1,863 research outputs found
Environmental effects on progesterone profile measures of dairy cow fertility
Environmental effects on fertility measures early in lactation, such as the interval from calving to first luteal activity (CLA), proportion of samples with luteal activity during the first 60 days after calving (PLA) and interval to first ovulatory oestrus (OOE) were studied. In addition, traditional measurements of fertility, such as pregnancy to first insemination, number of inseminations per service period and interval from first to last insemination were studied as well as associations between the early and late measurements. Data were collected from an experimental herd during 15 years and included 1106 post-partum periods from 191 Swedish Holsteins and 325 Swedish Red and White dairy cows. Individual milk progesterone samples were taken twice a week until cyclicity and thereafter less frequently. First parity cows had 14.8 and 18.1 days longer CLA (LS-means difference) than second parity cows and older cows, respectively. Moreover, CLA was 10.5 days longer for cows that calved during the winter season compared with the summer season and 7.5 days longer for cows in tie-stalls than cows in loose-housing system. Cows treated for mastitis and lameness had 8.4 and 18.0 days longer CLA, respectively, compared with healthy cows. OOE was affected in the same way as CLA by the different environmental factors. PLA was a good indicator of CLA, and there was a high correlation (−0.69) between these two measurements. Treatment for lameness had a significant influence on all late fertility measurements, whereas housing was significant only for pregnancy to first insemination. All fertility traits were unfavourably associated with increased milk production. Regression of late fertility measurements on early fertility measurements had only a minor association with conception at first AI and interval from first to last AI for cows with conventional calving intervals, i.e. a 22 days later, CLA increased the interval from first to last insemination by 3.4 days. Early measurements had repeatabilities of 0.14–0.16, indicating a higher influence by the cow itself compared with late measurements, which had repeatabilities of 0.09–0.10. Our study shows that early fertility measurements have a possibility to be used in breeding for better fertility. To improve the early fertility of the cow, there are a number of important factors that have to be taken into account
Covers of acts over monoids II
In 1981 Edgar Enochs conjectured that every module has a flat cover and
finally proved this in 2001. Since then a great deal of effort has been spent
on studying different types of covers, for example injective and torsion free
covers. In 2008, Mahmoudi and Renshaw initiated the study of flat covers of
acts over monoids but their definition of cover was slightly different from
that of Enochs. Recently, Bailey and Renshaw produced some preliminary results
on the `other' type of cover and it is this work that is extended in this
paper. We consider free, divisible, torsion free and injective covers and
demonstrate that in some cases the results are quite different from the module
case
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Effects of Cryogenic Processing on Rapid Prototyping Materials (DSMSomos-8110 and DuraForm PA)
This research investigates the effects of cryogenic processing on the properties of rapid
prototyped materials. Not much research has been done on the post-processing (aging) of rapid
prototyped (RP) polymers at temperatures below 159K (–173˚F). Test specimens of RP
thermoplastic resin DSM-Somos 8110 and DuraformPA Nylon were fabricated and
cryogenically aged from 5-30 hours. The tensile strength and impact toughness were measured.
The goal of this work was to study the effect of cryogenic aging on yield strength and ductility.
This research investigated (1) the cryogenic aging of DSM-Somos 8110 and DuraformPA Nylon,
(2) the effects of controlled ramp-downs/ups on the ultimate and tensile strengths of samples, (3)
the experimental methods, and (4) the analysis and interpretation of the data.Part of this work was funded by a NSF Grant under Research Experiences for
Undergraduates.Mechanical Engineerin
On covers of cyclic acts over monoids
In (Bull. Lond. Math. Soc. 33:385–390, 2001) Bican, Bashir and Enochs finally solved a long standing conjecture in module theory that all modules over a unitary ring have a flat cover. The only substantial work on covers of acts over monoids seems to be that of Isbell (Semigroup Forum 2:95–118, 1971), Fountain (Proc. Edinb. Math. Soc. (2) 20:87–93, 1976) and Kilp (Semigroup Forum 53:225–229, 1996) who only consider projective covers. To our knowledge the situation for flat covers of acts has not been addressed and this paper is an attempt to initiate such a study. We consider almost exclusively covers of cyclic acts and restrict our attention to strongly flat and condition (P) covers. We give a necessary and sufficient condition for the existence of such covers and for a monoid to have the property that all its cyclic right acts have a strongly flat cover (resp. (P)-cover). We give numerous classes of monoids that satisfy these conditions and we also show that there are monoids that do not satisfy this condition in the strongly flat case. We give a new necessary and sufficient condition for a cyclic act to have a projective cover and provide a new proof of one of Isbell’s classic results concerning projective covers. We show also that condition (P) covers are not unique, unlike the situation for projective covers
A theory on reports of constructive (real) and illusory posttraumatic growth
It has been suggested that self-reported posttraumatic growth could sometimes be considered as a way for people to protect themselves from the distress of trauma. In this case, reports of posttraumatic growth could be illusory. We suggest a theory on self-reported constructive (real) posttraumatic growth and illusory posttraumatic growth by using Rogers’s (1959) theory and the work by Vaillant (1995). Through this theoretical framework we attempt to explain when reports of posttraumatic growth are likely to be constructive and real and when such reports are likely to represent aspects of illusions. We will also consider the implications for research practice
Selected Computing Research Papers Volume 7 June 2018
Contents
Critical Evaluation of Arabic Sentimental Analysis and Their Accuracy on Microblogs (Maha Al-Sakran)
Evaluating Current Research on Psychometric Factors Affecting Teachers in ICT Integration (Daniel Otieno Aoko)
A Critical Analysis of Current Measures for Preventing Use of Fraudulent Resources in Cloud Computing (Grant Bulman)
An Analytical Assessment of Modern Human Robot Interaction Systems (Dominic Button)
Critical Evaluation of Current Power Management Methods Used in Mobile Devices (One Lekula)
A Critical Evaluation of Current Face Recognition Systems Research Aimed at Improving Accuracy for Class Attendance (Gladys B. Mogotsi)
Usability of E-commerce Website Based on Perceived Homepage Visual Aesthetics (Mercy Ochiel)
An Overview Investigation of Reducing the Impact of DDOS Attacks on Cloud Computing within Organisations (Jabed Rahman)
Critical Analysis of Online Verification Techniques in Internet Banking Transactions (Fredrick Tshane
Things change: Women’s and men’s marital disruption dynamics in Italy during a time of social transformations, 1970-2003
We study women’s and men’s marital disruption in Italy between 1970 and 2003. By applying an event-history analysis to the 2003 Italian variant of the Generations and Gender Survey we found that the spread of marital disruption started among middle-highly educated women. Then in recent years it appears that less educated women have also been able to dissolve their unhappy unions. Overall we can see the beginning of a reversed educational gradient from positive to negative. In contrast the trend in men’s marital disruption risk appears as a change over time common to all educational groups, although with persisting educational differentials.determinants, educational differences, event history analysis, gender difference, Italy, marital disruption
Psychological growth in aging Vietnam veterans: redefining shame and betrayal
This study offers alternative interpretations of war-related distress embedded within the social and political context of the Vietnam War. Subjective interpretations from aging Vietnam veterans were analyzed using interpretative phenomenological analysis. A central theme—Moral authenticity: Overcoming the betrayal and shame of war—overarched five subordinate themes. Four subordinate themes encapsulated layers of war-related betrayal associated with shame. Shame was likely to be described as either (a) internal/sense of personal failure, with no acts of rage; or (b) external/reckless or threatening acts of others, engendering rage. A fifth theme, reparation with self, reflected humility, gratitude, and empathy, currently undefined domains of the growth construct
Ambiguous loss and incomplete abduction narratives in Kosovo
Ten mothers of men and boys who were abducted and listed as missing during the war in Kosovo in 1998/1999 were interviewed in Kosovo in the spring of 2012. Although the missing are presumed dead by the authorities, the mothers continue to live in a state of emotional ambiguity where a presumption of death is balanced with the hope of being reunited. In the absence of absolute proof, finding the remains of their loved ones becomes a major preoccupation. Using a social phenomenological approach, this study explored the social and political complexities existing within the life-world of these women. The findings suggest that they live in a continual state of psychological distress, and even when remains are returned, the unknown elements of the narrative of their abduction and murder only add to their distress and force many into self-imposed emotional exile away from community and close family
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