A normative theory of accounting for Zimbabwe : a third world country

Accountants generally agree that accounting systems should harmonize with their environments and consequently it is commonly observed that Less Developed Countries (LOCs) should have systems different from those of the Western developed nations. The study constructs a normative accounting theory for Zimbabwe which accords with the aforementioned opinions. Further uniqueness occurs through the provision of a wholly generalizable paradigm for constructing explicit linkages between an environment and an accounting system. The paradigm is utilized firstly as an instrumental framework for the structured analysis of the extant literature, resulting in a morphology of environmental properties relevant to harmony with accounting, the revelation of varied accounting practices, and relationships existing between practices and environments. Subsequently, the paradigm is used as a puzzle-solution model for the development of the normative theory of accounting for Zimbabwe. Extensive argumentation supports the general environmental propositions, concepts of the firm, objectives, principles and fundamental practices constituting the normative theory. The major tenets of the theory, distilled from the LOC-type of environment; are that Zimbabwean companies should represent an amalgam of societal interests, dominated by controlling shareholders, employee representatives and government; and, that accounting should be concerned not only with portraying wealth, wealth creation, and wealth transfers but also with their societal equitableness. The resultant theory supports the cammon assertion that LDC accounting systems should be different fram those of developed nations. The practices presented are pragmatic and in many instances unconventional but deemed necessary to positively stimulate national development (cammon-wealth) and, to more fully satisfy the needs of decision-makers than conventional systems. The system's normative nature and detailed structure affords numerous opportunities for further (especially empirical) research

Adolescent methylphenidate treatment differentially alters adult impulsivity and hyperactivity in the Spontaneously Hypertensive Rat model of ADHD

Impulsivity and hyperactivity are two facets of attention deficit/hyperactivity disorder (ADHD). Impulsivity is expressed as reduced response inhibition capacity, an executive control mechanism that prevents premature execution of an intermittently reinforced behavior. During methylphenidate treatment, impulsivity and hyperactivity are decreased in adolescents with ADHD, but there is little information concerning levels of impulsivity and hyperactivity in adulthood after adolescent methylphenidate treatment is discontinued. The current study evaluated impulsivity, hyperactivity as well as cocaine sensitization during adulthood after adolescent methylphenidate treatment was discontinued in the Spontaneously Hypertensive Rat (SHR) model of ADHD. Treatments consisted of oral methylphenidate (1.5mg/kg) or water vehicle provided Monday-Friday from postnatal days 28-55. During adulthood, impulsivity was measured in SHR and control strains (Wistar Kyoto and Wistar rats) using differential reinforcement of low rate (DRL) schedules. Locomotor activity and cocaine sensitization were measured using the open-field assay. Adult SHR exhibited decreased efficiency of reinforcement under the DRL30 schedule and greater levels of locomotor activity and cocaine sensitization compared to control strains. Compared to vehicle, methylphenidate treatment during adolescence reduced hyperactivity in adult SHR, maintained the lower efficiency of reinforcement, and increased burst responding under DRL30. Cocaine sensitization was not altered following adolescent methylphenidate in adult SHR. In conclusion, adolescent treatment with methylphenidate followed by discontinuation in adulthood had a positive benefit by reducing hyperactivity in adult SHR rats; however, increased burst responding under DRL compared to SHR given vehicle, i.e., elevated impulsivity, constituted an adverse consequence associated with increased risk for cocaine abuse liability.P50 DA005312 - NIDA NIH HHS; R01 DA011716 - NIDA NIH HHS; P50 DA05312 - NIDA NIH HH

Effects of Environmental Conditions on c-fos Expression in Rat Nucleus Accumbens After Remifentanil

Previous studies have shown that adolescents raised in impoverished conditions are more likely to develop drug abuse in adulthood. In addition, both stress-inducing living conditions (impoverishment/isolation) and drugs of abuse may lead to an increase in the c-fos transcription factor in the reward circuit of the brain, particularly in the nucleus accumbens. The aim of the current study was to quantify the number of c-fos positive cells in the nucleus accumbens of enriched and isolated rats exposed to the opioid remifentanil. Thirty-two male Sprague-Dawley rats were raised in either enriched or isolated conditions for one month, after which they received 10 i.v. infusions of 3 μg/kg remifentanil or saline through the jugular vein. Eighty-five minutes after the last infusion, rats underwent perfusions. After immunohistochemistry was performed on tissue containing the nucleus accumbens, the average number of c-fos positive cells per slice was obtained using ImageJ. Using a 2x2 between subjects ANOVA, with drug and environment as factors, this research demonstrated a main effect of environment on c-fos expression in the nucleus accumbens, with isolated rats expressing more c-fos positive cells than enriched rats. However, there was no significant effect of drug treatment, suggesting that remifentanil did not increase total c-fos as expected. This study demonstrated the cellular consequences of being raised in different living conditions, as it showed that individuals raised under high levels of stress may be at risk of altered cell signaling and gene expression in the reward system of the brain

Modified Single Prolonged Stress Reduces Cocaine Self-Administration During Acquisition Regardless of Rearing Environment

Until recently, there were few rodent models available to study the interaction of post-traumatic stress disorder (PTSD) and drug taking. Like PTSD, single prolonged stress (SPS) produces hypothalamic-pituitary-adrenal (HPA) axis dysfunction and alters psychostimulant self-administration. Other stressors, such as isolation stress, also alter psychostimulant self-administration. However, it is currently unknown if isolation housing combined with SPS can alter the acquisition or maintenance of cocaine self-administration. The current study applied modified SPS (modSPS; two hours restraint immediately followed by cold swim stress) to rats raised in an isolation condition (Iso), enrichment condition (Enr), or standard condition (Std) to measure changes in cocaine self-administration and HPA markers. Regardless of rearing condition, rats exposed to modSPS had greater corticosterone (CORT) release and reduced cocaine self-administration during initial acquisition compared to non-stressed controls. In addition, during initial acquisition, rats that received both Iso rearing and modSPS showed a more rapid increase in cocaine self-administration across sessions compared to Enr and Std rats exposed to modSPS. Following initial acquisition, a dose response analysis showed that Iso rats were overall most sensitive to changes in cocaine unit dose; however, modSPS had no effect on the cocaine dose response curve. Further, there was no effect of either modSPS or differential rearing on expression of glucocorticoid receptor (GR) in hypothalamus, medial prefrontal cortex, amygdala, or nucleus accumbens. By using modSPS in combination with Iso housing, this study identified unique contributions of each stressor to acquisition of cocaine self-administration

Effects of Environmental Enrichment on Self-Administration of the Short-Acting Opioid Remifentanil in Male Rats

Background Opioid abuse is a major problem around the world. Identifying environmental factors that contribute to opioid abuse and addiction is necessary for decreasing this epidemic. In rodents, environmental enrichment protects against the development of low dose stimulant self-administration, but studies examining the effect of enrichment and isolation (compared to standard housing) on the development of intravenous opioid self-administration have not been conducted. The present study investigated the role of environmental enrichment on self-administration of the short-acting μ-opioid remifentanil. Methods Rats were raised in an enriched condition (Enr), standard condition (Std), or isolated condition (Iso) beginning at 21 days of age and were trained to lever press for 1 or 3 μg/kg/infusion remifentanil in young adulthood. Acquisition of self-administration and responding during increasing fixed ratio requirements were assessed, and a dose-response curve was generated. Results In all phases, Enr rats lever pressed significantly less than Std and Iso rats, with Enr rats pressing between 9 and 40% the amount of Iso rats. Enr rats did not acquire remifentanil self-administration when trained with 1 μg/kg/infusion, did not increase responding over increasing FR when trained at either dose, and their dose-response curves were flattened compared to Std and Iso rats. When expressed as economic demand curves, Enr rats displayed a decrease in both essential value (higher α) and reinforcer intensity (Q0) compared to Std and Iso rats at the 1 μg/kg/infusion training dose. Conclusion Environmental enrichment reduced remifentanil intake, suggesting that social and environmental novelty may protect against opioid abuse

Motor-sensory biases are associated with cognitive and social abilities in humans

Across vertebrates, adaptive behaviors, like feeding and avoiding predators, are linked to lateralized brain function. The presence of the behavioral manifestations of these biases are associated with increased task success. Additionally, when an individual’s direction of bias aligns with the majority of the population, it is linked to social advantages. However, it remains unclear if behavioral biases in humans correlate with the same advantages. This large-scale study (N = 313–1661, analyses dependent) examines whether the strength and alignment of behavioral biases associate with cognitive and social benefits respectively in humans. To remain aligned with the animal literature, we evaluate motor-sensory biases linked to motor-sequencing and emotion detection to assess lateralization. Results reveal that moderate hand lateralization is positively associated with task success and task success is, in turn, associated with language fluency, possibly representing a cascade effect. Additionally, like other vertebrates, the majority of our human sample possess a ‘standard’ laterality profile (right hand bias, left visual bias). A ‘reversed’ profile is rare by comparison, and associates higher self-reported social difficulties and increased rate of autism and/or attention deficit hyperactivity disorder. We highlight the importance of employing a comparative theoretical framing to illuminate how and why different laterization profiles associate with diverging social and cognitive phenotypes

Motor-sensory biases are associated with cognitive and social abilities in humans

Across vertebrates, adaptive behaviors, like feeding and avoiding predators, are linked to lateralized brain function. The presence of the behavioral manifestations of these biases are associated with increased task success. Additionally, when an individual’s direction of bias aligns with the majority of the population, it is linked to social advantages. However, it remains unclear if behavioral biases in humans correlate with the same advantages. This large-scale study (N = 313–1661, analyses dependent) examines whether the strength and alignment of behavioral biases associate with cognitive and social benefits respectively in humans. To remain aligned with the animal literature, we evaluate motor-sensory biases linked to motor-sequencing and emotion detection to assess lateralization. Results reveal that moderate hand lateralization is positively associated with task success and task success is, in turn, associated with language fluency, possibly representing a cascade effect. Additionally, like other vertebrates, the majority of our human sample possess a ‘standard’ laterality profile (right hand bias, left visual bias). A ‘reversed’ profile is rare by comparison, and associates higher self-reported social difficulties and increased rate of autism and/or attention deficit hyperactivity disorder. We highlight the importance of employing a comparative theoretical framing to illuminate how and why different laterization profiles associate with diverging social and cognitive phenotypes

From fossils to mind

Fossil endocasts record features of brains from the past: size, shape, vasculature, and gyrification. These data, alongside experimental and comparative evidence, are needed to resolve questions about brain energetics, cognitive specializations, and developmental plasticity. Through the application of interdisciplinary techniques to the fossil record, paleoneurology has been leading major innovations. Neuroimaging is shedding light on fossil brain organization and behaviors. Inferences about the development and physiology of the brains of extinct species can be experimentally investigated through brain organoids and transgenic models based on ancient DNA. Phylogenetic comparative methods integrate data across species and associate genotypes to phenotypes, and brains to behaviors. Meanwhile, fossil and archeological discoveries continuously contribute new knowledge. Through cooperation, the scientific community can accelerate knowledge acquisition. Sharing digitized museum collections improves the availability of rare fossils and artifacts. Comparative neuroanatomical data are available through online databases, along with tools for their measurement and analysis. In the context of these advances, the paleoneurological record provides ample opportunity for future research. Biomedical and ecological sciences can benefit from paleoneurology's approach to understanding the mind as well as its novel research pipelines that establish connections between neuroanatomy, genes and behavior

Gonad shielding in paediatric pelvic radiography: disadvantages prevail over benefit

Objective To re-evaluate gonad shielding in paediatric pelvic radiography in terms of attainable radiation risk reduction and associated loss of diagnostic information. Methods A study on patient dose and the quality of gonad shielding was performed retrospectively using 500 pelvic radiographs of children from 0 to 15 years old. In a subsequent study, 195 radiographs without gonad shielding were included. Patient doses and detriment adjusted risks for heritable disease and cancer were calculated with and without gonad shielding. Results For girls, gonad shields were placed incorrectly in 91% of the radiographs; for boys, in 66%. Without gonad shielding, the hereditary detriment adjusted risk for girls ranged between 0.1?×?10?6 and 1.3?×?10?6 and for boys between 0.3?×?10?6 and 3.9?×?10?6, dependent on age. With shielding, the reduction in hereditary risk for girls was on average 6?±?3% of the total risk of the radiograph, for boys 24?±?6%. Without gonad shielding, the effective dose ranged from 0.008 to 0.098 mSv. Conclusions With modern optimised X-ray systems, the reduction of the detriment adjusted risk by gonad shielding is negligibly small. Given the potential consequences of loss of diagnostic information, of retakes, and of shielding of automatic exposure-control chambers, gonad shielding might better be discontinued.Support TNWApplied Science

Pre- and Posttranslational Regulation of Β-Endorphin Biosynthesis in the CNS: Effects of Chronic Naltrexone Treatment

There appear to be two anatomically distinct Β-endorphin (ΒE) pathways in the brain, the major one originating in the arcuate nucleus of the hypothalamus and a smaller one in the area of the nucleus tractus solitarius (NTS) of the caudal medulla. Previous studies have shown that these two proopiomelanocortin (POMC) systems may be differentially regulated by chronic morphine treatment, with arcuate cells down-regulated and NTS cells unaffected. In the present experiments, we examined the effects of chronic opiate antagonist treatment on ΒE biosynthesis across different CNS regions to assess whether the arcuate POMC system would be regulated in the opposite direction to that seen after opiate agonist treatment and to determine whether different ΒE-containing areas might be differentially regulated. Male adult rats were administered naltrexone (NTX) by various routes for 8 days (subcutaneous pellets, osmotic minipumps, or repeated intraperitoneal injections). Brain and spinal cord regions were assayed for total ΒE-ir, different molecular weight immunoreactive Β-endorphin (ΒE-ir) peptides, and POMC mRNA. Chronic NTX treatment, regardless of the route of administration, reduced total ΒE-ir concentrations by 30–40% in diencephalic areas (the arcuate nucleus, the remaining hypothalamus, and the thalamus) and the midbrain, but had no effect on ΒE-ir in the NTS or any region of the spinal cord. At the same time, NTX pelleting increased POMC mRNA levels in the arcuate to ∼ 140% of control values. These data suggest that arcuate POMC neurons are up-regulated after chronic NTX treatment (whereas NTS and spinal cord systems remain unaffected) and that they appear to be under tonic inhibition by endogenous opioids. Chromatographic analyses demonstrated that, after chronic NTX pelleting, the ratio of full length ΒE 1–31 to more processed ΒE-ir peptides (i.e., ΒE 1–27 and ΒE 1–26 ) tended to increase in a dose-dependent manner in diencephalic areas. Because ΒE 1–31 is the only POMC product that possesses opioid agonist properties, and ΒE 1–27 has been posited to function as an endogenous anatgonist of ΒE 1–31 , the NTX-induced changes in the relative concentrations of ΒE 1–31 and ΒE 1–27 /ΒE 1–26 may represent a novel regulatory mechanism of POMC cells to alter the opioid signal in the synapse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65603/1/j.1471-4159.1993.tb05820.x.pd