Preferred Height Research Articles

The effect of season and post-fire on habitat preferences of the endangered Swayne\u2019s hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park, Ethiopia

BackgroundThe availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and burning on the habitat preference on Swayne’s hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne’s hartebeest in grassland habitat. Starting from the first week of burning, we recorded the abundance of Swayne’s hartebeest in both burned and unburned grassland patches.ResultsFrom detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne’s hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne’s hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since burning.ConclusionSwayne’s hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using controlled burning as a tool for the conservation of Swayne’s hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance.

Rose-ringed parakeet (Psittacula krameri) and starling (Sturnus vulgaris) syntopics in a Mediterranean urban park: evidence for competition in nest-site selection?

Introduced species may compete with indigenous ones, e.g. for space resources, but evidence for syntopic cavity-nester birds is limited, at least for Mediterranean urban parks. In this work we report data on nest-site habitat use, availability and selection in two species: the introduced rose-ringed parakeet (Psittacula krameri) and the autochthonous starling (Sturnus vulgaris) nesting in ornamental tree (Cedrus libanotica) patches occurring in an historical urban park (Rome, central Italy). In particular, in our study we hypothesize that parakeets negatively affect starling nest-site selection. On 55 trees, we detected 73 available holes for nesting (38.4 % of which hosted nests: 9 of rose-ringed parakeet, 16 of starling, 3 of house sparrow). Birds utilized for nesting only a limited number (< 20%) of the ornamental trees (all larger than 80 cm in diameter). Compared to the total number of available trees, nesting trees had a significantly larger diameter at breast height. We observed a shift in the frequency distribution of nest hole height classes between starlings and parakeets suggesting competition for nesting sites between these two species. Starlings located their nests significantly lower than did rose-ringed parakeets, resulting in a higher specialization for starlings (as measured by the Feinsinger index) than for rose-ringed parakeets. The analysis of co-occurrence highlights a spatial segregation in nest holes. We argue that these differences in preferred nest height are indicative of parakeet dominance over starlings in cavity selection for nesting.

Relationships between Plant Architecture Traits and Cotton Yield within the Plant Height Range of 80–120 cm Desired for Mechanical Harvesting in the Yellow River Valley of China

Mechanical harvesting has become inevitable for cotton production in China due to the rising labor cost in the country. It usually requires a moderate plant height and compact plant architecture. Correlation and stepwise regression were employed to analyze databases of our 24 field experiments between 2010 and 2017 in Hebei Province. The purpose is to identify the relationships between plant architecture traits and seed cotton yield within natural plant height range (58.6–163.2 cm) or preferred plant height range (80–120 cm) for mechanical harvesting in the Yellow River Valley of China, and define some important factors affecting seed cotton yield. Under natural plant height range across all experiments, there was a significantly negative correlation (r = −0.452) between plant height and yield. On limited plant height range desired for mechanical harvesting, the degree of this negative correlation decreased to r = −0.366. The correlation of plant height with seed cotton yield varied greatly with year, cultivar, plant density and mepiquat chloride (MC) application. Moreover, stepwise regression analysis picked internode length of the 1st (generally including 1st–7th mainstem node from bottom), 2nd (8th–12th node) and 4th (above 17th node) mainstem section and the length of lower fruiting branch (LFB) as significant factors influencing seed cotton yield under plant height range of 80–120 cm. The results have implications for precise control of cotton plant architecture preferred for mechanized harvesting in China.

Design and Fabrication of Automated Inbuilt Hydraulic Jack for Light Motor Vehicle

In the feat of changing the wheel of a light motor vehicle, lifting the vehicle is an unavoidable and a complicated practice. Manual lifting using jack systems requires more human effort and comparatively time consuming also. The proposed model is an alternative solution which reduces both the human effort and vehicle lifting time. To lift the vehicle, the user need to exert a gentle push over the lever, that actuates the desired hydraulic jack to the preferred height. In various proposals carried earlier regarding lifting the vehicle more number of jack systems, various power source terminals and requires an additional actuating means, which is redesigned with optimized conditions. The proposed system increases the comfort of the light motor vehicle users which brings them more closer to the technological up gradation. The proposed project is also mainly concentrated towards the ease of differently abled and aged persons.

Development of a Virtual Floor Maze Test - Effects of Distal Visual Cues and Correlations With Executive Function in Healthy Adults.

Virtual reality (VR) is a useful tool to assess and improve spatial navigation, a complex skill and relevant marker for progression of dementia. A fully-immersive VR system that allows the user to physically navigate in the space can provide an ecologically valid environment for early detection and remediation of cognitive and navigational deficits. The aim of this study was to develop a virtual version of the floor maze test (VR-FMT), a navigational test that requires navigating through an unfamiliar two-dimensional floor maze. With the VR-FMT, mazes of desired complexity and walls of preferred height can be built to challenge navigational ability and mask visual clues. Fifty-five healthy adults completed the FMT in three different conditions: real environment (RE), virtual environment with no walls (VE-NW), and virtual environment with walls (VE-W). In addition, they completed two neuropsychological tests, the Trail Making Test and Digit Symbol Substitution Test. Results showed that the time to complete the maze in the VE was significantly higher than in the RE. The introduction of walls increased the number of errors, the completion time, and the length of the path. Only time to exit in the VE-W correlated with results of the cognitive tests. Participants were further subdivided on the basis of their time to exit the maze in the RE, VE-NW, and VE-W (low navigational time - LNT, and high navigational time - HNT). Only when analyzing the time to exit the maze in the VE-W, the LNT group outperformed the HNT group in all cognitive tests.

Relationship between preferred saddle height and pedalling kinematics in professional cyclists

Background: Proper saddle height in cycling can improve health, comfort, and performance (Millour et al. 2019). Methods based on knee angle (KA) for saddle height adjustment are frequently employed (Ferrer-Roca et al. 2011). They are considered accurate because they consider individual differences in thigh, shank, and foot length (Bini and Hume 2016). Ferrer-Roca et al. (2011) advocate KA between 30° and 40° during maximum knee extension while pedalling to prevent injuries. However, this method does not consider ankle angle (AA) which can vary considerably according to the individual pedalling technique (Peveler et al. 2012). Purpose: The purpose of this study was to analyse lower limb joint angle of professional cyclists in their preferred saddle height. The hypothesis was that AA should be taken into consideration for an accurate adjustment of saddle height in cycling. Methods: Seventeen professional cyclists volunteered for this experiment (Mean ± SD: 28 ± 5 years old, 1.80 ± 0.05 m, 70 ± 7 kg). A 1 st step was to optimise cycling cleat position with a ML Cleat® device (Morphologics, Saint-Malo, France) and to adjust saddle and handlebar positioning according to the Morphologics ergonomist advices. Then, all the cyclists have 1 month to validate this position or to modify it according to this comfort’s feeling. In a 2 nd step, the cyclists performed a submaximal pedalling test of 3 min at 150 W and 80 rpm on their personal road bike which was mounted on an Elite Turno ergometer ® (Elite, Fontaniva, Italy) enabling to control break resistance. To measure KA, AA, and hip angle (HA) during maximum knee extension (Figure 1), markers were placed on the left side of each participant on greater trochanter, lateral femoral epicondyle, lateral malleolus, and 5 th metatarsal head. A high-resolution digital camera (Go Pro Hero 3, San Mateo, California, USA) was positioned at 4 m and perpendicular to the cyclists. Joint angles data of 10 consecutive pedalling cycles were analysed using kinematic analysis software (Kinovea V0.8.24). A correction of parallax and a correction of distortion were made with this software. Results: The results showed that the means of KA, AA, and HA were 38.0 ± 4.5°, 124.7 ± 5.2°, and 59.2 ± 3.8°, respectively. Although this mean of KA was in the range of 30°-40°, we can observe a large discrepancy between the cyclists and 5 of them had a KA outside the optimal range advocated by Ferrer-Rocca et al. (2011). Figure 2 shows that KA was positively correlated to AA (r = 0.57, p<0.01) but negatively to HA (r = 0.73, p<0.01). Discussion: Our results suggest that professional cyclists can exhibit different pedalling kinematic patterns. Athletes with higher KA present lower HA and important plantarflexion during maximum knee extension. Conversely, athletes with lower KA exhibit higher HA and large dorsiflexion during maximum knee extension. These results are in accordance with Ryan and Gregor (1992) who showed a strong inter-subject variability in pedalling kinematics of well-trained cyclists. Peveler et al. (2012) suggested that optimisation of the cycling position must take into account individual anthropometry as well as pedalling technique, and notably the foot orientation during pedalling. Cyclists who pedal with an important plantarflexion during maximum knee extension may use higher KA than those pedalling with a large dorsiflexion. Conclusion: This study suggests that saddle height adjustment optimisation should take into consideration each rider's pedalling technique, notably foot orientation, and that KA outside optimal Ferrer-Roca range is not necessarily related to a poor saddle height adjustment. Acknowledgements: MorphoLogics Company and Team Arkea Samsic.

Appropriate height of dental chairs for effective administration of chest compressions by female dentists.

ObjectivesThe aim of this study was to determine the appropriate height of a dental chair for the administration of effective chest compressions by female dentists.Materials and methodsWe asked 19 female dentists to perform metronome‐guided chest compressions at a rate of 100 compressions per minute for 2 min on the floor and on a dental chair. We set the height of the dental chair to 76, 73, 70, 67, and 64 cm. We measured the compression depth and proportion of compressions performed at an adequate depth. We then compared the quality of chest compressions between the tall and short (relative to the average body height) groups of participants. We also asked the participants to specify their preferred compression height or condition for chest compression administration.ResultsThe participants recorded their maximum chest compression depth (35.0 ± 8.8 mm) at a height of 67 cm. There was no significant difference in chest compression depth between the tall and short groups, irrespective of the compression height. The maximum depth of chest compressions was achieved at a height of 67 cm (from the floor to the compression surface) in both groups, with no significant difference. The participants most frequently identified 67 cm as the most suitable height for the administration of chest compressions.ConclusionFor female dentists, a height of 67 cm is considered suitable for the administration of chest compressions in the standing position, regardless of physique.

Oviposition site preference and reproductive ecology of Teratohyla midas (Anura: Centrolenidae) in the Colombian Amazon

ABSTRACTThe family Centrolenidae (Glass frogs) includes 157 species of anurans with a Neotropical distribution. Although glass frogs have been the subject of several studies encompassing various aspects of their biology, natural history data on their reproductive ecology is still scarce. One of the important aspects of reproductive ecology is the oviposition site since it can impact the reproductive success of a species. Herein, we provide detailed information on the reproductive ecology of a population of Teratohyla midas from the Colombian Amazon foothills and test whether this species shows a preference on substrate and height of oviposition site. We monitored a population using capture-mark-recapture of individuals identified by a photograph of their unique pattern of dorsal yellow spots. Wild-ID Software was used to corroborate if the dorsal pattern was different between individuals. Additionally, we monitored the presence of egg clutches, amplexus and oviposition behaviour. We observed 110 males and 5 females of T. midas, seen at an average height of 3.1 m ± 2.9 (0–17.8 m) from the ground. Likewise, we recorded the amplexus behaviour of two pairs for approximately 150 min. Once the oviposition happened, the male retreated, and the female covered the egg clutches for approximately 60 min. We observed 25 egg clutches with 60% being deposited in leaves of Selaginella sp and found at an average height of 2.9 ± 1.7 m (1.1–7.0 m). Thus, the selection of oviposition site was not random but mostly specific to one type of substrate. Furthermore, there was an overlap of the re-sampled median height distributions of active individuals and clutches, which suggests that oviposition does not occur at a preferred height within the vertical distribution of individuals. The information presented here is the first detailed record of reproductive ecology for this species and we hope to provide a basis to improve our knowledge on the biology of this species and other glass frogs.

Food and feeding behaviour of Chestnut-tailed Starling, Sturnia malabarica at Jahangirnagar University Campus, Bangladesh

Food and feeding behaviour of Chestnut-tailed Starling, Sturnia malabarica were studied at Jahangirnagar University Campus, Bangladesh, from August 2016 to March 2017. A total of 414 observations were made on the feeding maneuver and it was noted that they were omnivorous consuming 67.15% animal diet compared to 20.53%plant diet.They predominantly consumedinsect larvae(39%) followed by beetles (16%), nectar (14%), food wastes (12%), fruits (7%), dragonflies (7%), damselflies (3%), and worms (2%).Among the five types of feeding modes recorded,hang-upmode (37.92%) was major feeding technique in Chestnuttailed Starling while pecking mode (6.76%)was least used. Rain tree (Samanea saman) (33.76%) followed by White siris (Albizia procera) (30.55%) was recorded as the most utilized foraging plant while mostly preferred perching height by Chestnut-tailed Starling was 6-9m (44.9%) followed by 3-6m (31.6%).&#x0D; Jahangirnagar University J. Biol. Sci. 8(1): 17-23, 2019 (June)

Preference for heights of feeding troughs in mares: a pilot study

AbstractPreferences for the height of feeding troughs of seven mares were evaluated and, as awareness of surroundings when feeding is adaptive for horses, the relationship between preference responses and attention behaviours was also assessed. First, feeding troughs at four heights (0, 25, 50, and 75 cm) were provided for 16 days, and the amount of time animals ate from each height option was measured daily. These data were used to determine the preferred/non-preferred options for each individual. An overall preference for heights of 50 and 75 cm was detected, but responses showed significant individual variation The same animals were subsequently observed, when feeding from preferred (four days) or non-preferred (four days) trough heights, while their behaviours were recorded. Moving ears/head (attention behaviours) occurred more frequently when feeding from preferred heights of feeding troughs. We concluded that to ensure better welfare conditions for the mares in this study, it was important to consider the individual variation of such preferences if possible, however, by using troughs positioned at 50 or 75 cm, the general preference could be assured. Moreover, when feeding from their preferred heights, the study mares paid more attention to their surroundings than when feeding from their non-preferred height and thus it is likely that they defended their preferred options more. However, further studies are needed to evaluate the generalisability of these findings. We have demonstrated a methodology to assess mares’ preferences and provided some preliminary data on the relationship between preferences/non-preferences and the possible emotional states of mares.

Resource use among sympatricCallosciurusspp. (Sciuridae) in tropical seasonal forests during the dry season in northeastern Thailand

Southeast Asia contains a diverse array of squirrels, with several species living sympatrically. However, limited data are available on how the squirrels coexist and share resources in the same habitat. Here, we examined resource-use variation between sympatric Callosciurus finlaysonii and C. caniceps in two habitats of northeastern Thailand: dry dipterocarp forest (DDF) and dry evergreen forest (DEF). Both species were bimodally crepuscular and did not differ in daily activity patterns. Callosciuruscaniceps was fewer in number than C. finlaysonii in DDF, but they had similar frequencies in DEF. The two species generally consumed different plant species, though some preferred fruits overlapped. Callosciurus finlaysonii from DEF remained higher in the trees than C. caniceps; all nests at elevated locations belonged to C. finlaysonii. When feeding, the preferred height of both species varied depending on food availability. In DEF, C. caniceps dominated C. finlaysonii during interactions. Together, our observations indicate that sympatry is possible because the two species differ in food choice and/or engage in vertical zonation.

Three-dimensional quantum size effects on the growth of Au islands on MoS2

Quantum confinement was found to play a critical role in the formation of Au(111) islands grown on the surface of MoS2. These confinement effects are fully three dimensional, with a strong correlation with the relatively large Fermi wavelength associated with the Au(111) planes. The confinement effects result in preferred heights with a periodicity of nearly 2 nm and persist to much higher temperatures than are typically seen in electronic growth mode systems. These findings indicate the potential to explore electronic growth modes in systems based on metal-layered semiconductor interfaces.

Sidewalk pollution flows caused by vehicular traffic place children at a higher acute exposure risk.

The objective of this work is to study the immediate transport flows of PM2.5 diesel exhaust emissions on a city sidewalk. Under calm conditions largest direct exhaust PM2.5 diesel concentrations tend to accumulate at two preferred heights: higher ones at 200-225 cm due to truck and buses aerodynamics, and lower ones at 130-160 cm due to light vehicles. Obtained flows indicate that exhaust emissions are transported to these heights via vortices generated by vehicular traffic. The lower height vortices transporting PM2.5 direct diesel emissions place children aged between 7 and 15 at a higher acute exposure risk due to their stature. Also, the hourly averaged PM2.5 concentrations tend to accumulate nearer to the roadside. This information was obtained using a specially designed electromechanical near-surface atmospheric profiler equipped with a PM2.5 measurement instrument, a thermistor and a sonic anemometer installed on a sidewalk. Using signal analysis techniques, coherent flows of direct PM2.5 emissions and thermal information were obtained. The proposed methodology can be used to evaluate before and after urban interventions, obtain full-scale sidewalk data for exposure studies and provides criteria on where to place sidewalk measurement instruments.

High, low, or familiar? Nest site preferences of experienced laying hens

ABSTRACT1. The aim of this study was to investigate which nest heights are preferred by laying hens in the absence of familiar nest locations and whether preferred nest heights are more attractive than a familiar location. In two experiments, a total of 108 hens of four different layer breeds, which were at least 50 weeks of age, were studied.2. In the first experiment, hens were given individual free choice between nests for 1-week at four different heights (0 cm, 39 cm, 78 cm, and 117 cm above ground). Hens of the four breeds differed in their nest height preferences (P = 0.0013). However, hens of three breeds preferred ground level nests (P < 0.007) and the fourth line showed an equal preference for the ground level and level three, the latter level corresponding to the height of the nests in their home compartments.4. In the second experiment, hens from the four breeds were given a choice between ground level nests and nests at a familiar location, i.e. at the same location as in their home compartment. Hens of all strains preferred the familiar nest location (P = 0.002) and preferences did not differ between strains (P = 0.77).5. Laying hens seem to prefer nests at ground level in the absence of a familiar nest. However, if possible, experienced 50 week old hens continue to use a familiar nest location instead of a ground nest location. The results are discussed with respect to a potential primary preference that may be modifiable by experience and with respect to possible relevance in commercial housing.

Height transitions, shape evolution and coarsening of equilibrating quantum nanoislands

Morphology evolution and coarsening of metal nanoislands is computed within the framework of a surface diffusion-type model that includes the effects of the electron energy confinement within the film, the charge spillage at the film/substrate interface, the energy anisotropy of the film surface and the surface stress. The conditions that result in large islands with flat tops, steep edges and strongly preferred heights are determined. A strong influence of the film height on the coarsening dynamics and final morphologies is found; the conditions leading to interrupted coarsening are highlighted. The dependence of the geometric parameters of the equilibrium island on the film height and on the island initial volume is computed.

Oviposition behavior of Haemagogus leucocelaenus (Diptera: culicidae), a vector of wild yellow fever in Brazil.

ABSTRACT Haemagogus leucocelaenus, which is considered a major vector of wild yellow fever, exhibits acrodendrophilic habits and mainly deposits its eggs in treeholes and bamboo internodes. The selection of nursery sites is essential in the life history and reproductive success of mosquitoes. The present work investigated the preferred oviposition height and period of Hg. leucocelaenus in an Atlantic forest area in Rio de Janeiro. Sampling was performed using oviposition traps that were placed on plant material at 0, 2, 4, 6, and 8 m above the ground, from August 2015 to July 2016. Eggs were more abundant during October and May, and the height of traps placement had no significant effect on the eggs number indicating that Hg. leucocelaenus explores different levels of forest habitats, a behavior that may favor the transmission of pathogens among arboreal animals including primates and humans. The findings of the present study are discussed from an ecological and epidemiological point of view.

Harmonic model of corrugations of incommensurate two-dimensional layers

We developed a method to predict the height corrugations of moir\'e structures resulting from varying azimuthal orientations of graphene on hexagonal boron nitride substrates. Our model accounts for the flexural rigidity of graphene and assumes a sinusoidal corrugation of the preferred height of C atoms above the substrate. Using four parameters derived from density functional theory (DFT), the model computes corrugations of incommensurate moir\'e structures currently inaccessible to DFT with an estimated accuracy on the order of 0.01 \AA{}. We predict that azimuthally aligned graphene domains are energetically favored over rotated ones.

An investigation into the efficacy of technical illustrations depicting physical orientation in sports procedures

AbstractThis study on mental imagery set out to investigate the efficacy of technical illustrations depicting physical orientation in sports procedures. The study was carried out by junior level students on an undergraduate degree in computer science at a Japanese technical university with no specialized knowledge of information design or visual communication. The study participants were asked to match body and overhead images shown from different height perspectives (waist and chest height) and camera positions (front, 1/3rd side, side, 1/3rd back, back) of a man holding a bat and a man hitting with a bat. These physical actions were selected by the researchers as they can typically be seen in multiple sports such as baseball, rounders or cricket, thus widening the potential applicability of the study findings. Overall, the study participants achieved relatively high levels of accuracy in matching the body and overhead images and no consistent or clear pattern emerged with regard to preferred height pers...

Male-Taller and Male-Not-Too-Tall Norms in Taiwan

This study proposed ordered probit models as a methodology to verify the male-taller norm and the male-not-too-tall norm while controlling for other factors. This study confirmed the prevalence of the male-taller and the male-not-too-tall norms in Taiwan. The frequency of the height difference between a husband and wife within the range of 5–15 cm was higher than what would be expected by chance. This range in Taiwan was smaller than the range in the United Kingdom, which may imply that there are preferred height differences between couples that vary across populations.

Acoustical investigation of ambience sound for auditory environments in music performance spaces

The optimal array pattern and height for ambience recording were investigated in a performance space through the use of microphone arrays, such as the Hamasaki-square, IRT-Cross, and Omni-square. The optimal array pattern was selected based on evaluations of ambient recorded sounds for subjective attributes such as spaciousness, envelopment, naturalness, balance, stereo compatibility, and overall preference. Then these attributes were compared with acoustical parameters such as clarity (C80), the inter-channel cross-correlation coefficient (ICCC), and the number of peaks (Np) from the measured room impulse responses. In addition, as an assessment of the optimal height of the array, auditory perception was evaluated with the method of paired comparisons. The results showed that the Hamasaki-square, which exhibited lower C80 and ICCC values and higher Np values, was preferred in the subjective listening test. It was also revealed that the listeners’ preferred height was characterized by uniformly distributed ambience sounds with low C80 value and small deviation for the early decay time (EDT), sound pressure level (SPL), Np, and C80.