Accurate Indirect Method Research Articles

Competition between sympatric hare species in the Alps is boostered by climate change and hybridisation

Climatic variation along the elevation gradient promotes the natural parapatric occurrence of the European hare (Lepus europaeus) and Alpine mountain hare (Lepus timidus varronis) in the Alps. Recent data indicate a displacement of mountain hares caused by competition with the European hare. Competitive exclusion might take place at a fine spatial scale and hybrids may sharpen competition. Genetic non-invasive sampling (gNIS) demonstrates to be effective to retrieve information from wild animals. However, based on the accuracy of the differing genetic analysis methods, the selection of the method might decisively influence results. To examine habitat preferences of Alpine mountain hares, European hares and their hybrids with particular interest in the influence of the accuracy of the genetic analysis method on the results, we performed gNIS in Grisons (Switzerland) for four years and compared habitat associations of the genotyped samples. We recorded 137 individuals (i.e., 35 hybrids, 49 European hares, 53 Alpine mountain hares). Combined nuclear and mitochondrial DNA analysis including individual identification revealed to be the most accurate indirect method for the study of habitat preferences of hares. Alpine mountain hares had a narrow habitat breadth and used little habitat diversity. Hybrids showed great similarities in their habitat preferences to European hares. Hybrids might increase the competition in favour of European hares and the displacement of Alpine mountain hares, since they show similar patterns of habitat use to European hares. Ongoing climate change potentiate the niche overlap between species, increasing the risk of Alpine hare decline due to hybridisation and displacement.

Predição do peso vivo de ovelhas deslanadas em crescimento usando a fórmula do volume corporal

ABSTRACT Due to the conditions in which traditional sheep production systems operate, the evaluation of animal growth from live weight (LW) is limited by the high cost of the livestock scale as well as the sophisticated maintenance required. In this scenario, in recent years, biometric measurements have been investigated as an accurate indirect method to predict the LW of farm animals. Therefore, the present study was undertaken to examine different models for predicting the body weight of growing lambs using the body volume (BV) formula. Body volume, heart girth (HG) and body length (BL) data of 290 lambs aged between two and eight months were recorded. Body volume was calculated from HG and BL data using a formula that calculates the volume of a cylinder. The estimation of LW from the BV formula was achieved through regression equations using three mathematical models (linear, quadratic and exponential). The mean values of LW, HG, BL and BV of the lambs were 29.12±12.04kg, 70.00±11.69cm, 38.40±6.43cm and 23.93±9.90dm3, respectively. The correlation coefficient between LW and BV was r = 0.96 (P<0.001). The quadratic model showed the highest coefficient of determination (0.93) and the lowest prediction error (3.29kg). Under the experimental conditions adopted in this study, it is possible to predict the live weight of growing lambs using the body volume formula.

How far can EPTs fly? A comparison of empirical flying distances of riverine invertebrates and existing dispersal metrics

The species composition of a community is driven by the dispersal capacity of the species forming that community and their ecological niche. While the ecological niches of EPTs (Ephemeroptera, Plecoptera and Trichoptera) are well-studied due to their wide use as indicators for the ecological status of freshwater ecosystems, their dispersal capacity has not yet been accurately characterized. Dispersion of the merolimnic EPT species during the terrestrial aerial adult stage is of special importance because the distance dispersed by active flight or passive wind drift is usually much larger compared to dispersion during the aquatic larval stage by active crawling or by drifting downstream.The aerial dispersal distance has been directly measured for only a small number of EPT species. For most other species, the dispersal capacity is assessed indirectly using species’ traits that are mainly based on expert judgement and dispersal indices derived from trait information. In this study, we compiled a database of European EPTs’ aerial dispersal distances reported in empirical studies and compared them to the dispersal capacity of the species as described by five different dispersal indices (original and modified versions of Li’s Dispersal Capacity Metric DCM and Sarremejane’s Species Flying Propensity SFP as well as relative wing length).The database included empirical data on 180 species, comprising 9.3% of European EPT species. Most data came from trap experiments with traps located at different distances from the assumed emergence point. Since the distance classes differed between studies and had to be translated to a fixed set of four distance classes here, several species had to be assigned to more than one class. To account for this uncertainty, five ordered logistic regression models, each one with a dispersal index as predictor and the ordinal-scaled aerial dispersal distance as response, were bootstrapped 10,000 times. In each run, species belonging to several distance classes were randomly assigned to a single class out of all possible classes. Since wing length had no significant effect on aerial dispersal distance in any of the 10,000 bootstrap runs, we question the use of this anatomical trait as an indicator for the aerial dispersal capacity. In contrast, a modified version of the DCM index was consistently related to the aerial dispersal distances (96%). The original SFP index had a significant effect in 100% of the model runs, indicating that this index is very well-suited as an indicator for the aerial dispersal capacity of European EPT species.This study facilitates the assessment of European EPT flying distances by providing a compilation of empirical data on the topic and by recommending an accurate indirect method when empirical data is not available.

Quantitative susceptibility mapping differentiates between parkinsonian disorders

IntroductionIt is often challenging to clinically distinguish between Parkinson's disease (PD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Quantitative susceptibility mapping (QSM) is an accurate indirect method for estimating brain iron levels in vivo. This method has yet to be applied in atypical parkinsonism. We aimed to investigate differences in brain iron accumulation parkinsonian disorders and healthy controls using QSM. Methods15 patients with PSP, 11 patients with MSA, 62 patients with PD and 14 healthy controls were included in the study and their phase and magnitude data from susceptibility-weighted magnetic resonance imaging were retrospectively analyzed with an in-house pipeline to create susceptibility maps. Two-way ANCOVA were used to assess group differences. Pairwise comparisons within the ANCOVA were corrected for multiple comparisons. ResultsRed nucleus susceptibility was higher in PSP compared with PD (p < 0.001), MSA (p < 0.001) and controls (p < 0.001), which separated PSP from these groups with areas under receiver operating characteristic curve of 0.97, 0.75 and 0.98 respectively. PSP showed higher globus pallidus susceptibility compared with PD (p < 0.001), MSA (p = 0.006) and controls (p < 0.001). Putamen susceptibility was higher in MSA than in PD (p = 0.022) and controls (p = 0.026). Substantia nigra susceptibility was increased in PD compared to controls (p = 0.030). ConclusionWe show that all studied parkinsonian disorders have increased susceptibility subcortically, reflecting distinct topographical patterns of abnormal brain iron accumulation. QSM, particularly of the red nucleus, is a promising biomarker in differentiating parkinsonian disorders, and would be interesting to study longitudinally for monitoring disease progression and treatment effects.

An Indirect Method for Inequality Constrained Optimal Control Problems

The inequality constrained nonlinear optimal control problem is difficult to handle using indirect numerical methods, since solving the resulting two-point boundary value problem (TPBVP) usually requires a priori information about the structure of the solution. In this paper, a fast and accurate indirect method is proposed for a class of inequality constrained optimal control problems. Firstly, the analytic form of the optimal control is proved for the problem subject to input saturations. Secondly, trigonometric regularization function is designed and incorporated in the cost function to implement the state constraints. Then the state and input constrained optimal control problem is directly converted into a standard TPBVP without constraints. Comparisons with the pseudospectral method are conducted to verify the effectiveness and efficiency of the proposed method. In the input constrained case, the proposed indirect method gives more accurate solution with much faster convergence speed. While for the problem with both input and state constraints, the proposed method sacrifices a little accuracy for a faster speed.

A Positional Analyzer for Measuring Centric Slide

Centric relation (CR) has been considered mainly as a position posterior to habitual occlusion or maximum intercuspation (MI). Awareness of the tooth contacts relationship in centric relation position of the mandible and diagnosing the case from this position is essential to consistently select treatment plans that will allow to treat to or very near to centric relation occlusion. Centric slide and other occlusal relationships are conceived of as positions, which can be studied in three dimensions. Clinically, the difference between the two occlusal positions namely CR and MI (centric slide) can easily be determined, but for a more precise evaluation of its length and directions, an occlusal analysis on articulator mounted casts is necessary. Study was under taken on the mounted casts of ten subjects on a semi adjustable articulator to which a stylus and recording table was devised and attached for measurement of CR-MI slide in the three planes namely anterior-posterior, medio-lateral and superior-inferior. It was found that there was a displacement from CR to MI (centric slide) in all the three planes and numerically the mean slide was 0.688±0.623, 0.261±0.627 and 0.127±0.541mm in the antero-posterior, medio- lateral and superior-inferior directions respectively. The stylus and table attachment may be an accurate indirect method to measure positional changes of the condyle in 3D.

Diagnostic value of the matrix metalloproteinase-8 rapid test for detecting microbial invasion of the amniotic cavity

The purpose of this paper was to compare the MMP-8 PTD Check (MPC) test with other indirect tests for detecting microbial invasion of the amniotic cavity (MIAC). Amniotic fluid (AF) was analyzed in 155 women for white blood cell (WBC) count, glucose concentration, and an MPC test and evaluated for MIAC using cultures for aerobic/anaerobic bacteria and mycoplasmas and polymerase chain reaction (PCR) of chlamydia. The median AF glucose concentration was lower and the median AF WBC count was higher in women with MIAC than in women without MIAC (p < 0.01 and p < 0.001, respectively). Also, the positive rate of the MPC test was higher in women with MIAC than in women without MIAC (p < 0.001). The sensitivities of AF glucose concentration, AF WBC count, and the MPC test for the detection of MIAC were 58.6%, 75.9%, and 86.2%, respectively. The specificities for the detection of MIAC were 76.2%, 80.2%, and 74.6%, respectively. We conclude that the MPC test is a rapid, easily performed, and accurate indirect method for detecting MIAC.

Mathematical model of chloride concentration in human blood

This paper deals with mathematical modelling of blood chloride concentration. The main features of the model are that it reveals mathematically the physiological relationship between blood chloride and other electrolytes and serves as an accurate indirect method for chloride measurements with accuracy fulfilling clinical requirements. The main advantages of the method based on this model are that it is more comfortable than traditional methods and clinically less harmful for the patient under study. Experimental verification of the developed model ensures that the results of chloride measurements obtained using this model are significantly correlated with the results for the blood samples obtained from standard chloride analysers.

Comparison of indirect methods of measuring intra-abdominal pressure in children

To determine the most accurate indirect method of measuring intra-abdominal pressure (IAP) in children. Single-centre, prospective, clinical study in a 23-bed specialist paediatric intensive care unit in Australia. 20 children admitted to paediatric intensive care with a peritoneal dialysis catheter in situ following congenital cardiac surgery. IAP was measured directly via the peritoneal dialysis catheter and by intragastric manometry via an indwelling nasogastric tube, and by intravesical manometry via an indwelling transurethral urinary catheter, using volumes of 0, 1, 3 and 5 ml/kg body weight of sterile saline instilled into the bladder. Across the range of IAPs of 1-8 mmHg the Bland-Altman method for assessing agreement between two methods of clinical measurement showed bladder pressure measured via the urinary catheter with 1 ml/kg body weight of saline instilled to be the most accurate indirect measurement technique, tending to give pressures between 0.07 and 1.23 mmHg higher than the direct measurement (95% CI for bias). Measuring bladder pressure with either no saline instilled or more saline per kilogram body weight instilled was less accurate over the same range of pressures, as was measuring the gastric pressure. The most accurate indirect method of measuring IAP in children over the normal range of IAPs involves measuring bladder pressure via a transurethral urinary catheter with 1 ml/kg body weight of sterile saline instilled into the bladder.

Estimating Carnivore Densities for Conservation Purposes: Indirect Methods Compared to Baseline Demographic Data

Using the cheetah Acinonyx jubatus as a model, we compared predictions from four indirect methods of estimating carnivore densities to estimates of density derived from baseline demographic data collected during behavioural ecological studies in three national parks of East Africa. Interviewing people locally was the most accurate indirect method and produced estimates representing 75 to 100% of reference densities. Regressing cheetah biomass against prey biomass further underestimated reference densities. Using an average cheetah density derived from reported densities in 13 African protected areas, and modeling cheetah densities from home range and demographic data were the least accurate approaches. When indirect methods' results were compared across ten study areas in East Africa, we found that log-transformed interview and prey biomass methods' estimates were significantly correlated, and that prey biomass and home range models produced significantly different outcomes. After discussing strengths and weaknesses of the methods, we outline the conditions under which each may provide valid results. Our findings highlight the importance of calibrating indirect methods of estimating carnivore densities, and demonstrate the difficulties that conservation planners face in integrating density estimates derived from different methods when devising conservation strategies.

Problems in Using State Estimation in Power Systems which have Poor Quality High Voltage Measurements, Phase Imbalance and High Levels of Harmonics

An accurate indirect method of high voltage measurement calibration is presented which uses only portable low voltage test equipment and measures the voltage, active and reactive power on the low voltage side of the generator (or supply) transformer and calculates high voltage on the other side. A one-to-one correspondence almost exists between the accuracy of the low voltage measurement and the accuracy of the high voltage calibration. Inaccuracies in the low voltage active and reactive power measurements have only a negligible effect on the accuracy of the high voltage calibration. The same technique can be used to recalibrate switchyards which are connected to calibrated switchyards by transmission lines. Redundant checks are also possible. When state estimation is used in power systems which have poor quality high voltage measurements then measurements should be made on the low voltage site of the generator (or supply) transformer because these readings are more accurate and more immune to harmonics and voltage imbalance than those on the high voltage side. The manner in which harmonics affect measurements is also discussed.