Polychronicity and multipresence: A grounded theory of e-learning time-awareness as expressed by Portuguese academics' time concepts

This paper makes an attempt to systematise and theorise the variety of time-bound terms and understandings used by academics for analysing and describing e-learning time properties. This temporal consideration has value in information systems development because, by taking into account polychronicity and multipresence as designated foci of academic processes and educational work rhythms, Higher Education Institutions will be able to implement e-learning systems which better fit academics' temporal behaviour. Recommendations are further advanced concerning the alignment of academics' time concepts with the properties of embedded e-learning

Contextual Sensitivity in Grounded Theory: The Role of Pilot Studies

Grounded Theory is an established methodological approach for context specific inductive theory building. The grounded nature of the methodology refers to these specific contexts from which emergent propositions are drawn. Thus, any grounded theory study requires not only theoretical sensitivity, but also a good insight on how to design the research in the human activity systems to be studied. The lack of this insight may result in inefficient theoretical sampling or even erroneous purposeful sampling. These problems would not necessarily be critical, as it could be argued that through the elliptical process that characterizes grounded theory, remedial loops would always bring the researcher to the core of the theory. However, these elliptical remedial processes can take very long periods of time and result in catastrophic delays in research projects. As a strategy, this paper discusses, contrasts and compares the use of pilot studies in four different grounded theory projects. Each pilot brought different insights about the context, resulting in changes of focus, guidance to improve data collection instruments and informing theoretical sampling. Additionally, as all four projects were undertaken by researchers with little experience of inductive approaches in general and grounded theory in particular, the pilot studies also served the purpose of training in interviewing, relating to interviewees, memoing, constant comparison and coding. This last outcome of the pilot study was actually not planned initially, but revealed itself to be a crucial success factor in the running of the projects. The paper concludes with a theoretical proposition for the concept of contextual sensitivity and for the inclusion of the pilot study in grounded theory research designs

Effect of betaine on growth performance and carcass composition of Alentejano pig breed.

The aim of this work was to evaluate the effect of fattening diets supplemented with betaine on growth performances and carcass characteristics of Alentejano pigs. Sixteen Alentejano pigs sexually neutralized, with a initial body weight (BW) of 36.3 kg, allocated to open-air individual pens (3m2), were divided into two experimental groups: Group C (n=8) consuming a commercial diet with 150 g/kg crude protein and 13.0 MJ digestible energy; and group CB (n=8) consuming the same diet supplemented with betaine (1g/kg). The diets were restrictively offered at 85% estimated ad libitum consumption. All pigs had free access to fresh water. Diet refusals were measured daily and pigs were weighed weekly. At 100 kg BW, pigs were submitted to a 24 h fasting period and killed. Carcass weight, backfat thickness and Longissimus muscle area were determined. The left side half carcass was submitted to commercial cuts according to the Portuguese norm and their weights recorded. No significant differences between treatments were detected in feed intake (297.3 vs. 286.5 kg), average daily gain (472 vs. 480g) and feed:gain (4.66 vs. 4.51). Hot carcass weight (82.2 vs. 83.6 kg), backfat thickness (5.0 vs. 5.3 cm), Longissimus muscle area (21.9 vs. 21.2 cm2) and weights of commercial cuts of the half carcass were also not significantly affected by betaine supplementation

The “montado”: determinant factor affecting the carcass characteristics and the quality of dry cured hams of Alentejano pig

The objective of this study was to assess the effect of the finishing system (under montanheira or with commercial feed) on carcass characteristics and dry cured-ham of Alentejano pigs. 24 pigs were fattening until 130 kg LW under montanheira and 24 pigs were fattening with commercial feed. Carcasses of pigs fattened under the montanheira system were slightly heavy (98,38 vs 96,13 kg), with significantly higher (P>0,01) dressing percentage (79,55% vs 78,11%), backfat thickness (6,09 vs 5,34 cm), percentage of fatty cuts (32,06% vs 30,44%) and weight (21,92 vs 19,77 kg) and percentage of adipose tissue (51,65% vs 47,71%). Percentage of lean cuts (50,03% vs 49,07%), bone cuts (19,53% vs 18,87%), weight (14,91 vs 13,77 kg) and percentage of lean (36,04% vs 32,54%), lean:bone (3,21 vs 3,01) and lean:fat (0,76 vs 0,63) ratios were significantly higher in pigs fed commercial feed. The content of ether extract in lean+fat was significantly higher (63,7% vs 60,41%), in pigs fattened under the montanheira system, while the content of crude protein (7,57% vs 8,41%) was significantly higher in pigs fed commercial feed. Energy retained was higher in pigs finished under montanheira (231,7 vs 217,0 Mcal). The dry cured hams from pigs fattened on acorns were more mono-unsaturated and less poly-unsaturated, especially on subcutaneous fat. It can be concluded that the fattening on pasture and acorns under the oak canopy is considered to be crucial for the quality of the raw material and meat products, as dry cured-ham

Betaine supplementation vs. exercise: effects on glucose, protein, urea and lipid plasma parameters from Alentejano pigs.

Swine, due to their physiologic and anatomical similarities to humans, are considered as good models for cholesterol metabolism studies. The Alentejano (AL) pig is a breed from the south of Portugal with a higher lipogenic activity than European breeds. The present study aimed to investigate the effects of betaine (a methyl donor and an osmoprotectant, with contradictory effects on backfat thickness) supplementation and of exercise in some plasma parameters of AL pigs. Weaned female and male AL pigs were castrated, allocated to individual pens and fed a commercial (C) diet offered at 85% of ad libitum. The pigs were slaughtered (~100 kg BW) in 3 groups: Group C (n=6), consuming the C diet; Group CB (n=8), consuming the C diet with betaine (1g/kg); and Group CE (n=5), consuming also the C diet, but with access to an exercise area. Fasting plasma concentrations of glucose, protein, urea, triacylglycerols, phospholipids, total and LDL- and HDL-cholesterol were determined. When compared to C and CE pigs, CB pigs presented higher concentrations (P<0.05) of triacylglycerols, phospholipids, cholesterol and lipoprotein cholesterol. As to CE pigs, they presented lower total cholesterol (P=0.08) and higher HDL-cholesterol and HDL:total cholesterol ratio (P<0.05) than C ones. These data suggest that betaine increases dyslipidemia. Furthermore, exercise had a beneficial effect on plasma cholesterol levels and on the cholesterol deposition in adipose tissues and muscles of CE pigs (lower than the ones observed in the subcutaneous fat and m. semimembranosus of C and CB pigs – preliminary data)

Utilização de óleo de girassol “Alto oleico” na alimentação de porcos Alentejanos: Efeitos sobre o crescimento e as características da carcaça.

Este trabalho teve como objetivo a utilização de óleo de girassol rico em ácido oleico na alimentação de suínos Alentejanos destinados à produção de carne para consumo em fresco. O ensaio foi realizado em condições de exploração

Utilização de óleo de girassol “Alto oleico” na alimentação de porcos Alentejanos: Efeitos sobre o crescimento e as características da carcaça.

Este trabalho teve como objetivo a utilização de óleo de girassol rico em ácido oleico na alimentação de suínos Alentejanos destinados à produção de carne para consumo em fresco. O ensaio foi realizado em condições de exploração

Models with commutative orthogonal block structure: a general condition for commutativity

This work was partially supported by national founds of FCT-Foundation for Science and Technology under UID/MAT/00297/2019 and UID/MAT/00212/2019.A linear mixed model whose variance-covariance matrix is a linear combination of known pairwise orthogonal projection matrices that add to the identity matrix, is a model with orthogonal block structure (OBS). OBS have estimators with good behavior for estimable vectors and variance components, moreover it may be interesting that the least squares estimators give the best linear unbiased estimators, for estimable vectors. We can achieve it, requiring commutativity between the orthogonal projection matrix, on the space spanned by the mean vector, and the orthogonal projection matrices involved in the expression of the variance-covariance matrix. This commutativity condition defines a more restrict class of OBS, named COBS (model with commutative orthogonal block structure). With this work we aim to present a commutativity condition, resorting to a special class of matrices, named U-matrices.publishersversioninpres

Desenvolvimento do tecido adiposo e muscular em suínos de raça Alentejana

To study the effects of slaughter weight on adipose and muscular tissues development of Alentejano hogs thirty animals were used. With an average live weight of 35 kg, pigs were allocated in individual pens at outdoor and fed a commercial diet (15% CP and 3100 Kcal ED/kg) offered at 85% Ad Libitum. Pigs were sequentially slaughtered in groups (n=5) with an average live weight of 40, 70,80, 90, 100 and 110 kg. After carcass chilling at 5º C for 24 h flare fat was weighed and subcutaneous backfat thickness and loin eye area were recorded at 10-11 ribs, last rib and 3-4 lombar vertebras. Flare fat increased significantly (P<0,01) with the increase of slaughter weight: 1,26, 2,08, 3,22, 3,36, 3,68 e 4,02 Kg, respectively at 40, 70, 80, 90, 100 e 110 Kg. Subcutaneous back fat thickness also increased strongly with the increase of slaughter weight: 1,56, 3,21, 4,12, 5,10, 5,41 and 5,38 cm, respectively at 40, 70, 80, 90, 100 e 110 Kg. Between 90 and 110 kg averages were similar. The area of Longissimus dorsi increased slightly (15,49 to 20,36 cm2) with the increase of slaughter weight. The results suggested that Alentejano pig breed have a limited genetic potential for lean gain and a high capacity for fat deposition