1,003 research outputs found
Methodological standards, quality of reporting, and regulatory compliance in animal research on amyotrophic lateral sclerosis: a systematic review
Objectives The amyotrophic lateral sclerosis (ALS) research community was one of the first to adopt methodology guidelines to improve preclinical research reproducibility. We here present the results of a systematic review to investigate how the standards in this field changed over the 10-year period during which the guidelines were first published (2007) and updated (2010).
Methods We searched for papers reporting ALS research on SOD1 (superoxide dismutase 1) mice published between 2005 and 2015 on the ISI Web of Science database, resulting in a sample of 569 papers to review, after triage. Two scores—one for methodological quality, one for regulatory compliance—were built from weighted sums of separate sets of items, and subjected to multivariable regression analysis, to assess how these related to publication year, type of study, country of origin and journal.
Results Reporting standards improved over time. Of papers published after the first ALS guidelines were made public, fewer than 9% referred specifically to these. Of key research parameters, only three (genetic background, number of transgenes and group size) were reported in >50% of the papers. Information on housing conditions, randomisation and blinding was absent in over two-thirds of the papers. Group size was among the best reported parameters, but the majority reported using fewer than the recommended sample size and only two studies clearly justified group size.
Conclusions General methodological standards improved gradually over a period of 8–10 years, but remained generally comparable with related fields with no specific guidelines, except with regard to severity. Only 11% of ALS studies were classified in the highest severity level (animals allowed to reach death or moribund stages), substantially below the proportion in studies of comparable neurodegenerative diseases such as Huntington’s. The existence of field-specific guidelines, although a welcome indication of concern, seems insufficient to ensure adherence to high methodological standards. Other mechanisms may be required to improve methodological and welfare standards
Continuous improvement in maintenance: a case study in the automotive industry involving Lean tools
Maintenance function assumes a key role in today’s industry. The automotive industry is not an exception and there are strict rules to comply with. Indeed, the IATF 16949:2016 imposes the implementation of key performance indicator as a mean to control the overall manufacturing performance. This work presents a case study carried out in a multinational company related with the production of parts for the automotive industry where it was necessary to implement key performance indicators to comply with the IATF 16949: 2016 standard and a model was also created for the management of spare parts linked to the maintenance of existing equipment. The introduction of these changes forced the application of some Lean tools, with a view to improving procedures and information flows. The work was completed successfully, and key performance indicators were implemented, whose support data, which is now collected and calculated automatically on a routine basis, and the spare-parts management was validated with a view to optimization of warehouse space and at a conveniently low inventory level in this type of parts, without endangering critical equipment in production. The SMED methodology was applied, which allowed the setup time to be reduced by 11%, and the Lean 5S tool was used to organize the mould exchange activities. An OEE of more than 90% has been achieved.info:eu-repo/semantics/publishedVersio
Comparação cinemática e neuromuscular de um exercÃcio de abdominais no solo e na fitball
O objectivo deste estudo foi comparar a cinemática e a actividade neuromuscular em
exercÃcios de abdominais no solo e na Fitball. Quinze jovens mulheres participaram voluntariamente
neste estudo. Cada sujeito efectuou duas vezes, três séries de dez abdominais com um intervalo mÃnimo
de 60 segundos entre cada série. O exercÃcio foi efectuado uma vez no solo e outra na Fitball. Os dados
cinemáticos e neuromusculares foram recolhidos ao longo de todo o protocolo. Foi avaliada a
actividades neuromuscular do recto femoral, do recto abdominal superior, do recto abdominal inferior e
do oblÃquo externo. Um electrogoniómetro foi colocado entre a sexta costela e a crista ilÃaca (coluna) e
outro entre a crista ilÃaca e a zona trocantérica (anca) para avaliação cinemática. O perÃodo do
exercÃcio entre as condições em estudo não foi significativo. O ângulo mÃnimo da anca e da coluna
lombar foram significativamente inferiores durante a execução do exercÃcio no solo do que na Fitball. A
actividade neuromuscular foi significativamente superior quando o exercÃcio foi realizado na Fitball do
que no solo em todos os grupos musculares. Como conclusão, actividade neuromuscular é superior
aquando da exercitação na Fitball do que no solo
Inter-relation of sylvatic and domestic transmission of Trypanosoma cruzi in areas with and without domestic vectorial transmission in Minas Gerais, Brazil
During the period 1980-1986, we captured triatomine bugs and mammalian
reservoir hosts from sylvatic and domestic situations in different
municipalities of the State of Minas Gerais. Trypanosoma cruzi was
isolated from captured bugs, mammals and patients. After cultivation in
LIT medium, the electrophoretic enzyme profiles were determined. We
obtained a total of 32 parasite isolates from regions with active
domestic transmission, and 24 isolates from areas under control. For
the first areas the results suggest introduction of T. cruzi from
sylvatic habitats, through incursion of infected opossums and/or
sylvatic T. sordida, which appears to have given rise to at least one
acute human infection. Of particular interest is the finding of
sylvatic opossums and a T. sordida nymph infected with ZB, that could
indicate return of parasites from chronic human infections to sylvatic
transmission cycles. For the areas under control we also interpret the
results as interaction between sylvatic and domestic cycles of
transmission, here through the invasion of houses by bugs carrying the
Z1 zymodeme from the sylvatic environment. The Multivariate
Correspondence Analysis gives a spatial description between the
different parasite isolates and confirms the existence of a bridge in
the opposite direction in the region with active vectorial transmission
including the exporting of Z2 through the peridomestic environment into
the sylvatic cycle. For the other areas this bridge corresponds
especially to Panstrongylus megistus, importing Z1 into the domestic
environment
Stereoselective reduction of imines with trichlorosilane using solid-supported chiral picolinamides
The stereoselective reduction of imines with trichlorosilane catalyzed by chiral Lewis bases is a well-established procedure for the synthesis of enantio-enriched amines. Five supported cinchona-based picolinamides have been prepared and their activity tested in a model reaction. The comparison of different supporting materials revealed that polystyrene gave better results than silica in terms of stereoselectivity. The applicability of the solid-supported catalyst of choice to the reduction of different imines was also demonstrated. Additionally, for the first time, a catalytic reactor containing a polymer-immobilized chiral picolinamide has been employed for the stereoselective reduction of imines with trichlorosilane under continuous flow conditions
Varying numbers of players in small-sided soccer games modifies action opportunities during training
This study examined the effects of the numbers of players involved in small-sided team games (underloading and overloading) on opportunities for maintaining ball possession, shooting at goal and passing to teammates during training. These practice constraint manipulations were assumed to alter values of key performance variables identified in previous research, such as interpersonal distances between players and time to intercept shots and passes. Fifteen male soccer players (age: 19.60±1.99 years) were grouped into three teams and played against each other in different versions of small-sided soccer games, in which the number of players was manipulated in three different conditions: 5 vs. 5, 5 vs. 4 and 5 vs. 3. Dependent variables were the values of interpersonal distance between an outfield attacker and nearest defender (ID), and the relative distance of a defender needed to intercept the trajectory of a shot (RDishot) or pass (RDipass). Statistical analyses revealed that mean ID values were significantly lower in 5 vs. 5 than in 5 vs. 4 and 5 vs. 3 conditions, and significantly lower in 5 vs. 4 than 5 vs. 3. They also revealed that mean values of RDishot were significantly higher in 5 vs. 3 than in 5 vs. 5 conditions. Finally, results showed that the mean values of RDipass were significantly higher in 5 vs. 3 than in 5 vs. 5. Findings revealed how task constraints in SSGs can be manipulated to vary values of key spatial and temporal performance variables (interpersonal distance and time to intercept) to influence the nature of interpersonal interactions between competing players during practice. We observed that these manipulations tended to decrease opportunities for maintaining ball possession during training when equal numbers of attackers and defenders existed in SSGs, and led to more shots and passes emerging when the number of defenders was decreased relative to attackers
Effects of shoulder compensatory strength training program in rotator cuff strength of young swimmers
INTRODUCTION
The purpose of this study was to evaluate de effects of 16 week compensatory strength
training program in shoulder strength and respective conventional ratios (concentric ER/IR).
METHODS
A total of 40 national level male swimmers were assessed and randomly divided in two
groups – experimental group (N=20)-(age:14.65±0.67 years old, height:173.48±6.87 cm,
body mass:63.15±5.68 kg) and control group (N=20)-(age:14.60±0.60 years old, height:
170.79±6.48 cm, body mass:61.73±4.68 kg). Experimental subjects participated in a 16 week
shoulder strength program with Thera-Band® elastic bands (3 times a week). The peak-torque
of shoulder internal (IR) and external rotators (ER) was measured in both groups at baseline
and after 16 weeks. Concentric action at 60º/s (3 rep) and 180º/s (20 rep) were measured, in a
seated position, with the shoulder at 90º of abduction and the elbow flexed to 90º, using an
isokinetic dynamometer (Biodex System 3 – Biodex Corp., Shirley, USA). Anova with
repeated measures was used to determine significant main effects in shoulder rotators strength
and unilateral ER/IR ratios. The level of significance was set at 0.05.
RESULTS
Significant differences were found in all variables that measure the ER shoulder strength at
60º/s in dominant(DT) (P=0.031) and non-dominant(NDT) shoulder (P=0.001). Meanwhile
concentric action at 180º/s, only showed significant differences on DT shoulder (P=0.032). In
respect of ER/IR ratio, a compensatory strength training programme induces significant
differences in both shoulders at 60º/s (DT: P=0.001; NDT: P=0.001). At 180º/s we just found
significant effects on the DT ER/IR ratio (P=0.002).
DISCUSSION
The results of this study support earlier research [1] that showed that the unilateral shoulder
strength ratios increases substantially after a period of a strength training program. Since the
ratios describe the quality of muscular balance/imbalance [1], we can conclude that a 16 week
compensatory shoulder strength training program using Thera-Band® elastic bands, reduces
muscular imbalances in rotator cuff of competitive young swimmers. These results highlight
the useful of this kind of compensatory program to prevent shoulder injuries
Possibilidade de autocura em gambá (Didelphis albiventris) naturalmente infectado pelo Trypanosoma cruzi
Epidemiological studies of Mansonella ozzardi (Nematoda, Onchocercidae) in indigenous communities of Pauini municipality, Amazonas, Brazil
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