Foraging behaviour of Scymnus coccivora Ayyar against cotton mealybug Phenacoccus solenopsis Tinsley

Predation is one of the significant biotic mortality factors reducing the insect pest population as functional response and the numerical response of the predator are the key factor regulating the population dynamics of predator prey species. This study is aimed to evaluate the functional response of all the developmental stages of Scymnus coccivora Ayyar (Coleoptera: Coccinellidae) against the different densities of cotton mealybug, Phenacoccus solenopsis (Tinsley) (Hemiptera: Pseudococcidae) and the numerical response of female predator. Experiments were carried out in controlled environment laboratory conditions at 25 ± 1 °C temperature, 60 ± 5% relative humidity and photoperiod of 16 h. Number of eggs consumed, number of eggs laid and the Efficiency of Conversion of Ingested food (ECI) were recorded daily. Results from the study revealed that all the developmental stages of S. coccivora exhibited a Type II response. Different parameters such as attack rate (a’), handling time (T_h) and the maximum rate of predation were estimated using Roger’s random attack equation and Holling Disc equation in which Rogers random attack equation was found best fit. Female has shown the highest attack rate (a’) followed by IV^th instar grub, male, III^rd, II^nd and I^st instar grub. With low handling time, IV^th instar grub has shown maximum predation rate of 76.40 per day followed by female (75.86), male (58.79), III^rd (22.84), II^nd (19.65) and I^st instar grub (15.39). The numerical response increase was curvilinearly related to different prey densities with the highest number of eggs (11.8 ± 3.44) produced at highest prey density (160). The Efficiency of Conversion of Ingested food (ECI) was highest (64.49 ± 8.03) at prey density of 10. Understanding the factors that lead to variation in functional response of predator in natural population will advance our understanding of the effects of predation on individual and the effectiveness of coccinellid predators as biocontrol agent against cotton mealybug.     

Predation potential and biology of Protogamasellopsis posnaniensis Wisniewski & Hirschmann (Acari: Rhodacaridae)

Rhodacaridae are cosmopolitan mites mentioned as predators, although nothing is known about their potential as biological control agents. One of the objectives of the work reported in this paper was to evaluate the potential of Protogamasellopsis posnaniensis (Acari: Rhodacaridae) as predator of representative species of insects of the families Sciaridae (Bradysia matogrossensis (Lane)) and Thripidae (Frankliniella occidentalis (Pergande)), of mites of the family Acaridae (Tyrophagus putrescentiae (Schrank) and Rhizoglyphus echinopus (Fumouze & Robin) and of nematodes of the family Rhabditidae (Protorhabditis sp.). Another objective was to determine the biological cycle of P. posnaniensis when fed the prey on which it performed best in the preceding predation test. The study was conducted in a laboratory where the experimental units were maintained at 25 ± 1 °C, 97 ± 3% RH and in the dark. Although the predator was able to kill all prey species considered in this study, the most favorable prey were T. putrescentiae, F. occidentalis and Protorhabditis sp. Survivorship of the predator in predation tests was always 98% or higher. Life table biological parameters when the predator was fed T. putrescentiae were: R_o = 109.29; T = 19.06 days; λ = 1.28 e r_m = 0.32 female/female/day. Despite preying upon larvae of B. matogrossensis, eggs of the former can also be killed by the latter. The results indicated that P. posnaniensis is a promising biological control agent, deserving additional studies on its possible use for the control of soil pests.     

Evaluation of the efficiency of metabolism of dinoflagellate phosphorus and carbon by a planktonic ciliate

The trophic transfer of nutrients through the microbial food web is a key top-down control in aquatic ecosystems which is notoriously difficult to evaluate, particularly for planktonic protists. In this study, a sensitive dual-radioactive tracer technique was developed to simultaneously assess the ingestion rate, and carbon- and phosphorus-specific assimilation efficiencies, of the marine planktonic ciliate Strobilidium neptuni feeding on the autotrophic dinoflagellate Heterocapsa triquetra. Dinoflagellate prey were simultaneously 16 h pulse labelled with NaH¹⁴CO₃ and H₃³³PO₄ before being fed to the ciliate, and radioactive labels were traced into ciliate biomass and the experimental medium, as well as being monitored in the prey cells. Rates measured in short-term (10 min) incubations, as commonly used to estimate protist uptake of fluorescently labelled prey, were approximately 6 times higher and 3–6 times more variable than rates measured in longer 3–5 h incubations. The efficiency of accumulation of prey carbon (54±9%) by ciliates was lower than that of prey phosphorus (68±3%) suggesting that the phosphorus to carbon ratio in the ciliates was 1.3 times higher than in the labelled dinoflagellate biomass. Rates of phosphorus accumulation and release were combined to reveal that ciliates consumed 3.2±0.6 dinoflagellates cell^?1 h^?1. The assessment of carbon tracer release by ciliates was less reliable due to ¹⁴CO₂ exchange between the experimental media and air. The study concludes that the dual phosphorus–carbon radioactive tracer labelling of algal prey allowed the quantification of protist herbivory and nutrient remineralisation in laboratory experiments, thereby providing a potential technique for studying planktonic microbial trophic interactions in situ.     

Exercise time to fatigue and the critical limiting temperature: effect of hydration

The purpose of this study was to investigate the effect of active pre-warming combined with three regimens of fluid ingestion: (1) fluid replacement equal to sweat rate (FF), (2) fluid replacement equal to half the sweat rate (HF), and (3) no fluid replacement (NF). Eight males cycled to voluntary fatigue at 70% of peak power output (PPO) in 31.3±0.4°C, 63.3±1.2% relative humidity in a randomised fashion in either of FF, HF or NF conditions. For each trial the time to fatigue test was preceded by 2×20 min active pre-warming periods where subjects also cycled at 70% PPO. Subjects commenced each exercise period with identical rectal temperatures (T_re). The rate of increase in T_re for each condition during the first 20 min of active pre-warming was not different. However, the rate of increase in T_re was significantly reduced in the second active pre-warming period for all fluid conditions but no differences between conditions were noted. During the fatigue test, the rate of increase in T_re for FF was 0.29°C h⁻¹ and 0.58°C h⁻¹ for HF but were not significantly different. The rate of increase in T_re for the NF trial was 0.92°C h⁻¹ and was significantly higher compared to the FF trial. Overall mean skin temperatures and mean body temperatures were higher for NF compared to FF and HF. The rate of heat storage during the fatigue test was similar for FF (80.1±11.7 W m⁻²) and HF (73.0±13.7 W m⁻²) conditions but increased to 155.8±31.2 W m⁻² (P<0.05) in the NF trial. The results indicate that fluid ingestion equal to sweat rate has no added benefit over fluid ingestion equal to half the sweat rate in determining time to fatigue over 40 min of sub-maximal exercise in warm humid conditions. Fluid restriction accelerates the rate of increase in T_re after 40 min of exercise, thereby reducing the time to fatigue. The data support the model that anticipation of impending thermal limits reduces efferent command to working skeletal muscle ensuring cellular preservation.     

Metabolic,hygric and ventilatory physiology of the red-tailed phascogale (Phascogale calura; Marsupialia,Dasyuridae): Adaptations to aridity or arboreality?

The red-tailed phascogale is a small arboreal dasyurid marsupial that inhabits semi-arid to arid regions of Western Australia's wheat belt. Its body mass (34.7 g) is only ～15% of that predicted based on its phylogenetic position among other dasyuromorphs; we interpret this as an adaptation to its scansorial and semi-arid/arid lifestyle. The standard physiology of this species at a thermoneutral ambient temperature of 30 °C conforms to that of other dasyurid marsupials; body temperature (34.7 ± 0.37 °C), basal metabolic rate (0.83 ± 0.076 mL O₂ g^?1 h^?1), evaporative water loss (1.68 ± 0.218 mg H₂O g^?1 h^?1) and wet thermal conductance (3.8 ± 0.26 J g^?1 h^?1 °C^?1) all fall within the 95% predication limits for the respective allometric relationships for other dasyurid species. Thermolability confers an energy savings at low T_a and water savings at high T_a. Torpor, observed at low T_a, was found to be more beneficial for energy savings than for water economy. The red-tailed phascogale therefore has a physiology suitable for the challenges of arid environments without any obvious requirement for adaptations to its scansorial lifestyle, other than its considerably lower-than-expected body mass.     

Temperature-dependent functional response of Scolothrips longicornis (Thysanoptera: Thripidae) preying on Tetranychus urticae

Environmental variables like temperature are important factors that affect the efficiency of biological control agents in greenhouse crops. This study examined the effect of temperature on the functional response of an acarophagous thrips Scolothrips longicornis Priesner to different densities of two spotted spider mite, Tetranychus urticae Koch in laboratory conditions. Five constant temperatures (15, 20, 26, 30, and 35 °C) and seven prey densities (2, 4, 8, 16, 32, 64, and 128) were used in the experiments. At each temperature, 2 to 128 adult of T. urticaue were exposed to a female S. longicornis for a 24 h period. The results indicated that the predatory thrips exhibited type II functional response to different densities of T. urticae at all examined temperatures. Temperature had significant effect on the predation capacity of the adult thrips over the range of 15–35 °C. Instantaneous attack rate (a) of the predator increased linearly with increasing temperature from 15 to 35 °C. At 35 °C, the highest instantaneous attack rate was estimated to be 0.0579 day^? 1 using the Holling model and 0.1480 day^? 1 using Rogers model. The estimated value of handling time (T_h) using both Holling and Rogers models decreased linearly with increasing temperature from 15 to 35 °C. Scolothrips longicornis achieved higher predation at higher temperature (16.1 preys/day at 35 °C). This observation suggested that S. longicornis may be more effective for biological control of two spotted spider mite in warmer conditions.     

Treatment of municipal wastewater using laterite-based constructed soil filter

The present study reports the performance of municipal wastewater treatment plant located at Mumbai, India using laterite soil-based constructed soil filter (CSF) system monitored over 17 months. The results indicated increase in dissolved oxygen levels and reduction of chemical oxygen demand (COD) from 135.4 ± 79.4 to 28.8 ± 19.5 mg/L with first order rate constant (K_d) of 0.23 h^?1. The bio-chemical oxygen demand (BOD) reduced from 92 to less than 10 mg/L with K_d of 0.35 h^?1; suspended solids reduction from mean 188 to 12–18 mg/L and turbidity reduction from mean 140 to 5.0 ± 3.4 NTU. The seasonal data showed 3.2 ± 0.9, 2.8 ± 0.4 and 2.85 ± 1.0 log order removal for total coliform, fecal coliform and heterotrophic plate count, respectively. The unique features of the system include a single unit, low HRT, high hydraulic loading, no chemicals, pretreatment and mechanical aeration, odor free, low energy requirement (0.04 kWh/m³), and green ambience.     

Diurnal exchanges of CO2 and CH4 across the water–atmosphere interface in a water chestnut meadow (Trapa natans L.)

CH₄ and CO₂ fluxes across the water–atmosphere interface were measured over a 24 h day–night cycle in a shallow oxbow lake colonized by the water chestnut (Trapa natans L.) (Lanca di Po, Northern Italy). Only exchanges mediated by macrophytes were measured, whilst gas ebullition was not considered in this study. Measurements were performed from 29 to 30 July 2005 with short incubations, when T. natans stands covered the whole basin surface with a mean dry biomass of 504 ± 91 g m⁻². Overall, the oxbow lake resulted net heterotrophic with plant and microbial respiration largely exceeding carbon fixation by photosynthesis. The water chestnut stand was a net sink of CO₂ during the day-light period (−60.5 ± 8.5 mmol m⁻² d⁻¹) but it was a net source at night (207.6 ± 6.1 mmol m⁻² d⁻¹), when the greatest CO₂ efflux rate was measured across the water surface (28.2 ± 2.4 mmol m⁻² h⁻¹). The highest CH₄ effluxes (6.6 ± 1.8 mmol m⁻² h⁻¹) were determined in the T. natans stand during day-time, whilst CH₄ emissions across the plant-free water surface were greatest at night (6.8 ± 2.1 mmol m⁻² h⁻¹). Therefore, we assumed that the water chestnut enhanced methane delivery to the atmosphere. On a daily basis, the oxbow lake was a net source to the atmosphere of both CO₂ (147.1 ± 10.8 mmol m⁻² d⁻¹) and CH₄ (116.3 ± 8.0 mmol m⁻² d⁻¹).     

Biology and demography of Glyphodes pyloalis Walker (Lepidoptera: Pyralidae) on mulberry

Lesser mulberry pyralid, Glyphodes pyloalis Walker, is a monophagous pest of mulberry and has recently been reported in northern Iran. The biology and life table of this pest were studied in controlled conditions (24 ± 1 °C, 75 ± 5% RH and 16:8 LD). Mortality rate, metamorphosis, appearance of adult insects and adult sex ratio were recorded daily. Data were analyzed based on an age-stage, two-sex life table. Developmental rate among individuals and between sexes were also considered. The developmental periods for the egg, first through fifth instar larvae, prepupae and pupae were 4.06 ± 0.03, 2.93 ± 0.03, 2.03 ± 0.02, 2.01 ± 0.01, 2.10 ± 0.03, 4.09 ± 0.03, 2.04 ± 0.02 and 9.7 ± 0.09 days, respectively. The mean total developmental period from egg to adult was 35.40 ± 0.37 days. The maximum adult longevity was 7 and 11 days for males and females, respectively. The pre-oviposition period lasted 2.14 ± 0.04 days. Laboratory observation showed that adults are nocturnal and female lay eggs at night. The intrinsic rate of increase (r_m) and the finite rate of increase (λ) were 0.14 ± 0.005 d^? 1 and 1.15 ± 0.01 d^? 1. The net reproductive rate (R₀), gross reproductive rate (GRR) and mean generation time (T) were 134.67 ± 20.6 female offspring, 294.71 ± 4.07 eggs/female and 34.44 ± 0.2 days, respectively. Life expectancy of freshly laid egg was 32.15 days.     

Potency optimization of Huwentoxin-IV on hNav1.7: A neurotoxin TTX-S sodium-channel antagonist from the venom of the Chinese bird-eating spider Selenocosmia huwena

The spider venom peptide Huwentoxin-IV (HwTx-IV) 1 is a potent antagonist of hNa_v1.7 (IC₅₀ determined herein as 17 ± 2 nM). Na_v1.7 is a voltage-gated sodium channel involved in the generation and conduction of neuropathic and nociceptive pain signals. We prepared a number of HwTx-IV analogs as part of a structure–function study into Na_v1.7 antagonism. The inhibitory potency of these analogs was determined by automated electrophysiology and is reported herein. In particular, the native residues Glu¹, Glu⁴, Phe⁶ and Tyr³³ were revealed as important activity modulators and several peptides bearing mutations in these positions showed significantly increased potency on hNa_v1.7 while maintaining the original selectivity profile of the wild-type peptide 1 on hNa_v1.5. Peptide 47 (Gly¹, Gly⁴, Trp³³-HwTx) demonstrated the largest potency increase on hNa_v1.7 (IC₅₀ 0.4 ± 0.1 nM).     

Kinetic analysis of photosynthetic growth and photohydrogen production of two strains of Rhodobacter Capsulatus

Two mutants of Rhodobacter Capsulatus (JP91 and IR3), a photosynthetic purple non-sulfur bacterium, were grown in a batch photobioreactor under illumination with 30 mmol l⁻¹ dl-lactate and 5 mmol l⁻¹ l-glutamate as carbon and nitrogen source, respectively. Bacterial growth was measured by monitoring the increase in absorbance at 660 nm. The photosynthetic growth processes under different cultivated temperatures are well fitted by a specific logistic model to analyze the kinetics of photosynthetic growth of two strains, thus the apparent growth rates (k) of these photosynthetic bacteria, the variations of cell dry weight (CDW) as well as their relationship with temperature are obtained. In present work, k is (0.1465 ± 0.0146), (0.2266 ± 0.0207) and (0.3963 ± 0.0257) h⁻¹ for JP91 and (0.1117 ± 0.0122), (0.1218 ± 0.0133) and (0.2223 ± 0.0152) h⁻¹ for IR3 at 26, 30 and 34 °C, respectively. And the difference between CDW_max and CDW₀ is (0.8997 ± 0.0097), (0.8585 ± 0.0093) and (0.9241 ± 0.0099) g l⁻¹ for JP91 and (0.8167 ± 0.0089), (0.7878 ± 0.0086) and (0.8358 ± 0.0091) g l⁻¹ for IR3 at 26, 30 and 34 °C, respectively. Also real-time monitoring of hydrogen production rates is acquired by recording the flow rates of photohydrogen for these two strains under different temperatures. The effects of temperature on the bacteria growth, hydrogen production capability and substrate conversion efficiency are discussed based on these results. The most preferment temperature, 30 °C, showed good substrate conversion efficiency of 52.7 and 68.2% for JP91 and IR3, respectively.     

Biological hydrogen production from CO: Bioreactor performance

This paper presents an alternative solution to the current problem faced by the world; diminishing of fossil fuel. Bioconversion of synthesis gas to hydrogen as clean fuel was catalyzed by a photosynthetic bacterium, Rhodospirillum rubrum. The clean fuel production was biologically mediated by the water–gas shift reaction in a 2 l bioreactor. The work performed was on agitation effects on hydrogen production, K_La and power consumption. The results show that 500 rpm was the suitable agitation rate to be employed. The hydrogen production was optimized at 0.44 ± 0.023 atm giving a K_La of 86.4 ± 3.5 h⁻¹. The production rate was 9.6 mmol H₂/h. The maximum light conversion efficiency at agitation speed of 800 rpm, light intensity of 500 lux (732 kW/m²) and 4 g/l inlet acetate concentration was about 10.84 ± 1.73%. At this condition, the maximum CO conversion efficiency was found to be 81 ± 5.6%. The ratio of power per volume was calculated to be 322.30 ± 12.14 kW/m³ and foaming problem was successfully avoided. The corresponding power consumption was estimated to be about 0.64 ± 0.03 kW, while the output hydrogen energy was determined to be 643.2 ± 26 kW. A prolonged operation of continuous hydrogen production employing a microsparger showed stable behaviour for a duration of 27 days.     

Assessment of the functional response parameters of Coccinella septempunctata to varying densities of Acyrthosiphon pisum

The functional response of a predator describes the rate at which it kills its prey at different prey densities and is, therefore, an important tool to determine the efficiency of a predator in regulating the population dynamics of a prey. We investigated the functional response of Coccinella septempunctata L. (Coleoptera: Coccinellidae) to varying densities of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the linear coefficient, P₁ in the reduced logistic model was found significantly negative for the 4^th instar larvae and adult male and female of C. septempunctata (?0.002, ?0.004 and???0.002, respectively) indicating a type II functional response. The parameter estimates of adult male, female and 4^thinstar larvae of C. septempunctata calculated through Holling's disc model revealed that the highest attack rate (a) (1.047?±?0.014), shortest handling time (T_h) (0.0984?±?0.024?h) and largest maximum capture rate (T/T_h) (243.902) was exhibited by female. Parameter estimates calculated through Rogers’s equation also showed the same sequence where maximum attack rate (a) of 0.00256?±?0.0003 was exhibited by female followed by 4^th instar larvae (0.00251?±?0.0005). The shortest handling time (T_h) (0.210?±?0.003?h) and highest maximum capture rate (T/T_h) (114.17) was also exhibited by female. Comparison of functional response curves of adult male, female and 4^th instar larvae revealed that maximum consumption of prey at all the densities offered was shown by female followed by 4^thinstar larvae. The study manifested that C. septempunctata could be an efficient biocontrol agent of pea aphid, A. pisum.     

Population densities,group size and biomass of ungulates in a lowland tropical rainforest forest of the eastern Himalayas

Large ungulate population monitoring is a crucial wildlife management tool as ungulates help in structuring and maintaining the large carnivore populations. Reliable data on population status of major ungulate prey species are still non-existent for most of the protected areas in the Indian part of the eastern Himalayan biodiversity hotspot. Twenty transects were monitored over a period of three years (2009–2011) totaling 600 km with an average length of 2 km. The estimated mean density of ungulates was 17.5 km⁻² with overall density of 48.7 km⁻². The wild pig Sus scrofa had the highest density (6.7 ± 1.2 km⁻²) among all the prey species followed by barking deer Muntiacus muntjak (3.9 ± 0.6 km⁻²), sambar Rusa unicolor (3.8 ± 0.5) and gaur Bos gaurus (3.5 ± 0.9 km⁻²). The estimated total ungulate biomass density was 2182.56 kg km⁻². This prey biomass can support up to 7.2 tigers per 100 km⁻². However, with two other sympatric carnivores sharing the same resources, the actual tiger numbers that can be supported will be lower. The estimated minor prey species was 31 km⁻² significantly 30.6% crop damages were reported by wild pig (p = 0.01) and 35.4% was elephant (p = 0.004). This data on ungulate densities and biomass will be crucial for carnivore conservation in this understudied globally significant biodiversity hotspot.     

A reduced core to skin temperature gradient,not a critical core temperature,affects aerobic capacity in the heat

The purpose of this study was to determine the impact of the core to skin temperature gradient during incremental running to volitional fatigue across varying environmental conditions. A secondary aim was to determine if a “critical” core temperature would dictate volitional fatigue during running in the heat. 60 participants (n=49 male, n=11 female; 24±5 yrs, 177±11 cm, 75±13 kg) completed the study. Participants were uniformly stratified into a specific exercise temperature group (18 °C, 26 °C, 34 °C, or 42 °C) based on a 3-mile run performance. Participants were equipped with core and chest skin temperature sensors and a heart rate monitor, entered an environmental chamber (18 °C, 26 °C, 34 °C, or 42 °C), and rested in the seated position for 10 min before performing a walk/run to volitional exhaustion. Initial treadmill speed was 3.2 km h⁻¹ with a 0% grade. Every 3 min, starting with speed, speed and grade increased in an alternating pattern (speed increased by 0.805 km h⁻¹, grade increased by 0.5%). Time to volitional fatigue was longer for the 18 °C and 26 °C group compared to the 42 °C group, (58.1±9.3 and 62.6±6.5 min vs. 51.3±8.3 min, respectively, p<0.05). At the half-way point and finish, the core to skin gradient for the 18 °C and 26 °C groups was larger compared to 42 °C group (halfway: 2.6±0.7 and 2.0±0.6 vs. 1.3±0.5 for the 18 °C, 26 °C and 42 °C groups, respectively; finish: 3.3±0.7 and 3.5±1.1 vs. 2.1±0.9 for the 26 °C, 34 °C, and 42 °C groups, respectively, p<0.05). Sweat rate was lower in the 18 °C group compared to the 26 °C, 34 °C, and 42 °C groups, 3.6±1.3 vs. 7.2±3.0, 7.1±2.0, and 7.6±1.7 g m⁻² min⁻¹, respectively, p<0.05. There were no group differences in core temperature and heart rate response during the exercise trials. The current data demonstrate a 13% and 22% longer run time to exhaustion for the 18 °C and 26 °C group, respectively, compared to the 42 °C group despite no differences in beginning and ending core temperatures or baseline 3-mile run time. This capacity difference appears to result from a magnified core to skin gradient via an environmental temperature advantageous to convective heat loss, and in part from an increased sweat rate.     

Copper,zinc superoxide dismutase of Curcuma aromatica is a kinetically stable protein

This study details on cloning and characterization of Cu,Zn superoxide dismutase (Ca–Cu,Zn SOD) from a medicinally important plant species Curcuma aromatica. Ca–Cu,Zn SOD was 692 bp with an open reading frame of 459 bp. Expression of the gene in Escherichia coli cells followed by purification yielded the enzyme with K_m of 0.047 ± 0.008 μM and V_max of 1250 ± 24 units/mg of protein. The enzyme functioned (i) across a temperature range of −10 to +80 °C with temperature optima at 20 °C; and (ii) at pH range of 6–9 with optimum activity at pH 7.8. Ca–Cu,Zn SOD retained 50% of the maximum activity after autoclaving, and was stable at a wide storage pH ranging from 3 to 10. The enzyme tolerated varying concentrations of denaturating agent, reductants, inhibitors, trypsin, was fairly resistant to inactivation at 80 °C for 180 min (k_d, 6.54 ± 0.17 × 10⁻³ min⁻¹; t_1/2, 106.07 ± 2.68 min), and had midpoint of thermal transition (T_m) of 70.45 °C. The results suggested Ca–Cu,Zn SOD to be a kinetically stable protein that could be used for various industrial applications.     

Potential for integrated control of Culex quinquefasciatus (Diptera: Culicidae) using larvicides and guppies

Acute toxicity tests were carried out to determine the effect of three larvicides, spinosad, pirimiphos methyl, and chlorpyrifos, on Culex quinquefasciatus Say, Anopheles gambiae s.s. Giles (Diptera: Culicidae), and guppies, Poecilia reticulata Peters (Pisces: Poeciliidae). Thereafter, larvae of Cx. quinquefasciatus were introduced to P. reticulata in containers of different volumes with low concentrations of each larvicide at established predator to prey densities of 1–35; 5–70 and 10–350 (fish to larvae) respectively. The experiment was replicated six times, and the larval consumption was counted after 24 h. Spinosad and pirimiphos methyl were significantly toxic to Cx. quinquefasciatus, the less susceptible mosquito species. Guppy consumption of Culex larvae was highest at a predator to prey density 5–70. Feeding activity of guppies increased in the spinosad treatment at 49 μg L⁻¹ compared to control and the synthetic larvicides. The synthetic larvicides generally reduced consumption of larvae except for the lowest concentration of pirimiphos methyl which increased it at the highest predator to prey density in a 3 L container. The highest percentage of Culex larvae was consumed by fish in the presence of spinosad at 49 μg L⁻¹ and a predator to prey density of 5–70 in 0.5 L plastic containers. Thus, predator to prey density, container size, type and concentration of larvicide are all important factors to be considered in integrated management of mosquito larvae.     

Fire service instructor's undergarment choice to reduce Interleukin-6 and minimise physiological and perceptual strain

Fire Service Instructors frequently experience high levels of physiological and perceptual strain during live fire exposures. Instructors are also at risk of cardiovascular illnesses, with cardiac death being the greatest cause of fire fighter death. Current practice for UK instructors is to select undergarment type based on personal preference, between a boiler suit (BOILER) and a wicking base layer (WBL). Research suggests that shorts and t-shirt (SHORTS) may also be a beneficial alternative undergarment choice. The UK South East Fire Service requested an investigation to identify if undergarment selection can lessen the strain experienced by instructors, and reduce the acute inflammatory response to fire exposures. Eight males completed three 45 min sessions in a heat chamber (49.5±1.4 °C and 16.9±4.3% RH) whilst performing intermittent walking. At the end of heat exposure change in heart rate was not effected by garment type (p=0.061, ηp²=0.373). Change in rectal temperature was different between garments (p=0.009, η_p²=0.271), with trends suggesting that BOILER resulted in a greater change (1.03±0.60 °C) than SHORTS (0.76±0.37 °C, p=0.589, d=0.21) and WBL (0.72±0.33 °C, p=0.545, d=0.25). Interleukin-6 post exposure was greater for BOILER (6.96±0.28 pg mL⁻¹) than both SHORTS (6.59±0.30 pg mL⁻¹, p=0.043, d=0.42) and WBL (6.45±0.43 pg mL⁻¹, p=0.031, d=0.51). Overall, undergarment type had little impact on physiological or perceptual strain. However, wearing WBL or SHORTS may reduce the inflammatory response, and consequently decrease the risk of cardiovascular events.     

Active compounds from a diverse library of triazolothiadiazole and triazolothiadiazine scaffolds: Synthesis,crystal structure determination,cytotoxicity, cholinesterase inhibitory activity,and binding mode analysis

In an effort to identify novel cholinesterase candidates for the treatment of Alzheimer’s disease (AD), a diverse array of potentially bioactive compounds including triazolothiadiazoles (4a–h and 5a–f) and triazolothiadiazines (6a–h) was obtained in good yields through the cyclocondensation reaction of 4-amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol (3) with various substituted aryl/heteroaryl/aryloxy acids and phenacyl bromides, respectively. The structures of newly prepared compounds were confirmed by IR, ¹H and ¹³C NMR spectroscopy and, in case of 4a, by single crystal X-ray diffraction analysis. The purity of the synthesized compounds was ascertained by elemental analysis. The newly synthesized conjugated heterocycles were screened for cholinesterase inhibitory activity against electric eel acetylcholinesterase (EeAChE) and horse serum butyrylcholinesterase (hBChE). Among the evaluated hybrids, several compounds were identified as potent inhibitors. Compounds 5b and 5d were most active with an IC₅₀ value of 3.09 ± 0.154 and 11.3 ± 0.267 μM, respectively, against acetylcholinesterase, whereas 5b, 6a and 6g were most potent against butyrylcholinesterase, with an IC₅₀ of 0.585 ± 0.154, 0.781 ± 0.213, and 1.09 ± 0.156 μM, respectively, compared to neostigmine and donepezil as standard drugs. The synthesized heteroaromatic compounds were also tested for their cytotoxic potential against lung carcinoma (H157) and vero cell lines. Among them, compound 6h exhibited highest antiproliferative activity against H157 cell lines, with IC₅₀ value of 0.96 ± 0.43 μM at 1 mM concentration as compared to vincristine (IC₅₀ = 1.03 ± 0.04 μM), standard drug used in this study.     

Synthesis and antioxidant evaluation of (S,S)- and (R,R)-secoisolariciresinol diglucosides (SDGs)

Secoisolariciresinol diglucosides (SDGs) (S,S)-SDG-1 (major isomer in flaxseed) and (R,R)-SDG-2 (minor isomer in flaxseed) were synthesized from vanillin via secoisolariciresinol (6) and glucosyl donor 7 through a concise route that involved chromatographic separation of diastereomeric diglucoside derivatives (S,S)-8 and (R,R)-9. Synthetic (S,S)-SDG-1 and (R,R)-SDG-2 exhibited potent antioxidant properties (EC₅₀ = 292.17 ± 27.71 μM and 331.94 ± 21.21 μM, respectively), which compared well with that of natural (S,S)-SDG-1 (EC₅₀ = 275.24 ± 13.15 μM). These values are significantly lower than those of ascorbic acid (EC₅₀ = 1129.32 ± 88.79 μM) and α-tocopherol (EC₅₀ = 944.62 ± 148.00 μM). Compounds (S,S)-SDG-1 and (R,R)-SDG-2 also demonstrated powerful scavenging activities against hydroxyl [natural (S,S)-SDG-1: 3.68 ± 0.27; synthetic (S,S)-SDG-1: 2.09 ± 0.16; synthetic (R,R)-SDG-2: 1.96 ± 0.27], peroxyl [natural (S,S)-SDG-1: 2.55 ± 0.11; synthetic (S,S)-SDG-1: 2.20 ± 0.10; synthetic (R,R)-SDG-2: 3.03 ± 0.04] and DPPH [natural (S,S)-SDG-1: EC₅₀ = 83.94 ± 2.80 μM; synthetic (S,S)-SDG-1: EC₅₀ = 157.54 ± 21.30 μM; synthetic (R,R)-SDG-2: EC₅₀ = 123.63 ± 8.67 μM] radicals. These results confirm previous studies with naturally occurring (S,S)-SDG-1 and establish both (S,S)-SDG-1 and (R,R)-SDG-2 as potent antioxidants and free radical scavengers for potential in vivo use.