Genetic gains in early maturing maize hybrids developed by the International Maize and Wheat Improvement Center in Southern Africa during 2000-2018.

Genetic gain estimation in a breeding program provides an opportunity to monitor breeding efficiency and genetic progress over a specific period. The present study was conducted to (i) assess the genetic gains in grain yield of the early maturing maize hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) Southern African breeding program during the period 2000-2018 and (ii) identify key agronomic traits contributing to the yield gains under various management conditions. Seventy-two early maturing hybrids developed by CIMMYT and three commercial checks were assessed under stress and non-stress conditions across 68 environments in seven eastern and southern African countries through the regional on-station trials. Genetic gain was estimated as the slope of the regression of grain yield and other traits against the year of first testing of the hybrid in the regional trial. The results showed highly significant (p< 0.01) annual grain yield gains of 118, 63, 46, and 61 kg ha-1 year-1 under optimum, low N, managed drought, and random stress conditions, respectively. The gains in grain yield realized in this study under both stress and non-stress conditions were associated with improvements in certain agronomic traits and resistance to major maize diseases. The findings of this study clearly demonstrate the significant progress made in developing productive and multiple stress-tolerant maize hybrids together with other desirable agronomic attributes in CIMMYT's hybrid breeding program.

LED lighting for improving trip object detection for a walk-thru roof bolter.

Proper lighting plays a critical role in enabling miners to detect hazards when operating a roof bolter, one of the most dangerous mining machines to operate; however, there has not been any lighting research to address the walk-thru type of roof bolter commonly used today. To address this, the Saturn light was designed to directly address walk-thru roof bolter safety by improving trip hazard illumination. The visual performances of 30 participants that comprised three age groups were quantified by measuring each participant's visual performance in detecting trip objects positioned on the two floor locations within the machine's interior working space. The lighting conditions were the existing compact fluorescent lights (CFLs) and the Saturn LED area light developed by NIOSH researchers. Three intensities of the Saturn lights were used, 100%, 75%, and 50%, all of which resulted in better visual performance, and up to a 48% reduction in average trip detection time compared to the CFL. For the Saturn trip object miss rates were <0.5% for all age groups in contrast to the CFL, which ranged between 32.5% for the youngest group and 50.4% for the oldest group.

Prevalence of pain flashbacks in posttraumatic stress disorder arising from exposure to multiple traumas or childhood traumatization.

BACKGROUND: Flashbacks are a form of multisensory memory that are experienced with a "happening in the present" quality. Pain flashbacks are a re-experiencing of pain felt at the time of a traumatic event. It is unclear how common pain flashbacks are. AIMS: The current study was designed primarily to assess the prevalence of pain flashbacks in a sample of patients with posttraumatic stress disorder (PTSD). METHODS: We assessed the prevalence of pain flashbacks over a period of 2 years in patients (n = 166) referred to a psychological trauma service in the UK. Patients underwent a clinical screen for PTSD and completed a self-report measure of pain flashbacks. RESULTS: Pain flashbacks were classified as present in 49% of a sample of complex trauma patients meeting criteria for PTSD. Pain flashbacks were positively associated with the extent of pain at the time of trauma. CONCLUSIONS: Pain re-experiencing in PTSD, and its relative absence in nonclinical populations, supports an account of memory in which perceptual details can be re-experienced when memories have been encoded under conditions of extreme stress. It may be possible to conceptualize some cases of unexplained pain as pain flashbacks or of having a trauma origin.

Contexte: Les flashbacks sont une forme de souvenir multisensoriel qui se manifeste en donnant l'impression de se dérouler dans le présent. Les flashbacks douleureux sont une reviviscence de la douleur ressentie au moment d'un évènement traumatique. On ne sait pas à quel point les flashbacks douleureux sont communs.But: La présente étude a été conçue principalement pour évaluer la prévalence des flashbacks douleureux au sein d'un échantillons de patients souffrant d'un trouble de stress post-traumatique (TSPT).Méthodes: Nous avons évalué la prévalence des flashbacks douleureux sur une période de deux ans chez des patients (n = 166) référés à un service spécialisé dans les traumstismes psychologiques en Grande-Bretagne. Les patients ont été soumis à un dépistage du TSPT et ont répondu à un questionnaire portant sur les flashbacks douleureux.Résultats: Les flashbacks douleureux étaient présents chez 49 % des participants d'un échantillon complexe de patients souffrant de traumatismes qui répondaient aux critères pour le TSPT. Une association positive a été observée entre les flashbacks douleureux et le degré de douleur ressenti au moment du traumatisme.Conclusions: La reviviscence de la douleur dans les cas de TSPT et son absence relative au sein de populations non cliniques semblent démontrer que les détails perceptuels d'un souvenir peuvent être revécus lorsqu'ils ont été encodés dans des conditions de stress extrême. Certains cas de douleur inexpliquée peuvent être considérés comme des flashbacks douleureux, ou comme ayant une origine traumatique.

Earth-tide-induced fluctuations in the salinity of an inland river, New South Wales, Australia: a short-term study.

Wybong Creek discharges salts into the agriculturally and industrially important Hunter River in New South Wales, Australia. Abrupt increases in salinity occur periodically in the mid-Wybong Creek catchment. In order to understand the processes which cause these abrupt increases, changes in surface and groundwater were investigated. It is shown that salinity increases can be attributed to highly discrete groundwater discharge directly into the river from below. Hourly electrical conductivity data measured in the river showed regular, diurnal electrical conductivity fluctuations of up to 350 µS cm-1. These fluctuations could not be attributed to barometric pressure, temperature, or evapotranspiration. Instead, a similar periodicity in surface water electrical conductivity and groundwater height in nearby groundwater wells was found. Fluctuations were of similar periodicity to the orthotides which cause fluctuations in surface water height and are induced by Earth tides. The geology in the mid-catchment area indicates conditions are optimal for Earth tides to impact groundwater. The reporting of orthotidal changes in water chemistry in this article is believed to be the first of its kind in the scientific literature, with the large fluctuations noted having important implications for water monitoring and management in the catchment. Further research investigating Earth-tide-induced phases of groundwater heights will better constrain the relationships between surface water chemistry and groundwater height.

Genetic analysis of tropical quality protein maize (Zea mays L.) germplasm.

Maize (Zea mays L.) is an important source of carbohydrates and protein in the diet in sub-Saharan Africa. The objectives of this study were to (i) estimate general (GCA) and specific combining abilities (SCA) of 13 new quality protein maize (QPM) lines in a diallel under stress and non-stress conditions, (ii) compare observed and predicted performance of QPM hybrids, (iii) characterize genetic diversity among the 13 QPM lines using single nucleotide polymorphism (SNP) markers and assess the relationship between genetic distance and hybrid performance, and (iv) assess diversity and population structure in 116 new QPM inbred lines as compared to eight older tropical QPM lines and 15 non-QPM lines. The GCA and SCA effects were significant for most traits under optimal conditions, indicating that both additive and non-additive genetic effects were important for inheritance of the traits. Additive genetic effects appeared to govern inheritance of most traits under optimal conditions and across environments. Non-additive genetic effects were more important for inheritance of grain yield but additive effects controlled most agronomic traits under drought stress conditions. Inbred lines CKL08056, CKL07292, and CKL07001 had desirable GCA effects for grain yield across drought stress and non-stress conditions. Prediction efficiency for grain yield was highest under optimal conditions. The classification of 139 inbred lines with 95 SNPs generated six clusters, four of which contained 10 or fewer lines, and 16 lines of mixed co-ancestry. There was good agreement between Neighbor Joining dendrogram and Structure classification. The QPM lines used in the diallel were nearly uniformly spread throughout the dendrogram. There was no relationship between genetic distance and grain yield in either the optimal or stressed environments in this study. The genetic diversity in mid-altitude maize germplasm is ample, and the addition of the QPM germplasm did not increase it measurably.

Contrasting Influences of Geographic Range and Distribution of Populations on Patterns of Genetic Diversity in Two Sympatric Pilbara Acacias.

The influence of geographic range on species persistence has long been of interest and there is a need for a better understanding of the genetic consequences for species with restricted distributions, particularly with the increasing rate of global species extinctions. However, the genetic effects of restricted range are often confounded by the impacts of population distribution. We compared chloroplast and nuclear genetic diversity and differentiation in two acacias, the restricted, patchily distributed Acacia atkinsiana and the widespread, semi-continuously distributed A. ancistrocarpa. Lower intra-population diversity and higher differentiation between populations were seen in A. atkinsiana compared to its widespread congener, A. ancistrocarpa. There was little evidence of geographical influences on population genetic structure in A. ancistrocarpa whereas A. atkinsiana exhibited nuclear genetic structure with isolation by distance, differentiation of near-coastal populations from those in the ranges, and differentiation of peripheral populations from those in the centre of the distribution. These results are consistent with expectations of the effect of geographic range and population distribution on genetic diversity, but indicate that distribution of populations rather than geographic range has influenced the observed genetic structure. The contrasting patterns observed here demonstrate that conservation approaches for species management and ecological restoration need to consider the distribution of populations in geographically restricted species.

Can Coarse Woody Debris Be Used for Carbon Storage in Open Grazed Woodlands?

Carbon dioxide off-setting policy in the agricultural sector is focused on manipulating the terrestrial carbon cycle by reafforestation and increasing the retention of carbon within agricultural soils. We quantified the amount of carbon stored in the living and dead biomass and the surface soils of a previously grazed woodland ecosystem. We demonstrate that modification of coarse woody debris management could potentially store 8 to 15 t C ha. This large carbon pool raises the prospect that appropriate management of temperate woodlands to retain coarse woody debris and increase its volume into the future could achieve increased landscape carbon storage.

Phylogeographic evidence for two mesic refugia in a biodiversity hotspot.

Phylogeographic studies of flora in species-rich south-western Australia point to complex evolutionary histories, reflecting patterns of persistence and resilience to climatic changes during the Pleistocene. We asked whether coastal areas of the mid-west and south, as well as granite outcrops and inland ranges, have acted as major refugia within this region during Pleistocene climatic fluctuations by analysing phylogeographic patterns in the shrub Calothamnus quadrifidus R.Br. (Myrtaceae). We determined variation in chloroplast DNA data for 41 populations across the geographic range. Relationships and major clades were resolved using parsimony and Bayesian analyses. We tested for demographic and spatial expansion of the major clades and estimated clade divergence dates using an uncorrelated, lognormal relaxed clock based on two conservative chloroplast mutation rates. Two distinct phylogeographic clades were identified showing divergence during the Pleistocene, consistent with other phylogeographic studies of south-west Australian flora, emphasising the impact of climatic oscillations in driving divergence in this landscape. The southern clade was more diverse, having higher haplotype diversity and greater genetic structure, while the northern clade showed evidence of fluctuation in population size. Regions of high haplotype diversity with adjacent areas of low diversity observed in each clade indicated the locations of two coastal refugia: one on the south coast and another along the mid-west coast. This is the first evidence for major Pleistocene refugia using chloroplast genetic data in a common, widespread species from this region.

Contemporary pollen-mediated gene immigration reflects the historical isolation of a rare, animal-pollinated shrub in a fragmented landscape.

Fragmentation is generally considered to have negative impacts on widespread outbreeders but impacts on gene flow and diversity in patchy, naturally rare, self-compatible plant species remain unclear. We investigated diversity, gene flow and contemporary pollen-mediated gene immigration in the rare, narrowly distributed endemic shrub Calothamnus quadrifidus ssp. teretifolius. This taxon occurs in an internationally recognized biodiversity hotspot subjected to recent human-induced fragmentation and the condition of the remnants ranges from intact to highly degraded. Using microsatellites, we found that inbreeding, historically low gene flow and significant population differentiation have characterized the genetic system of C. quadrifidus ssp. teretifolius. Inbreeding arises from self-pollination, a small amount of biparental inbreeding and significant correlation of outcross paternity but fecundity was high suggesting populations might have purged their lethals. Paternity analyses show that pollinators can move pollen over degraded and intact habitat but populations in both intact and degraded remnants had few pollen parents per seed parent and low pollen immigration. Genetic diversity did not differ significantly between intact and degraded remnants but there were signs of genetic bottlenecks and reduced diversity in some degraded remnants. Overall, our study suggests human-induced fragmentation has not significantly changed the mating system, or pollen immigration to, remnant populations and therefore genetic connectivity need not be the highest conservation priority. Rather, for rare species adapted to higher levels of inbreeding, conservation efforts may be best directed to managing intact habitats and ecosystem processes.

Rare case of cerebral MALToma presenting with stroke-like symptoms and seizures.

Mucosa-associated lymphoid tissue (MALT) cells are present in gastrointestinal mucosa but rarely found in the central nervous system (CNS). We describe an unusual and rare case of CNS MALT lymphoma in a patient presenting with stroke-like symptoms.

Predicting the external formation of callus tissues in oblique bone fractures: idealised and clinical case studies.

It is proposed that the external asymmetric formation of callus tissues that forms naturally about an oblique bone fracture can be predicted computationally. We present an analysis of callus formation for two cases of bone fracture healing: idealised and subject-specific oblique bone fractures. Plane strain finite element (FE) models of the oblique fractures were generated to calculate the compressive strain field experienced by the immature callus tissues due to interfragmentary motion. The external formations of the calluses were phenomenologically simulated using an optimisation style algorithm that iteratively removes tissue that experiences low strains from a large domain. The resultant simulated spatial formation of the healing tissues for the two bone fracture cases showed that the calluses tended to form at an angle equivalent to the angle of the oblique fracture line. The computational results qualitatively correlated with the callus formations found in vivo. Consequently, the proposed methods show potential as a means of predicting callus formation in pre-clinical testing.

Computational modelling of long bone fractures fixed with locking plates - How can the risk of implant failure be reduced?

BACKGROUND AND PURPOSE: The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled. METHODS: Upon validation, a finite element model of an LCP attached to a cylinder was developed to simulate and analyse the biomechanics of a transverse long bone fracture fixed with a locking plate. Of special interest were the factors influencing the mechanical conditions at the fracture site, the control of interfragmentary movement and implant failure. RESULTS: Several factors were shown to influence stability in compression. Increasing translation and/or fracture angle post fixation reduced construct stability. Axial stiffness was also influenced by the working length and plate-bone distance. The fracture gap had no effect on the construct stability when no bone contact occurred during loading. Stress analysis of the LCP demonstrated that the maximum Von Mises stresses were found in the innermost screws at the screw-head junction. INTERPRETATION: For the clinical use of the LCP as a locked internal fixator in fractures with an interfragmentary gap of 1 mm, at least two to four plate holes near the fracture gap should be omitted to allow fracture motion and bone contact to occur. This will also achieve a larger area of stress distribution on the plate and reduce the likelihood of fatigue failure due to cyclic loading.

Ataxia, ophthalmoplegia, and areflexia: what would you think?

We present here a case of carcinomatous meningitis presenting as Miller Fisher syndrome (MFS). There are four further cases described in the literature with evidence of tumour invasion within the central nervous system (CNS) shown either in cerebrospinal fluid examination or on histology. There are further five cases described in which an association between cancer and a Miller Fisher phenotype has been shown. Some of these have identified antiganglioside antibodies in the serum and, in one case, also showed antibodies deposited within the primary tumour itself. This raises a question as to whether there is a paraneoplastic form. It would be informative when further cases present in this way to histologically examine for malignant CNS invasion, and the presence of antiganglioside antibodies in both the malignant primary and areas of nervous system thought to be affected by MFS.

Predicting the external formation of a bone fracture callus: an optimisation approach.

The formation of a fracture callus in vivo tends to form in a structurally efficient manner distributing tissues where mechanical stimulus persists. Therefore, it is proposed that the formation of a fracture callus can be modelled in silico by way of an optimisation algorithm. This was tested by generating a finite element model of a transversal bone fracture embedded in a large tissue domain which was subjected to axial, bending and torsional loads. It was found that the relative fragment motion induced a compressive strain field in the early callus tissue which could be utilised to simulate the formation of external callus structures through an iterative optimisation process of tissue maintenance and removal. The phenomenological results showed a high level of congruence with in vivo healing patterns found in the literature. Consequently, the proposed strategy shows potential as a means of predicting spatial bone healing phenomena for pre-clinical testing.

The role of interfragmentary strain on the rate of bone healing-a new interpretation and mathematical model.

It is postulated that there is a causal relationship between mechanical stimulus and the rate of bone healing post fracture. However, despite numerous experimental studies in the literature, no quantifiable relationship has been proposed. It is hypothesized in the present study that the temporal rate of bone fracture healing, measured in terms of callus stiffening per week, can be described mathematically based on the relative motions between bone fragments at the initial stage of the healing process. To test this, a comparative reanalysis of experimental data found in the literature was conducted. These individual data sets described a relationship between an initial intermittently applied peak interfragmentary strain and the change in interfragmentary motion or the increase in callus stiffness over time. The data were converted into a relative increase in stiffness, which normalised the results and reduced inter-study variability. The rates of healing for the various initial strains were compared, and based on this a mathematical phenomenological model was derived. Error analyses were then performed, which showed a high level of congruence between the in-vivo and simulated rates of healing. The results of the comparative analysis revealed that there is a positive correlation between the rate of callus stiffening and interfragmentary strain. Finally, the proposed model has shown for the first time that a quantifiable cause-and-effect relationship exists between the rate of bone healing and mechanical stimulus.

Use of transilial pinning for the treatment of sacroiliac separation in 25 dogs and finite element analysis of repair methods.

A retrospective study of 25 cases of sacroiliac separation showed that transilial pinning is an effective method of repair for sacroiliac separations. Only 8% of cases of sacroiliac separation had transilial pinning as the sole surgical intervention as other concomitant minor injuries, such as fractured ischium or pubis, did not require surgery. Even though pin loosening and migration along with local soft tissue irritation occurred in all cases, 92% of the cases had 'good' or 'excellent' outcomes. Sacroiliac separation heals by fibrosis, not directly by bone healing, and therefore can heal sufficiently in four weeks to allow pain free weight bearing in four weeks. Additionally, finite element modelling was undertaken to analyse micro-movement of repaired sacroiliac separations. The micro-motion analysis showed that the lag screw fixation method was more stable than the transilial fixation method since the relative motion between the two indicated that the latter allowed more unsupported iliac movement.

School feeding for improving the physical and psychosocial health of disadvantaged elementary school children.

BACKGROUND: Early malnutrition and/or micronutrient deficiencies can adversely affect physical, mental, and social aspects of child health. School feeding programs are designed to improve attendance, achievement, growth, and other health outcomes. OBJECTIVES: The main objective was to determine the effectiveness of school feeding programs in improving physical and psychosocial health for disadvantaged school children. SEARCH STRATEGY: We searched a number of databases including CENTRAL (2006 Issue 2), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006), PsycINFO (1980 to May 2006) and CINAHL (1982 to May 2006). Grey literature sources were also searched. Reference lists of included studies and key journals were handsearched and we also contacted selected experts in the field. SELECTION CRITERIA: Data from randomized controlled trials (RCTs), non-randomised controlled clinical trials (CCTs), controlled before and after studies (CBAs), and interrupted time series studies (ITSs) were included. Feeding had to be done in school; the majority of participants had to be socio-economically disadvantaged. DATA COLLECTION AND ANALYSIS: Two reviewers assessed all searches and retrieved studies. Data extraction was done by one of four reviewers and reviewed by a second. Two reviewers independently rated quality. If sufficient data were available, they were synthesized using random effects meta-analysis, adjusting for clustering if needed. Analyses were performed separately for RCTs and CBAs and for higher and lower income countries. MAIN RESULTS: We included 18 studies. For weight, in the RCTs and CBAs from Lower Income Countries, experimental group children gained an average of 0.39 kg (95% C.I: 0.11 to 0.67) over an average of 19 months and 0.71 kg (95% C.I.: 0.48 to 0.95) over 11.3 months respectively. Results for weight were mixed in higher income countries. For height, results were mixed; height gain was greater for younger children. Attendance in lower income countries was higher in experimental groups than in controls; our results show an average increase of 4 to 6 days a year. Math gains were consistently higher for experimental groups in lower income countries; in CBAs, the Standardized Mean Difference was 0.66 (95% C.I. = 0.13 to 1.18). In short-term studies, small improvements in some cognitive tasks were found. AUTHORS' CONCLUSIONS: School meals may have some small benefits for disadvantaged children. We recommend further well-designed studies on the effectiveness of school meals be undertaken, that results should be reported according to socio-economic status, and that researchers gather robust data on both processes and carefully chosen outcomes.

Prenatal diagnosis of horseshoe kidney by measurement of the renal pelvic angle.

OBJECTIVE: The aim of this study was to evaluate the usefulness of measurement of the angle between bilateral renal pelves on axial views in the prenatal ultrasonographic diagnosis of horseshoe kidney. METHODS: We retrospectively measured the renal pelvic angle in 19 fetuses with horseshoe and 20 fetuses with normal kidneys in the second and third trimesters. Renal pelvic angle was defined as the angle between the long axis of the renal pelves on the axial view of the abdomen. We compared the renal pelvic angles of horseshoe and normal kidneys with unpaired t-test. Taking 140 degrees as a cut-off value, we calculated the sensitivity, specificity and accuracy of pelvic angle measurement for the prenatal diagnosis of horseshoe kidney. RESULTS: The mean pelvic angles in the fetuses with horseshoe kidney were 116 degrees and 110 degrees in the second and third trimester, respectively. In the normal fetuses, the equivalent angles were 172 degrees and 161 degrees. The difference between the two groups was statistically significant (P < 0.01). Using 140 degrees as the discriminating criterion, the sensitivity, specificity and accuracy of renal pelvic angle measurement for the prenatal diagnosis of horseshoe kidney were all 100%. Fifteen of 19 fetuses with horseshoe kidney had no other abnormality. Four (21%) fetuses had severe complex abnormalities which were associated with trisomy 18 in three cases. CONCLUSION: Observation and measurement of the renal pelvic angle is a simple and useful method in the prenatal diagnosis of the horseshoe kidney.

Increased Phase Synchronization between Intracranial Pressure and Arterial Blood Pressure during Elevated Intracranial Pressure in Dogs.

We applied the concept of "phase synchronization" from nonlinear dynamics to the complex relationship between intracranial pressure (ICP) and arterial blood pressure (ABP) signals. This method is based on multiresolution wavelet transform (MRWT) in which the signals are divided into different frequency bands. We examined ICP and ABP signals from anaesthetized dogs, exploring normal ICP and elevated ICP by 1~3 ml injection of saline into the cerebral ventricles. Phase synchronization analyses show an interesting phenomenon of phase reset from relatively uniform phase distribution to phase clustering around 0° after injection. To further quantitatively measure phase synchronization, phase coherence is used to distinguish the dynamics of normal ICP and elevated ICP by saline injection. Elevated ICP exhibits higher phase coherence than that of normal ICP. The results suggest that the association between ICP and ABP may involve nonlinear mechanisms of regulation. The clinical application of this method is in investigation.