 0.54 and 0.22‰ ± 1.18, respectively. Non-lipid extracted diet discrimination factors in liver were highly influenced by lipid content and studies that examine stable isotopes in shark liver, and likely any high lipid tissue, should strive to remove lipid effects through standardising C:N ratios, prior to isotope analysis. Mean vertebral cartilage ?¹⁵N and ?¹³C values were 1.45‰ ± 0.61 and 3.75‰ ± 0.44, respectively. Organ ?¹⁵N and ?¹³C values were more variable among individual sharks but heart tissue was consistently enriched by ~ 1–2.5‰. Minimal variability in muscle and liver δ¹⁵N and δ¹³C sampled at different intervals along the length of individual sharks and between liver lobes suggests that stable isotope values are consistent within tissues of individual animals. To our knowledge, these are the first reported diet–tissue discrimination factors for large sharks under semi-controlled conditions, and are lower than those reported for teleost fish.     

Nutritional value of Chlorella vulgaris: Effects of ultrasonication and electroporation on digestibility in rats

Three processed products derived from the green algae C. vulgaris were investigated: (1) spray-dried only (S-DA); (2) spray-dried and electroporated (ES-DA); (3) spray-dried; ultrasonicated treated (US-DA). A nitrogen-balance study was performed. Male growing Wistar rats, housed separately in metabolism cages, were fed the three algal products as the sole protein source at 150 mg N per 100 g of body weight. A control group of rats was fed with casein at a level to give the same protein nitrogen intake. The coefficients of total intestinal tract apparent crude protein digestibility for the different C. vulgaris products were: S-DA = 0.47 ± 0.127% (mean ± S.D.), ES-DA = 0.44 ± 0.075%, US-DA = 0.57 ± 0.137%. Protein efficiency ratio was 1.4 ± 0.3, 1.0 ± 0.5 and 2.1 ± 0.3, respectively. N-balance was 41.86 ± 32.8 mg, 31.3 ± 17.3 mg and 66.7 ± 30.1 mg, respectively. The biological value was 93 ± 9.5%, 93.6 ± 10%, and 101 ± 5%, respectively. The coefficient of total intestinal tract apparent crude protein digestibility and biological value of C. vulgaris was enhanced by ultrasonic treatment and reduced by electroporating, thus ultrasonication may be a helpful technological process in practical processing of green algae in food industry.     

Acute effect of heel-drop exercise with varying ranges of motion on the gastrocnemius aponeurosis-tendon’s mechanical properties

The objectives of this study was to investigate the acute effects of various magnitudes of tendon strain on the mechanical properties of the human medial gastrocnemius (MG) in vivo during controlled heel-drop exercises. Seven male and seven female volunteers performed two different exercises executed one month apart: one was a heel-drop exercise on a block (HDB), and the other was a heel-drop exercise on level floor (HDL). In each regimen, the subjects completed a session of 150 heel-drop exercises (15 repetitions × 10 sets; with a 30 s rest following each set). Before and immediately after the heel-drop exercise, the ankle plantar flexor torque and elongation of the MG were measured using a combined measurement system of dynamometry and ultrasonography and then the MG tendon strain and stiffness were evaluated in each subject. The tendon stiffness measured prior to the exercises was not significantly different between the two groups 23.7 ± 10.6 N/mm and 24.1 ± 10.0 N/mm for the HDB and HDL, respectively (p > .05). During the heel-drop exercise, it was found that the tendon strain during the heel-drop exercise on a block (8.4 ± 3.7%) was significantly higher than the strain measured on the level floor (5.4 ± 3.8%) (p < .05). In addition, the tendon stiffness following the heel-drop exercise on a block (32.3 ± 12.2 N/mm) was significantly greater than the tendon stiffness measured following the heel-drop exercise on the level floor (25.4 ± 11.4 N/mm) (p < .05). The results of this study suggest that tendon stiffness immediately following a heel-drop exercise depends on the magnitude of tendon strain.