Light Body Research Articles

A Newly Formulated Vinyl Polysiloxane Impression Material with Improved Mechanical Properties.

To evaluate the mechanical properties of a newly formulated vinyl polysiloxane (VPS) impression material. Experimental, Capture (S&C Polymer), Express, Imprint 3 and Imprint 4 (3M ESPE), Start VPS (Danville), Honigum (DMG), Virtual (Ivoclar Vivadent), Elite HD+ (Zhermack) were evaluated for tear strength, tensile strength, and elongation at break. Un-nicked specimens with a 90° angle on one side (type C) for tear strength were prepared and tested according to ASTM-D624. Dumbbell-shaped specimens (type 1) for tensile strength and elongation at break were prepared and tested according to ISO 37. All tests were carried out at 500 mm/min on a Shimadzu (AGS-X-10 KN-table top) tester. A one-way analysis of variance (ANOVA) was used to analyze the data. Experimental material showed significantly higher or higher tear strength and elongation at break compared to other impression materials for both light body (LB) and heavy body (HB). For tensile strength, Experimental is similar to most impression materials; however, significantly lower than Imprint 3 and Start VPS for LB. This parameter for HB is higher or significantly higher than other impression materials except Start VPS. Tear strength and tensile strength were not correlated for LB but have a weak or moderate correlation for HB. Elongation at break is inversely proportional to tensile strength moderately for LB; however, there is no or very weak relation for HB. Experimental VPS impression material demonstrated a significantly higher tear strength and adequate tensile strength with higher elongation compared to other commercially available VPS impression materials. Adequate mechanical properties can provide accurate impressions for successful clinical fabrication of restorations. Experimental VPS impression material is suitable for use in dental impressions for fabrication of restorations.

Excellent Hybrid Polyurethane-Graphite Filler Micro Powder as a Lightweight Structure

Weight plays a significant role in the automotive and aerospace fields due to the demand of lightweight material structures. A lighter body in weight (BIW) and in structure can reduce fuel consumption, lessen emissions, and support the SDGs 9, 11, 12, and 13. Therefore, polyurethane (PU) foam is suitable for applications that require low weight. The characteristics of hybrid polyurethane-graphite micro were successfully evaluated in this study. Several tests have been used to characterize these structures, such as, compression, hardness, density, surface evaluation, and FTIR analysis. The results showed that the expansion and shrinkage variations lead to different shapes at specific ratios. Compression tests show that the highest value occurred at 0.84 kN, with a 4:1 ratio found in pure PU foam without any reinforcement. PU foam with 2% graphite filler showed the highest results at the 4:1 ratio with a value of 0.45 kN. Furthermore, the highest hardness test result was 37.7 SHD. Density testing indicates that the highest value is obtained from specimens with a 4:1 ratio of 0.077 g/cm3. FTIR testing reveals that adding graphite as a filler alters the chemical bonds during the formation of solid PU foam. Surface observations show that adding graphite as a filler influences the variation in material structure formation. All the evaluation has tended to conclude the present combination as suitable for lightweight structures applications.

Liability of Commercial Air Transport Service Providers in the Carriage of Corpse

In general, objects in air transportation are passengers, baggage, cargo, and/or post. However, in its development, the existing air transportation also carries out the transportation of corpses. If it is related to the responsibility of the air carrier, then the position of the corpse in air transport is important to be studied in order to determine the form and limits of the air carrier's responsibility. Therefore, this study aims to discuss the position of the corpse in the law of air transportation, as well as the responsibility of the carrier in transporting the corpse by air. The method used in this research is legal research with conceptual approach, statutory approach, comparative approach, and case approach. Based on the research that has been done, it can be found that the position of the corpse in international and national air transportation law has been positioned as cargo. Consequently, the responsibility of the air carrier in the transportation of corpses is also based on the responsibility of the carrier in the carriage of cargo. This is of course inappropriate when applied to the transportation of corpses, because with such arrangements, heavier body will receive greater compensation than lighter body.
 Keywords: air transportation; corpse; responsibility; legal protection.

Stellar triples on the edge

Context. Hierarchical triple stars are ideal laboratories for studying the interplay between orbital dynamics and stellar evolution. Both mass loss from stellar winds and strong gravitational perturbations between the inner and outer orbit cooperate to destabilise triple systems. Aims. Our current understanding of the evolution of unstable triple systems is mainly built upon results from extensive binary-single scattering experiments. However, destabilised hierarchical triples cover a different region of phase space. Therefore, we aim to construct a comprehensive overview of the evolutionary pathways of destabilised triple-star systems. Methods. Starting from generic initial conditions, we evolved an extensive set of hierarchical triples using the code TRES, combining secular dynamics and stellar evolution. We detected those triples that destabilise due to stellar winds and/or gravitational perturbations. Their evolution was continued with a direct N-body integrator coupled to stellar evolution. Results. The majority of triples (54–69%) preserve their hierarchy throughout their evolution, which is in contradiction with the commonly adopted picture that unstable triples always experience a chaotic, democratic resonant interaction. The duration of the unstable phase was found to be longer than expected (103 − 4 crossing times, reaching up to millions), so that long-term stellar evolution effects cannot be neglected. The most probable outcome is dissolution of the triple into a single star and binary (42–45%). This occurs through the commonly known democratic channel, during which the initial hierarchy is lost and the lightest body usually escapes, but also through a hierarchical channel, during which the tertiary is ejected in a slingshot, independent of its mass. Collisions are common (13–24% of destabilised triples), and they mostly involve the two original inner binary components still on the main sequence (77–94%). This contradicts the idea that collisions with a giant during democratic encounters dominate (only 5–12%). Together with collisions in stable triples, we find that triple evolution is the dominant mechanism for stellar collisions in the Milky Way. Lastly, our simulations produce runaway and walk-away stars with speeds up to several tens of km/s, with a maximum of a few 100 km s−1. We suggest that destabilised triples can explain – or at least alleviate the tension behind – the origin of the observed (massive) runaway stars. Conclusions. A promising indicator for distinguishing triples that will follow the democratic or hierarchical route, is the relative inclination between the inner and outer orbits. Its influence can be summed up in two rules of thumb: (1) prograde triples tend to evolve towards hierarchical collisions and ejections, and (2) retrograde triples tend to evolve towards democratic encounters and a loss of initial hierarchy, unless the system is compact, which experience collision preferentially. The trends found in this work complement those found previously from binary-single scattering experiments, and together they will help to generalise and improve our understanding on the evolution of unstable triple systems of various origins.

Chemical composition of commercial tambaqui (Colossoma macropomum) cuts in different body weight classes (Amazon: Brazil)

It is important to know the nutritional composition of the fish, especially the nutritional value of the commercial cuts most consumed by the population. The aimed of this study was to evaluate the chemical composition of commercial tambaqui (Colossoma macropomum) cuts in different classes of body weight. The sample collections were carried out in processing units in two municipalities in the state of Rondônia, Brazil. The Data on 200 fish were recorded, with weight ranging from 1000 to 4700 g. Five classes of body weight were established, class 1 - below 1.2 kg; class 2 - from 1.21 to 1.8 kg; class 3 - from 1.81 to 2.4 kg; class 4 - from 2.41 to 3.5 kg; class 5 - over 3.5kg. The commercial cuts were lyophilized and intended for chemical analysis. The Kruskal-Wallis test (α=0.05) was used to compare the averages. The composition of commercial cuts was different in weight classes (p<0.05). The filet presented more representative values in mineral matter, crude protein and total lipids and lower humidity for class 4 (from 2.41 to 3.5 kg). The classes 1 and 5 (below 1.2 and over 3.5 kg) were different (p<0.05) in relation to the lipid and moisture content in the commercial filet and rib cuts. The tambaqui steak in class 4 have a higher lipid content compared to the average of the lightest body weight classes, 9.99 vs 4.50%, in addition to having a lower moisture content (p<0.05). The tambaqui band was different (p<0.05) in relation to nutritional components between body weight classes, with class 4 being richer in minerals, crude protein and lipids in dry matter. Therefore, the class 4 was the most efficient (p<0.05) for production and commercialization. Because the tambaquis with body weight between 2.4 to 3.5 kg stood out in relation to the nutritional components in the different commercial cuts.

Response to laboratory selection for darker and lighter body color phenotypes in Drosophila melanogaster: correlated changes for larval behavioral traits

Laboratory selection of stress-related traits in adult flies of Drosophila melanogaster has resulted in contrasting phenotypes but coevolution of larval traits has received lesser attention. The hypothesis whether laboratory selection of adult body melanization to derive dark and light body color lines exhibit covariation of larval behavioral traits of D. melanogaster was tested. The larvae of selected light lines showed longer foraging path, higher relative feeding rate, and lower pupation height whereas opposite trend values were observed for the larvae of selected dark lines. The larvae of dark lines stored significantly higher level of carbohydrates while light lines stored lipids. Larval pupating behavior of selected dark and light lines also showed divergence. For water balance-related traits, significantly higher trait values in the larvae of selected darker lines were found while lighter body color lines showed greater starvation resistance. Thus, laboratory selection of adult body melanization led to correlated selection responses for larval behavioral traits which are adaptive in nature.

One step at a time to feel lighter: Understanding the impact of sound and smell on body image perception

How people mentally represent their body image does not always match their actual body. A negative body image perception (i.e., BIP) can cause risks of eating disorders, isolation, and emotional disease. Thus, being able to manipulate this perception through technology can open up the opportunity to increase healthy behaviours. Previous works showed that technology can be used to change people’s BIP combining visual and tactile stimulation. However, can other senses make the difference? Can audio and smell impact on our BIP? We based our work on a well-established link between walking sounds and the perceived walker’s weight: heavier bodies produce lower spectral mode sounds than lighter bodies. We ran a multisensory user-study in which we altered in real-time the frequency spectra of the sound of participants' footstep. In the meantime, we delivered previously selected scents. Our results show that the combination of audio and scent stimuli can be used to make participants feel lighter or heavier and that highly arousing scents (e.g., lemon) enhance the effect of sound. We discuss limitations (e.g., the use of headphones and wired devices) and potentials of our findings (e.g., the use of multisensory to overcome BIP misperception). With this work, we want to make the community aware of the power of audio on BIP, and inform future research towards the creation of novel virtual multisensory experiences and devices that can positively impact the way we feel about ourselves.

Anakinra in COVID-19: important considerations for clinical trials

Anakinra in COVID-19: important considerations for clinical trials

Influence of Cattle Backgrounding Systems on Animal and Carcass Characteristics

ObjectivesCattle can be managed differently during the backgrounding segment, which may alter long-term animal and carcass characteristics. Therefore, the objectives of this study were to 1) measure carcass composition over time, and 2) determine the effect of different backgrounding diets on animal growth and carcass characteristics.Materials and MethodsAngus and Angus × Simmental crossed calves (n = 65) were stratified by dam age, birth date, weaning weight, breed, and sex post weaning in a completely randomized design to one of three treatments: (1) perennial pasture (PP; grazing quack grass, orchard grass; smooth brome grass, red clover, and alfalfa); (2) summer annual cover crop (CC; grazing cereal oats, purple top turnips, hunter forage brassica, and graza forage radish); and (3) dry lot (DL; bunk fed a haylage ration consisting of 28 NEm Mcal/50.8 kg DM) during backgrounding for 55 d. Concluding backgrounding, the CC and PP treatments were transported to pens where all treatments were sorted by gender and acclimated to a finishing ration over a period of 14 d and continued receiving 3 step-up diets over the next 25 d. Two pens during the finishing segment were utilized to house heifers and steers, respectively. The heifers were top dressed with melengestral acetate till harvest, which was determined by targeting a common backfat thickness per treatment. From backgrounding to harvest, cattle were weighed to determine body weight (BW), average daily gain (ADG) and hip height (HH) measurements were recorded every 28 d. Five periodic carcass ultrasound measures were recorded to evaluate ultrasound rib eye area (uREA), rib fat thickness (uRFT), and percent intramuscular fat (uIMF). At harvest, carcass measurements included hot carcass weight (HCW), LMA, 12th rib backfat (FT), kidney, pelvic and heart fat (KPH), marbling and maturity score and objective color (L*, a*, b*). Statistical analyses were conducted using mixed model procedures and animal weaning weight was used as a covariate. Least square means were computed and separated using least significant differences when treatment effects were significant at α ≤ 0.05.ResultsCattle ADG, uREA, uRFT, and HH did not differ (P ≥ 0.05) among treatments from backgrounding to harvest (Table 2). Cattle in DL were heavier (P ≤ 0.05) in BW than CC and PP, which were similar (P ≥ 0.05). Percent uIMF was greater (P ≤ 0.05) for DL and similar (P ≥ 0.05) to PP though CC was lower (P ≤ 0.05) and similar (P ≤ 0.05) to PP.ConclusionTreatments utilizing different backgrounding diets influence average body weights and ultrasound intramuscular adipose. Cattle grazing forages have lighter body weights and lower ultrasound intramuscular adipose though, cattle grazing perennial pastures were most variable in carcass ultrasound intramuscular adipose.Table 2Least squares mean performance responses and ultrasound-measured composition (averaged across all periodic measurements) according to the backgrounding treatment1

Inchworm-Inspired Soft Robot With Light-Actuated Locomotion

In this work, a light-actuated inchworm-inspired soft robot capable of directional locomotion has been proposed, developed, and characterized. The robot is designed and divided into three parts according to the functions during locomotion, which are the body, front leg, and back leg. The body of inchworm should provide contraction and stretching force. Thus, bilayer reduced graphene oxide and graphene oxide-polydopamine soft film is fabricated acting as robot body since it could implant light-induced deformation rapidly when stimulated. When applying near-infrared laser on it, bending would generate and unbending would take place after withdrawing laser, which imitates the longitudinal body muscle controlling contraction and stretching behavior of the inchworm during locomotion. Besides, robot legs are designed owning different heights and contact angles to the ground. Due to such structure, the directional movement could be realized. Then, by coordinating the body and two legs, the robot achieves a biomimetic inchworm gait. Experiments are carried out to characterize the robot body's light sensitivity as well as the robot's locomotive performance. As the experiment results showed, robot body bends at a speed of 17 °/s when laser is applied on it and the whole robot could realize forward locomotion mimicking inchworm by applying laser light periodically. The step length during one locomotion cycle could achieve 0.6 mm, which is 1/10 of body length.

Phenotypic variability of rusty crayfish (Faxonius rusticus) at the leading edge of its riverine invasion

Abstract Species around the globe are undergoing phenotypic shifts at ecologically relevant timescales as they invade new ecosystems and respond to changing environments. Disentangling the contribution of environmental gradients from the process of range expansion in shaping these changes, and identifying the specific traits undergoing selection, are both critical to anticipate the secondary spread and impact of invasive species. Here, we investigate phenotypic changes in rusty crayfish (Faxonius rusticus), a nuisance invasive species, through an extensive survey of their invasion gradient in multiple tributaries of the John Day River (JDR, Oregon, U.S.A.), a major tributary of the Columbia River. Rusty crayfish in the JDR have developed better physiological condition (intrinsic growth and/or reproductive potential measured as RNA/DNA ratio) but less competitive morphology (lighter body and smaller claws) as they spread upstream and downstream from their location of initial introduction. In addition, rusty crayfish in invasion front populations are at a lower trophic level than conspecifics closer to core areas. By accounting for variations in temperature, primary productivity, and prey (macroinvertebrates) biomass throughout the invasion extent of rusty crayfish, our findings suggest that low conspecific densities at the invasion edge and spatial sorting primarily drive these phenotypic changes. The trends observed here are thus likely to intensify over time as rusty crayfish continues to rapidly spread throughout the JDR and reach the mainstem Columbia River. Our study shows that phenotypic shifts can manifest rapidly over environmental gradients experienced during the range expansion of aquatic invasive species. Patterns in both morphological and functional traits documented in the JDR demonstrate the importance of both environmental factors and dispersal processes in shaping these responses in riverine networks.

PO-132 Exogenous VD3 alleviates chronic fatigue syndrome by activating MEKs/ERKs-SIRT1 signaling pathway in skeletal muscle

Objective To investigate the effects of exogenous VD3 on exercise-induced chronic fatigue syndrome (CFS) and its mechanism.
 Methods 80 male mice were randomly divided into 5 groups（n=16）. One group was named as quiet control group (C) while the other four were used to build CFS model by forced swimming. Among the four groups, three were selected for feeding VD3 1 h before exercise (bVD), 15 min after starting exercise (mVD) and 1 h after exercise (aVD) respectively, and the group without VD3 feeding was CFS model group (CFS). The behavior and condition of mice was observed during the whole process. After the training was completed totally, the tail suspension test and the forced swimming test were implemented, and then the blood and quadriceps were dissected. Serum testosterone and corticosterone content, as well as the antioxidant system indexes in the quadriceps, including malondialdehyde (MDA), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD), were measured. Routine western blotting experimentation was used to measure signal pathway indicators, containing SIRT1, SIRT3, ERK1/2, p-ERK1/2 and MEK1/2.
 Results Compared with C group, CFS group appeared serious damage caused by fighting, and the concentration of serum testosterone decreased significantly (p<0.01 or p<0.05) while cortisol concentration increased significantly (p<0.01 or p<0.05). Regarding antioxidant stress system indexes, the expression of MDA, T-SOD and GSH-PX significantly increased (p<0.05). The concentration of MEK and SIRT3 decreased significantly (p<0.01 or p<0.05). Compared with CFS group, VD intervention group (bVD, mVD and aVD) showed less damage caused by fighting and significantly lighter body weight (p<0.05), and the concentration of serum testosterone increased significantly (p<0.05) while that of cortisol decreased significantly (p<0.01 or p<0.05). The expression of MDA decreased significantly (p<0.05), on the countrary, T-AOC, T-SOD and GSH-PX increased significantly (p<0.05). The expressions of MEK, p-ERK/ERK, SIRT1 and SIRT3 were significantly upregulated (p<0.01 or p<0.05).
 Conclusions Exogenous VD3 could alleviate CFS, which probably related to activate the MEKs/ERKs-SIRT1 signal transduction axis and hence regulate the expression of SIRT3.

Formation control for car-like mobile robots using front-wheel driving and steering

To solve the problem of front wheels being jammed due to the passive trajectory tracking of the conventional car-like robot in the leader–follower formation control, we propose a novel car-like robot with the integration of front-wheel driving and steering. We establish its kinematic model, then analyze its controllability via the method of chained form system, and design the trajectory-tracking controller via the backstepping method. Simulations and experimental results validate our algorithm. This novel car-like robot with the integration of front-wheel driving and steering system not only avoids the jamming in the formation motion, but also owes the advantages of compacter structure, lighter body, and lower energy consumption.

Assessment of Disordered Eating and Orthorexia Nervosa in Endurance Athletes Following Gluten and Wheat-free Diets

Endurance athletes recognize that a leaner and lighter body can improve performance outcomes. Currently, there is limited data assessing disordered eating, including orthorexia nervosa, in endurance athletes choosing to adhere to GWDs. Purpose: The aim of this study was to assess disordered eating, including orthorexia behaviors, in endurance athletes following GWDs compared to athletes following a normal diet (ND). Methods: Endurance athletes (ages 18-55y) were invited to participate in a web-based questionnaire via multiple sporting websites. The survey included demographic information, questions regarding beliefs and attitudes about GWDs, and two validated disordered eating and orthorexia questionnaires: Three Factor Eating Questionnaire (TFEQ-R18) and the ORTO-15. Athletes following GWDs were combined. Descriptive statistics and independent sample t-tests comparing groups using SPSS with significance set at p<0.05. Results: Of the athletes responding (n=100), only 73 had usable data (63 females; 9 males; 1 transgender). One-third (37%; n=27) reported being on GWDs (clinically diagnosed gluten sensitivity (n=10); celiac (n=1)). ND’s were significantly older (44+11 y) than GWD (39+12 y, p=0.05). There were no differences between groups for self-reported body mass index (GWD=22+3 vs. ND=24+4 kg/m2), orthorexia scores (GWD=37.1+6.9 vs. ND=39.0+6.3), and TFEQ subscale scores for emotional eating (GWD=8.2+2.1 vs. ND=8.2+2.2), dietary restraint (GWD=14.4+4.1 vs. ND=15.8+3.9) and uncontrolled eating (GWD=24.7+5.3 vs. ND=25.1+4.8). Athletes classified with orthorexia (75.3%; n=55) had significantly lower TFEQ scores in restrained, emotional, and cognitive disordered eating than those not categorized as having orthorexia (24.7%; n=18) (p<0.001). Conclusion: This sample of endurance athletes displayed high levels of orthorexia and disordered eating behaviors but there were no differences between GWD and ND diet groups. Further studies are needed to determine the extent of nutritional and behavioral risk in endurance athletes presenting with orthorexia.

A new partitioned staggered scheme for flexible multibody interactions with strong inertial effects

In generic flexible multibody interaction problems, the differences in the mass, damping and stiffness of the bodies can be very large. Of particular interest is a small change in the higher mass structure which triggers relatively large inertial effects on the lower mass structure. In this work, a new partitioned staggered time integration scheme is developed and its applicability is extended to the problems involving low mass ratios in coupled multibody problems. The equation of motion of body with larger inertia is integrated by implicit Newmark method, whereas the smaller inertia is solved using a robust self-starting explicit integration procedure. The coupled formulation includes explicit correction terms that adjusts the amount of interfacial velocity, which plays a key role in the stability and accuracy of the simulations. A wide range of mass (10−6–10−1), damping and stiffness (10−3–103) ratios are chosen to assess the stability and accuracy characteristics of the proposed scheme. The closed-form expressions for the coupling parameter have been constructed for both matching and non-matching time stepping through the Godunov–Ryabenkii normal mode analysis. The stability of the proposed method is observed as a function of the relative properties and temporal discretisation of the coupled system. The time step of the heavier body significantly influences the stability more than the lighter body. To maintain the staggering error minimal, an optimal range of the coupling parameter is identified. The error computed with uniform variation in the time step revealed that the present method is more accurate than the existing methods. The partitioned method is an energy preserving integration method for the dynamic analysis of multibody systems. As a potential application of this scheme, flexible multibody problems in the field of offshore engineering, viz., wave energy converter and floater–mooring systems are presented and validated with experimental measurements.

Postglacial colonisation and diversification of the Jungle Crow (Corvus macrorhynchos) in its north-eastern frontier as revealed by morphological analysis

The Jungle Crow (Corvus macrorhynchos) is a widespread species in Asia that underwent remarkable postglacial recolonisations during the Pleistocene and Holocene. In order to better understand the pattern of its settling and diversification, we investigated the morphological differences among adult Jungle Crow samples obtained from locations in northern Japan and the Russian Far East: Hokkaido, Sakhalin Island, the continental seaboard adjacent to the Tatarsky Strait and the region to the west of the Sikhote-Alin Mountains. We studied four cranial measurements and five bill measurements, as well as body mass from 195 samples. We found clear differences among most populations for both males and females when the various characteristics were observed, especially on Hokkaido and Sakhalin Island; crows from Hokkaido had larger bills and lighter body mass. The differences between the Hokkaido and Sakhalin populations correspond to Bergman’s and Allen’s rules, but this was not the case with the longitudinal cline revealed among the three populations from the Russian Far East. In conclusion, our results suggest that La Perouse Strait separates two assumed recolonisation movements, the first being along the mainland via Ussuriland to Sakhalin and the second along the Japanese Archipelago to Hokkaido. It is evident that this strait is a more effective barrier between Jungle Crow populations than either the Tatarsky Strait or the Sikhote-Alin mountain range.

Total-Ionizing-Dose Response of Narrow, Long Channel 45 nm PDSOI Transistors

Measured results and 3D TCAD simulations demonstrate that narrow, long channel PDSOI devices may exhibit a total-ionizing-dose response more like FDSOI devices, attributable to regions of lighter body doping and trapped charge in the isolation regions.

Strength, Speed and Power Characteristics of Elite Rugby League Players

The purpose of this article was to compare strength, speed, and power characteristics between playing position (forwards and backs) in elite rugby league players. A total of 39 first team players (height, 183.8 ± 5.95 cm; body mass, 100.3 ± 10.7 kg; age, 24 ± 3 years) from a National Rugby League club participated in this study. Testing included 10-, 40-m sprint times, sprint mechanics on an instrumented nonmotorized treadmill, and concentric isokinetic hip and knee extension and flexion. Backs, observed to have significantly (p ≤ 0.05) lighter body mass (effect size [ES] = 0.98), were significantly faster (10-m ES = 1.26; 40-m ES = 1.61) and produced significantly greater relative horizontal force and power (ES = 0.87 and 1.04) compared with forwards. However, no significant differences were found between forwards and backs during relative isokinetic knee extension, knee flexion, relative isokinetic hip extension, flexion, prowler sprints, sprint velocity, contact time, or flight time. The findings demonstrate that backs have similar relative strength in comparison with forwards, but run faster overground and produce significantly greater relative horizontal force and power when sprinting on a nonmotorized instrumented treadmill. Developing force and power in the horizontal direction may be beneficial for improving sprint performance in professional rugby league players.

Hormone-mediated maternal stress affects embryonic development during incubation without adverse effect on chick weight and body composition

1. The objective of this study was to evaluate the effect of maternal stress (MS) induced by supplementing the hen’s diet with 2 mg/hen/d dietary corticosterone (CORT) on embryonic development, biochemical blood parameters and hatching performance of broiler chicks.2. A total of 200 Ross broiler breeder hens at 42 weeks of age were randomly divided into two groups: MS or control. Hens in the MS were fed 2 mg/hen/d CORT for 14 d. Eggs (648 and 635 eggs for MS and control, respectively) were collected from d 3 to 14 of dietary CORT supplementation and incubated. Weights of embryo, chicks and organs and body composition were determined during incubation and at hatch. Biochemical blood parameters were measured at internal pipping stage and day of hatch. Hatching performance and embryonic mortalities were recorded.3. Hens fed a diet supplemented with CORT had lighter body weight and produced less eggs at the end of the 14-d treatment period. Although MS embryos were heavier than control from 12 to 18 d of incubation, chick weight was similar at the day of hatch. Lower relative weights for yolk sac and bursa were observed at 12 d of incubation for MS chicks compared to control. Chicks from both groups had similar body content in spite of higher fat content of MS embryos on d 18 of incubation.4. MS had no effect on the duration of incubation or hatching performance but increased mortality at the pipping stage.5. The results suggest that hormone-mediated MS might affect embryonic development during incubation without adverse effect on chick weight and body composition.

A priori knowledge of the way the world works

Science is last place one might expect to find thought experiments. Thought experiments happen entirely in our minds, but science is supposed to tell us about how the world works. So how can something that happens entirely in our minds give us reason to believe anything about the nature of the world? This is the philosophical puzzle at the heart of James Robert Brown’s classic, The Laboratory of the Mind, now in its second edition. With two new chapters and extensive additions to two others, the single best introduction to the philosophical issues raised by thought experiments in science has just gotten better. Brown’s book can be usefully divided into three parts. Chapters 1–3 set forth the raw evidence that any theory of thought experiments must explain. These chapters introduce many examples of thought experiments and attempt to organize them in terms of how they work in science. Chapters 4 and 5 make the case for scientific Platonism. For Brown, thought experiments in science are successful because we are capable of acquiring a priori knowledge of the way the world works. Laws of nature are abstract objects that we have some sort of cognitive access to. The last three chapters, 6–8, display the power of Brown’s Platonism by applying it to scientific practice. This review will focus primarily on the first two parts of the book. The opening chapter offers a clear, patient and extremely valuable introduction to over a dozen important thought experiments. Chapters 2 and 3 set forth a perspicacious framework that taxonomizes thought experiments in terms of how they work epistemically in science. To understand the core of this taxonomy, it will be useful to begin with Brown’s favorite thought experiment. Galileo on Free Fall: Suppose, we attach a heavy cannon ball to a light musket ball and release them from a tower. If heavier bodies fall faster than lighter bodies, then the musket ball should