Threshold Values Of Density Research Articles

Using QCT for the prediction of spontaneous age- and gender-specific thoracolumbar vertebral fractures and accompanying distant vertebral fractures.

To investigate the value and age- and gender-specific threshold values of bone mineral density (BMD) by quantitative computed tomography (QCT) for the prediction of spontaneous thoracolumbar vertebral fractures and thoracolumbar junction fractures accompanying distant vertebral fractures. Among the 556 patients included, 68 patients had thoracolumbar vertebral fractures (12 patients with distant vertebral fractures, 56 patients without distant vertebral fractures) and 488 patients had no vertebral fractures. All patients were grouped by gender and age. According to the principle of Youden index, the threshold values were calculated from receiver operating characteristic (ROC) curves. The threshold values for predicting thoracolumbar vertebral fractures were 89.8mg/cm3 for all subjects, 90.1mg/cm3 for men, and 88.6mg/cm3 for women. The threshold values for men aged < 60years old and ≥ 60years old were 117.4mg/cm3 and 87.5mg/cm3, respectively. The threshold values for women aged < 60years old and ≥ 60years old were 88.6 and 68.4mg/cm3, respectively. The threshold value for predicting spontaneous thoracolumbar junction fractures with distant vertebral fractures was 62.7mg/cm3. QCT provides a good ability to predict age- and gender-specific spontaneous thoracolumbar vertebral fractures, and to further predict spontaneous thoracolumbar junction fractures with distant vertebral fractures.

An Endurance Equation for Hybrid-Electric Aircraft

This paper introduces a new endurance equation for a hybrid-electric aircraft. This research follows the derivation of a range equation for a hybrid-electric aircraft case using constant power split that was carried out by authors in their earlier work. Thus, the derivation of the endurance equation maintains the use of efficiency-based degree of hybridization (φ) used in the earlier research. For coherence, the paper also uses the same case study to assess endurance values over a range of battery energy density values and degree of hybridization (φ) values. Results show that any aircraft design has an Energy Density Threshold (EDT) value, before which the endurance of the aircraft reduces with an increase in the degree of hybridization values. Conversely, once EDT is exceeded, the endurance of the aircraft enhances with the increase in the degree of hybridization values. The EDT values are specific to the aircraft type, its specifications and key design parameters.

ALMA High-resolution Spectral Survey of Thioformaldehyde (H2CS) toward Massive Protoclusters

Investigating the temperature and density structures of gas in massive protoclusters is crucial for understanding the chemical properties therein. In this study, we present observations of the continuum and thioformaldehyde (H2CS) lines at 345 GHz of 11 massive protoclusters using the Atacama Large Millimeter/submillimeter Array telescope. High spatial resolution and sensitivity observations have detected 145 continuum cores from the 11 sources. H2CS line transitions are observed in 72 out of 145 cores, including line-rich cores, warm cores, and cold cores. The H2 column densities of the 72 cores are estimated from the continuum emission, which are larger than the density threshold value for star formation, suggesting that H2CS can be widely distributed in star-forming cores with different physical environments. The rotation temperature and column density of H2CS are derived using the XCLASS software. The results show that the H2CS abundances increase as temperature rises and higher gas temperatures are usually associated with higher H2CS column densities. The abundances of H2CS are positively correlated with its column density, suggesting that the H2CS abundances are enhanced from cold cores, warm cores, and line-rich cores in star-forming regions.

The key determinant for forming pollen density and using crop barriers to mitigate wind-blown pollen dispersal in alfalfa (Medicago sativa L.)

The potential for commercial cultivation of genetically engineered (GE) alfalfa has raised ecological concerns due to the possibility of introgression of GE alleles into conventional populations. The main objectives of this study were to determine the key affecting factors (i.e. size of pollen source, number of pollinating bees) on forming alfalfa pollen cloud density and test the mitigating effect using maize barrier rows on alfalfa pollen dispersal. The results showed that the mean pollen densities of alfalfa pollen source (Ø = 10 or 20 m) were statistically similar when treated with the same number of worker bumblebees and increased accordingly with increasing the worker bees (887 and 853 pollens m−3 h−1 for Ø = 10 and 20 m with 100–150 worker bees, respectively; 1040 and 1070 pollens m−3 h−1 for the two plots with 200–300 worker bees, respectively), demonstrating that the number of worker bees but not the size of the pollen source was the key determinant for forming alfalfa pollen density. A maize barrier row established at 0.5 m from the alfalfa edge consistently decreased downwind pollen densities (percent pollen density of pollen source) to 0.2–4.4 % at 1–9 m compared to 3.4–25.4 % and 7.5–37.8 % at the same distance range for the upwind and downwind sites without maize barrier rows, respectively. Based on the pods formed on the emasculated alfalfa flowers (due to pollen dispersal) located at various distances from the pollen source and subsequent prediction model, the pollen density threshold value for fertilizing alfalfa recipient under the wind-blown condition was determined of 65.8 pollens m−3 h−1 at 14.7 m from the pollen source edge. The results would help in understanding the pollination biology (minimum pollen density for fertilizing alfalfa recipient ovule) and the process of pollen-mediated gene flow and helpful in developing management strategies to reduce the pollen density and thus mitigate the gene flow in alfalfa.

Delfin++: A Delaunay based algorithm for finding 3D polyhedral voids in galaxy surveys

Delfin++ (Delaunay Edge Void Finder) is a simple and time-efficient algorithm, with a single input variable, designed to find cosmological voids within a 3-dimensional distribution of galaxies by characterizing them as polyhedral regions from a Delaunay tessellation. Two density metrics are defined and used to search for density minima and construct polyhedra that represent the underdense zones. A density threshold is used to define the limit above which a galaxy will not be considered part of a void. This threshold is commonly defined as 0.2n̄, where n̄ is the mean point density of the sample, whereas the values used in this work range from 0.2n̄ to 0.33n̄. The algorithm is applied to artificial data, with different density contrasts, as well as to galaxy data from SDSS DR10. The detected voids are compared with voids that have been produced through the application of vide. Our algorithm detects roundish underdense regions in the galaxy samples, with differences and overlaps compared to the vide algorithm’s results. Closer agreement is revealed when the edge length density metric is used over large galaxy samples, allowing for the detection of up to 90% of the largest vide voids. We measure ellipticities of Delfin++ detected voids and find that their distribution is shifted towards smaller values in comparison with vide’s distribution, and with predictions from an analytical model. The voids found with Delfin++ are not intended to generate a catalog, but rather represent a proof of concept of a simpler algorithm or with fewer rules for further calibration and future production of a final catalog. Delfin++ performance tests suggest that enhanced characterization of voids can be achieved through (i) choice of other density threshold values, and (ii) early recognition and rejection of deformed polyhedra induced by missing data.

El Niño Southern Oscillation (ENSO) effects on local weather, arboviral diseases, and dynamics of managed and unmanaged populations of Aedes aegypti (Diptera: Culicidae) in Puerto Rico.

We investigated the effects of interannual El Niño Southern Oscillation (ENSO) events on local weather, Aedes aegypti populations, and combined cases of dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) viruses in 2 communities with mass mosquito trapping and 2 communities without mosquito control in southern Puerto Rico (2013-2019). Gravid adult Ae. aegypti populations were monitored weekly using Autocidal Gravid Ovitraps (AGO traps). Managing Ae. aegypti populations was done using 3 AGO traps per home in most homes. There were drought conditions in 2014-2015 concurrent with the emergence of a strong El Niño (2014-2016), wetter conditions during La Niña (2016-2018), a major hurricane (2017), and a weaker El Niño (2018-2019). The main factor explaining differences in Ae. aegypti abundance across sites was mass trapping. Populations of Ae. aegypti reached maximum seasonal values during the wetter and warmer months of the year when arbovirus epidemics occurred. El Niño was significantly associated with severe droughts that did not impact the populations of Ae. aegypti. Arbovirus cases at the municipality level were positively correlated with lagged values (5-12 mo.) of the Oceanic El Niño Index (ONI), droughts, and abundance of Ae. aegypti. The onset of strong El Niño conditions in Puerto Rico may be useful as an early warning signal for arboviral epidemics in areas where the abundance of Ae. aegypti exceeds the mosquito density threshold value.

Measurement-Based Analysis on Vehicle-to-Vehicle Connectivity in Tunnel Environment

Vehicular ad hoc network (VANET) brings an excellent solution to ensure road safety and transportation efficiency in critical environment like tunnel. Particularly, radio link connectivity of vehicle-to-vehicle (V2V) significantly influences the performance of VANETs. The communication range of the radio systems is a random variable in reality due to the channel fading effect. Therefore, the connectivity model between vehicles in realistic environment is a key for accurate evaluation of system performances. In this paper, we study the V2V connectivity performance in the presence of channel randomness for tunnel environment. Firstly, based on channel measurement campaign, empirical path loss (PL) and small-scale fading channel models are established. Secondly, we study the influence of large-scale fading parameters on V2V connectivity. Thirdly, based on real small-scale fading characteristics, we derive the V2V connectivity probability between any two vehicles under Nakagami fading channel for one-dimensional VANET, and give the closed-form of V2V connectivity probability. Finally, we study the influences of various parameters (i.e., Nakagami fading factor, vehicle density, and neighbor order) on V2V connectivity performance. Results show that with the Nakagami fading shape factor increases, the connectivity probability increases. The shadowing fading can improve connectivity in the VANET; the path loss exponent, transmission distance, and signal-to-noise ratio (SNR) threshold have a negative impact on connectivity probability. The transmit power, vehicle density, and path loss threshold value have a positive impact on connectivity.

Efficient Need Based Nitrogen Management in Rabi Maize (Zea mays L.) using Leaf Colour Chart Under Varied Planting Density

The field experiments were conducted for two consecutive rabi seasons (November –March) of 2017–18 and 2018–19 at the Wet land farm of S.V. Agricultural College, Tirupati to calibrate leaf colour chart (LCC) for increasing growth yield, nitrogen uptake under varied plant density to establish and evaluate threshold leaf colour greenness as a guide for in-season need based fertilizer N in maize. Research results indicated that the planting density, nitrogen levels and LCC threshold values significantly influenced all the growth and yield attributes, yield and nitrogen uptake. Plant height, days required to 50% tasselling and silking, cob yield, harvest index and nitrogen uptake increased significantly with increase in plant density i.e., 1,11,111 plants ha-1 with application of fertilizer nitrogen at higher dose i.e. 40 kg ha-1 and by using higher LCC threshold value (LCC 5) in different splits. Whereas, leaf area planr-1, cob girth, number of kernels rows cob-1 and number of kernels cob-1 was lessened significantly with increase in planting density, however it was increased with application of nitrogen at higher rate i.e., 40 kg ha-1 by using higher LCC threshold value (LCC 5) at various splits. Eventually, experimental results manifested that, fine-tuning of N dose and time of application by number of splits which synchronize the crop demand was the best management strategy for sustainable crop growth, production and productivity of maize.

Level-Specific Volumetric BMD Threshold Values for the Prediction of Incident Vertebral Fractures Using Opportunistic QCT: A Case-Control Study.

PurposeTo establish and evaluate the diagnostic accuracy of volumetric bone mineral density (vBMD) threshold values at different spinal levels, derived from opportunistic quantitative computed tomography (QCT), for the prediction of incident vertebral fractures (VF).Materials and MethodsIn this case-control study, 35 incident VF cases (23 women, 12 men; mean age: 67 years) and 70 sex- and age-matched controls were included, based on routine multi detector CT (MDCT) scans of the thoracolumbar spine. Trabecular vBMD was measured from routine baseline CT scans of the thoracolumbar spine using an automated pipeline including vertebral segmentation, asynchronous calibration for HU-to-vBMD conversion, and correction of intravenous contrast medium (https://anduin.bonescreen.de). Threshold values at T1-L5 were calculated for the optimal operating point according to the Youden index and for fixed sensitivities (60 – 85%) in receiver operating characteristic (ROC) curves.ResultsvBMD at each single level of the thoracolumbar spine was significantly associated with incident VFs (odds ratio per SD decrease [OR], 95% confidence interval [CI] at T1-T4: 3.28, 1.66–6.49; at T5-T8: 3.28, 1.72–6.26; at T9-T12: 3.37, 1.78–6.36; and at L1-L4: 3.98, 1.97–8.06), independent of adjustment for age, sex, and prevalent VF. AUC showed no significant difference between vertebral levels and was highest at the thoracolumbar junction (AUC = 0.75, 95%-CI = 0.63 - 0.85 for T11-L2). Optimal threshold values increased from lumbar (L1-L4: 52.0 mg/cm³) to upper thoracic spine (T1-T4: 69.3 mg/cm³). At T11-L2, T12-L3 and L1-L4, a threshold of 80.0 mg/cm³ showed sensitivities of 85 - 88%, and specificities of 41 - 49%. To achieve comparable sensitivity (85%) at more superior spinal levels, resulting thresholds were higher: 114.1 mg/cm³ (T1-T4), 92.0 mg/cm³ (T5-T8), 88.2 mg/cm³ (T9-T12).ConclusionsAt all levels of the thoracolumbar spine, lower vBMD was associated with incident VFs in an elderly, predominantly oncologic patient population. Automated opportunistic osteoporosis screening of vBMD along the entire thoracolumbar spine allows for risk assessment of imminent VFs. We propose level-specific vBMD threshold at the thoracolumbar spine to identify individuals at high fracture risk.

Ultra-short optical pulse generation in micro OLEDs and the perspective of lasing

We report experimental and theoretical investigations with an in-house fabricated tris(8‐hydroxyquinoline)‐aluminum (Alq3)-based high-speed micro-organic light-emitting diodes (μ-OLEDs) and demonstrate very promising optical pulse responses as short as 400 ps. With a model for an electrically pumped OLED, we simulate the emission of sub-nanosecond optical pulses. The model includes field-dependent (Poole-Frenkel) Langevin recombination and reabsorption of photons by singlets (Stokes-shifted), and by triplets (TA). The good agreement between the measurement and the simulation is the basis for further study of the prospects on the ps time scale, i.e. stimulated emission and conditions for laser operation. For an Alq3-based micro-OLED with high-Q optical cavity, we predict pulsed laser operation with damped relaxation oscillations in the GHz regime and several orders of magnitude linewidth narrowing, but only during 3 ns at most. The simulated current density threshold values vary from 10 kA cm−2 for Q= 500 to less than 1 kA cm−2 for Q = 1000. No continuous-wave (CW) lasing is found due to the accumulation of triplet excitons for t > 5 ns, which has two deteriorating effects, (a) suppression of the gain-providing singlet excitons due to singlet-triplet absorption and (b) suppression of the photon density due to photon absorption by triplets (TA). Prospects for CW-lasing with other organic molecules are discussed.

Human body electrification in vicinity of charged container - medium charge density limits

Results of numerical simulation of a human body charging in the vicinity of charged dielectric objects, e.g. FIBC (i.e. Flexible Intermediate Bulk Container) or other containers are presented in the paper. The effects of object shape, the permittivity of the container contents as well as human-to-container distance on the induced charge on a human body were investigated. Based on the simulations, the threshold values of the space charge density of the dielectric filling (the perception and shock levels for the human beings) were determined. The obtained results allowed to derive theoretical curves defining safe limits of charge density on given dielectric objects (container). The results may be useful for nuisance or risk assessment in industrial conditions.

Optimal Design for Demand Responsive Connector Service Considering Elastic Demand

Differing from the conventional fixed-route transit, Demand Responsive Connector (DRC) is scheduled to pick up passengers based on requests, and delivers them to a common destination (e.g., a metro station). The demand for DRC is affected by not only the fare and travel time, but also time reliability. The latter' impact is non-negligible because of the uncertainty nature of DRC on collecting the temporally and spatially distributed passengers. This paper explicitly introduces an elastic demand function embedded with a time deviation penalty model. Based on that, one-vehicle and two-vehicle DRC models are formulated to maximize the social welfare. The decision variables include fare, service area, and operating cycle time. Augmented Lagrange Multiplier Method is applied to solve the optimization problem. Simulation is performed to verify the validity of the models. In numerical studies, sensitivity analysis unveils the influences of several key parameters, e.g., potential demand density, vehicle capacity, line-haul distance and elasticity factors. By comparison, threshold values of demand density are revealed for the applicability of the one-vehicle and two-vehicle schemes. The proposed model provides a decision-making tool for DRC operators considering local conditions.

A novel clustering technique to stop congestion occur vehicular ad-hoc networks using node density based on received signal strength

Vehicular Ad Hoc Network (VANET) has received better consideration from academic researcher and automobile companies in modern years. Meanwhile, Congestion control remains the major area of research in VANET due to its characteristics such as high mobility, high vehicle density, and unbounded network size, frequent exchange of information, rapidly changing network topology, and lack of central management. Congestion in the VANET broadcast channel may occur, because of number of vehicles in a relatively tiny area raises, the communications channel becomes exceed by beacon message, and event-driven messages. Researchers have suggested a number of answers to control these issues and also to reduce congestion in VANET atmosphere. Congestion in VANET occurs when the vehicles are in the dense part while the network node is carrying more data than it can handle. More vehicles in cluster area are attempting to broadcast simultaneously in dense condition, it will reduce Packet Delivery Ratio and thus congestion will occur. We proposed density based dynamic clustering (DBDC) which finds the high dense region in the cluster and do sub-clustering. First, we find Average Vehicle Density Threshold Value using Received Signal Strength (RSS) to determine the high dense part. Performance result shows our approach is better in all aspects comparing with VWCA clustering approach and also provides high cluster stability.

Pika burrow and zokor mound density and their relationship with grazing management and sheep production in alpine meadow

AbstractPlateau pikas (Ochotona curzoniae) and plateau zokors (Myospalax baileyi) occur naturally in the alpine meadow of the Qinghai–Tibet Plateau (QTP). Their feeding and burrowing activities affect plant composition and soil properties (e.g., soil carbon accumulation and soil nitrogen cycling), but research to study the complex interactions between small mammals, livestock, and habitat is currently lacking. We conducted a sheep grazing trial to determine the effect of grazing management on pika burrow and zokor mound density, and the relationships between sheep production and pika burrow and zokor mound density. The grazing management approaches were warm‐season rotational grazing at 24 and 48 sheep months (SM)/ha, cold‐season rotational grazing at 24 and 48 SM/ha, seasonal continuous grazing at 24 SM/ha, and whole‐year continuous grazing at 48 SM/ha. The results of this study suggested that warm‐season rotational grazing at low stocking rate did not significantly change both pika and zokor densities. Cold‐season rotational grazing at both high and low stocking rates and seasonal continuous grazing at low stocking rate led to an increase in zokor mound density, but not pika burrow density. Whole‐year continuous grazing at high stocking rate increased both pika and zokor densities. The influence of pika and zokor activities on sheep production was complex and differed between grazing management. Sheep liveweight gain peaked at moderate pika burrow and zokor mound density at low stocking rate under both warm‐ and cold‐season rotational grazing. The threshold values of pika density were about 110 and 70 burrows per hectare in warm and cold seasons, respectively. The threshold value of zokor density was about 400 mounds per hectare in the cold season. In contrast, under high stocking rate regardless of management approach, sheep liveweight gain declined significantly as both pika burrow and zokor mound density increased. This paper provides a theoretical understanding and experimental evidence for sustainable grazing management and restoration of degraded grassland by local herders and policymakers.

Approach to ensure set traffic safety level at signalized intersections

The article presents a functional block diagram of the findings of studies on the developed approach to automatic control systems (ACSs) at signalized intersections with assessment and assurance of compliance with the levels of traffic safety requirements. The approach uses traffic patterns with conflict loads at different methods of control over traffic signalization cycles: without a change of the scenarios in the paradigm of traditional traffic control methods I (phased traffic control) or II (traffic control by directions) and with a new method of combined traffic control III. The latter allows us to combine a change of the scenarios of traditional traffic control methods I and II in different phases of the cyclic traffic control. The change of the scenarios in phases of method III depends on the vehicle density threshold values for left-turn and right-turn flows as well as pedestrians. If these values are within the set limit and the Traffic Rules of the Russian Federation are met, traffic control method I is used, when the density threshold is not maintained, the scenario in phases changes to method II and, therefore, road traffic safety is ensured.

Laser Mutagenesis of Phellinus igniarius Protoplasts for the Selective Breeding of Strains with High Laccase Activity.

Phellinus igniarius is a medicinal fungus that utilizes lignin as a nutrient substrate. This fungus has a weak lignin degradation ability and, as a result, a slow growth rate. Laccases are crucial enzymes for lignin degradation in P. igniarius, and thus, the cultivation of strains with high laccase activity is expected to increase the growth rate of P. igniarius. To generate P. igniarius strains with high laccase activity, we performed laser mutagenesis of P. igniarius protoplasts and screened for mutants with high laccase activity. Our results showed that the laser power density and P. igniarius protoplast survival rate exhibited a power-function relationship. The power density threshold value between lethality and growth promotion was 0.24mW/mm2. Mutagenesis was carried out using a laser beam diameter of 3mm and an irradiation period of 40min. After five generations of selection, we identified a high laccase activity strain, termed SJZ2. The laccase activity in SJZ2 during 4h of fermentation was increased by 36.84% in comparison with the control and ranged from 0.20216 to 0.27664U. The Km and Vmax of the laccase produced by SJZ2 were 0.21mmol/mL and 0.53mmol/L/min, respectively. This study demonstrated the feasibility of laser mutagenesis of P. igniarius protoplasts for the selection of high laccase activity. This study characterized the key factors in the laser mutagenesis process of P. igniarius protoplasts and provided a reference for the application of lasers in biological mutagenesis. Future studies should evaluate the bioactive functionality and stability of this novel strain of P. igniarius, particularly the organoleptic and medical characteristics of the fruiting bodies.

Falx cerebri Calcifications and Ossifications in CT Scans – A Data Collection on Frequency, Position and Size

Background: The aim of this study is the acquisition of data regarding the frequency, position, size, sex- and age distribution of falx cerebri calcifications (FCC, including ossifications) using CT scans. Methods: An explorative-retrospective data collection using skull CT scans of all CT devices (in use for patient examinations) at the University Hospital Graz. From August 20 to August 31, 2015, 365 cases of undisturbed and non-contrast brain images were determined. FCC with a density threshold value of &gt; = 100 HU was recorded, analysed according to certain target parameters and evaluated using descriptive statistics. Additionally, lateral views of three-dimensional image reconstructions of certain FCC were produced and measured. Also, superior sagittal sinus calcifications were examined. Results: The occurrence of FCC accounted for 34% in general and was slightly more frequent in older men. Among all FCC 95% were located in anterior and medial falx area. The Spearman’s rank correlation between age and occurrence of FCC was r = .96, p &lt; .001. Considering a sagittal dimension (max. length x max. height x sin (90°-Gantry Tilt) computed in axial layers) of &gt; = 2cm² , FCC incidences still amounted to 9, 8%. Conclusions: The FCC frequency of 10% with a size of &gt; = 2 cm² (sagittal dimension computed in axial layers) corresponded to values of previous x-ray studies. However, the dimension or diameter was never mentioned. FCC of the size mentioned above is relevant to an osteopath’s work since they might influence the craniosacral palpation and treatment of the falx cerebri. Therefore, there is further need for investigation concerning the possible effects of FCC on craniosacral palpation of the falx cerebri, precise measurements of size, as well as a histological comparison alongside CT-imaging. Keywords: Falx cerebri, calcification, ossification, computed tomography

DEVELOPMENT OF PCI-CAPABLE HOSPITALS NECESSITY CALCULATION ALGORITHM

Introduction. Today there is no method to assess whether number of PCI-capable centers in Russia corresponds to the real needs. The aim of the study was to develop a PCI-capable hospitals necessity calculation algorithm. Material and methods. We used population densities, maximum/optimal distances (areas) to which delivery of patients with acute coronary syndrome by sanitary transport is possible and maximum/optimal areas where patients can be transported by ambulance transport. Then we calculated the density threshold values: Group 1: 53 persons/km2 or more; Group 2: 53-27 people/km2; Group 3: 27-18 people/km2; Group 4: 18-8 people/km2; Group 5: 8 persons/km2 and less. Results. Formulas were proposed for calculating the need for PCI-centers. For group 1: population/60000 people, for group 2: area/11,310 km2, group 3: area/31,416 km2, group 4 with functioning of sanitary aviation: area/70,686 km2 (additional strengthening of the prehospital medical care); in the absence of functioning sanitary aviation: area/31,416 km2 (also additional strengthening of the pre-hospital stage of medical care); for group 5: population/600,000 in large cities (in addition, the use of sanitary aviation, increased prehospital medical care, the organization of primary vascular departments). Discussion. The existing amount of percutaneous interventions in Russia is not enough to meet the real needs for this treatment. At the same time, simple multiplying of PCI-centers is not expedient. Conclusion. According to the developed algorithm, in Russia it is necessary to organize 239 PCI-centers 24/7. In regions with a high population density it is possible to combine several cathlabs in one center.

Sexing free-ranging adult Cuvier's beaked whales ( Ziphius cavirostris ) using natural marking thresholds and pigmentation patterns.

Sex identification of adult cetaceans is an important ecological parameter that should be incorporated into studies such as population dynamics and animal behavior. In Cuvier’s beaked whale ( Ziphius cavirostris ), sex determination may be achieved through genetics, observation of genitals, the presence/absence of erupted teeth, and calf association. However, these features are difficult to ascertain due to the shy behavior of this species. Therefore, this study aimed to create a robust sex identification method using only external characteristics. Particularly, this work analyzed pigmentation patterns and levels of natural marks from adult individuals of known sex in order to identify gender differences, using frequency analysis and generalized linear models. Photographic captures of 73 free-ranging animals were utilized. The frequencies of the individual pigmentation patterns were found to be sex dependent. The 63% of the animals could be classified into either a “soft” or “sharp” pigmentation cluster. The “soft” cluster was only displayed by females, while the “sharp” cluster was present in both the sexes. However, the model selection process indicated that natural marking is the best determinative factor for sex classification. The density of the visible intraspecific natural marks was found to differ between the sexes ( P value < 0.001) and was incorporated as a predictor variable into several candidate models. All candidate models had a high predictive power (mean area under the curve 0.973) and correctly predicted the sex, by means of a density threshold value, in 85–90% of the analyzed animals. The density threshold ranged from 4.1% to 6.4% according to the different body area analyzed. These density threshold values represent a robust post hoc sexing method to classify individuals to sex from opportunistic photos in the absence of other sexing methods.

Modelling benthic habitats and biotopes off the coast of Norway to support spatial management

Habitat conservation, and hence conservation of biodiversity hinges on knowledge of the spatial distribution of habitats, not least those that are particularly valuable or vulnerable. In offshore Norway, benthic habitats are systematically surveyed and described by the national programme MAREANO (Marine AREAl database for NOrwegian waters). Benthic habitats and biotopes are defined in terms of the species composition of their epibenthic megafauna. Some habitats are of special conservation interest on account of their intrinsic value and/or vulnerability (e.g., long-lived species, rareness, to comply with international regulations such as OSPAR). In Norway, off Nordland and Troms, the following habitats of special interest can be found: Umbellula encrinus Stands, Radicipes sp. Meadows, Deep Sea Sponge Aggregations, Seapen and Burrowing Megafauna Communities, Hard Bottom Coral Gardens. In this paper, we used underwater video data collected within the MAREANO programme to define and describe benthic habitats and biotopes of special interest, and to map the geographic distribution thereof by means of habitat modelling.We first evaluated the community structure of each habitat in the list using a SIMPROF test. We determined that the class Deep Sea Sponge Aggregations, as defined by OSPAR, had to be split into at least three classes. We then re-defined seven new types of ecological features, including habitats and biotopes that were sufficiently homogeneous. Then we modelled the spatial distributions of these habitats and biotopes using Conditional Inference Forests. Since the purpose of the distribution maps is to support spatial planning we classified the heat maps using density thresholds.The accuracy of models ranged from fair to excellent. Hard Bottom Coral Gardens were the most rare habitat in terms of total area predicted (224km2, 0.3% of the area modelled), closely followed by Radicipes Meadows (391km2, 0.6%). Soft Bottom Demosponges (Geodid sponges and other taxa) represent the largest habitat, with a predicted area of 9288km2 (14%). Distribution maps of classes defined by habitat-forming species (Hard Bottom Coral Gardens) were more reliable than those defined by a host of species, or where no single species was a clear habitat provider (e.g. Seapen and Burrowing Megafauna Communities). We also put forward that a scale of patchiness larger than the scale of observation, and homogeneity of the community both play a role in model performance, and hence in map usefulness. These along with density threshold values based on observed data should all be taken into account in marine classifications and habitat definitions.