False Absence Research Articles

ENDOBRONCHIAL TUBERCULOSIS: A CASE BASED APPROACH

Endobronchial tuberculosis is defined as tuberculous infection of the tracheobronchial tree. Although clinical features differ between various types and stages of endobronchial tuberculosis, common symptoms are cough, hemoptysis, sputum production, wheezing, chest pain, fever and dyspnea. Although endobronchial lesions usually result in sputum positivity for acid fast bacilli (AFB), a false negative sputum or absence of radiological lesions may result in delayed diagnosis. On the other hand, sputum positivity with presence of signs on chest radiology may lead to consideration of parenchymal TB as the primary diagnosis and the coexistence of endobronchial lesions may be missed until sequelae of the latter ensue. Bronchoscopy is essential for confirmation of endobronchial TB. This write up aims to summarize various clinico-radiological manifestations of endobronchial tuberculosis which were encountered in 45 years of clinical practice and will help respiratory clinicians in future for early and prompt diagnosis and management of the same.

Anatomical Variations of the External Jugular Vein: A Pictorial and Critical Review

(1) Background: The external jugular vein (EJV) descends on the sternocleidomastoid muscle to drain deep into the subclavian vein. Anatomical variations of the EJV are relevant for identification of the greater auricular nerve, flap design and preparation, or EJV cannulation. (2) Methods: Different publications were comprehensively reviewed. Dissections and three-dimensional volume renderings of peculiar cases were used to sample the review. (3) Results: Different anatomical possibilities of the EJV were critically reviewed and documented: fenestrations and double fenestrations, true or false duplications, triplication, absence, aberrant origin or course, or bifurcation. Tributaries of the EJV, such as the facial and posterior external jugular veins, are discussed. The internal jugular vein termination of the EJV is also presented. (4) Conclusions: Care should be taken when different morphological features of the EJV are encountered or reported.

Endovascular Repair of the Thoracic Aorta Combined with Drug Therapy in Acute Uncomplicated Type B Aortic Dissection.

Objective This study was to evaluate the clinical efficacy of thoracic endovascular aortic repair (TEVAR) combined with Best Medical Therapy (BMT) in acute uncomplicated type B aortic dissection (TBAD). Methods Using the random method, 90 patients admitted to our hospital between January 2018 and January 2020 with acute uncomplicated TBAD were randomly divided into a control group and a study group, with 45 cases in each of the groups. The effectiveness of BMT combined with TEVAR treatment was compared. Results The incidence of recent adverse reactions did not differ significantly between the two groups. Compared to the control group, the 1-year survival rate and 2-year survival rate of patients in the study group were considerably higher. In order to examine the relationship between survival and time, the Kaplan-Meier curve was used. Both groups reached the median survival time after 24 months of follow-up. The expected survival time of the study group was longer than that of the control group. False lumen thrombosis or absence of thrombus was significantly more prevalent in the study group than in the control group. Conclusion For patients with acute uncomplicated TBAD, BMT combined with TEVAR can significantly improve the long-term survival rate and increase the expected survival time.

Present but not detected: new records increase the jaguar's area of occupancy in the coastal Atlantic Forest

AbstractThe jaguar Panthera onca has lost 85% of its habitat in the Atlantic Forest, where it persists in small and isolated populations in the largest fragments. In the absence of recent records, the jaguar had previously been presumed extinct in the large Atlantic Forest fragments of the Serra do Mar in southern Brazil. However, as this region is mountainous, densely forested and difficult to access, the jaguar could still be present, but undetected. We carried out an intensive survey using camera traps and interviews with local people in a large (c. 6,500 km2) forest block. During 2011–2019, 98 camera-trap stations were established (14,239 trap-days), and 249 interviews were conducted in 102 grid cells of 5 × 5 km. We obtained the first images of the jaguar in the region, from which five individuals were identified, and interviewees provided records of the jaguar in 24 grid cells. Our findings increase the range of this species in the Atlantic Forest by 9%, and we recommend that the area should be classified as a jaguar conservation unit. As the area we surveyed is adjacent to the Serra do Mar jaguar conservation unit, the combined area of 19,262 km2 is the largest priority area for jaguar conservation in the Atlantic Forest. This proposed jaguar conservation unit could serve as a vital source of jaguar individuals for the coastal forests further south. We recommend that surveys are extended southwards to Santa Catarina state to determine whether the presumed extinction of jaguars in this state is another case of a false absence.

Bone conducted vibration is an effective stimulus for otolith testing in cochlear implant patients.

BACKGROUND:Treatment with a cochlear implant (CI) poses the risk of inducing a behaviorally unmeasurable air-bone gap leading to false negative absence of cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) to air conducted sound (ACS).OBJECTIVE:To investigate VEMP response rates to ACS and bone conducted vibration (BCV) in CI patients and the applicability of the B81 transducer for BCV stimulation.METHODS:Prospective experimental study including unilateral CI patients, measuring cVEMPs and oVEMPs to ACS and to BCV, comparing response rates, signed asymmetry ratios, latencies, and amplitudes.RESULTS:Data of 13 CI patients (mean age 44±12 years) were analyzed. For the CI side, oVEMP and cVEMP response rates were significantly higher for BCV (77%cVEMP, 62%oVEMP) compared to ACS (23%cVEMP, 8%oVEMP). For the contralateral side, no difference between response rates to ACS (85%cVEMP, 69%oVEMP) and BCV (85%cVEMP, 77%oVEMP) was observed. Substantially higher asymmetries were observed for ACS (–88±23%for cVEMPs, –96±11%for oVEMPs) compared to BCV (–12±45%for cVEMPs, 4±74%for oVEMPs).CONCLUSIONS:BCV is an effective stimulus for VEMP testing in CI patients. The B81 is a feasible stimulator.

Comparing methods to detect Garden Dormice (Eliomys quercinus) in mountainous forest habitats

Garden Dormouse populations show a severe and ongoing decline all over Europe. The drivers for this process are still unknown, as well as the exact distribution of the remaining populations. An evaluation of the occupied habitats could give information on important habitat parameters. Therefore, it is essential to improve detection methods and to evaluate the efficiency of available techniques. In this study, three different methods were tested on ten transects in the Fichtel Mountains, Germany. On each transect we installed two camera traps (CT), one autonomous sound recording unit (AudioMoth, AM) and 25 footprint tunnels (FT), which were checked weekly from the beginning of June until the end of October. AMs did not record a single call, FT detected Garden Dormice in seven and CT detected them in all ten transects. FT worked best during July, when they provided evidence of Garden Dormouse on six transects. CT worked best in August and September, confirming Garden Dormice in all ten transects. In every month, CT outperformed FT in the number of positive findings, and in the time interval until initial detection. CT worked most efficiently in this type of habitat, whereas FT produced false absence data. As Garden Dormice inhabit a variety of different habitats, this study should be repeated to see if the results are transferable.

Metabarcoding of canopy arthropods reveals negative impacts of forestry insecticides on community structure across multiple taxa

Abstract Insecticides used to combat outbreaks of forest defoliators can adversely affect non‐target arthropods. Forestry insecticides typically suppress Lepidoptera larvae which are the cornerstone of the canopy community of deciduous oak forests. The abrupt removal of this dominant component of the food web could have far‐reaching implications for forest ecosystems, yet it is rarely investigated in practice owing to several methodological shortcomings. The taxonomic impediment and the biased nature of arthropod sampling techniques particularly impede the assessment of insecticide impacts on diverse communities. To tackle this issue, we propose an experimental approach combining sampling by pyrethrum knockdown and species determination via DNA metabarcoding, using community subsampling to derive estimates of species abundances. We applied this protocol to investigate the short‐term effects of the insecticides diflubenzuron (DFB) and Bacillus thuringiensis var. kurstaki (BTK) on canopy‐dwelling arthropod communities in German oak woodlands. Our approach allowed us to detect most of the diversity and integrate species abundances in our analyses. By classifying arthropod species into assemblages based on their expected sensitivity rather than coarse taxonomic groupings, we could unveil substantial effects of DFB across multiple taxa 5 weeks after application. Although strong effects on single species appear related to direct toxicity, substantial impacts of DFB on parasitoids and xylophagous beetles suggest that anti‐defoliator treatments can have previously unsuspected indirect effects on some components of forest arthropod communities. The impacts of BTK on community structure were consistent with that of DFB though much weaker. Synthesis and applications. Comparing diversity patterns in the arthropod communities of sprayed and unsprayed oak canopies, our results show that selective insecticides can alter species diversity in presumably non‐sensitive taxa. Even though the ecological significance of these impacts has yet to be assessed in an operational setting, their existence calls for increased regulatory scrutiny on indirect effects. As community approaches become more attainable with the rapid development of DNA metabarcoding, we suggest the inclusion of community‐level end points as regulatory requirements for the approval of forest‐use insecticides.

Living memories and State archives: A false absence. Top civil servants and scotomisation of public archives in Lebanon

Contrary to what is often argued, public archives in Lebanon are not only abandoned or (made) unavailable by the State, through decision made at the highest level or the absence of decision in a State deprived of any clear direction. They are also, in a more practical way, held in places known only to happy fews: in the homes of former top civil servants who have become “living memories” and “bootleg archivists” of their institutions, guardians of the “possibility of a State”. Why and how these documents are to be found in such places? What are the historicity and social dynamics behind such a phenomenon? How do these people account (or not) for this situation, which could legally be considered as theft or concealment? Finally, how does the Lebanese state cope with the existence of these “wild” archives, and possibly manage its own archives located outside of itself?

The upward elevational shifts of pond breeding amphibians following climate warming

While poorly dispersing taxa such as amphibians may have limited scope to track recent and rapid climate change by means of large range shifts, they may follow their climate envelope with short elevational shifts in mountain areas. Such elevational shifts are poorly documented by empirical data for amphibians. In this study, we analysed a 15-year data series on the distribution of three amphibian species (Bufo bufo, Triturus carnifex and Rana temporaria) inhabiting a mountain pond network in the southern Italian Alps, where temperatures have increased significantly over the last decades. By using multi-season occupancy models, we estimated the occupancy trend of each species over the study period and tested the occurrence of an actual elevational shift after accounting for the probability of false absence. The upper elevational limit of the two eurythermal species (B. bufo and T. carnifex) underwent a significant and progressive upward shift of ca. 200 m. Our results provide evidence of the ability of amphibians to perform rapid elevational shifts, great enough to track predicted rates of climate warming. Preserving and improving habitat connectivity between lowlands and highlands could safeguard the opportunity for such elevational migrations, but mountain aquatic habitats must be preserved in order to provide a safe refuge for amphibians escaping climate warming.

Gimme shelter: The effect of rocks and moonlight on occupancy and activity pattern of an endangered rodent, the garden dormouse Eliomys quercinus

Information on spatial behaviour and temporal activity patterns is paramount for the conservation of animal species. This is particularly true for endangered taxa that are threatened by ongoing climatic and environmental changes. The garden dormouse Eliomys quercinus is a native European rodent (family Gliridae), whose populations are declining throughout the Continent. Notwithstanding this, neither International nor National laws explicitly require mandatory monitoring of populations. As a result, compelling information on the spatiotemporal behaviour of dormouse is lacking. We aimed to fill this gap by investigating occupancy patterns in relation to environmental features and activity rhythms in relation to moonlit nights in an Alpine population of dormouse within the Stelvio National Park, northern Italy. Data were collected between May and October 2015. Twenty camera-traps were deployed in a 500 ha coniferous forest, using a random tessellation approach; camera trap data were analyzed with occupancy models and kernel smoothers. Camera-traps provided a reliable assessment of the presence of the garden dormouse, with only 1 % of false absence and a high detection probability (68 %). The occurrence of the garden dormouse was positively influenced by the percentage of rock coverage on the ground. The species showed a strictly nocturnal behaviour, with an activity peak before midnight, negatively related to moonlit nights. The use of rocky areas for nesting, shelter site and thigmotactic movements and moonlight avoidance may represent adaptations of the garden dormouse to avoid predation risk. Our results shed some light on the habitat requirement of a poorly known, near-threatened species, and provide baseline information for future monitoring and conservation activities.

Reducing the rate of false absences of cryptic species in inventory and sampling work

When doing inventory for cryptic and rare species, it can be difficult to determine with great confidence that a sampled area has no occurrences of the target species. Boreal Felt lichen (Erioderma pedicellatum (Hue.) P.M.Jorg.) and Vole Ears lichen (Erioderma mollissimum (G.Sampaio) Du Rietz) are two rare species of cyanolichens that have several populations in North America, including Nova Scotia, Newfoundland and Alaska. These lichens occur in small numbers and are difficult to spot with the untrained eye; therefore, they are likely to be overlooked in standard sampling protocols. In this paper, we develop and test a sampling method that enables us to determine with confidence that a sample site has zero occurrences of the species of interest within a defined area (i.e., an absence of detections indicates an absence of the target lichen species and is not a false absence). On 50 sites, we randomly assigned “decoy lichen” treatments (small pieces of felt that resemble boreal felt lichen) and three seekers with different survey experience and time limits carried out their respective searches for these decoys. This sampling method is very applicable to sessile, rare organisms, such as lichens and mosses. Using circular sample plots of 5m in radius, we determined that 20 minutes is the required search effort to detect at least one rare and cryptic lichen individuals within the plot. We also found that decoy density on a plot had a strong influence on decoy detectability, regardless of seeker experience. Detection reliability was greater for the two seekers with prior cryptic survey experience compared to the seeker with none. High confidence in the “true absence” rate is useful for comparative studies of optimal and non-optimal habitat, and the methods here are useful to estimate detection rates for other cryptic organisms.

Lens Raster as a Source of Distortions in Integral Photography

Analysis of methods for recording and reproducing a three-dimensional image allows to distinguish two different approaches. The fi approach consists in formation of stereoscopic images, the second one provides the formation of an optical object model and includes particularly a group of integral photography methods .The use of integral photography methods for recording and reproducing volumetric images is relevant due to the lack of fl inherent for stereoscopic methods and relative simplicity of technical implementation. Lens raster used in this method is a possible source of image distortion. This paper aim is to determine the range of parameters of the lens system, namely, the allowable values of the pitch of the lens raster, providing distortions absence caused this raster.Types of possible distortions and sources of their occurrence are indicated. The requirements for the pitch of the lenticular raster are formulated, based on conditions of false information absence, absence of discontinuity of the image in depth and in the transverse direction, and invisibility of lens elements of the reproduction matrix.Studies shoed that the lenticular pitch is limited by the four inequalities, three of which limit the pitch value from below, and the fourth one from above. A set of conditions limiting the step of the lens matrix was analyzed. The boundaries of allowable step values depend on four groups of parameters: raster dimensions, location of the subjects, reproduction and observation parameters. Result of the method usage as a dependence of the allowable range of the pitch of the lenticular raster on transverse coordinate of the recorded point with fi values of other parameters is presented.

Non-equilibrium plant metapopulation dynamics challenge the concept of ancient/recent forest species

Previous analyses of the regional distribution of forest plants have revealed that some species have a biased distribution towards either ancient or recent forest patches. It has been therefore proposed to classify forest plant species according to their affinity for ancient or recent patches. In this contribution, we aimed at providing a dynamical perspective on this static concept of ancient/recent forest species. We developed an inference method to estimate the metapopulation dynamics of forest plants based on landscape history and static (and incomplete) biodiversity data accounting for false absence records. We assessed the power of this novel inference method using simulated metapopulation and landscape dynamics. We finally applied this method to occupancy data of 174 and 121 forest species in two networks of 9208 and 9201 forest patches respectively. These patch networks are located in two French regions, with corresponding landscape historical data based on two forest maps conceived in 1840 and 2000. Our analyses revealed that i) the inference method enables to satisfactorily infer three parameters of the metapopulation model: the rates of colonization, extinction and decay of colonization with distance; ii) this three parameter metapopulation model is sufficient to reproduce the occurrence spatial structure of 72% and 61% of the investigated species in the two regions; iii) forest plant species are distributed along a spectrum of turn-over speed, in which small (large) colonization capacity are associated with small (large) propensity to extinction; iv) species position along this spectrum can be partially predicted from plant functional traits; and v) species metapopulation dynamics are driven by the interaction between landscape and species intrinsic properties, suggesting that ancient/recent forest species lists are unlikely to be easily extrapolated to novel landscapes.

Grizzly Bear Noninvasive Genetic Tagging Surveys: Estimating the Magnitude of Missed Detections.

Sound wildlife conservation decisions require sound information, and scientists increasingly rely on remotely collected data over large spatial scales, such as noninvasive genetic tagging (NGT). Grizzly bears (Ursus arctos), for example, are difficult to study at population scales except with noninvasive data, and NGT via hair trapping informs management over much of grizzly bears’ range. Considerable statistical effort has gone into estimating sources of heterogeneity, but detection error–arising when a visiting bear fails to leave a hair sample–has not been independently estimated. We used camera traps to survey grizzly bear occurrence at fixed hair traps and multi-method hierarchical occupancy models to estimate the probability that a visiting bear actually leaves a hair sample with viable DNA. We surveyed grizzly bears via hair trapping and camera trapping for 8 monthly surveys at 50 (2012) and 76 (2013) sites in the Rocky Mountains of Alberta, Canada. We used multi-method occupancy models to estimate site occupancy, probability of detection, and conditional occupancy at a hair trap. We tested the prediction that detection error in NGT studies could be induced by temporal variability within season, leading to underestimation of occupancy. NGT via hair trapping consistently underestimated grizzly bear occupancy at a site when compared to camera trapping. At best occupancy was underestimated by 50%; at worst, by 95%. Probability of false absence was reduced through successive surveys, but this mainly accounts for error imparted by movement among repeated surveys, not necessarily missed detections by extant bears. The implications of missed detections and biased occupancy estimates for density estimation–which form the crux of management plans–require consideration. We suggest hair-trap NGT studies should estimate and correct detection error using independent survey methods such as cameras, to ensure the reliability of the data upon which species management and conservation actions are based.

Modelling of species distributions, range dynamics and communities under imperfect detection: advances, challenges and opportunities

Building useful models of species distributions requires attention to several important issues, one being imperfect detection of species. Data sets of species detections are likely to suffer from false absence records. Depending on the type of survey, false positive records can also be a problem. Disregarding these observation errors may lead to important biases in model estimation as well as overconfidence about precision. The severity of the problem depends on the intensity of these errors and how they correlate with environmental characteristics (e.g. where species detectability strongly depends on habitat features). A powerful modelling framework that accounts for imperfect detection in the modelling of species distributions has developed in the last 10–15 yr. Fundamental to this framework is that data must be collected in a way that is informative about the observation process. For instance, such data can be in the form of multiple detection/non‐detection records obtained from several visits/observers/detection methods at (at least) some of the sites, or from data on times to detection within a survey visit. The framework can extend to studying species’ range dynamics and the modelling of communities, as well as approaches for analysing data on abundance and multiple occupancy states (rather than binary presence/absence). This paper summarizes these modelling advances, discusses evidence about effects of imperfect detection and the difficulties of working with it, and concludes with the current outlook for future research and application of these methods.

Habitat preferences of two deep-diving cetacean species in the northern Ligurian Sea

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 508:247-260 (2014) - DOI: https://doi.org/10.3354/meps10851 Habitat preferences of two deep-diving cetacean species in the northern Ligurian Sea Paola Tepsich1,2,*, Massimiliano Rosso1, Patrick N. Halpin3,4, Aurélie Moulins1 1CIMA Research Foundation, via Magliotto 2, 17100 Savona, Italy 2DIBRIS, Università degli studi di Genova, viale Causa 13, 16145 Genova, Italy 3Duke University Marine Laboratory, Beaufort, North Carolina 28516, USA 4Nicholas School of the Environment, Duke University, Durham, North Carolina 27708-0328, USA *Corresponding author: paola.tepsich@cimafoundation.org ABSTRACT: We used generalized additive models (GAMs) as exploratory habitat models for describing the distribution of 2 deep-diving species, Cuvier’s beaked whale Ziphius cavirostris Cuvier, 1823 and sperm whale Physeter catodon Linnaeus, 1758, in the Pelagos Sanctuary (northwestern Mediterranean). We analyzed data collected from research surveys and whale-watching activities during summer months from 2004 to 2007. The dataset encompassed 147 Cuvier’s beaked whale sightings and 52 sperm whale sightings. We defined and applied a post hoc workflow to the data, to minimize false absence bias arising from the unique ecology of the species and the lack of a dedicated sampling design. We calculated a novel topographic predictor, distance from the canyon axis, as a covariate for use in the habitat model. Given the complex topography of the area, the analysis was performed on a high-resolution spatial grid (1 km). Our methods allowed effective use of the non-dedicated sampling dataset for building habitat models of elusive and cryptic species (Cuvier’s beaked whale final model sensitivity = 0.88 and specificity = 0.84; sperm whale final model sensitivity = 0.65 and specificity = 0.77). The GAM results confirmed the preference for submarine canyons for both species and also highlighted the importance of the deeper portion of the Ligurian basin, especially for Cuvier’s beaked whale. Habitat overlap nevertheless is resolved by a well-defined spatial partitioning of the area, with sperm whale occupying the western part and Cuvier’s beaked whale the central and eastern parts. KEY WORDS: Cuvier’s beaked whale · Sperm whale · GAM · Habitat modeling · Northwestern Mediterranean Sea Full text in pdf format PreviousNextCite this article as: Tepsich P, Rosso M, Halpin PN, Moulins A (2014) Habitat preferences of two deep-diving cetacean species in the northern Ligurian Sea. Mar Ecol Prog Ser 508:247-260. https://doi.org/10.3354/meps10851 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 508. Online publication date: August 04, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Pattern-recognition ecological niche models fit to presence-only and presence-absence data

Summary Identifying the boundary of a species' niche from observational and environmental data is a common problem in ecology and conservation biology and a variety of techniques have been developed or applied to model niches and predict distributions. Here, we examine the performance of some pattern-recognition methods as ecological niche models (ENMs). Particularly, one-class pattern recognition is a flexible and seldom used methodology for modelling ecological niches and distributions from presence-only data. The development of one-class methods that perform comparably to two-class methods (for presence/absence data) would remove modelling decisions about sampling pseudo-absences or background data points when absence points are unavailable. We studied nine methods for one-class classification and seven methods for two-class classification (five common to both), all primarily used in pattern recognition and therefore not common in species distribution and ecological niche modelling, across a set of 106 mountain plant species for which presence–absence data was available. We assessed accuracy using standard metrics and compared trade-offs in omission and commission errors between classification groups as well as effects of prevalence and spatial autocorrelation on accuracy. One-class models fit to presence-only data were comparable to two-class models fit to presence–absence data when performance was evaluated with a measure weighting omission and commission errors equally. One-class models were superior for reducing omission errors (i.e. yielding higher sensitivity), and two-classes models were superior for reducing commission errors (i.e. yielding higher specificity). For these methods, spatial autocorrelation was only influential when prevalence was low. These results differ from previous efforts to evaluate alternative modelling approaches to build ENM and are particularly noteworthy because data are from exhaustively sampled populations minimizing false absence records. Accurate, transferable models of species' ecological niches and distributions are needed to advance ecological research and are crucial for effective environmental planning and conservation; the pattern-recognition approaches studied here show good potential for future modelling studies. This study also provides an introduction to promising methods for ecological modelling inherited from the pattern-recognition discipline.

A global 1‐km consensus land‐cover product for biodiversity and ecosystem modelling

AbstractAimFor many applications in biodiversity and ecology, existing remote sensing‐derived land‐cover products have limitations due to among‐product inconsistency and their typically non‐continuous nature. Here we aim to help address these shortcomings by generating a 1‐km resolution global product that provides scale‐integrated and accuracy‐weighted consensus land‐cover information on an approximately continuous scale.LocationGlobal.MethodsUsing a generalized classification scheme and an accuracy‐based integration approach, we integrated four global land‐cover products. We evaluated the performance of this product compared with inputs for estimating subpixel 30‐m resolution land cover. We also compared the accuracy of deductive and inductive species distribution models built with the different products for modelling the continental distributions of six avian habitat specialists.ResultsOur product offers accuracy‐weighted consensus information on the prevalence of 12 land‐cover classes within every nominal 1‐km pixel across the globe (except for Antarctica). Compared with the four base products, it better captures the land‐cover information contained in the fine‐grain validation data for all classes combined and for most individual classes. It also has the highest sensitivity and overall accuracy for detecting the presence of every fine‐grain land‐cover class. Both deductive and inductive models built with the consensus dataset have the highest or second highest accuracy for modelling bird species distributions.Main conclusionsOur consensus product integrates the four base products and successfully maximizes accuracy and reduces errors of omission. Specifically, the consensus product reduces limitations caused by misclassifications, false absence rates and the categorical format of existing land‐cover products. Consequently, it surpasses single base products in the ability to capture subpixel land‐cover information and the utility for modelling species distributions. Both the presented methodology and the consensus product have multiple applications in biodiversity research and for understanding and modelling of global terrestrial ecosystems.

TRANSESOPHAGEAL ECHO STUDY IN PATIENTS WITH ACUTE ISCHEMIC STROKE

Background: Stroke is one of the major causes of death and disability and due to the high mortality and morbidity rates associated with stroke ,it is becoming a major community health problem worldwide. It has been estimated that cardiogenic emboli are a source of transient ischemic attack (TIA) or stroke in 20% to 40% of all cases. Transesophageal echocardiography (TEE) has been proven superior to transthoracic echocardiography (TTE) for the detection of potential sources of cardiac embolism in patients with previous stroke. In particular, the additional value of TEE in the patients above 45 years of age, in whom TEE is still far from routine procedure, was evaluated. In addition, emphasis was placed on therapeutic consequences, ie, the indication for anticoagulation, based on the results of TEE. Aim of the work : The aim of our study is to evaluate the role of TEE (transesophagealecho) to find indications of anticoagulation despite false absence of its benefit by clinical and transthoracicecho (TTE) examination. Patient and methods: The study was conducted in Zagazig university hospitals and included 100 patients diagnosed with ischemic stroke The diagnosis of stroke was made based on clinical data and brain CT. A full TEE was done and the presence of the following potential sources of embolism was specifically examined (a)left atrial spontaneous echo contrast and thrombus , (b)Impaired Left atrial appendage velocity and the presence of LAA (Left atrial appendage )thrombi , (c)Atheroma in the thoracic aorta, (d)Patent foramen ovale and atrial septal aneurysm (e) others, including valvular vegetations and intracardiac masses . Results:Among the different age groups studied , the prevalence of PFO and MVP (mitral valve prolapse) were highest in patients ˂ 45 years old while the prevalence of complex aortic atheroma was highest in patients ˃45 years old .Risk of stroke recurrence was highest in patients with complex aortic atheroma .Among patients with dyslipidemia,prevalance of ischemic stroke was highest in those older than 45 years old and was significantly higher in low HDL (high density lipoprotein ) (˂40 mg/dl ) and high cholesterol (˃200 mg/dl) group.Furthermore, the risk of stroke recurrence was significantly higher in patients with hypercholesterolemia. Conclusion: TEE has proved to be a very useful tool in diagnosing causes of ischemic stroke .The benefit was not only seen in young age (˂45 years old), but also in those in older age groups . Key words: Mitral valve prolapse, patent foramen ovale, interatrial septal aneurysm , complex aortic ahteroma ,Transesophageal Echocardiography.

Endobronchial tuberculosis: two case reports and review of the literature.

Endobronchial tuberculosis commonly affects young patients and presents as acute or insidious onset cough, wheeze, low grade fever, and constitutional symptoms. Although endobronchial lesions usually result in sputum positivity for acid fast bacilli (AFB), a false negative sputum or absence of radiological lesions may result in delayed diagnosis. On the other hand, sputum positivity with presence of signs on chest radiology may lead to consideration of parenchymal TB as the primary diagnosis and the coexistence of endobronchial lesions may be missed until sequelae of the latter ensue. Besides, in elderly patients, consideration of other differentials like malignancy and pneumonia may lead to misdiagnosis. Hence, bronchoscopy is essential for confirmation of endobronchial TB. We hereby report two cases of endobronchial TB which stress the importance of bronchoscopic diagnosis for timely institution of treatment and prevention of permanent sequelae, respectively.