K S Krishnan’s 1948 perception of the sampling theorem

K S Krishnan discovered in 1948 that the sum over samples of a band-limited function gives the value of the integral of the function exactly, provided the sampling interval does not exceed a threshold value. This result of Krishnan is shown to be equivalent to the Shannon sampling theorem.     

Families Created by Egg Donation: Parent–Child Relationship Quality in Infancy

Increasing numbers of children are being born through egg donation and thus do not share a genetic relationship with their mother. Parent–infant relationship quality was examined in 85 egg donation families and a comparison group of 65 in vitro fertilization families (infant M = 11 months). Standardized interview and observational measures were used to assess mother–infant and father–infant relationship quality at the representational and behavioral levels. Few differences were found between family types in parents’ representations of the parent–infant relationship. Differences were found between family types in the observational assessment of mother–infant relationship quality, indicating less optimal interactions in egg donation families. Findings suggest that egg donation families function well in infancy overall, but there may be subtle yet meaningful differences in mother–infant interaction quality.     

Investigating populations via penguins and their poo!

We describe an activity that introduces students to population modelling, enables them to use estimates obtained from a sample to infer back to the population, and understands how the findings are translatable via penguins and their poo!     

An examination of achievement-related behavior of high- and low-achieving inner-city pupils

Incorporating the academic engaged time model, the present study investigated behavioral differences between high- and low-achieving inner-city children. Two hundred observations of “on-task”-“off task” behavior of 136 children within the elementary grades (1 through 6) were noted during reading and mathematics lessons. Findings suggested that high- and low-achieving inner-city children spend a large proportion of time actively engaged in academic tasks, with high achievers spending somewhat more time than low achievers. No significant developmental trends were noted, and discrepant academic attainment levels of children are discussed in terms of an “academic learning time” model.     

Anthropometric dimensions of male powerlifters of varying body mass

In this study, we examined the anthropometric dimensions of powerlifters across various body mass (competitive bodyweight) categories. Fifty-four male Oceania competitive powerlifters (9 lightweight, 30 middleweight, and 15 heavyweight) were recruited from one international and two national powerlifting competitions held in New Zealand. Powerlifters were assessed for 37 anthropometric dimensions by ISAK (International Society for the Advancement of Kinanthropometry) level II and III accredited anthropometrists. The powerlifters were highly mesomorphic and had large girths and bony breadths, both in absolute units and when expressed as Z(p)-scores compared through the Phantom (Ross & Wilson, 1974). These anthropometric characteristics were more pronounced in heavyweights, who were significantly heavier, had greater muscle and fat mass, were more endo-mesomorphic, and had larger girths and bony breadths than the lighter lifters. Although middleweight and heavyweight lifters typically had longer segment lengths than the lightweights, all three groups had similar Zp-scores for the segment lengths, indicating similar segment length proportions. While population comparisons would be required to identify any connection between specific anthropometric dimensions that confer a competitive advantage to the expression of maximal strength, anthropometric profiling may prove useful for talent identification and for the assessment of training progression in powerlifting.     

Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.     

Perpetrators and their acts: data from 365 adults molested as children

Intake interviews were analyzed from 365 adults molested as children (AMACs). The AMACs were entering treatment at the Child Sexual Abuse Treatment Program (San Jose, CA). This study presents data on the relationship of the perpetrator to the victim, and whether most molestations include intercourse. The majority of the perpetrators (62%) were either biological fathers or father-surrogates. Ninety-nine percent of the perpetrators were known to the victim; 97% were male. As in past studies, fondling from the waist down was the most common type of molestation, occurring in 92% of the cases. Forty-four percent of cases included intercourse. The present findings are compared with past research and are discussed in the context of common misconceptions associated with child sexual abuse.