The One Dimensional Damped Forced Harmonic Oscillator Revisited

In this paper we give a general solution to the problem of the damped harmonic oscillator under the influence of an arbitrary time-dependent external force. We employ simple methods accessible for beginners and useful for undergraduate students and professors in an introductory course of mechanics.Comment: 4 Latex page

Cultural differences in postnatal quality of life among German-speaking women - a prospective survey in two countries.

Assessment of quality of life after childbirth is an important health-outcome measurement for new mothers and is of special interest in midwifery. The Mother-Generated Index (MGI) is a validated instrument to assess postnatal quality of life. The tool has not been applied for making a cross-cultural comparison before. This study investigated (a) responses to the MGI in German-speaking women in Germany and Switzerland; and (b) associations between MGI scores on the one hand and maternity and midwifery care on the other

On the regular-geometric-figure solution to the N-body problem

The regular-geometric-figure solution to the $N$-body problem is presented in a very simple way. The Newtonian formalism is used without resorting to a more involved rotating coordinate system. Those configurations occur for other kinds of interactions beyond the gravitational ones for some special values of the parameters of the forces. For the harmonic oscillator, in particular, it is shown that the $N$-body problem is reduced to $N$ one-body problems.Comment: To appear in Eur. J. Phys. (5 pages

An integrative literature review of psychosocial factors in the transition to parenthood following non-donor-assisted reproduction compared with spontaneously conceiving couples

An integrative literature review of research into the psychosocial factors which shape the transition to parenthood in couples following non-donor in vitro fertilisation in comparison with spontaneously conceiving couples was undertaken following adapted PRISMA guidelines. Nineteen papers of non-donor IVF and SC mothers and fathers were included in the review. This is the first review to report on research comparing the transition to parenthood of couples following successful non-donor singleton AR and SC couples. The small number of studies were over reliant on survey methodologies. Differences between groups were reported on a range of psychosocial measures during the transition from pregnancy to parenthood: locus of control, parental adjustment and child behaviour, parental stress, parental investment in the child, self-esteem and self-efficacy, greater levels of protectiveness (separation anxiety) towards child, marital and family functioning, family alliance, marital satisfaction and communication as well anxiety, indirect aggression and less respect for child. We have conceptualised these differences as three substantive themes which reflect psychosocial factors shaping transition to parenthood in parents after non-donor AR: social support, relationships, and emotional well-being which are in turn intersected by gender differences. These findings have implications for health care professionals’ assessment of individual couples’ support needs

The Abundance of Lactic Acid Bacteria in the Gastrointestinal Tract of Lake Victoria Nile Perch

This study was carried out to determine the presence and abundance of lactic acid from gastrointestinal tracts of Latesniloticus fish with the specific objective of determining fish size effect on lactic acid bacteria (LAB) population. The study was conducted in Lake Victoria between April-June and July-September, 2014. Statistical analysis was performed by using Minitab 9.1.3 software version. Analysis of Variance (ANOVA) and east significant difference (LSD) was used for statistical comparisons. Differences were considered significant at α=0.05 level.  The average weight of small fish sampled during the wet season was 667.9g that gave an average colony forming units/g of 9.2x 103; medium averaging 1485.1g had an average of 2.1x104cfu and big averaging 3210.8g had 4.9 x 104cfu. In the dry spells, the small fish averaging 614.6g had 6.7 x 103, medium averaging 1392.9g had an average of 1.7x104cfu and big averaging 2756.3g had 3.4 x 104cfu. The mean of counts of LABs are significantly different for the three sizes tested, with the big size giving the highest followed by medium and small respectively. This could be due to ability to access more variety of foods. The means of counts of LABs are insignificantly different for the eight sites tested. The mean of counts of LABs are significantly different for the wet and dry seasons tested. In conclusion, this study showed availability of lactic acid bacteria in the gut of Lake Victoria Nile perch which can be used as a source of potential bio preservative. Key words: Lactic Acid Bacteria (LAB), Gastrointestinal tracts, Nile perch, L. Victoria, ANOVA

Do Cues Matter? Highly Inductive Settlement Cues Don't Ensure High Post-Settlement Survival in Sea Urchin Aquaculture

Increasing settlement and post-settlement survival during the critical transition from planktonic larvae to benthic juveniles will increase efficiency for sea urchin aquaculture. This study investigated the effects of temperature and settlement cues on the settlement and post-settlement survival of the sea urchin Tripneustes gratilla during this phase. The current commercial methodology, which utilises natural biofilm settlement plates, was tested and resulted in low settlement (<2%) and poor post-settlement survival (<1% of settled urchins). In laboratory trials, settlement was high and unaffected by temperatures between 24 and 30°C, but significantly decreased at 33°C. Development of spines, however, was significantly affected by temperatures over 29°C. Mirroring this result, post-settlement survival was optimal between 24–28°C. In laboratory assays, the macroalgae Sargassum linearifolium and Corallina officinalis, and seawater conditioned with these algae, induced significantly higher settlement (>90%) than a natural biofilm (∼25%). The addition of macroalgae-conditioned seawater to natural biofilm significantly increased settlement rates (>85%). Mixed consortia and single strains of bacteria isolated from macroalgae, biofilms and adult conspecifics all induced significant settlement, but at significantly lower rates than macroalgae. No evidence was found that higher rates of settlement to bacteria on macroalgae were generated by a cofactor from the macroalgae. Age of bacterial cultures, culturing bacteria on solid and liquid media and concentration of nutrients in cultures had little effect on settlement rates. Finally, macroalgae-conditioned seawater combined with natural biofilm settlement plates induced significantly higher settlement than to the biofilm plates alone in a commercial scale trial. However, high post-settlement mortality resulted in equivalent survival between treatments after 25 days. This study highlights that settlement studies should extend to post-settlement survival, which remains poor for T. gratilla and is a significant obstacle to increasing efficiency for aquaculture

Undergraduate student experience in dental service delivery in rural South Australia: An analysis of costs and benefits

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Rural experience for dental students can provide valuable clinical education, change attitudes to rural practice, and make a valuable contribution to clinical service provision. The aim of this paper is to assess the costs and benefits of service delivery by students through rural training programmes. Methods: Groups of two students worked in the public dental clinics in adjacent rural centres where there had been long-term difficulties in recruiting staff. The costs and benefits of the programme were assessed by the impact on waiting lists, the total cost per patient of a course of care and by the marginal cost of adding service provision by students to existing arrangements. Results: The total costs of emergency and complete treatment provided by students were greater than the costs of treatment provided by public-sector dentists but less than the costs of private providers treating public patients. However, the value of services were greater when care was provided by students or private providers and the marginal cost of students providing services was 50-70 per cent of the cost of care provided by public dentists. Conclusion: This assessment suggests that the service benefits achieved compliment the primary objective of influencing the attitude of students to rural practice.L Richards, B Symon, D Burrow, A Chartier, G Misan and D Wilkinso

Time-course analysis following initial warm-up to inform pre-pitch entry preparations of soccer substitutes.

The purpose of this study was to investigate the time-course of decrements in physical performance following a pre-match warm-up in soccer players. Knowledge of this information could be used to inform re-warm-ups and pre-pitch entry practices of soccer substitutes. Data were collected over five sessions with 12 male youth professionals (15-17 yrs). Across the five sessions each player performed countermovement jumps (CMJ) and drop jumps (30 and 40 cm), pre-warm-up, immediately post-warm-up, and following 10-, 20-, 30-, 40-, and 50-minutes of inactivity. Physical performance was assessed by jump height and calculation of reactive strength index (RSI). Hierarchical generalized linear models (HGLMs) were fitted within a Bayesian framework to identify plausible time to achieve 10 to 50% decrements of the initial pre to post warm-up improvement. Mean improvements of 5.4 cm (95%CrI: 4.8 to 6.0), 0.24 ms-1 (95%CrI: 0.19 to 0.29), and 0.32 ms-1 (0.27 to 0.36) were obtained for the CMJ, and RSI measured from the 30 and 45 cm box, respectively. Decrements for all assessments were non-linear with the steepest rates of decline measured in the initial periods following warm-up. High probabilities were calculated (p ≥ 0.979) that up to 50% of the initial warm-up improvement for the CMJ would be lost between 20 and 30 minutes. The results of this study provide a guide for future research and practitioners managing the pre-pitch entry of soccer substitutes. It is suggested that practitioners consider and assess the effectiveness of exposing players to a re-warm-up between 20- and 30-minutes prior to pitch entry to maintain performance capabilities