Asking the right questions: Developing diagnostic tests in undergraduate physics

Being able to discover students‟ conceptions and more importantly alternate- and misconceptions about a topic is vital in order to be able to assess and thus be able to improve student learning. It is well known that this can be achieved via the use of well-designed diagnostic tests, a widely used example of which is the Force Concept Inventory. Creating the right questions in order to form a reliable diagnostic test can be a lengthy and complicated process. This article reports work on a Development Project funded in 2008 to develop such a test for introductory Quantum Mechanics courses in both physics and chemistry. We present details of our methodology, which involves augmenting a „standard‟ multiple-choice question set with free-response boxes to determine the reasons for a student choosing a particular answer, and a self-assessment of their level of confidence in their choice. The responses from piloting this initial test in different institutions are used to inform the subsequent refinement of the test, as well as assessing the reliability and validity of the questions. We highlight examples of misconceptions that have been found during the development of the diagnostic tests

Adaptive and maladaptive personality traits as predictors of violent and nonviolent offending behavior in men and women

he aim of this study was to assess both violent and nonviolent offending behavior in a single, mixed-sex population. The rationale for this is that the two types of offending are usually researched separately, despite evidence that they overlap. A comprehensive measure of general violence, intimate partner violence (IPV), and nonviolent offending behavior was administered to 116 men and 181 women, together with measures of personality and personality disorder (PD) traits, to investigate whether predictors of violent and nonviolent offending were similar or different for men and women. Men were found to perpetrate higher levels of general violence and nonviolent offenses than women, but women perpetrated significantly more IPV than men. Cluster B PD traits predicted all three offense types for women and also men's general violence and nonviolent offending. Women's general violence and men's non-violence also had one unique risk factor each, low agreeableness, and low conscientiousness, respectively. The main difference was for IPV, where men's IPV was predicted by cluster A PD traits, indicating that men's and women's risk factors for IPV may be different, although their risk factors for the other offense types were fairly consistent

Constraints in Production and Marketing of Arecanut in Salem District of Tamil Nadu, India

Arecanut is an important cash crop in our country. The study was carried out to ascertain the constraints faced by arecanut farmers in Salem district of Tamil Nadu with a sample size of 120, by employing proportionate random sampling technique. Majority of the respondents expressed lack of specific grading of nuts in marketing as a constraint. More than three-fourths of the respondents suggested that there should be a mechanism to regulate import of nuts from other countries and to create market potential for nuts in the local markets

Influence of somatic cell count in heifers on lifetime milk yield and disease management

The aim was to assess the impact of milk somatic cell count (SCC) during the first lactation on the lifetime milk production of cows, and therefore estimate potential savings through heifer mastitis control. Cow level SCC over the first lactation was summarised as SCC between 5 and 30 days in milk (SCC1), and the geometric mean and variance of first lactation SCC. The impact of SCC1 on cumulative milk yield over different time periods was assessed for cows in Irish, English, and Welsh dairy herds. The impact of SCC1 and the geometric mean and variance of first lactation SCC on lifetime milk yield, and the association between SCC1 and disposal risk were assessed for cows in Irish dairy herds. Increase in SCC throughout the first lactation was associated with large reductions in the milk yield of cows, and increased disposal risk. Bayesian micro-simulation was used to demonstrate the impact in different herd scenarios. This was extended to synthesise evidence on potential savings using previous research, to estimate the economic impact of specific interventions to reduce the prevalence of cows with high SCC1. There was considerable variation between herds in the apparent impact of SCC1 on SCC throughout the first lactation, indicating the importance of a herd specific approach to control. ‘Cost effectiveness’ of interventions to reduce the prevalence of cows with high SCC1, was found to be highly dependent on the willingness of decision makers to pay for control measures. Increase in herd size was associated with increase in cow SCC, highlighting a need for improved management of mastitis when expansion is planned. An important component of this should be through monitoring and control of mastitis in heifers, especially those in spring-calving Irish dairy herds

Hydrochemical determination of source water contributions to Lake Lungo and Lake Ripasottile (central Italy)

Lake Lungo and Lake Ripasottile are two shallow (4-5 m) lakes located in the Rieti Basin, central Italy, that have been described previously as surface outcroppings of the groundwater table. In this work, the two lakes as well as springs and rivers that represent their potential source waters are characterized physio-chemically and isotopically, using a combination of environmental tracers. Temperature and pH were measured and water samples were analyzed for alkalinity, major ion concentration, and stable isotope (δ2H, δ18O, δ13C of dissolved inorganic carbon, and δ34S and δ18O of sulfate) composition. Chemical data were also investigated in terms of local meteorological data (air temperature, precipitation) to determine the sensitivity of lake parameters to changes in the surrounding environment. Groundwater represented by samples taken from Santa Susanna Spring was shown to be distinct with SO4 2- and Mg2+ content of 270 and 29 mg/L, respectively, and heavy sulfate isotopic composition (δ34S=15.2‰ and δ18O=10‰). Outflow from the Santa Susanna Spring enters Lake Ripasottile via a canal and both spring and lake water exhibits the same chemical distinctions and comparatively low seasonal variability. Major ion concentrations in Lake Lungo are similar to the Vicenna Riara Spring and are interpreted to represent the groundwater locally recharged within the plain. The δ13CDIC exhibit the same groupings as the other chemical parameters, providing supporting evidence of the source relationships. Lake Lungo exhibited exceptional ranges of δ13CDIC (±5‰) and δ2H, δ18O (±5 ‰ and ±7 ‰, respectively), attributed to sensitivity to seasonal changes. The hydrochemistry results, particularly major ion data, highlight how the two lakes, though geographically and morphologically similar, represent distinct hydrochemical facies. These data also show a different response in each lake to temperature and precipitation patterns in the basin that may be attributed to lake water retention time. The sensitivity of each lake to meteorological patterns can be used to understand the potential effects from long-term climate variability

Polymorphisms in the circadian expressed genes PER3 and ARNTL2 are associated with diurnal preference and GNβ3 with sleep measures

Sleep and circadian rhythms are intrinsically linked, with several sleep traits, including sleep timing and duration, influenced by both sleep homeostasis and the circadian phase. Genetic variation in several circadian genes has been associated with diurnal preference (preference in timing of sleep), although there has been limited research on whether they are associated with other sleep measurements. We investigated whether these genetic variations were associated with diurnal preference (Morningness-Eveningness Questionnaire) and various sleep measures, including: the global Pittsburgh Sleep Quality index score; sleep duration; and sleep latency and sleep quality. We genotyped 10 polymorphisms in genes with circadian expression in participants from the G1219 sample (n = 966), a British longitudinal population sample of young adults. We conducted linear regressions using dominant, additive and recessive models of inheritance to test for associations between these polymorphisms and the sleep measures. We found a significant association between diurnal preference and a polymorphism in period homologue 3 (PER3) (P < 0.005, recessive model) and a novel nominally significant association between diurnal preference and a polymorphism in aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) (P < 0.05, additive model). We found that a polymorphism in guanine nucleotide binding protein beta 3 (GNβ3) was associated significantly with global sleep quality (P < 0.005, recessive model), and that a rare polymorphism in period homologue 2 (PER2) was associated significantly with both sleep duration and quality (P < 0.0005, recessive model). These findings suggest that genes with circadian expression may play a role in regulating both the circadian clock and sleep homeostasis, and highlight the importance of further studies aimed at dissecting the specific roles that circadian genes play in these two interrelated but unique behaviours

Perspective of corporate governance and ethical issues with profit sharing investment accounts in Islamic banks

Purpose The purpose of this paper is to examine the practices of Islamic banks in managing the so-called profit sharing investment accounts (PSIA) which they offer as a Shari’ah-compliant alternative to interest-bearing deposit accounts using an unrestricted Mudarabah contract. In particular, the paper aims to examine the risk-return characteristics of such accounts and to compare these to the returns and risks of shareholders in the same banks. It is relevant that PSIA holders (unrestricted investment account holders – UIAH) are exposed to losses on the assets in which their deposits are invested, while the bank as asset manager (Mudarib) does not bear these losses and as Mudarib typically receives more than 50 per cent of the profits earned on the PSIA. The issue is whether the UIAH are being treated equitably. The influence of a set of corporate governance variables on this issue was also analyzed. Design/methodology/approach A sample of 28 Islamic banks was selected from five countries for the period 2002-2013, with data being obtained from Bankscope and Bloomberg and, where necessary, from the banks’ annual reports. First, the risk-return characteristics of the UIAHs’ rates of return and shareholders’ rates of return on equity (ROE) were compared by calculating for each bank the coefficients of variation (CV) of the two series of rates of return. Second, a panel data approach was used to evaluate the effectiveness of corporate governance by examining the extent to which the size of the difference between the rates of return for shareholders and for UIAH was associated with a set of corporate governance variables. Third, a comparison was made between the risk-return characteristics of UIAH’s rates of return and shareholders’ dividend yield rate for a sub-sample of 20 banks for which the information was available. Findings For a significant proportion of the banks (9 out of 28), the CVs of the PSIA returns were higher than those of the shareholders’ ROEs, which suggested that in these cases the PSIA holders were receiving inequitable treatment. Likewise, for 7 out of the 20 banks in the sub-sample, the CVs of the PSIA holders’ rates of return were higher than those of the shareholders’ dividend yield rate. In explaining the size of the differences between the rates of return on PSIA and the shareholders’ ROEs, the variable with the greatest explanatory power was the return on assets, implying that when this was high the bank took a maximum Mudarib share of profits. Some other corporate governance variables had the expected signs, as did a country dummy representing the maturity of the market for Islamic banking, but there was little evidence of the effectiveness of corporate governance in protecting the interests of the UIAH. Research limitations/implications A limitation of the research was that the inefficiency of the stock markets in the relevant countries and the fact that a few of the banks were not listed made it impossible to use shareholders’ stock market returns. ROE is not a very good proxy, as it is unclear how much value should be placed on retained earnings. Dividend yield rates provide a better comparison with UIAH rates of return, but the data were available for only 20 of the banks. Nevertheless, the results of the analysis strongly suggest that in a significant proportion of cases, UIAH are not being treated equitably. Practical implications The implication is that the regulation of Islamic banks needs to be improved to provide better protection to UIAH. Social implications Islamic banks operate mainly in emerging markets where the effectiveness of regulation is limited. The ethical basis of Islamic finance provides some mitigation of this problem but apparently fails to do so in a significant proportion of cases. This should be borne in mind when assertions are made about the ethical basis of Islamic finance. Originality/value There is a dearth of empirical studies of the practices of Islamic banks and in particular of their treatment of their customers. This is because of various factors: the relative novelty of Islamic finance, the paucity of data and the relatively small size of the body of researchers in the field. This paper aims to contribute to filling this gap

Association between somatic cell count early in the first lactation and the lifetime milk yield of cows in Irish dairy herds

Change in lifetime milk yield is an important component of the cost of diseases in dairy cows. Knowledge of the likelihood and scale of potential savings through disease prevention measures is important to evaluate how much expenditure on control measures is rational. The aim of this study was to assess the association between somatic cell count (SCC) at 5 to 30 d in milk during parity 1 (SCC1), and lifetime milk yield for cows in Irish dairy herds. The data set studied included records from 53,652 cows in 5,922 Irish herds. This was split into 2 samples of 2,500 and 3,422 herds at random. Linear models with lifetime milk yield and first-lactation milk yield as the outcomes and random effects to account for variation between herds were fitted to the data for the first sample of herds; data for the second sample were used for cross-validation. The models were developed in a Bayesian framework to include all uncertainty in posterior predictions and parameters were estimated from 10,000 Markov chain Monte Carlo simulations. The final model was a good fit to the data and appeared generalizable to other Irish herds. A unit increase in the natural logarithm of SCC1 was associated with a median decrease in lifetime milk yield of 864kg, and a median decrease in first-lactation milk yield of 105kg. To clarify the meaning of the results in context, microsimulation was used to model the trajectory of individual cows, and evaluate the expected outcomes for particular changes in the herd-level prevalence of cows with SCC1 ≥400,000cells/mL. Differences in mean lifetime milk yield associated with these changes were multiplied by an estimated gross margin for each cow to give the potential difference in milk revenue. Results were presented as probabilities of savings; for example, a 75% probability of savings of at least€97 or€115/heifer calved into the herd existed if the prevalence of cows with SCC1 ≥400,000cells/mL was reduced from ≥20 to <10 or <5%, respectively, and at least€71/heifer calved into the herd if the prevalence of cows with SCC1 ≥400,000cells/mL was reduced from ≥10 to <5%. The results indicate large differences in lifetime milk yield, depending on SCC early in the first lactation and the findings can be used to assess where specific interventions to control heifer mastitis prepartum are likely to be cost effective. Key words: dairy heifer, somatic cell count, lifetime milk yiel