Outdoor Range Research Articles

Vehicle Platform Effects on Performance of Flexible, Lightweight, and Dual-Band Antenna for Vehicular Communications

This paper highlights the impact of the ground, of the vehicle surroundings and of the car body on signal transmission and reception of a dual-band microwave antenna tested on two automotive plastic parts on a convertible vehicle for cellular and Cellular - Vehicle To Everything (C-V2X) communications. The implemented antenna operates at 975 MHz and 5.5 GHz and facilitates the future vehicular communications in vehicles without steady rooftops. Four experiments are performed with the antenna placed (a) in the Satimo near field system; (b) on a stanchion at an outdoor range facility without the presence of a car; (c) at the outdoor facility in the side mirror of the convertible vehicle; and (d) on the trunk lid of the same vehicle. Antenna co- and cross- polarization radiation patterns are measured and results indicate that the ground and the vehicle’s body affect the radiation performance of the antenna. The presence of ground causes an increase in the antenna’s cross-polarization level. The reflections caused by the car’s body perturb the omni-directional radiation pattern of the antenna and may degrade the vehicular microwave signal transmission due to the presence of nulls.

Dual Band GNSS Antenna Phase Center Characterization for Automotive Applications

High-accuracy Global Navigation Satellite System (GNSS) positioning is a prospective technology that will be used in future automotive navigation systems. This system will be a composite of the United States' Global Positioning System (GPS), the Russian Federation's Global Orbiting Navigation Satellite System (GLONASS), China Beidou Navigation Satellite System (BDS) and the European Union’s Galileo. The major improvement in accuracy and precision is based on (1) multiband signal transmitting, (2) carrier phase correction, (3) Real Time Kinematic (RTK). Due to the size and high-cost of today’s survey-grade antenna solutions, this kind of technology is difficult to use widely in the automotive sector. In this paper, a low-cost small size dual-band ceramic GNSS patch antenna is presented from design to real sample. A further study of this patch antenna illustrates the absolute phase center variation measured in an indoor range to achieve a received signal phase error correction. In addition, this low-cost antenna solution is investigated when integrated into a standard multi-band automotive antenna product. This product is evaluated both on its own in an indoor range and on a typical vehicle roof at an outdoor range. By using this evaluation file to estimate the receiver position could achieve phase motion error-free result.

Radiological assessment subjected to outdoor radon and thoron concentrations and terrestrial gamma radiation measurements in Perak Malaysia

The concentrations of radon, thoron and terrestrial gamma radiation were measured to evaluate the outdoor effective dose. The outdoor radon activity concentration ranged from 5.79 to 5110 ± 46.36 Bq m−3, with a mean of 320.03 Bq m−3 which is higher than the EPA level of 14.8 Bq m−3. The range of the thoron activity concentration outdoor was from 0.00 to 4226.7 ± 58.5 Bq m−3, with a mean of 226.1 Bq m−3 which was above the UNSCEAR recommended level of 10 Bq m−3. The terrestrial gamma radiation dose rates range was from 98.31 to 3769.71 nGy h−1 with a mean of 446.27 nGy h−1. The effective dose contribution from radon exposures in the study was estimated to be 3.2 ± 0.5 mSv y−1 is about 84% total annual effective dose received by the population in those areas. The estimated thoron and gamma dose contributions (15%, and 1% respectively) were not significant. The outdoor doses for thoron and gamma were lower than the ICRP (2007) value of 1 mSv. The total annual outdoor effective dose with an occupancy factor of 1825 h (5 h day−1) was estimated to be within the range of 0.30–551.41 ± 0.65 mSv, with a mean of 3.75 mSv which is a little higher than the world average of 2.4 mSv.

Self-supervised learning for using overhead imagery as maps in outdoor range sensor localization

Traditional approaches to outdoor vehicle localization assume a reliable, prior map is available, typically built using the same sensor suite as the on-board sensors used during localization. This work makes a different assumption. It assumes that an overhead image of the workspace is available and utilizes that as a map for use for range-based sensor localization by a vehicle. Here, range-based sensors are radars and lidars. Our motivation is simple, off-the-shelf, publicly available overhead imagery such as Google satellite images can be a ubiquitous, cheap, and powerful tool for vehicle localization when a usable prior sensor map is unavailable, inconvenient, or expensive. The challenge to be addressed is that overhead images are clearly not directly comparable to data from ground range sensors because of their starkly different modalities. We present a learned metric localization method that not only handles the modality difference, but is also cheap to train, learning in a self-supervised fashion without requiring metrically accurate ground truth. By evaluating across multiple real-world datasets, we demonstrate the robustness and versatility of our method for various sensor configurations in cross-modality localization, achieving localization errors on-par with a prior supervised approach while requiring no pixel-wise aligned ground truth for supervision at training. We pay particular attention to the use of millimeter-wave radar, which, owing to its complex interaction with the scene and its immunity to weather and lighting conditions, makes for a compelling and valuable use case.

Associations between neck plumage and beak darkness, as well as comb size measurements and scores with ranging frequency of Sasso and Green-legged Partridge chickens

Despite the intensive genetic selection in modern poultry, variability of domestic fowl phenotypes has remained, especially in breeds adapted to local conditions. The relevance of this variability to the chicken outdoor ranging activities remains unknown. The aim of this study was to investigate if external features were associated with the ranging frequency of the 48 female chickens from each of the 2 breeds: Sasso and Green-legged Partridge. In each of 6 single-breed pens, 8 hens and 2 roosters were housed under conditions of EU requirements for organic meat chicken production, including free access to an outdoor range, from wk 5 to 10 of age. The birds were video-recorded during the experiment to obtain frequencies of individual birds' use of the ranges. Comb size (length and height) was measured using a digital ruler, while the sizes of the dark area of neck plumage and beak were processed and analyzed using ImageJ software. The same traits were scored using direct visual assessment by a trained observer on a scale of 1-3. In addition, the eye color of the bird was recorded. Statistical analysis was conducted independently for each breed using regression models, ANOVAs and Spearman correlations. Significant positive associations between neck plumage (P < 0.01), beak darkness (P = 0.03) measurements, comb length (P < 0.01) and comb height (P < 0.01) and frequency of range use were identified for Sasso. Sasso hens scored with darkest neck plumage (P = 0.03) and biggest comb size (P = 0.04) ranged the most, while their external features were significantly and positively correlated between each other, except beak darkness and comb length. No significant associations between ranging and external features were found in Green-legged Partridge birds, except that their comb height was significantly and positively correlated with neck plumage and beak darkness (r = 0.39 and 0.33, respectively). In some genetic strains, better understanding of the associations between chickens’ external features with ranging behavior could contribute to improve selection programs and bird welfare, assuring production of breeding stock suitable for outdoor conditions.

Associations between weather conditions and individual range use by commercial and heritage chickens

Ranging area use by domestic poultry is not always optimal and differences in it exist on the levels of breed, flock and individual bird. Outdoor shelters are usually not protective for all weather parameters and may not fulfil a protective role to all birds within the flock all time, if individuals are sensitive to different weather conditions. The aim of this study was to investigate associations between different weather parameters and the use of the range by individual Green-legged Partridge and Sasso C44 chickens. In August 2018, 60 birds per genetic strain were housed in groups of 10 from wks 5 to 10, under conditions exceeding minimal EU requirements of organic meat chicken production. Birds in each pen had access to an outdoor range that was video-recorded during the experiment to obtain frequencies of individual birds' use of the ranges. Weather data were collected each minute throughout the whole experiment by an automatic weather station. In each pen, birds tagged individually with a laminated color tag, had access to an outdoor range that was video-recorded during the experiment. Frequencies of individual birds' use of the ranges were manually obtained from the recordings. Univariate and multivariate linear regression models were used to investigate the associations between the variables. The results showed significant associations between weather parameters and range use for one third of Green-legged Partridge and Sasso chickens (n = 21 in both breeds). Between breeds, range use associations with different weather parameters were identified. Negative associations with relative humidity occurred most frequently in Green-legged Partridges (n = 8; R2 from 0.1 to 0.17), while positive associations with atmospheric pressure (n = 7; R2 from 0.09 to 0.17) were most common in Sasso chickens. Further investigations into the reasons behind individual sensitivity of meat-purpose chickens to specific weather conditions would increase the understanding of their preferences and needs, which over time will improve animal welfare.

Normal stress distribution of timber-concrete composite panels with an adhesive shear connection under thermal and humidity loadings

Humidity and temperature conditions have a substantial influence on the stresses and total deformation of timber-concrete composite panels, especially in terms of the high rigidity of the shear connection. In the present research, the normal stresses that resulted from the hygrothermal load of timber-concrete composite panels with an adhesive shear connection were analyzed. Three timber-concrete composite panel specimens were placed in controlled climate conditions. Strains in two orthogonal directions were measured. The stress distribution resulted from an approximate analytical calculation model. The results show that the highest stresses occurred near the shear connection. An increase in timber moisture content by 2.1% was predicted to result in exceeding the flexural tensile strength in the concrete perpendicular to the timber grain direction. At an outdoor temperature range, stresses influenced only by the temperature alone will possibly not cause a failure of timber or concrete. Under winter environmental conditions, the stress in timber can possibly reach 12% of the bending strength of the timber used.

Preference for artificial range enrichment design features in free-range commercial laying hens

ABSTRACT 1. This study examined what elements of artificial enrichment structures attract hens in the outdoor range, and what behaviours hens perform around these structures. Three principles of cover design (height, orientation and visual density) were tested for laying hen preference in the outdoor range of a commercial egg farm using a 2 × 3 × 3 factorial design. The factors were height: 0.5 m or 1.5 m; orientation: vertical, horizontal or horizontal cover with one vertical side; and visual density: 0% (control), 50% or 90% UV blocking cloth. 2. A significant three-way interaction between all factors was found (P < 0.001). The most preferred visual density of these structures was the 90%, followed by 50% UV blocking cloth. Horizontal structures with one vertical side, of either height, were highly preferred. Short horizontal structures were preferred to tall ones, and tall vertical structures were slightly preferred over short ones. 3. The most common behaviours observed around the structures were interaction with the structure (pecks, scratches and vigilance directed at the structure; 32.7%), foraging (32.2%), locomotion (9.9%), and air foraging (pecks and snapping in the air; 9.0%). A three-way interaction between the design principles influenced the proportion of hens performing each of these behaviours (P < 0.001). Hens foraged more around structures with no shade cloth and interacted more with structures that had dense shade cloth. 4. These results highlighted the complexity of designing attractive outdoor environments for laying hens. By testing the combination of elements that hens prefer it is possible to understand how to design attractive outdoor ranges that attract hens and promote a diverse range of behaviours on commercial farms.

Preference testing for UV light spectrum and intensity in laying hens

Sunlight intensity and UV radiation may affect free-range hens' use of the outside range, particularly when sunlight is intense with a high UV index. However, it is uncertain what aspect of sunlight (brightness or UV) may be most aversive to hens to discourage them from leaving standard indoor lighting conditions to venture outdoors. A controlled indoor-based choice study was conducted to determine whether hens showed preferences for different light wavelengths and intensities that may affect outdoor range usage. Cage-reared ISA Brown laying hens (n = 84) at 44 wk of age in 3 groups (28 hens/group) were tested for preferences of indoor standard light emitting diode (LED) white light (control) vs. one of three different treatment lights: 1) visible spectrum plus infrared wavelengths (VIS); 2) visible spectrum plus UVA wavelengths (UVA); and (iii) visible spectrum plus UVA and UVB wavelengths (UVA/B) presented successively at low, medium, or high levels of intensity. Hens within each group were individually tested for 2 h in an apparatus with 2 compartments (control vs. treatment) connected by a tunnel on both sides. Videos of hens' time spent in each compartment and behaviors were decoded and analyzed using GLMM. Hens spent more time under the low intensity of the UVA/B light treatment (62%), the low intensity of VIS light (61%), medium intensities of both UVA/B light (60%), and UVA light (59%), and the high intensity of the VIS light (58%) when compared with control light (all P ≤ 0.05). Hens spent less time feeding under all intensities of UVA light (all P ≤ 0.03) and showed more foraging, ground pecking, and preening at lower levels of UVA/B light (P < 0.05). The study suggests that UVA/B light (sunlight) may have positive effects for hen range use, but during peak sun intensities, hens may need additional measures (e.g., shelter) to protect themselves. Confirmation of these findings in a free-range setting is needed.

Temporal Dynamics of Cloacal Microbiota in Adult Laying Chickens With and Without Access to an Outdoor Range.

Associations between animal health and performance, and the host’s microbiota have been recently established. In poultry, changes in the intestinal microbiota have been linked to housing conditions and host development, but how the intestinal microbiota respond to environmental changes under farm conditions is less well understood. To gain insight into the microbial responses following a change in the host’s immediate environment, we monitored four indoor flocks of adult laying chickens three times over 16 weeks, during which two flocks were given access to an outdoor range, and two were kept indoors. To assess changes in the chickens’ microbiota over time, we collected cloacal swabs of 10 hens per flock and performed 16S rRNA gene amplicon sequencing. The poultry house (i.e., the stable in which flocks were housed) and sampling time explained 9.2 and 4.4% of the variation in the microbial community composition of the flocks, respectively. Remarkably, access to an outdoor range had no detectable effect on microbial community composition, the variability of microbiota among chickens of the same flock, or microbiota richness, but the microbiota of outdoor flocks became more even over time. Fluctuations in the composition of the microbiota over time within each poultry house were mainly driven by turnover in rare, rather than dominant, taxa and were unique for each flock. We identified 16 amplicon sequence variants that were differentially abundant over time between indoor and outdoor housed chickens, however none were consistently higher or lower across all chickens of one housing type over time. Our study shows that cloacal microbiota community composition in adult layers is stable following a sudden change in environment, and that temporal fluctuations are unique to each flock. By exploring microbiota of adult poultry flocks within commercial settings, our study sheds light on how the chickens’ immediate environment affects the microbiota composition.

Effects of Housing Locations on Feather Damages of Laying Hens in a Free-Range Housing System

This study was made to evaluate the effects of different locations of a free range housing system on feather damages of laying hens. The experimental house consisted of three different locations as closed indoor plastic slats, closed indoor litter and outdoor range area. The birds were able to move freely between the locations of the experimental house and they had continuous access to outdoor range during the day. The feather damages of the birds was evaluated with a distance scoring system at 64 weeks of age. Five area in each location of the experimental house were determined at first and then feather damages of five body parts of ten birds in each location were scored to measure plumage quality. Total feather score was defined as the sum of the scores of five body parts of the birds. Best plumage quality was measured in neck in all housing locations (P&lt;0.01, P&lt;0.05 and P&lt;0.01) and total feather score of the birds was significantly greatest (worst) in slats (P&lt;0.05).

Occupational Lead Exposures among University Police Officers and Instructors at an Outdoor Shooting Range in Southcentral Kentucky

There is a potentially high risk of lead exposure among police officers and instructors at an outdoor firing range. In the United States, occupational lead exposure remains an important and significant public health problem. Lead causes both acute and chronic adverse health effects in multiple human organ systems. The Occupational Safety and Health Administration (OSHA) has promulgated a Permissible Exposure Limit and Action Level of 50 µg/m3 and 30 µg/m3 for lead averaged over an 8-hour period, respectively (general industry standards). Excessive lead exposures have been previously reported in several studies that evaluated groups of firearm shooters and instructors at firing ranges. Many of those studies focused mainly on personal lead exposures at either indoor or covered outdoor firing ranges. The present study was conducted with a sample of 17 university police officers (14 shooters and 3 instructors) to assess their occupational lead exposures at an uncovered outdoor firing range in Bowling Green, Kentucky. The study occurred over a period of three days during the months of June and July. The results showed that personal exposures to lead ranged from a concentration of 5.5 to 146 µg/m3. In addition, personal exposures reported for some police officers significantly exceeded OSHA’s general industry lead standards, without consideration of the use of personal protective equipment. The use of copper-jacketed ammunition and personal protective equipment combined with adequate work practices are highly recommended for this group of police officers and instructors. The effective implementation of proactive control measures is necessary to reduce airborne lead levels and invariably minimize potential inhalation and absorption of lead by police officers at firing ranges.

UHF-Band Radar Cross Section Measurements With Single-Antenna Reflection Coefficient Results

This article discusses the challenges and advantages of measuring radar cross section (RCS) using reflection coefficient measurements from a single-antenna test setup. In practice, arranging two ultrahigh-frequency (UHF) antennas in a quasi-monostatic configuration is difficult due to their large physical size. In addition, the coupling power between the two antennas can be much larger than the signal of interest, imposing further limitations on this configuration. However, traditional RF measurement hardware and postprocessing algorithms are combined to extract RCS across frequency and azimuthal angle accurately with the $S_{11}$ values collected from a single antenna. This is made possible by using vector background subtraction and time-gating windowing techniques to suppress multipath reflections, clutter, and mismatch reflection while increasing the measurement’s dynamic range. The test setup utilizes the National Instruments LabVIEW software for control and automation, a General Purpose Interface Bus (GPIB)-enabled vector network analyzer, and a rotary table allowing for experiments to be conducted in an anechoic chamber or an outdoor measurement range. Experiments are conducted at the University of Oklahoma in the far-field anechoic chamber and outdoors using the components mentioned above to validate the derived algorithms and measurement concepts. The chamber setup is calibrated using a metal sphere to extract the RCS of a smaller metal sphere. The initial RCS extraction had an average error of 4.9 dBsm over the 300–1000-MHz frequency range using only calibration and vector background subtraction. After applying time gating, the error is further reduced to 0.54 dBsm. The implemented test setup is accomplished using traditional measurement equipment and a single antenna allowing for a portable, flexible, and low-cost solution for RCS measurements in the UHF band.

Natural Radioactivity of the Crystalline Basement Rocks of the Peloritani Mountains (North-Eastern Sicily, Italy): Measurements and Radiological Hazard.

Crystalline rocks can produce dangerous radiation levels on the basis of their content in radioisotopes. Here, we report radiological data from 10 metamorphic and igneous rock samples collected from the crystalline basement of the Peloritani Mountains (southern Italy). In order to evaluate the radiological properties of these rocks, the gamma radiation and the radon emanation have been measured. Moreover, since some of these rocks are employed as building materials, we assess the potential hazard for population connected to their use. Gamma spectroscopy was used to measure the 226Ra, 232Th and 40K activity concentration, whereas the radon emanation was investigated by using a RAD 7 detector. The results show 226Ra, 232Th and 40K activity concentration values ranging from (17±4) to (56±8) Bq kg-1, (14±3) to (77±14) Bq kg-1 and (167±84) to (1760±242) Bq kg-1, respectively. Values of the annual effective dose equivalent outdoor range from 0.035 to 0.152mSv y-1, whereas the gamma index is in the range of 0.22-0.98. The 222Rn emanation coefficient and the 222Rn surface exhalation rate vary from (0.63±0.3) to (8.27±1.6)% and from (0.12±0.03) to (2.75±0.17) Bq m-2h-1, respectively. The indoor radon derived from the building use of these rocks induces an approximate contribution to the annual effective dose ranging from 8 to 176μSv y-1. All the obtained results suggest that the crystalline rocks from the Peloritani Mountains are not harmful for the residential population, even though they induce annual effective doses due to terrestrial gamma radiation above the worldwide average values. Moreover, their use as building materials does not produce significant health hazards connected to the indoor radon exposure.

Reduction in lead exposures with lead-free ammunition in an advanced urban assault course

The training of soldiers for urban conflict involves marksmanship instruction on outdoor flat ranges and the teaching of close-quarter battle techniques in indoor facilities, referred to as shoot houses, where intense firing exercises can generate high air lead levels from small arms ammunition, flash bang grenades, and explosive devices. Levels of lead and copper in air were evaluated during five training activities of a 45-day training course using both stationary general area and breathing zone sampling over a 2-year period. Individual blood lead values were determined prior to and at course completion. Mean breathing zone lead concentrations for the five training activities ranged from 0.014 on the outdoor flat range to 0.064 mg/m3 inside shoot houses; with a change to lead-free ammunition the values were reduced to a range of 0.006–0.022 mg/m3. Isolated flash bang grenades generated very high general area lead concentrations (2.0 mg/m3), which in training were associated with the highest measured breathing zone concentration (0.16 mg/m3). For copper, mean breathing zone concentrations increased from 0.010 to 0.037 mg/m3 with the change to lead-free frangible ammunition on the outdoor range, but remained below the permissible exposure limit for copper fume. Inside shoot houses, mean breathing zone copper concentrations exceeded the permissible exposure limit with ball and lead-free frangible ammunition, ranging from 0.077–0.13 mg/m3. With the introduction of lead-free ammunition, when comparing the blood lead differences between start and finish of the course, there was a significant reduction in the mean blood lead difference from 13.3 µg/dL to 5.4 µg/dL. Options for mitigation of potentially high exposure areas using improved ventilation designs are discussed. These results advocate for improved designs for shoot house training facilities, stress the importance of removing lead from ammunition and explosive devices for training, and promote the continued need for implementation of controls to mitigate and manage metal exposures during training.

Outdoor concert monitoring, community noise, and the Cavanaugh Criterion

Sound from outdoor concerts and other sources can be challenging to measure, especially in the midst of ambient noises and environmental effects. It can be even more challenging to evaluate the data toward resolution of complaints and satisfaction for neighbors. In the mid 1980s through the 1990s, Bill Cavanaugh was deeply involved in important projects involving measurement and especially evaluation of outdoor concert sound levels, and he became a recognized leader in the field, consulting on amphitheater and outdoor venue sound and addressing community relations throughout the country. This presentation will review one of the most significant projects, then called Great Woods Center for the Performing Arts, now the Xfinity Center, in Mansfield, MA, an outdoor amphitheater with total 16 000 seats (now nearly 20 000), in which the Cavanaugh Criterion took shape, more in response to the many touring rock shows (and for which one of the first “green-yellow-red lights” was developed for the sound mixers' easy visual reference and better sound level control) than as the summer home of The Pittsburgh Symphony Orchestra. Recent application of the Cavanaugh Criterion for concert level evaluation of loud, powerful sound systems will also be reviewed, along with implications for application to a much wider range of possible outdoor and even indoor noise intrusions.

Frequent Visits to an Outdoor Range and Lower Areas of an Aviary System Is Related to Curiosity in Commercial Free-Range Laying Hens.

Simple SummaryIndividual hens’ preferences to spend time at particular locations within free-range aviary housing system may be influenced by personality and behavioral characteristics such as curiosity or fear. We monitored hens’ location for their production life on a commercial free-range farm: time spent in the outdoor range, upper feeder, lower feeder, and nest box tier. At the end of lay, we conducted a series of validated behavioral tests to assess fearfulness and exploration. We hypothesized that if temperament encouraged preferences for particular areas, we would find relationships with early life behavior. Conversely, relationships with choice of space and whole production life ranging would indicate environmental influences on temperament. Whilst we could not determine causation, more time spent on the range and lower feeder tier was associated with increased curiosity but only when considering whole-life not early-life ranging. We found little evidence that fearfulness or individual coping styles was associated with time spent at a specific housing location in early or whole life. Body weight prior to range access was the strongest predictor of more time spent at the lower and less on upper feeder tier. We provide evidence that preference for more complex environments such as range may increase hen curiosity.Individual hen preferences to spend time at particular locations within a free-range aviary system and relationships with temperament is relatively unknown. Hens (n = 769) from three commercial flocks were monitored with Radio Frequency Identification technology to determine time spent on the range, upper and lower aviary tiers, and nest boxes. Prior depopulation, novel arena (NA) and novel object (NO) tests assessed exploration and fearfulness. During early life; more time on the lower tier was associated with more lines crossed in the NA test (p < 0.05). No other evidence suggested preference during early life was related to fear or curiosity. More time on the range and lower tier were associated with heavier pre-ranging body weight and gain (p = 0.0001). Over the hens’ whole life; time spent on range and lower tier was associated with approaching the NO (p < 0.01). More time spent on the upper tier was associated with less time near the NO and fewer lines crossed in NA (p < 0.01). The relationships during early and whole life use of space and some potential indicators of fearfulness were inconsistent and therefore, no strong, valid, and reliable indicators of hen fearfulness such as freezing were identified.

An observational field study of the cloacal microbiota in adult laying hens with and without access to an outdoor range

BackgroundLaying hens with access to outdoor ranges are exposed to additional environmental factors and microorganisms, including potential pathogens. Differences in composition of the cloacal microbial community between indoor- and outdoor-housed layers may serve as an indicator for exposure to the outdoor environment, including its pathogens, and may yield insights into factors affecting the chickens’ microbiota community dynamics. However, little is known about the influence of outdoor housing on microbiota community composition in commercial layer flocks. We performed a cross-sectional field study to evaluate differences in the cloacal microbiota of indoor- vs outdoor-layers across farms.Eight layer flocks (four indoor, four outdoor) from five commercial poultry farms were sampled. Indoor and outdoor flocks with the same rearing flock of origin, age, and breed were selected. In each flock, cloacal swabs were taken from ten layers, and microbiota were analysed with 16S rRNA gene amplicon sequencing.ResultsHousing type (indoor vs outdoor), rearing farm, farm and poultry house within the farm all significantly contributed to bacterial community composition. Poultry house explained most of the variation (20.9%), while housing type only explained 0.2% of the variation in community composition. Bacterial diversity was higher in indoor-layers than in outdoor-layers, and indoor-layers also had more variation in their bacterial community composition. No phyla or genera were found to be differentially abundant between indoor and outdoor poultry houses. One amplicon sequence variant was exclusively present in outdoor-layers across all outdoor poultry houses, and was identified as Dietzia maris.ConclusionsThis study shows that exposure to an outdoor environment is responsible for a relatively small proportion of the community variation in the microbiota of layers. The poultry house, farm, and rearing flock play a much greater role in determining the cloacal microbiota composition of adult laying hens. Overall, measuring differences in cloacal microbiota of layers as an indicator for the level of exposure to potential pathogens and biosecurity seems of limited practical use. To gain more insight into environmental drivers of the gut microbiota, future research should aim at investigating community composition of commercial layer flocks over time.

Deriving sequences of operation for air handling units through building performance optimization

Operational parameters of air handling units (AHUs) play an important role in the energy and comfort performance of commercial buildings. Current guidelines to determine these parameters are based on heuristics and are not informed by formal optimization. This paper presents a building performance optimization method to derive sequence of operations for multi-zone AHUs. To this end, 27 variants of a generic EnergyPlus office building model are built representing three levels of occupancy, envelope, and HVAC capacity scenarios. The supply temperature, morning start time, and economizer settings of the model are optimized for the 27 scenarios by using a genetic algorithm. The results highlight that optimal supply temperature setpoints transition from ∼12°C to a range of ∼16°C to ∼20°C over an outdoor temperature range of ∼20°C to ∼0°C. Energy savings are estimated as ∼20% relative to a reference case with a constant supply temperature and preheating/precooling period.

Range use is related to free-range broiler chickens’ behavioral responses during food and social conditioned place preference tests

Free-range broiler chickens usually show an uneven spatial utilization of an outdoor range. Due to behavioral and cognitive between-individual differences, some animals may be driven to associate food and conspecifics more strongly to the barn, causing them to be less prone to explore the range. In this study, we aimed to understand how broiler chickens with different ranging levels (low- and high-ranging chickens) would behave under conditioned place preference (CPP) test situations. We used two cohorts conditioned to two natural rewarding stimuli: food and social companions. In a two-chambered apparatus, one cohort (n = 31, 16 high-ranging, and 15 low-ranging chickens) was conditioned to one chamber that always contained a cup with a food reward (mealworms), while the cup in the other chamber was always empty. The same design was also used with the second cohort (n = 31, 15 high-ranging and 16 low-ranging chickens), although instead of food, the reward was the physical presence of two conspecifics. During the testing trials, the animals had access to both empty chambers, and the time spent in each chamber was quantified. For the first day of the food CPP test, both the high- and low-ranging chickens spent significantly more time in the conditioned chamber, where they had previously found mealworms. During the following extinction days, the animals showed a gradual loss of their learned preference, increasing their immobility in the apparatus. High-ranging chickens were more immobile than low-ranging chickens, however, as their number of trials without moving was significantly higher. Unexpectedly, during the first day of the social CPP test, only high-ranging chickens showed a place preference. An overall place preference was observed only on the second day, with no chamber preference during the extinction days. Our results suggest that whether and how a stimulus-reward association occurs for free-range chickens may also be dependent on individual differences and the nature of the reward (food or social). Since associative learning occurs on a daily basis for farmed animals and the way individuals learn or value the reward varies, this research advanced our knowledge of animal behavior and individual cognitive differences that can be highly beneficial in improving animals’ living conditions; this new understanding will allow for a more individualized approach to rearing broiler chickens in outdoor systems.