An exploration of the accentuation effect: errors in memory for voice fundamental frequency (F0) and speech rate

The accentuation effect demonstrates how memory often reflects category typical representations rather than the specific features of learned items. The present study investigated the impact of manipulating fundamental frequency (F0) and speech rate (syllables per second) on immediate target matching performance (selecting a voice from a pair to match a previously heard target voice) for a range of synthesised voices. It was predicted that when participants were presented with high or low frequency target voices, voices even higher or lower in frequency would be selected. The same pattern was also predicted for speech rate. Inconsistent with the accentuation account, the results showed a general bias to select voices higher in frequency for high, moderate, and low frequency target voices. For speech rate, listeners selected voices faster in rate for slow rate target voices. Overall it seems doubtful that listeners rely solely on categorical information about voices during recognition

The pathology of tuberculosis, caused by mycobacterium tuberculosis, in a herd of semi free-ranging springbok (Antidorcas marsupialis)

This first detailed description of the pathology of tuberculosis, caused by Mycobacterium tuberculosis in springbok is reported. The springbok were part of a semi free-ranging herd kept on the grounds of iThemba Laboratory for Accelerator Based Science (LABS) in the Kuils River district of the Western Cape Province, South Africa. Of the 33 animals sampled, two animals had tuberculosis lesions. Mycobacterium tuberculosis was isolated from these two animals, as well as an animal that did not show tuberculosis pathology. The index case was an adult ewe that was presented for necropsy in a severely weakened condition. The ewe showed advanced miliary tuberculosis with marked macroscopic lesions in the lungs, pleura and respiratory lymph nodes. Limited sampling was done but microscopic tuberculosis lesions were found in almost all the organs sampled, and acid-fast bacilli were generally numerous. Six healthy rams were culled nine months later and a pilot study indicated miliary tuberculosis lesions in one ram, which again were macroscopically most prominent in the lungs, pleura and respiratory lymph nodes. Macroscopic lesions were also noted in the sternal, iliac, prefemoral and retropharyngeal lymph nodes. Microscopy in this animal revealed lesions in the macroscopically affected organs as well as numerous other lymph nodes, and suspected lesions occurred in the testicle and colon. Acid-fast bacilli were scarce to moderate in affected organs. Because of the miliary nature of the lesions in both affected animals, the route of infection could not be established conclusively. The lesions in most affected organs of both animals resembled classical tuberculous granulomas, viz. central caseous necrosis, with various degrees of calcification, surrounded by various numbers macrophages, epithelioid cells, multinucleated giant cells and lymphoplasmacells, and mild to moderate fibrous encapsulation. Necrotic lesions in the spleen, liver and kidney of the ewe were more disseminate and coagulative. A main study conducted on healthy culled animals 19 months after the pilot study failed to find any animal with tuberculosis lesions in the group of 25 sampled. These animals were all negative for mycobacteria via mycobacterial culture. The Interferon-gamma (INFg) assay was performed on all the animals of the pilot and main study but failed to identify the culture-positive animals and showed one false-positive reaction.Dissertation (MMedVet (Pathology))--University of Pretoria, 2007.Paraclinical Sciencesunrestricte

Differential Haemoparasite Intensity between Black Sparrowhawk (Accipiter melanoleucus) Morphs Suggests an Adaptive Function for Polymorphism

Recent research suggests that genes coding for melanin based colouration may have pleiotropic properties, in particular conveying raised immune function. Thus adaptive function of polymorphism may be associated with parasite resistance. The black sparrowhawk Accipiter melanoleucus is a polymorphic raptor with two morphs. Over most of its range the light morph is commonest, however within the recently colonised Western Cape of South Africa the dark morph predominates. The species breeds in winter throughout South Africa, however unlike in the rest of the species' South African range, the Western Cape experiences a winter rainfall regime, where arthropod vectors which transmit haematozoan parasites may be more abundant. We hypothesise that the higher frequency of dark morph birds in this region may be due to their improved parasite resistance, which enables them to cope with higher parasite pressure. If so, we predict that dark morph black sparrowhawks would have lower parasite burdens than light morph birds. Within our population the prevalence of the two most common haematozoan parasites was high, with 72% of adults infected with Haemoproteus nisi and 59% of adults infected with Leucocytozoon toddi. We found no difference in prevalence for either parasite between adult morphs, or between chicks of different parental morphs. However, within adults infected with H. nisi, infection intensity was significantly higher in light morphs than dark morphs. This suggests that dark morphs have lower parasite loads than light morphs due to resistance rather than morph-specific habitat exploitation. Greater resistance to Haemoproteus parasites may therefore be one of the mechanisms through which dark morph black sparrowhawks have a selective advantage in this region and may explain why they are most common in our study area. In other regions, the cost to benefit ratio may be in favour of the light morph, where parasites are less abundant or virulent

Diagnosing childhood pulmonary tuberculosis using a single sputum specimen on Xpert MTB/RIF at point of care

Background. The GeneXpert MTB/RIF (Cepheid, USA) (Xpert) has proved successful for pulmonary  tuberculosis (TB) diagnosis on decontaminated/concentrated induced sputum specimens from children.  Capacity to perform induction in many settings is limited.Objective. To assess: (i) volumes of ‘routinely obtained’ sputum in a district-level academic hospital; (ii) whether sputum specimens not meeting Xpert-required testing volumes could still be tested; and (iii) performance of Xpert on a single paediatric sputum specimen at point of care (POC).Methods. Two sputa were collected from paediatric TB suspects (≤14 years) at Rahima Moosa Mother and Child Hospital, Johannesburg, South Africa. One specimen was weighed at POC; if the volume was  ≥0.1 mL but <0.5 mL, it was increased to 0.5 mL using saline. On-site Xpert testing (G3 cartridge) was performed by a dedicated laboratory technician. The second specimen was referred for TB smear microscopy and culture as per standard of care (SOC).Results. A total of 484 patients presumed to have TB (median age 24 months) were eligible for this  study, performed between June 2011  and May 2012. Xpert could not be used on 4.1% of specimens because of volumes <0.1 mL, and 62.8% required addition of saline prior to Xpert testing. Xpert  generated a 2.2% error and 3.7% invalid rate, compared with the SOC that rejected 2.3% because of insufficient volume and 2.3% that were contaminated. The diagnostic performance compared with culture was 62.5% (95% confidence interval (CI) 24.7 - 91) and 99.1% (95% CI 97.4 - 99.8) sensitivity and specificity, respectively, for Xpert (n=345) and 33.3% (7.9 - 69.9) and 99.5% (98.1 - 99.9) sensitivity and specificity, respectively, for smear microscopy (n=374).Conclusions. Up to 67% of ‘routinely obtained’ sputum specimens from children (≤14 years) are below the required volume for Xpert testing but can be ‘topped up’ with saline. Xpert MTB/RIF performed better than microscopy and generated clinically relevant, timeous results, but sensitivity did not reach the  same levels as culture in children

Investigating the need for therapeutic drug monitoring of imipenem in critically ill patients: Are we getting it right?

Background. The drug levels and clearances of imipenem in critically ill patients are not comprehensively described in current literature, yet it is vital that adequate levels be achieved for therapeutic success.Objectives. To determine the proportion of critically ill patients treated with imipenem/cilastatin with sub-therapeutic imipenem plasma levels, and to compare the clinical outcomes of those patients with therapeutic levels with those who had sub-therapeutic levels.Methods. Trough imipenem plasma levels of 68 critically ill patients from a surgical intensive care unit were measured using a validated high-performance liquid chromatography method. Imipenem trough levels were compared with the minimum inhibitory concentration (MIC) of the causative bacterial agents, based on a target value of 100% time above MIC (¦T >MIC).Results. The proportion of participants with sub-therapeutic imipenem levels was 22% (95% confidence interval (CI) 13% - 34%). The 14- and 28-day mortality rates in the sub-therapeutic group were 33% and 40%, respectively, compared with 19% (p=0.293) and 26% (p=0.346), respectively, in the therapeutic group. Sub-therapeutic imipenem plasma levels are associated with adjusted hazard ratio of 1.47 (95% CI 0.55 - 3.91).Conclusions. The lower proportion of critically ill patients with sub-therapeutic imipenem plasma levels in this study compared with previous studies may be attributed to the practice of higher dosages and the administration method of extended infusions of imipenem/cilastatin in our setting. The results demonstrate a trend of higher mortality in patients with sub-therapeutic imipenem levels, although the results were not statistically significant at this sample size.

Investigating the need for therapeutic drug monitoring of imipenem in critically ill patients: Are we getting it right?

Background. The drug levels and clearances of imipenem in critically ill patients are not comprehensively described in current literature, yet it is vital that adequate levels be achieved for therapeutic success. Objectives. To determine the proportion of critically ill patients treated with imipenem/cilastatin with sub-therapeutic imipenem plasma levels, and to compare the clinical outcomes of those patients with therapeutic levels with those who had sub-therapeutic levels. Methods. Trough imipenem plasma levels of 68 critically ill patients from a surgical intensive care unit were measured using a validated high-performance liquid chromatography method. Imipenem trough levels were compared with the minimum inhibitory concentration (MIC) of the causative bacterial agents, based on a target value of 100% time above MIC (ƒT >MIC). Results. The proportion of participants with sub-therapeutic imipenem levels was 22% (95% confidence interval (CI) 13% - 34%). The 14- and 28-day mortality rates in the sub-therapeutic group were 33% and 40%, respectively, compared with 19% (p=0.293) and 26% (p=0.346), respectively, in the therapeutic group. Sub-therapeutic imipenem plasma levels are associated with adjusted hazard ratio of 1.47 (95% CI 0.55 - 3.91). Conclusions. The lower proportion of critically ill patients with sub-therapeutic imipenem plasma levels in this study compared with previous studies may be attributed to the practice of higher dosages and the administration method of extended infusions of imipenem/ cilastatin in our setting. The results demonstrate a trend of higher mortality in patients with sub-therapeutic imipenem levels, although the results were not statistically significant at this sample size

Goat Genomic Resources: The Search for Genes Associated with Its Economic Traits

Goat plays a crucial role in human livelihoods, being a major source of meat, milk, fiber, and hides, particularly under adverse climatic conditions. The goat genomics related to the candidate gene approach is now being used to recognize molecular mechanisms that have different expressions of growth, reproductive, milk, wool, and disease resistance. The appropriate literature on this topic has been reviewed in this article. Several genetic characterization attempts of different goats have reported the existence of genotypic and morphological variations between different goat populations. As a result, different whole-genome sequences along with annotated gene sequences, gene function, and other genomic information of different goats are available in different databases. The main objective of this review is to search the genes associated with economic traits in goats. More than 271 candidate genes have been discovered in goats. Candidate genes influence the physiological pathway, metabolism, and expression of phenotypes. These genes have different functions on economically important traits. Some genes have pleiotropic effect for expression of phenotypic traits. Hence, recognizing candidate genes and their mutations that cause variations in gene expression and phenotype of an economic trait can help breeders look for genetic markers for specific economic traits. The availability of reference whole-genome assembly of goats, annotated genes, and transcriptomics makes comparative genomics a useful tool for systemic genetic upgradation. Identification and characterization of trait-associated sequence variations and gene will provide powerful means to give positive influences for future goat breeding program

Predicted optimum ambient temperatures for broiler chickens to dissipate metabolic heat do not affect performance or improve breast muscle quality

<p></p><p>An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality.</p><p>The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment.</p><p>There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen.</p><p>Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology.</p><p>It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative.</p><p></p> <p>An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality.</p> <p>The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment.</p> <p>There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen.</p> <p>Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology.</p> <p>It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative.</p

Marker-assisted introgression of broad-spectrum blast resistance genes into the cultivated MR219 rice variety

Background: The rice cultivar MR219 is famous for its better yield and long and fine grain quality; however, it is susceptible to blast disease. The main objective of this study was to introgress blast resistance genes into MR219 through marker-assisted selection (MAS). The rice cultivar MR219 was used as the recurrent parent, and Pongsu Seribu 1 was used as the donor. Results: Marker-assisted foreground selection was performed using RM6836 and RM8225 to identify plants possessing blast resistance genes. Seventy microsatellite markers were used to estimate recurrent parent genome (RPG) recovery. Our analysis led to the development of 13 improved blast resistant lines with Piz, Pi2 and Pi9 broad-spectrum blast resistance genes and an MR219 genetic background. The RPG recovery of the selected improved lines was up to 97.70% with an average value of 95.98%. Selected improved lines showed a resistance response against the most virulent blast pathogen pathotype, P7.2. The selected improved lines did not express any negative effect on agronomic traits in comparison with MR219. Conclusion: The research findings of this study will be a conducive approach for the application of different molecular techniques that may result in accelerating the development of new disease-resistant rice varieties, which in turn will match rising demand and food security worldwide. © 2016 Society of Chemical Industry

Evaluating the usefulness of the estimated glomerular filtration rate for determination of imipenem dosage in critically ill patients

BACKGROUND. Antibiotic dosing in critically ill patients is complicated by variations in the pharmacokinetics of antibiotics in this group. The dosing of imipenem/cilastatin is usually determined by severity of illness and renal function. OBJECTIVES. To determine the correlation between estimated glomerular filtration rates (eGFRs) calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and imipenem trough levels in critically ill patients. METHODS. This prospective observational study was done in the surgical intensive care unit (ICU) at Steve Biko Academic Hospital, Pretoria, South Africa. Imipenem trough levels were measured by high-performance liquid chromatography and compared with eGFRs calculated with the CKD-EPI equation. Correlation was evaluated by the Pearson product-moment correlation coefficient. RESULTS. The study population consisted of 68 critically ill patients aged between 18 and 81 years; 43 (63%) were male, and the mean weight was 78 kg (range 40 - 140). On admission, 30 patients (44%) had sepsis, 16 (24%) were admitted for trauma, and 22 (32%) were admitted for miscellaneous surgical conditions. Acute Physiology and Chronic Health Evaluation II (APACHE II) scores ranged from 4 to 39 (mean 18). The 28-day mortality rate was 29%. The mean albumin level was 16 g/L (range 7 - 25), the mean creatinine level 142 μmol/L (range 33 - 840), and the mean eGFR 91 mL/min/1.73 m2 (range 6 - 180). Imipenem trough levels ranged between 3.6 and 92.2 mg/L (mean 11.5). The unadjusted Pearson product-moment correlation coefficient between eGFR and imipenem trough level was –0.04 (p=0.761). CONCLUSION. Considering the high mortality rate of sepsis in ICUs and the rapid global increase in antimicrobial resistance, it is crucial to dose antibiotics appropriately. Owing to the variability of antibiotic pharmacokinetics in critically ill patients, this task becomes almost impossible when relying on conventional dosing guidelines. This study found that eGFRs do not correlate with imipenem blood levels in critically ill patients and should not be used to determine the dose of imipenem/cilastatin. Instead, the dose should be individualised for patients through routine therapeutic drug monitoring.A Federation of Infectious Diseases Societies of South Africa-GlaxoSmithKline Research Fellowship.http://www.samj.org.zadm2022Critical CareMedical Microbiolog