344 research outputs found
Autocorrelation function for human gait analysis
The paper presents applying of the autocorrelation function to human gait analysis. The series of angle signals at the hip, knee and ankle joints of patients with different pathological states were analyzed. The signals were processed by means of the autocorrelation function. This approach allowed to apply the simple mathematical function for analytic description of curves. By using curve fitting, parameters of 5th order polynomial function were evaluated. Mean values and standard deviation of six parameters were observed in relation to human gait pathology. The results indicate new possibilities for applying the method to diagnose human gait using the autocorrelation functio
Morphological Comparisons of Five Species of Tamarins in Peru
Tamarins of the genus Leontocebus (formerly Saguinus), subfamily Callitrichinae, represent one of the most diverse primate taxa but detailed information about their phylogeny is still lacking. Recent molecular phylogenetic analyses have led to the reclassification of many taxa. In Peru, ten subspecies of tamarins were reclassified as eight new species and four new subspecies based on genetic differences among these taxa. However, no one has attempted to determine whether these new “genetic species” have distinguishable morphological traits. To do this, we examined twenty crania and skins representing five Peruvian “genetic species” housed in the Mammals Collection at the Field Museum of Natural History in Chicago, Illinois. We measured thirty linear craniofacial characters using digital calipers and photographed the pelage of all specimens. We log-transformed and analyzed the data using the Discriminant Analysis module of SPSS 23. We qualitatively compared the pelage color and pattern of all furs. Our study demonstrates that the “genetic species” can be distinguished by their cranial anatomy. Thus, the “genetic species” represent morphologically distinct populations, as is expected if they represent evolutionarily distinct taxa.B.S. (Bachelor of Science
Tight Bell inequalities with no quantum violation from qubit unextendible product bases
We investigate the relation between unextendible product bases (UPB) and Bell
inequalities found recently in [R. Augusiak et al., Phys. Rev. Lett. 107,
070401 (2011)]. We first review the procedure introduced there that associates
to any set of mutually orthogonal product vectors in a many-qubit Hilbert space
a Bell inequality. We then show that if a set of mutually orthogonal product
vectors can be completed to a full basis, then the associated Bell inequality
is trivial, in the sense of not being violated by any nonsignalling
correlations. This implies that the relevant Bell inequalities that arise from
the construction all come from UPBs, which adds additional weight to the
significance of UPBs for Bell inequalities. Then, we provide new examples of
tight Bell inequalities with no quantum violation constructed from UPBs in this
way. Finally, it is proven that the Bell inequalities with no quantum violation
introduced recently in [M. Almeida et al., Phys. Rev. Lett. 104, 230404 (2010)]
are tight for any odd number of parties.Comment: 14 pages, 1 figure, some minor improvement
Simultaneous Bedside Assessment of Global Cerebral Blood Flow and Effective Cerebral Perfusion Pressure in Patients with Intracranial Hypertension
Background: We examined a bedside technique transcerebral double-indicator dilution (TCID) for global cerebral blood flow (CBF) as well as the concept of effective cerebral perfusion pressure (CPPeff) during different treatment options for intracranial hypertension, and compared global CBF and CPPeff with simultaneously obtained conventional parameters. Methods: Twenty-six patients developing intracranial hypertension in the course of traumatic brain injury or subarachnoid hemorrhage were prospectively analyzed using a combined assessment during elevated ventilation (n=15) or osmotherapy (hypertonic saline or mannitol). For calculation of global CBF, injections of ice-cold indocyanine green boluses were performed and temperature and dye concentration changes were monitored in the thoracic aorta and the jugular bulb. CBF was then calculated according to the mean transit time principle. Estimation of CCP, the arterial pressure at which cerebral blood flow becomes zero, was performed by synchronized registration of corresponding values of blood flow velocity in the middle cerebral artery and arterial pressure and extrapolation to zero-flow velocity. CPPeff was calculated as mean arterial pressure minus critical closing pressure (CPPeff=MAPc−CCP). Results: Elevated ventilation causes a decrease in both ICP (P<0.001) and CBF (P<0.001). While CPPconv increased (P<0.001), CPPeff decreased during this observation (P=0.002). Administration of osmotherapeutic agents resulted in a decrease of ICP (P<0.001) and a temporary increase of CBF (P=0.052). CPPconv and CPPeff showed no striking difference under osmotherapy. Conclusion: TCID allows repeated measurements of global CBF at the bedside. Elevated ventilation lowered and osmotherapy temporarily raised global CBF. In situations of increased vasotonus, CPPeff is a better indicator of blood flow changes than conventional CP
An optimization of hematopoietic stem and progenitor cell isolation for scientific and clinical purposes by the application of a new parameter determining the hematopoietic graft efficacy.
The transplantation of hematopoietic stem and progenitor cells (HSPC) is an established lifesaving therapy. Bone marrow (BM), harvested from heparinized cadaveric organ donors, peripheral blood (PB) and cord blood (CB), are important sources of hematopoietic stem cells. HSPCs, which are used for transplantation purposes, are routinely evaluated in terms of number of mononuclear cells (MNCs), CD34+ MNCs count and viability. The efficacy of grafting is determined additionally in clonogenic tests in vitro. These tests deliver important information about the number of HSPCs and their proliferative potential. Unfortunately, they do not give a possibility to evaluate the functional HSPC chemotactic reactivity in the SDF-1 gradient, which is probably the key phenomenon for HSPC homing after transplantation procedure. Thus, the aim of our study was to optimize HSPC isolation according to their chemotactic reactivity in SDF-1 gradient. Using multiparameter cell sorter (FACS Aria, BD) we examined the HSPCs attracted by SDF-1 on a single cell level. The population of cells which participated in the chemotactic process was highly enriched in CXCR4+lin-AC133+CD45+ cells (referred as hematopoietic stem cells) and to our surprise in CXCR4+lin-AC133+CD45- cells (referred as pluripotent stem cells) in quantitative amounts. Since reactivity of HSPCs may depend on various factors involved in the protocol of their isolation and short-term storage, we tested the most commonly used anticoagulants (ACD, CPDA-1, EDTA and Heparin) and culture media (DME, IMDM, RPMI). HSPCs, harvested from CB, PB and BM, were subsequently investigated for clonogenic growth of CFU-GM in methylcellulose cultures and for the level of apoptosis by employing annexin V staining. Evaluating clonogenic potential, ability of chemotactic reactivity in SDF-1 gradient and intensification of apoptosis of HSPC as the most safe anticoagulant and medium were selected. This study has proved that chemotactic reactivity of HSPCs is a new but very important parameter which should be included in the procedure of their isolation
Symplectic geometry of entanglement
We present a description of entanglement in composite quantum systems in
terms of symplectic geometry. We provide a symplectic characterization of sets
of equally entangled states as orbits of group actions in the space of states.
In particular, using Kostant-Sternberg theorem, we show that separable states
form a unique Kaehler orbit, whereas orbits of entanglement states are
characterized by different degrees of degeneracy of the canonical symplectic
form on the complex projective space. The degree of degeneracy may be thus used
as a new geometric measure of entanglement and we show how to calculate it for
various multiparticle systems providing also simple criteria of separability.
The presented method is general and can be applied also under different
additional symmetry conditions stemming, eg. from the indistinguishability of
particles.Comment: LaTex, 31 pages, typos correcte
Managing Workflows on top of a Cloud Computing Orchestrator for using heterogeneous environments on e-Science
[EN] Scientific workflows (SWFs) are widely used to model processes
in e-Science. SWFs are executed by means of workflow management systems
(WMSs), which orchestrate the workload on top of computing infrastructures.
The advent of cloud computing infrastructures has opened the door of using
on-demand infrastructures to complement or even replace local infrastructures.
However, new issues have arisen, such as the integration of hybrid resources
or the compromise between infrastructure reutilisation and elasticity. In this
article, we present an ad hoc solution for managing workflows exploiting the
capabilities of cloud orchestrators to deploy resources on demand according to
the workload and to combine heterogeneous cloud providers (such as on-premise
clouds and public clouds) and traditional infrastructures (clusters) to minimise
costs and response time. The work does not propose yet another WMS but
demonstrates the benefits of the integration of cloud orchestration when running
complex workflows. The article shows several configuration experiments from
a realistic comparative genomics workflow called Orthosearch, to migrate
memory-intensive workload to public infrastructures while keeping other blocks
of the experiment running locally. The article computes running time and cost
suggesting best practices.This paper wants to acknowledge the support of the EUBrazilCC project, funded by the European Commission (STREP 614048) and the Brazilian MCT/CNPq N. 13/2012, for the use of its infrastructure. The authors would like also to thank the Spanish 'Ministerio de Economia y Competitividad' for the project 'Clusters Virtuales Elasticos y Migrables sobre Infraestructuras Cloud Hibridas' with reference TIN2013-44390-R.Carrión Collado, AA.; Caballer Fernández, M.; Blanquer Espert, I.; Kotowski, N.; Jardim, R.; Dávila, AMR. (2017). Managing Workflows on top of a Cloud Computing Orchestrator for using heterogeneous environments on e-Science. International Journal of Web and Grid Services. 13(4):375-402. doi:10.1504/IJWGS.2017.10003225S37540213
Non-assisted versus neuro-navigated and XperCT-guided external ventricular catheter placement: a comparative cadaver study
Background and purpose: Accurate placement of an external ventricular drain (EVD) for the treatment of hydrocephalus is of paramount importance for its functionality and in order to minimize morbidity and complications. The aim of this study was to compare two different drain insertion assistance tools with the traditional free-hand anatomical landmark method, and to measure efficacy, safety and precision. Methods: Ten cadaver heads were prepared by opening large bone windows centered on Kocher's points on both sides. Nineteen physicians, divided in two groups (trainees and board certified neurosurgeons) performed EVD insertions. The target for the ventricular drain tip was the ipsilateral foramen of Monro. Each participant inserted the external ventricular catheter in three different ways: 1) free-hand by anatomical landmarks, 2) neuronavigation-assisted (NN), and 3) XperCT-guided (XCT). The number of ventricular hits and dangerous trajectories; time to proceed; radiation exposure of patients and physicians; distance of the catheter tip to target and size of deviations projected in the orthogonal plans were measured and compared. Results: Insertion using XCT increased the probability of ventricular puncture from 69.2 to 90.2% (p = 0.02). Non-assisted placements were significantly less precise (catheter tip to target distance 14.3 ± 7.4mm versus 9.6 ± 7.2mm, p = 0.0003). The insertion time to proceed increased from 3.04 ± 2.06min. to 7.3 ± 3.6min. (p < 0.001). The X-ray exposure for XCT was 32.23mSv, but could be reduced to 13.9mSv if patients were initially imaged in the hybrid-operating suite. No supplementary radiation exposure is needed for NN if patients are imaged according to a navigation protocol initially. Conclusion: This ex vivo study demonstrates a significantly improved accuracy and safety using either NN or XCT-assisted methods. Therefore, efforts should be undertaken to implement these new technologies into daily clinical practice. However, the accuracy versus urgency of an EVD placement has to be balanced, as the image-guided insertion technique will implicate a longer preparation time due to a specific image acquisition and trajectory planning
Browsers, grazers or mix-feeders? Study of the diet of extinct Pleistocene Eurasian forest rhinoceros Stephanorhinus kirchbergensis (J¨ager, 1839) and woolly rhinoceros Coelodonta antiquitatis (Blumenbach, 1799)
The wooly rhinoceros (Coelodonta antiquitatis) and forest rhinoceros (Stephanorhinus kirchbergensis) were prominent representatives of the Middle and Late Pleistocene glacial and interglacial faunas of Eurasia. Their diet has traditionally been inferred on functional morphology of the dentition and skull. In rare cases, food remains are preserved in the fossas of the teeth or as gut content. New approaches to infer diet include the study of isotopes and mesowear. Here we apply all four methods to infer the diet of these emblematic rhinoceros’ species and compare the food actually taken with the food available, as indicated by independent botanical data from the localities where the rhinoceros’ fossils were found: Gorz´ow Wielkopolski (Eemian) and Starunia (Middle Vistulian) as well as analysis of literature data. We also made inferences on the season of death of these individuals. Our results indicate that the woolly rhino in both Europe and Asia (Siberia) was mainly a grazer, although at different times of the year and depending on the region its diet was also supplemented by leaves of shrubs and trees. According to the results of isotope studies, there were important individual variations. The data show a clear seasonal variation in the isotope composition of this rhino’s diet. In contrast, Stephanorhinus kirchbergensis was a browser, though its diet included low-growing vegetation. Its habitat consisted of various types of forests, from riparian to deciduous and mixed forests, and open areas. The diet of this species consisted of selected items of vegetation, also including plants growing near both flowing and standing waters. The food remains from the fossae of the teeth indicated flexible browsing, confirming the previous interpretations based on functional morphology and stable isotopes. Long-term data from mesowear and microwear across a wider range of S. kirchbergensis fossils indicate a more mixed diet with a browsing component. The different diets of both of rhinoceros reflect not only the different habitats, but also climate changes that occurred during the Late Pleistocene
Ergonomics observation: harvesting tasks at oil palm plantation
Objectives: Production agriculture is commonly associated with high prevalence of ergonomic injuries, particularly during intensive manual labor and during harvesting. This paper intends to briefly describe an overview of oil palm plantation management highlighting the ergonomics problem each of the breakdown task analysis. Methods: Although cross-sectional field visits were conducted in the current study, insight into past and present occupational safety and health concerns particularly regarding the ergonomics of oil palm plantations was further exploited. Besides discussion, video recordings were extensively used for ergonomics analysis. Results: The unique commodity of oil palm plantations presents significantly different ergonomics risk factors for fresh fruit bunch (FFB) cutters during different stages of harvesting. Although the ergonomics risk factors remain the same for FFB collectors, the intensity of manual lifting increases significantly with the age of the oil palm trees-weight of FFB. Conclusions: There is urgent need to establish surveillance in order to determine the current prevalence of ergonomic injuries. Thereafter, ergonomics interventions that are holistic and comprehensive should be conducted and evaluated for their efficacy using approaches that are integrated, participatory and cost-effective
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