Prolonged hypervolemic hemodilution decreases functional capillary density of ileal mucosa in pigs revealed by sidestream dark-field imaging

Objective  

Hemodilution changes the physical properties of blood by reducing its hematocrit and blood viscosity. We tested whether prolonged hypervolemic hemodilution (HHD) impairs functional capillary density (FCD) of ileal mucosa in healthy mechanically-ventilated pigs and if there is any correlation between changes in FCD of ileal and sublingual mucosas during HHD.     

Effective teaching methods-- Project-based learning in physics

The paper presents results of the research of new effective teaching methods in physics and science. It is found out that it is necessary to educate pre-service teachers in approaches stressing the importance of the own activity of students, in competences how to create an interdisciplinary project. Project-based physics teaching and learning seems to be one of the most effective methods for teaching science for understanding. It is necessary to provide in-service teachers instruction （seminars） and prepare sample projects with proposals how to develop, run and evaluate interdisciplinary projects. Projects are important ＂real-world＂ physics modules, modern physics and everyday life problems can be integrated into the high school curriculum. Examples of projects that were worked out are presented.     

Study and Conservation of the St. Nicola's Basilica Mosaics (Bari,Italy) by Photogrammetric Survey: Mapping of Polychrome Marbles,Decorative Patterns and Past Restorations

ABSTRACT

This present work focuses on the mapping of marbles, decorative patterns and area of the mosaics of the St. Nicola’s Basilica in Bari (Italy) by their photogrammetric survey. The extraordinary importance of these mosaics is due to the stylistic uniqueness and the undisputed workmanship and to the employed materials for tesserae. These mosaics include the white and polychrome marbles, used in the Roman age and reused in medieval artistic production, and imitation stones used as substitutes during the past restorations. The digital survey was realised by the photogrammetric reconstruction of mosaics collecting a photo dataset, after the mosaics redrawing by an image processing software and finally implemented it with lithological identification marbles. It allowed to obtain a punctual mapping of materials, through which to identify original areas and restoration areas, decorative patterns, recurring geometries. The research carried out, supported by the photogrammetric reconstruction as established method for high resolution digital reproduction and mapping, not only ensures the conservation and improvement of the enjoyment of the mosaic floors of the St. Nicola’s Basilica, but allows to conduct studies on materials, decorative patterns and restoration areas directly on the digitized product.     

Complexity and action research: exploring the theoretical and methodological connections

Complexity theory is essentially a formal attempt to question how coherent and purposive wholes emerge from the interactions of simple and sometimes non-purposive components. Explicit recognition of complexity can provide a fresh and enlightening perspective on action research. Through an expository discussion of the foundational postulates of complexity theory this article demonstrates the theoretical and methodological connections between complexity and action research, with particular emphasis on the relevance of complexity in educational and workplace contexts. Complexity is an emerging theoretical perspective, which presents possibilities for revolutionizing approaches to action research, as well as strengthening arguments promoting the value of action research in a wide range of contexts. Complexity, it is argued, can provide a valuable theoretical underpinning for action research. Furthermore, action research provides a valid methodological approach to the study of complexity. This article is primarily theoretical and attempts to demonstrate the application of complexity to a specific action research project will be left to future publication(s). Rather, this article explores the general applicability of complexity as both theory and metaphor in action research. The article begins with a brief exploration of the theory, particularly focusing on its application in the social sciences. The theoretical and methodological connections between complexity and action research are discussed through several of the foundational postulates of complexity, how these manifest in action research and how they add to our understanding of action research itself.     

The influence of hip mobility and quadriceps fatigue on sagittal spinal posture and muscle activation in rugby scrum performance

Rugby Union scrumming puts the spine under a high degree of loading. The aim of the current study was to determine how sagittal hip range of motion and quadriceps fatigue influence force output, spinal posture, and activation of the trunk and quadriceps muscles in rugby scrumming. Measures of sagittal hip flexion/extension range of motion were collected from 16 male varsity and club first XV level participants. Sagittal spine motion (electromagnetic motion capture), trunk and quadriceps activation (electromyography), and applied horizontal compressive force (force plate) were measured during individual machine scrumming. Participants performed a 5-trial scrum block involving 5?s of contact with 1–2?min recovery between each trial. They then performed a fatiguing protocol (wall sit to failure) and immediately returned to the scrum machine to perform another five trials. Though there was no significant influence of fatigue on the horizontal compressive force applied during contact (P?=?.83), there was a 52% increase in cervical flexion (P?P?P?相似文献   

Unravelling the dynamics of knowledge creation in communities of practice though complexity theory lenses

Drawing on a longitudinal case study of Alpha Chemicals, we use four complexity theory constructs – adaptive tension, enabling leadership, enhanced cooperation, and boundary spanning – to explain the continuous knowledge creation dynamics in Communities of practice (CoPs). Our findings show that the virtual cycle of knowledge creation results from CoPs oscillating between guided and self-directed modes. In a guided mode, adaptive tension and enabling leadership prevail, resulting in knowledge expansion. In a self-directed mode, enhancing cooperation and boundary spanning are the most significant, resulting in knowledge probing. This research uncovers the value of conceptualizing CoPs as complex adaptive systems with emergent and intentional processes coexisting to create a virtual knowledge creation cycle. Our findings complement the dominant theory on CoPs’ insights by moving beyond the control/autonomy debate and highlighting that knowledge creation dynamics results from a flexible combination and recombination of the different top-down and bottom-up forces.     

Through the fingers: Use of plastinated anatomical specimens for visually impaired students

The plastination technique produces non-toxic human tissues, ensuring their safe handling in educational settings. This investigation aimed to understand if visually impaired students profit from the use of plastinated anatomical specimens in learning the anatomy of the nervous system. For this purpose, their learning performance was compared to sighted and blindfolded students recruited from three primary schools in Fortaleza city, in the state of Ceará. Initially, a questionnaire was applied before carrying out the pedagogical practice, followed by an anatomy lecture with practical components with the use of plastinated anatomical specimens and synthetic anatomical models of the nervous system. After these steps, the students answered the questionnaire previously applied. Our results showed that the tactile perception of the visually impaired participants was significantly more developed compared to sighted (p < 0.001) and the blindfolded (p < 0.0001) students. The average of correct answers in the reapplied questionnaire was higher in the groups that used plastinated specimens (p < 0.05). In conclusion, the use of plastinated specimens has proven to be an effective tool in promoting a better understanding of anatomical structures, mainly for students with or without visual impairments, making it a valuable asset in anatomy teaching.     

Platelet satellitism in infectious disease?

Background

Platelet satellitism is a phenomenon of unknown etiology of aggregating platelets around polymorphonuclear neutrophils and other blood cells which causes pseudothrombocytopenia, visible by microscopic examination of blood smears. It has been observed so far in about a hundred cases in the world.

Case subject and methods

Our case involves a 73-year-old female patient with a urinary infection. Biochemical serum analysis (CRP, glucose, AST, ALT, ALP, GGT, bilirubin, sodium, potassium, chloride, urea, creatinine) and blood cell count were performed with standard methods on autoanalyzers. Serum protein fractions were examined by electrophoresis and urinalysis with standard methods on autoanalyzer together with microscopic examination of urine sediment. Erythrocyte sedimentation rate, blood culture and urine culture tests were performed with standard methods.

Results

Due to typical pathological values for bacterial urinary infection, the patient was admitted to the hospital. Blood smear examination revealed phenomenon, which has persisted for three weeks after the disease has been cured. Blood smears with EDTA as an anticoagulant had platelet satellitism whereas the phenomenon was not observed in tubes with different anticoagulants (Na, Li-heparin) and capillary blood.

Discussion

We hypothesize that satellitism was induced by some immunological mechanism through formation of antibodies which have mediated platelets binding to neutrophil membranes and vice versa. Unfortunately we were unable to determine the putative trigger for this phenomenon. To our knowledge this is the second case of platelet satellitism ever described in Croatia.Key words: blood platelets, thrombocytopenia, EDTA, urinary infection     

Neuromuscular,biomechanical, and energetic adjustments following repeated bouts of downhill running

Purpose:This study used downhill running as a model to investigate the repeated bout effect(RBE) on neuromuscular performance,running biomechanics,and metabolic cost of running.Methods:Ten healthy recreational male runners performed two 30-min bouts of downhill running(DR1 and DR2) at a-20% slope and 2.8 m/s3 weeks apart.Neuromuscular fatigue,level running biomechanics during slow and fast running,and running economy parameters were recorded immediately before and after the downhill bouts,and at...