Electromyographic validation of the trapezius and serratus anterior muscles in rowing exercises with middle and closed grip

Because the lack of specialized textbooks on the select and indication of basic exercises for physical conditioning programmes, an electromyographic study of the trapezius (upper portion) (TS) and the serratus anterior (lower portion) (SI) muscles in rowing exercises with middle and closed grip in three different modalities, upright, sitting and bent over was performed. The tests were carried out with 24 male volunteers, 18 to 25 years old, by using a two-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For exercises execution, a supine bench, a straight board and a 1,20 m-long bar made of light wood were used. The results showed that TS acted preferentially with closed grip sitting and bent over modalities, and presented no difference among the grips for upright rowing. SI acted preferentially with closed grip in all modalities, however, with activity levels that do not justify its indication for physical conditioning programmes.

Inequality in education in Costa Rica: The gap between students in public and private schools. An analysis of the results of the Programme for International Student Assessment (PISA)

Includes bibliography.

Fluoride release and secondary caries inhibition by adhesive systems on root dentine

This study tested the fluoride-release rate and the root caries inhibitory effect of dental adhesives. In phase 1, the fluoride released from samples (n = 5) of the adhesives A (Optibond Solo), B (One-up Bond F), C (Prime & Bond NT), D (Tenure Quick), and also of the controls [+] (glass-ionomer cement) and [-] (non-fluoride releasing adhesive), was quantified on a daily basis during a pH-cycling, caries-simulating phenomenon. In phase 2, restorations were made in bovine root dentine slabs (n = 16) with the same adhesives associated with a non-fluoridated composite. Control [+] restorations were made entirely with glass-ionomer cement. Specimens were thermocycled and submitted to the pH-cycling regimen. Demineralization areas and the presence of the wall lesion (WL) and the inhibition zone (IZ) were determined by polarizing light microscopy in dentine adjacent to the restoration. The highest concentration of fluoride was released by the control [+]; adhesives A, B and C, also released fluoride. No detectable amount of fluoride was released by D or [-]. Smaller areas of demineralization were found with control [+], whereas the demineralization areas of adhesives A-D and [-] did not differ from each other. No WL was detected, and higher percentages of IZ were recorded to [+] and to adhesive A. Although some dental adhesives were able to release fluoride, they could not inhibit secondary caries development as well as the glass-ionomer cement.

Building Leadership: The Knowledge of Principals in Creating Collaborative Communities of Professional Learning

Research literature is replete with the importance of collaboration in schools, the lack of its implementation, the centrality of the role of the principal, and the existence of a gap between knowledge and practice--or a "Knowing-Doing Gap." In other words, there is a set of knowledge that principals must know in order to create a collaborative workplace environment for teachers. This study sought to describe what high school principals know about creating such a culture of collaboration. The researcher combed journal articles, studies and professional literature in order to identify what principals must know in order to create a culture of collaboration. The result was ten elements of principal knowledge: Staff involvement in important decisions, Charismatic leadership not being necessary for success, Effective elements of teacher teams, Administrator‘s modeling professional learning, The allocation of resources, Staff meetings focused on student learning, Elements of continuous improvement, and Principles of Adult Learning, Student Learning and Change. From these ten elements, the researcher developed a web-based survey intended to measure nine of those elements (Charismatic leadership was excluded). Principals of accredited high schools in the state of Nebraska were invited to participate in this survey, as high schools are well-known for the isolation that teachers experience--particularly as a result of departmentalization. The results indicate that principals have knowledge of eight of the nine measured elements. The one that they lacked an understanding of was Principles of Student Learning. Given these two findings of what principals do and do not know, the researcher recommends that professional organizations, intermediate service agencies and district-level support staff engage in systematic and systemic initiatives to increase the knowledge of principals in the element of lacking knowledge. Further, given that eight of the nine elements are understood by principals, it would be wise to examine reasons for the implementation gap (Knowing-Doing Gap) and how to overcome it.

Paleotemperature oscillations in the Middle and Late Miocene of the northeastern Pacific

The paleoclimatic and paleoceanographic history of the Middle and Late Miocene marginal eastern North Pacific as been studied in a north-to-south transect encompassing DSDP Site 173, the Newport Beach surface section, and DSDP Site 470, based on quantitative diatom and planktic foraminiferal analyses. Fourteen cold and 12 warm events that show close agreement with other microfossil studies as well as oxygen isotope records from low-latitude Pacific sites have been identified. Hiatuses are recognized at 7 to 6.5 Ma. 9.8 to 8.5 Ma, and 12 to 11 Ma at the three reference localities, and they correspond to widely recognized deep-sea hiatuses in the World Ocean.

The Enhanced Tool-Kit of Two Groups of Wild Bearded Capuchin Monkeys in the Caatinga: Tool Making, Associative Use, and Secondary Tools

The use of stones to crack open encapsulated fruit is widespread among wild bearded capuchin monkeys (Cebus libidinosus) inhabiting savanna-like environments. Some populations in Serra da Capivara National Park (Piaui, Brazil), though, exhibit a seemingly broader toolkit, using wooden sticks as probes, and employing stone tools for a variety of purposes. Over the course of 701.5 hr of visual contact of two wild capuchin groups we recorded 677 tool use episodes. Five hundred and seventeen of these involved the use of stones, and 160 involved the use of sticks (or other plant parts) as probes to access water, arthropods, or the contents of insects` nests. Stones were mostly used as ""hammers""-not only to open fruit or seeds, or smash other food items, but also to break dead wood, conglomerate rock, or cement in search of arthropods, to dislodge bigger stones, and to pulverize embedded quartz pebbles (licking, sniffing, or rubbing the body with the powder produced). Stones also were used in a ""hammer-like"" fashion to loosen the soil for digging out roots and arthropods, and sometimes as ""hoes"" to pull the loosened soil. In a few cases, we observed the re-utilization of stone tools for different purposes (N = 3), or the combined use of two tools-stones and sticks (N = 4) or two stones (N = 5), as sequential or associative tools. On three occasions, the monkeys used smaller stones to loosen bigger quartz pebbles embedded in conglomerate rock, which were subsequently used as tools. These could be considered the first reports of secondary tool use by wild capuchin monkeys. Am. J. Primatol. 71:242-251, 2009. (c) 2008 Wiley-Liss, Inc.

Speleogenesis and secondary cave minerals in quartz-sandstone and quartzite environment

The main objective of this research is to improve the comprehension of the processes controlling the formation of caves and karst-like morphologies in quartz-rich lithologies (more than 90% quartz), like quartz-sandstones and metamorphic quartzites. In the scientific community the processes actually most retained to be responsible of these formations are explained in the “Arenisation Theory”. This implies a slow but pervasive dissolution of the quartz grain/mineral boundaries increasing the general porosity until the rock becomes incohesive and can be easily eroded by running waters. The loose sands produced by the weathering processes are then evacuated to the surface through processes of piping due to the infiltration of waters from the fracture network or the bedding planes. To deal with these problems we adopted a multidisciplinary approach through the exploration and the study of several cave systems in different tepuis. The first step was to build a theoretical model of the arenisation process, considering the most recent knowledge about the dissolution kinetics of quartz, the intergranular/grain boundaries diffusion processes, the primary diffusion porosity, in the simplified conditions of an open fracture crossed by a continuous flow of undersatured water. The results of the model were then compared with the world’s widest dataset (more than 150 analyses) of water geochemistry collected till now on the tepui, in superficial and cave settings. All these studies allowed verifying the importance and the effectiveness of the arenisation process that is confirmed to be the main process responsible of the primary formation of these caves and of the karst-like superficial morphologies. The numerical modelling and the field observations allowed evaluating a possible age of the cave systems around 20-30 million of years.

Surgical treatment of upper, middle and lower cervical injuries and non-unions by anterior procedures

The goals of any treatment of cervical spine injuries are: return to maximum functional ability, minimum of residual pain, decrease of any neurological deficit, minimum of residual deformity and prevention of further disability. The advantages of surgical treatment are the ability to reach optimal reduction, immediate stability, direct decompression of the cord and the exiting roots, the need for only minimum external fixation, the possibility for early mobilisation and clearly decreased nursing problems. There are some reasons why those goals can be reached better by anterior surgery. Usually the bony compression of the cord and roots comes from the front therefore anterior decompression is usually the procedure of choice. Also, the anterior stabilisation with a plate is usually simpler than a posterior instrumentation. It needs to be stressed that closed reduction by traction can align the fractured spine and indirectly decompress the neural structures in about 70%. The necessary weight is 2.5 kg per level of injury. In the upper cervical spine, the odontoid fracture type 2 is an indication for anterior surgery by direct screw fixation. Joint C1/C2 dislocations or fractures or certain odontoid fractures can be treated with a fusion of the C1/C2 joint by anterior transarticular screw fixation. In the lower and middle cervical spine, anterior plating combined with iliac crest or fibular strut graft is the procedure of choice, however, a solid graft can also be replaced by filled solid or expandable vertebral cages. The complication of this surgery is low, when properly executed and anterior surgery may only be contra-indicated in case of a significant lesion or locked joints.

A Comparative Study of English Word Order Acquisition by Elementary and Secondary School Pupils - Native Speakers of Serbian and Hungarian

Kitic investigated the phenomenon of English word order acquisition by Serbian and Hungarian speakers, examining both the theoretical and empirical aspects of this phenomenon. She began by looking at language learning and language acquisition, viewing word order acquisition in the context of relevant linguistic and psycholinguistic knowledge. The main hypothesis of her empirical investigation was that the majority of word order mistakes in the language production of Serbian and Hungarian speakers of English is due to mother tongue interference. Three supporting hypotheses were introduced to specify the phenomenon of interference in its correlation to (1) language proficiency, (2) sentence patterns, and (3) optional adverbials. The conclusions were based on error analysis of 9280 sentences of 464 elementary and high school learners. The results showed that a learner's level of proficiency seems to be a relevant factor in mother tongue interference as this decreases with increased proficiency. Word order errors are however fossilised at the highest levels. The causes of interference errors, which increase with the number of sentence elements, are either absent sentence patterns or similar ones. In the case of adverbials, word order errors have two forms: interrelation (with canonical elements) and mixed adverbials.

Emphysema and secondary pneumothorax in young adults smoking cannabis

BACKGROUND: We observed a remarkable increase in the number of young patients who presented with lung emphysema and secondary spontaneous pneumothorax (SSP) at our institution for over a period of 30 months; most of them have a common history of marijuana abuse. STUDY DESIGN: Retrospective case series. METHODS: Seventeen young patients presented with spontaneous pneumothorax with bullous lung emphysema were systematically evaluated over a period of 30 months. All were regular marijuana smokers. Clinical history, chest X-ray, CT-scan, lung function test, and laboratory and histological examinations were assessed. We compared the findings of this group (group I) with the findings of non-marijuana smoking patients (group II) in the same period. The findings of this series were also compared with the findings of 75 patients presented with pneumothorax in a previous period from January 2000 till March 2002 (group III). RESULTS: In group I, there were 17 patients: the median age of the patients was 27 years (range 19-43 years), 16 males and 1 female. All were living in Switzerland. All but one smoked marijuana daily for a mean of 8.8 years and tobacco for 11.8 years. CT-scan showed multiple bullae at the apex or significant bullous emphysema with predominance in the upper lobes only in two patients. Only two patients had reduced forced first second expiratory volume (FEV1) and one reduced vital capacity (VC) below the predicted 50%. This correlated with the subjectively asymptomatic condition of the patients. All but two patients were treated by video-assisted thoracoscopic surgery (VATS) for prevention of relapsing pneumothorax. Histology showed severe lung emphysema, inflammation, and heavily pigmented macrophages. In group II, there were 85 patients: there were 78 males, the median age was 24 years (range 17-40 years), 74 patients smoked tobacco for 13.4 years but no marijuana. CT-scan in 72 patients showed only small bullae at the apex but no significant emphysema; other clinical, laboratory, and histopathological findings showed no significant difference in group I. In group III, there were 75 patients: there were 71 males and 4 females. Mean age was 25 years (range 16-46 years). Six smoked marijuana daily for a mean of 3.2 years, and 62 smoked tobacco for 14 years. CT-scan done in 59 patients showed few small bullae at the apex but no significant lung emphysema. The presence of lung emphysema on CT-scan in group I was significantly different than in groups II and III (p=0.14). No significant difference was found among all groups in the form of clinical, laboratory, and histopathological findings. CONCLUSIONS: In case of emphysema in young individuals, marijuana abuse has to be considered in the differential diagnosis. The period of marijuana smoking seems to play an important role in the development of lung emphysema. This obviously quite frequent condition in young and so far asymptomatic patients will have medical, financial, and ethical impact, as some of these patients may be severely handicapped or even become lung transplant candidates in the future.