Variable Distances Research Articles

Female song in eastern bluebirds varies in acoustic structure according to social context

Most of our knowledge about the function, evolution, neurobiology and ontogeny of complex vocalizations in birds comes from previous work on male song. However, the recent increase in focus on female bird song over the last few decades has helped bridge that gap in our knowledge and has vastly changed our understanding of the function, phylogeny and evolution of bird song. Here we present evidence that female song may be modifiable based on signal function. Eastern bluebirds primarily use female song for within-pair communication with their social mate. We examined the female songs of eastern bluebirds sung during within-pair communication and compared the acoustic structure to female songs used in other contexts. Within-pair communication songs differed significantly from other female songs that we measured by six of the eight acoustic variables we measured. Additionally, we examined the song structure of within-pair communication songs at variable distances between mates and between neighbour females. Song structure did not vary over distance. However, we found significant differences between neighbouring females and the number of syllables and frequency modulations each female included in her within-pair communication songs. We propose that female songs have the potential to indicate individual identity, through acoustic structure modification. Our findings further highlight the need for additional study of female song and functional acoustic plasticity in bird song. Animal signals may be stereotyped to convey honest information, they may be functionally plastic to convey additional information, or elements of a signal may fall in both categories. Historically, bird song has been primarily studied as a stereotyped male trait. Whereas male bird song may have variable acoustic structure in some instances, such as extreme aggression, the functional plasticity of female song is largely unknown. We examined female song plasticity for within-pair communication songs of female eastern bluebirds. We present some of the first evidence that female song structure may be variable between functional contexts and that females may alter their song structure to encode additional information, such as individual identity. Our results inform future work on the function and ontogeny of female bird song. Additionally, our findings support the need for further study on female bird song and the functional plasticity of complex acoustic signals.

Total grain size distribution of components of fallout deposits and implications for magma fragmentation mechanisms: examples from Campi Flegrei caldera (Italy)

In this paper, we present results of the reconstruction of the total grain size distribution (TGSD) of the material erupted during explosive volcanic eruptions at Campi Flegrei (Italy) considering all components (juvenile, lithic and crystal clasts). To date, the few TGSDs made available have been mostly reconstructed by assuming that the tephra deposits consisted of only one component. This simplification can introduce substantial bias in the interpretation of magma fragmentation mechanisms and significantly affect ash dispersion forecasts, since each tephra component has specific aerodynamic characteristics. By means of field investigations and laboratory analyses on samples collected from deposits of the Agnano-Monte Spina and Astroni eruptions, we reconstructed the TGSDs of juvenile, lithic and crystal components via the Voronoi tessellation method. Our results show how the systematic reconstruction of a TGSD, from the component-specific to the bulk TGSD, can provide important information on magma fragmentation mechanisms and wall-rock erosion processes. Results confirm that the bulk TGSD is the combination of the merging of different component subpopulations, according to their own TGSD, density and relative mass proportions. In addition, the integration of component analysis, TGSD and settling velocity data allowed characterization of the aerodynamic behaviour of each component at variable distances from the vent, which can be related to their own parent grain size distribution. The integration of new data from distal tephra deposits for the considered eruptions has thus allowed a reassessment of the erupted volumes of eruptions considered in this research, which are now 3.17 and 0.63 km3, for Agnano-Monte Spina and Astroni, respectively.

Velocity measurements with structured light transmitted through a multimode optical fiber using digital optical phase conjugation.

Lensless fiber microendoscopes enable optical diagnostics and therapy with minimal invasiveness. Because of their small diameters, multimode fibers are ideal candidates, but mode scrambling hinders the transmission of structured light fields. We present the generation of a localized fringe system at variable distances from the distal fiber end by exploiting digital optical phase conjugation. The replayed fringe system was used for quantitative metrology. Velocity measurements of a microchannel flow in the immediate proximity of the fiber end without the use of any imaging lenses are shown. Lensless multimode fiber systems are of interest especially for biomedical imaging and stimulation as well as technical inspection and flow measurements.

Wildflower plantings promote blue orchard bee, Osmia lignaria (Hymenoptera: Megachilidae), reproduction in California almond orchards.

Concerns over the availability of honeybees (Apis mellifera L.) to meet pollination demands have elicited interest in alternative pollinators to mitigate pressures on the commercial beekeeping industry. The blue orchard bee, Osmia lignaria (Say), is a commercially available native bee that can be employed as a copollinator with, or alternative pollinator to, honeybees in orchards. To date, their successful implementation in agriculture has been limited by poor recovery of bee progeny for use during the next spring. This lack of reproductive success may be tied to an inadequate diversity and abundance of alternative floral resources during the foraging period. Managed, supplementary wildflower plantings may promote O. lignaria reproduction in California almond orchards. Three wildflower plantings were installed and maintained along orchard edges to supplement bee forage. Plantings were seeded with native wildflower species that overlapped with and extended beyond almond bloom. We measured bee visitation to planted wildflowers, bee reproduction, and progeny outcomes across orchard blocks at variable distances from wildflower plantings during 2015 and 2016. Pollen provision composition was also determined to confirm O. lignaria wildflower pollen use. Osmia lignaria were frequently observed visiting wildflower plantings during, and after, almond bloom. Most O. lignaria nesting occurred at orchard edges. The greatest recovery of progeny occurred along the orchard edges having the closest proximity (80 m) to managed wildflower plantings versus edges farther away. After almond bloom, O. lignaria nesting closest to the wildflower plantings collected 72% of their pollen from Phacelia spp., which supplied 96% of the managed floral area. Phacelia spp. pollen collection declined with distance from the plantings, but still reached 17% 800 m into the orchard. This study highlights the importance of landscape context and proximity to supplementary floral resources in promoting the propagation of solitary bees as alternative managed pollinators in commercial agriculture.

Conduction mechanisms study in CaCu2.8Ni0.2Ti4O12 ceramics sintered at different temperatures

CaCu2.8Ni0.2Ti4O12 ceramics were prepared via the solid-state reaction. The pellets were sintering at 950 °C, 1000 °C, 1050 °C and 1100 °C for 24h. The X-ray diffraction (XRD) exhibits the crystallization of all the samples in the cubic structure with Im3‾ space group. The scanning electronic microscope (SEM) analysis show the growth of grain size by increasing sintering temperature from 0.65 to 18.58 μm. The conductivity analysis present a notable increase with the heating treatment. Both ac and dc electrical conductivity are fully examined as function of frequency and temperature. The ac conductivity discloses that correlated barrier hopping and non-overlapping small polaron tunneling models are the dominated conduction mechanisms existing in our compounds. By rising the sintering temperature the barrier height, above which jump the polarons or the electrons, tends to lower. The dc conductivity reveals that the conduction is achieved by the jump of polaron to the neighboring site and at variable distances.

Animal welfare in the U.S. slaughter industry-a focus on fed cattle.

Animal welfare within the U.S. slaughter industry continues to prevail as one of the top priorities for livestock producers, businesses, and consumers alike. There are federal regulations that enforce the humane transport, handling, and slaughter of cattle. The journey that cattle must make to the slaughter facility is comprised of many environmental and human factors that can positively or negatively affect animal welfare. Cattle may be exposed to multiple stressors, such as noise, unfamiliar animals and humans, temperature extremes, temporary food/water deprivation, variable transport distances and experiences, and new pen conditions. The animal caretakers involved in these processes attempt to minimize stress and discomfort for the animals, but research is needed to focus on the gaps in knowledge and to support the implementation of strategies known to enhance the human–animal interactions that occur from farm to slaughter. This literature review will provide a summary of fed cattle welfare topics, research, and industry tools that span across the beef animal’s journey from the farm/feedlot through the slaughter process. In addition, areas that have had little research focus are identified to highlight the need for future work and development of industry tools. Some of these topics include examining trailer design, the use of trailer slats during weather extremes, the welfare aspects of cattle destined for salvage slaughter, multiple preslaughter factors and interactions, abnormal mobility and nonambulatory cattle, lairage environmental conditions, new stunning methods, and the impact of a well-trained, motivated, and stable workforce on cattle and people welfare. The authors conducted a survey at the 2019 North American Meat Institute Animal Care and Handling Conference, which comprised of stakeholders within the meat packing industry, packing plant employees, and food company employees, educators, and auditors. The survey responses identified training/education and communication as areas of need in animal welfare, whereas the majority of survey responses focused on the aspects of the human–animal interaction as the top challenges for the industry. By continuously identifying, measuring, monitoring, and managing animal welfare challenges within the beef cattle slaughter industry, prioritization and execution of programs and training that improve the welfare of cattle can be achieved as animals move through this final stage of the meat production system.

Geocentric Spherical Surfaces Emulating the Geostationary Orbit at Any Latitude with Zenith Links

According to altitude, the orbits of satellites constellations can be divided into geostationary Earth orbit (GEO), medium Earth orbit (MEO), and low Earth orbit (LEO) constellations. We propose to use a Walker star constellation with polar orbits, at any altitude, to emulate the geostationary orbit with zenith paths at any latitude. Any transmitter/receiver will be linked to a satellite as if the site were at the equator and the satellite at the local zenith. This constellation design can have most of the advantages of the current GEO, MEO, and LEO constellations, without having most of their drawbacks. Doppler phenomena are largely minimized because the connected satellite is always seen almost at the local zenith. The extra free-space loss, due to the fixed pointing of all antennas, is at most 6 dBs when the satellite enters or leaves the service area. The connections among satellites are easy because the positions in the orbital plane and in adjacent planes are constant, although with variable distances. No steering antennas are required. The tropospheric propagation fading and scintillations are minimized. Our aim is to put forth the theoretical ideas about this design, to which we refer to as the geostationary surface (GeoSurf) constellation.

Visual outcomes of binocular implantation of a new extended depth of focus intraocular lens.

Purpose:To evaluate the visual outcomes of bilateral implantation of a new hydrophobic foldable extended depth of focus (EDOF) IOL.Methods:All cases undergoing phacoemulsification with bilateral implantation of Supraphob Infocus IOL between December 2017 and July 2018 at a tertiary eye care center were recruited in this prospective interventional study. The primary outcome measures were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA). Postoperative follow-up was done on day 1, 1 week, 1 month, and 3 months.Results:One hundred and four eyes of 52 patients with a mean age of 58.4 ± 9.3 years were included. The mean UDVA improved from 0.84 ± 0.32 logMAR preoperatively to 0.11 ± 0.08 logMAR at 3 months following surgery. At the final follow-up, the binocular UDVA, UIVA, and UNVA was 0.03 ± 0.07, 0.14 ± 0.06, and 0.36 ± 0.05 logMAR, respectively. The mean CS was 1.47 ± 0.06 logCS. The distance and near stereopsis was 90.2 ± 24.8 s of arc (arcsec) and 62.5 ± 19.4 arcsec, respectively. The mean total higher-order aberration (HOA), point spread function, and modulation transfer function were 0.30 ± 0.13, 0.07 ± 0.08, and 0.26 ± 0.07, respectively.Conclusion:The Supraphob Infocus EDOF IOL provides good unaided visual acuity for distance, intermediate, and near along with a high quality of vision as assessed by contrast sensitivity, HOAs, and stereoacuity. It may be a potential alternative to the currently available EDOF IOLs in providing good visual acuity at variable distances.

Morbidity profile of communities in Bhopal city (India) vis-à-vis distance of residence from Union Carbide India Limited plant and drinking water usage pattern.

Objective:A cross-sectional study was undertaken to assess the prevalence of morbidities in communities residing at variable distances from the closed down insecticide manufacturing plant premises of Union Carbide India Limited (UCIL), Bhopal, India and to determine association of morbidities, if any, with their drinking water usage pattern and distance of localities from the UCIL plant.Materials and Methods:A total of 10,827 individuals belonging to 2,184 families, residing within 0-1 km (Stratum I) and 2.5-5.0 km (Stratum II) radial distances from UCIL plant were surveyed and 9,306 of them (86%) were clinically examined. Data were analyzed to examine the association between the groups of morbidities, likely due to biological and chemical water contamination, and the distance of locality from the UCIL plant. Multiple logistic regression was used to explore the risk factors for morbidities.Results:Nearly similar prevalence (25.3% in stratum I, 25.8% in stratum II) and the trend of all-cause morbidities were recorded in the two strata. While morbidities related to gastrointestinal tract system (P < 0.05), auditory system (P < 0.01), neoplasm/cancers (P < 0.01) and congenital anomalies (P < 0.01) were significantly higher in stratum I, the prevalence of hypertension (6.4% stratum II, 4.7% stratum I; P < 0.01) and diabetes mellitus (3.4% stratum II, 2.0% stratum I; P < 0.001) was found significantly higher in stratum II. No association (P > 0.05) was observed between the prevalence of morbidities, likely due to the consumption of biologically or chemically contaminated drinking water, and the distance of locality/stratum from the UCIL plant.Discussion and Conclusion:By and large similar pattern of morbidities were recorded in the two strata suggesting that the communities, irrespective of the distance of their residences from UCIL plant or sources of their drinking water, are equally vulnerable to various morbidities.

ВЗАЄМОДІЯ ДРЕНАЖНИХ СВЕРДЛОВИН У ПРОТИФІЛЬТРАЦІЙНИХ ЗАВІСАХ

The decrease of water levels in the drainage wells of the coastal anti-filtration drainage system with the siphon method of water intake from them was analyzed. The interaction of water-lowering wells with different depths and located at variable distances from each other is considered, which makes it possible to ensure uniform drainage from each well and to achieve a steady decrease in the level of groundwater over the entire length of the antifiltration drainage system.The results of the performed analytical studies are presented. The example of the Kamyanka-Dniprovska's anti-filtration drainage system shows that the decrease in water levels in wells at the same flow rate of pumped water depends on their hydraulic interaction, hydrogeological conditions of water filtration from the aquifer and the distance of the antifiltration drainage system from the bank-side. The results obtained indicate that the highest level of water depletion of the coastal vertical anti-filtration drainage system line with siphon drainage from wells is achieved at a distance of a number of wells from the Kakhovsky reservoir bank-side a = 100 m, at the same water flow rate from each of the drainage wells (Q = 604,8 m3 /day), located at different distances from each other. The highest rate of additional reduction of water obtained through mutual hydraulic action was obtained in the 7th well, which has a depth of 14,9 m, and it is located at a distance of 100 m from the 6th well and at a distance of 110 m from the 8th well. The lowest indicator of the level of groundwater reductions at different indicators of the distance of a number of drainage wells to the bank-side a (30, 50, 80, 100 m) is observed in the first well, farthest from the water collection well.

Perceived wintering latitude determines timing of song output in a migratory bird.

Migratory bird populations frequently consist of individuals that overwinter variable distances from the breeding site. Seasonal changes in photoperiod, which varies with latitude, underlie seasonal changes in singing frequency in birds. Therefore, migratory populations that consist of individuals that overwinter at different latitudes with large overwintering ranges could experience within‐population variation in seasonal production of song. To test the influence of overwintering latitude on intrapopulation variance in song production in the spring, we subjected two groups of Eastern Song Sparrows (Melospiza melodia melodia) from the same partially migratory breeding population to different photoperiodic schedules associated with a 1,300‐km difference in overwintering location. One group remained on the natural photoperiodic schedule of the breeding site (resident group) while the other group experienced a nonbreeding photoperiod that mimicked a southern migration in the fall followed by a northern migration back to the breeding site in the spring (migratory group). We compared song output between the two groups in three different stages (nonbreeding, prebreeding, and breeding). Little singing occurred during nonbreeding stage sample dates (20 November, 6 December) for the resident group, and no singing occurred for the migrant group. During the prebreeding stage (27 January, 7 February), significantly more singing occurred in the resident group than in the migrant group. During the breeding stage (21 March, 4 April), after a simulated migration for the migrants, song output was similar in both groups. These results suggest that within‐population variation in wintering latitude may contribute to variation in seasonal changes in singing behavior, which may covary with readiness to breed. Studies utilizing confirmed migrants and residents, rather than merely simulated migrants and residents, are also needed to better understand these processes.

Approximation of generalized offset surfaces by bicubic splines

We present an approximation problem of surfaces of a generalized offset surface with offset variable distances and directions. Such approximating surface fits some given data points and minimizes a Sobolev’s semi-norm of order 3. The study of the new results, from a mathematical point of view, carefully establishing the proof of the convergence between the generalized offset surface and its approximating spline in an adequate parametric bicubic spline space. Moreover, the approximating spline function is computed and an estimation of the relative error is introduced. Finally, some numerical and graphic examples are shown in order to prove the useful and the effectiveness of our method.

Nonlinear Finite Element Analysis for shear strength and behavior of Reinforced Concrete T-Beam with Openings in Both Web and Flange by ANSYS 14.5

In this study, a three-dimensional T-beam consisting of circular openings in web and/or in the flange with variable distances from the support is analyzed numerically. The beam is simulated and analyzed non-linearly by using computer software of ANSYS V.14.5. In the simulation, the calibration for the model is carried out by taking the effects of openings, including their numbers and locations in the beam, on the behavior of the beams in general and their shear strength in particular after comparing the results with the experimental work. Thirteen cases are studied for investigating crack patterns and load capacity accompanied with graphing load-displacement envelope for each case. From these in thirteen cases, a case is control beam which is penetrated with holes. The rest of the samples, however, contain openings in their webs and/or flanges with variable distances from the support. A parametric study is carried out on high strength concrete to compare it with normal concrete.&#x0D; After the calibration, the numerical results of the load-displacement curve, crack pattern and ultimate load significantly matches the results obtained from experimental works. The results show a substantial decrease of load carrying capacity by up to 11.7% with a decrease in openings distance from support from d (effective depth of the T-beam) to (d/3). However, the capacity of the beam to carry load increases by 17.6% by reducing the space between the openings and the support to (d/4).

A time-space Hausdorff derivative model for anomalous transport in porous media

Abstract This paper presents a time-space Hausdorff derivative model for depicting solute transport in aquifers or water flow in heterogeneous porous media. In this model, the time and space Hausdorff derivatives are defined on non-Euclidean fractal metrics with power law scaling transform which, respectively, connect the temporal and spatial complexity during transport. The Hausdorff derivative model can be transformed to an advection-dispersion equation with time- and space-dependent dispersion and convection coefficients. This model is a fractal partial differential equation (PDE) defined on a fractal space and differs from the fractional PDE which is derived for non-local transport of particles on a non-fractal Euclidean space. As an example of applications of this model, an explicit solution with a constant diffusion coefficient and flow velocity subject to an instantaneous source is derived and fitted to the breakthrough curves of tritium as a tracer in porous media. These results are compared with those of a scale-dependent dispersion model and a time-scale dependent dispersion model. Overall, it is found that the fractal PDE based on the Hausdorff derivatives better captures the early arrival and heavy tail in the scaled breakthrough curves for variable transport distances. The estimated parameters in the fractal Hausrdorff model represent clear mechanisms such as linear relationships between the orders of Hausdorff derivatives and the transport distance. The mathematical formulation is applicable to both solute transport and water flow in porous media.

Wave induced motions of partially submerged bodies near a fixed structure

Wave driven impact of small icebergs with offshore structures is a design consideration in Arctic and sub-Arctic regions. The near field hydrodynamic interaction of these wave driven ice masses has been investigated through experimental and CFD studies by Sayeed et al. (2017b, 2018a, 2018b). These studies found that motions were significantly influenced by the standing wave generated due to the superposition of the incident and reflected waves in front of the fixed structure. In regular waves the small bodies may or may not impact the structure, depending on initial starting condition whereas in irregular waves the ice masses hit the structure in all cases. Spectrum analysis carried out over the entire distance travelled by the free floating ice mass in irregular waves revealed relatively small difference in surge and heave velocity due to the presence of the structure (Sayeed et al. (2018b)). The reason is attributed to insufficient data at each separation distances to capture the motion responses for all the frequencies in the spectrum. In this paper, the surge and heave motion time series data in irregular waves are reanalyzed in a similar manner as was previously done for regular waves (Sayeed et al. (2018a). The present analysis reveals correlation of significant wavelength with the motion history at variable separation distances in front of the fixed structure. A statistical approach is then adopted to both regular and irregular wave motion data sets to identify percentiles of velocity response vs position as the small floating bodies approach head on to the fixed structure. These findings enable the identification of the motions of small bodies at specific locations in front of the structure and provide understanding of how wave-induced surge and heave velocities change as small floating bodies approach a fixed structure in a realistic wave field.

Drifting away. Seawater survival and stochastic transport of the invasive Carpobrotus edulis

Coastal areas are vulnerable and fluctuating habitats that include highly valuable spaces for habitat and species conservation and, at the same time, they are among the most invaded ecosystems worldwide. Occupying large areas within Mediterranean-climate coastlines, the “ecosystem engineer” Carpobrotus edulis appears as a menace for coastal biodiversity and ecosystem services. By combining the observation, current distribution, glasshouse experiment, and dispersion modeling, we aim to achieve a better understanding of the successful invasion process and potential dispersion patterns of C. edulis.We analyzed the response of plant propagules (seeds and plant fragments) to seawater immersion during increasing periods of time (up to 144 h). After 2 months of growth, plant fragments showed a total survival rate (100%) indicating high tolerance to salinity. During this time, fragment length was increased (up to 60%) and root length was higher than control in all cases. Also, immersed fragments consistently accumulated more biomass than control fragments. After two months of growth, photosynthetic parameters (Fv'/Fm', ΦNO, and ΦII) remained stable compared to control fragments. Physiologically, osmolyte and pigment content did not evidence significant changes regardless of immersion time.Based on the capacity of propagules to survive seawater immersion, we modeled the potential transport of C. edulis by combining an oceanic model (ROMS-AGRIF) with a particle-tracking model. Results indicated that propagules may travel variable distances maintaining physiological viability. Our model suggested that short-scale circulation would be the dominant process, however, long-scale circulation of propagules may be successfully accomplished in <6 days. Furthermore, under optimal conditions (southerly winds dominance), propagules may even travel large distances (250 km alongshore). Modeling transport processes, in combination with the dynamics of introduction and expansion, will contribute to a better understanding of the invasive mechanisms of C. edulis and, consequently, to design preventive strategies to reduce the impact of plant invasion.

The assembly line feeding problem: An extended formulation with multiple line feeding policies and a case study

As the number of car models in the automotive industry increases, automotive manufacturers are increasingly implementing multi-model assembly lines. These require more part numbers at the assembly line, which results in a shortage of space at the line. Manufacturers use a broad range of line feeding policies to achieve feasible solutions and lower costs. This increases the complexity of assigning line feeding policies to part numbers. To address this problem, we extend existing mixed-integer programming formulations from the literature by modeling nine different line feeding policies as well as different line feeding policies per part family and considering variable walking distances not only at the assembly line but also in the supermarket. Moreover, we extend our formulation by allowing flexible line side spacing. The mathematical model is applied in a case study at a large German automotive company. While models from the literature have been able to reduce total costs by only 0.49%, our proposed model reduces total costs by 3.36% compared to manual planning. By allowing flexible line side spacing, a reduction of 7.54% is possible. An extension of the base model to a rounding of operators without flexible line side spacing allows us to reduce the needed operators by 6.88% compared to manual planning.

Simulation Analysis of Wireless Power Transfer for Future Office Communication Systems

A Wireless Power Transfer system consists of a transmitter coil which is inductively coupled with secondary coil and is popular for wireless charging of future office communication system. Wireless power transfer is used in different applications ranging from mobile chargers to charging stations. In this paper simulation of Wireless Power Transfer for future office communication systems has been conducted over Maxwell 3d of Ansys electromagnetic suite. The input frequency of primary coil is varied from 1kHz -120kHz with respect to the change in resonant capacitance and observed that input frequency between 20kHz-30 kHz, the output power in secondary coil appears to be maximum at variable distances between transmitter coil and receiver coil. There is an improvement of 72% seen in the output power of secondary coil for 25kHz input frequency of primary coil as compared with 40kHz input frequency. This model can be helpful to design future Office Communication systems for charging the mobile phones, Laptops and to turn on the printer wirelessly.

Characteristics of the transverse 2D uniserial arrangement of rows of decussating enamel rods in the inner enamel layer of mouse mandibular incisors.

The 2D arrangement of rows of enamel rods with alternating (decussating) tilt angles across the thickness of the inner layer in rat and mouse incisor enamel is well known and assumed to occur in a uniform and repetitive pattern. Some irregularities in the arrangement of rows have been reported, but no detailed investigation of row structure across the entire inner enamel layer currently exists. This investigation was undertaken to determine if the global row pattern in mouse mandibular incisor enamel is predominately regular in nature with only occasional anomalies or if rows of enamel rods have more spatial complexity than previously suspected. The data from this investigation indicate that rows of enamel rods are highly variable in length and have complex transverse arrangements across the width and thickness of the inner enamel layer. The majority of rows are short or medium in length, with 87% having < 100 rods per row. The remaining 13% are long rows (with 100–233 rods per row) that contain 46% of all enamel rods seen in transverse sections. Variable numbers of rows were associated with the lateral, central and mesial regions of the enamel layer. Each region contained different ratios of short, medium and long rows. A variety of relationships was found along the transverse length of rows in each region, including uniform associations of alternating rod tilts between neighboring rows, and instances where two rows having the same rod tilt were paired for variable distances then moved apart to accommodate rows of opposite tilt. Sometimes a row appeared to branch into two rows with the same tilt, or conversely where two rows merged into one row depending upon the mesial‐to‐lateral direction in which the row was viewed. Some rows showed both pairing and branching/merging along their length. These tended to be among the longest rows identified, and they often crossed the central region with extensions into the lateral and mesial regions. The most frequent row arrangement was a row of petite length nestled at the side of another row having the same rod tilt (30% of all rows). These were termed ‘focal stacks’ and may relate to the evolution of uniserial rat and mouse incisor enamel from a multilayered ancestor. The mesial and lateral endpoints of rows also showed complex arrangements with the dentinoenamel junction (DEJ), the inner enamel layer itself, and the boundary area to the outer enamel layer. It was concluded that the diversity in row lengths and various spatial arrangements both within and between rows across the transverse plane provides a method to interlock the enamel layer across each region and keep the enamel layer compact relative to the curving DEJ surface. The uniserial pattern for rows in mouse mandibular incisors is not uniform, but diverse and very complex.

Movement ecology of the carnivorous woolly false vampire bat (Chrotopterus auritus) in southern Mexico.

Deforestation is a critical threat to bats. The woolly false vampire bat Chrotopterus auritus is a carnivorous bat that is both an indicator species for well-conserved forests and a threatened species in Mexico and other countries due to deforestation. We currently lack the information needed to assess the effects of forest fragmentation and destruction on their populations and to develop plans for their conservation. We used GPS loggers to study the movement patterns of C. auritus in southern Mexico. We observed 72 foraging nights by GPS-tagging 10 individuals from two colonies on 32 occasions in a highly disturbed heterogeneous landscape with extensive deforestation (Hormiguero), and in a more homogeneous, well-preserved forested landscape (Monterrey). Tracked false vampire bats averaged a home range of 108.24 ha, a core foraging area of 3.78 ha and average maximum flight distances of 2.06 km. The bats ranged farther and flew significantly longer distances in Hormiguero than in Monterrey, with males flying longer and more variable distances. They used the well-preserved semi-deciduous forest more often than secondary forest and agricultural fields for traveling and foraging, but the bats occasionally moved and hunted along the borders of secondary forest and agricultural fields adjacent to semi-deciduous conserved forest areas. Although this carnivorous bat might cope with some fragmentation, we suggest that large well-preserved forested areas are highly important for its conservation.