Can Flow Cytometry Reduce the Workload For Cervical Screening? the Results of A Series of 622 Specimens

A simple method permitting the flow cytometric examination of cervical specimens has been developed and an assessment made of the feasibility of relying on this method to screen women for cervical neoplasia. Examination of four flow cytometric parameters showed differences between morphologically normal and abnormal specimens and allowed identification of a proportion of the normal specimens. The system had a false negative rate of 8%. Our experience with cervical specimens has revealed a number of problems associated with their examination by flow cytometry and these are discussed.     

Can Arbuscular Mycorrhizal Fungi Reduce the Growth of Agricultural Weeds?

Background

Arbuscular mycorrhizal fungi (AMF) are known for their beneficial effects on plants. However, there is increasing evidence that some ruderal plants, including several agricultural weeds, respond negatively to AMF colonization. Here, we investigated the effect of AMF on the growth of individual weed species and on weed-crop interactions.

Methodology/Principal Findings

First, under controlled glasshouse conditions, we screened growth responses of nine weed species and three crops to a widespread AMF, Glomus intraradices. None of the weeds screened showed a significant positive mycorrhizal growth response and four weed species were significantly reduced by the AMF (growth responses between −22 and −35%). In a subsequent experiment, we selected three of the negatively responding weed species – Echinochloa crus-galli, Setaria viridis and Solanum nigrum – and analyzed their responses to a combination of three AMF (Glomus intraradices, Glomus mosseae and Glomus claroideum). Finally, we tested whether the presence of a crop (maize) enhanced the suppressive effect of AMF on weeds. We found that the growth of the three selected weed species was also reduced by a combination of AMF and that the presence of maize amplified the negative effect of AMF on the growth of E. crus-galli.

Conclusions/Significance

Our results show that AMF can negatively influence the growth of some weed species indicating that AMF have the potential to act as determinants of weed community structure. Furthermore, mycorrhizal weed growth reductions can be amplified in the presence of a crop. Previous studies have shown that AMF provide a number of beneficial ecosystem services. Taken together with our current results, the maintenance and promotion of AMF activity may thereby contribute to sustainable management of agroecosystems. However, in order to further the practical and ecological relevance of our findings, additional experiments should be performed under field conditions.     

“Solution-Focused Risk Assessment”: A Proposal for the Fusion of Environmental Analysis and Action

For 30 years, more attention and resources have been expended on dissecting problems (risk assessment) than on evaluating actual solutions that reduce risks. The basic dogma holds that risk assessment must precede risk management. But there is an opposite and perhaps better way: the opening question should not be “How bad is the problem?” but “How good are the solutions we might apply to the problem?” Rethinking risk assessment in this context offers three classes of benefits over the status quo. First, it can help break the endless cycle of analysis: when the goal is to know enough to decide, rather than to know everything, natural stopping points emerge. Second, it can lead to more decisions that actually achieve risk reduction, rather than pronouncements about how much risk reduction would be optimal. Third, it can highlight ways to resolve multiple risks simultaneously, avoid needless and tragic risk-risk tradeoffs, and involve affected stakeholders in debating what should be done. Arguably, the longer the disembodied analysis of risk information is allowed to proceed, the more likely it is that the “problem” will be defined in a way that blunts the free-wheeling discussion of solutions, to the detriment of human health, the environment, and the economy.     

Inheritance of Chiari-Like Malformation: Can a Mixed Breeding Reduce the Risk of Syringomyelia?

Canine Chiari-like malformation (CM) is a complex abnormality of the skull and craniocervical junction associated with miniaturization and brachycephaly which can result in the spinal cord disease syringomyelia (SM). This study investigated the inheritance of CM in a Griffon Bruxellois (GB) family and feasibility of crossbreeding a brachycephalic CM affected GB with a mesaticephalic normal Australian terrier and then backcrossing to produce individuals free of the malformation and regain GB breed characteristics. The study family cohort (n = 27) included five founder dogs from a previous baseline study of 155 GB which defined CM as a global malformation of the cranium and craniocervical junction with a shortened skull base and increased proximity of the cervical vertebrae to the skull. T1-weighted sagittal DICOM images of the brain and craniocervical junction were analysed for five significant traits (two angles, three lines) identified from the previous study and subsequent Qualitative Trait Loci analysis. Mean measurements for mixed breed, pure-breed and baseline study groups were compared. Results indicated that mixed breed traits posed less risk for CM and SM and were useful to distinguish the phenotype. Moreover on the MR images, the filial relationships displayed by the traits exhibited segregation and those presenting the greatest risk for CM appeared additive towards the severity of the condition. The external phenotypes revealed that by outcrossing breed types and with careful selection of appropriate conformation characteristics in the first generation, it is possible to regain the GB breed standard and reduce the degree of CM. The four GB affected with SM in the study all exhibited reduced caudal skull development compared to their relatives. The craniocervical traits may be useful for quantifying CM and assessing the possibility of SM thus assisting breeders with mate selection. However, such a system requires validation to ensure appropriateness for all breeds at risk.     

Evolutionism and the Teaching of Science: How Portugal Has Been “Playing with the Big Tree of Evolution”

The concept of evolution is fundamental to the teaching of biological sciences. Nevertheless, it seems frequently neglected and/or forgotten in our classrooms and absent from the school syllabus. These difficulties are present today in the Portuguese educational system, especially concerning the issue of human evolution. To overcome this difficulty, a multidisciplinary pilot project entitled Playing with the Big Tree of Evolution was developed by a nonprofit association called Group of Studies in Human Evolution in Portuguese schools and in other public and private organizations. Combining non-formal and informal apprenticeship, the project is composed of a set of pedagogical and experimental activities that aim to promote the broad concept of human evolution as well as to demystify the anthropocentric perspective that places humans at the top of the chain of life.     

Can Clues from Evolution Unlock the Molecular Development of the Cerebellum?

The cerebellum sits at the rostral end of the vertebrate hindbrain and is responsible for sensory and motor integration. Owing to its relatively simple architecture, it is one of the most powerful model systems for studying brain evolution and development. Over the last decade, the combination of molecular fate mapping techniques in the mouse and experimental studies, both in vitro and in vivo, in mouse and chick have significantly advanced our understanding of cerebellar neurogenesis in space and time. In amniotes, the most numerous cell type in the cerebellum, and indeed the brain, is the cerebellar granule neurons, and these are born from a transient secondary proliferative zone, the external granule layer (EGL), where proliferation is driven by sonic hedgehog signalling and causes cerebellar foliation. Recent studies in zebrafish and sharks have shown that while the molecular mechanisms of neurogenesis appear conserved across vertebrates, the EGL as a site of shh-driven transit amplification is not, and is therefore implicated as a key amniote innovation that facilitated the evolution of the elaborate foliated cerebella found in birds and mammals. Ellucidating the molecular mechanisms underlying the origin of the EGL in evolution could have significant impacts on our understanding of the molecular details of cerebellar development.     

Can Biospecimen Science Expedite the Ex Situ Conservation of Plants in Megadiverse Countries? A Focus on the Flora of Brazil

Increasing the number of species conserved ex situ in Megadiverse countries is a major task exacerbated by many intricate factors including: biome complexity, wide range of biodiversity and an incomplete knowledge of life cycles, reproductive strategies, adaptations and species interactions. Although, establishing safe reserves is a crucial conservation measure their security and effective maintenance can be unfavourably compromised by climate change and the risks incurred by socioeconomic instability and changes in land use. Anthropogenic impacts, non-sustainable practices and habitat erosion have motivated current international efforts which focused on Brazil as host of ‘Rio+20’ the United Nation's twentieth anniversary conference on sustainable development. The revised targets of the Global Strategy for Plant Conservation (GSPC) are responses to species decline and realizing Target 8, which concerns ex situ conservation, places the heaviest burdens on countries that are custodians of the highest levels of global biodiversity. At the scientific level, ex situ conservation of endemic species in genebanks is often hindered by a lack of information about molecular genetics and problematic (recalcitrant) storage behaviors that restrict the preservation of flora native to Megadiverse countries. The potential for applying the ‘Biospecimen Science’ paradigm in expediting conservation in biodiversity-rich biomes is considered using Brazil as an exemplar of a Megadiverse country. The impacts of process chains on the quality of preserved plant germplasm and using evidence-based research to improve conservation outcomes, risk and quality management systems are appraised. The Biospecimen Science approach is not intended to displace conventional conservation practices but rather, to enhance their effectiveness in terms of the scale and efficiency of their scientific and technical operations.     

A Spatiotemporal Analysis of Brazilian Science from the Perspective of Researchers’ Career Trajectories

The growth of Brazilian scientific production in recent years is remarkable, which motivates an investigation on the factors, inside and outside the country, that helped shape this wealthy research environment. This article provides a thorough analysis of the education of researchers that constitute the main Brazilian research groups, using data on about 6,000 researchers involved in the country’s National Institutes of Science and Technology (INCT) initiative. Data on the steps taken by each researcher in her education, from the bachelor’s degree to doctorate, including a possible postdoctoral experience, and employment, are extracted from an official curriculum vitae repository. The location and the time at which each career step occurred define spatiotemporal career trajectories. We then analyze such trajectories considering additional data, including the area of knowledge of the INCTs to which each researcher is associated. We found an increasing prevalence of Brazilian institutions in the education of Brazilian scientists, as the number of doctorates earned abroad is decreasing over time. Postdoctoral stages, on the other hand, often take place in Europe or in the United States. Taking an international postdoctoral position after a full education in Brazil suggests a drive towards seeking higher-level exchange and cooperation with foreign groups in a more advanced career stage. Results also show that Brazilian researchers tend to seek employment in regions that are close to the institutions at which they received their bachelor’s degrees, suggesting low mobility within the country. This study can be instrumental in defining public policies for correcting distortions, and can help other developing countries that aim to improve their national science systems.     

Politics of Plasticity: Implications of the New Science of the “Teen Brain” for Education

Culture, Medicine, and Psychiatry - In recent years, claims that developmental brain science should inform pedagogical approaches have begun to influence educational policies. This article...     

Can Ascending Infection from Bladder Serve as the Portal of Entry for Primary Renal Zygomycosis?

Mucormycosis is an uncommon opportunistic infection by filamentous fungi that usually develops in immmunocompromised patients. Most individuals have an underlying systemic disease, such as diabetes mellitus, malignancy, uraemia, burns, renal transplant recipients and those on corticosteroid and immunosuppressive therapy. Many cases of primary renal zygomycosis with lungs serving as the portal of entry have been reported from this region. We describe two autopsy cases of renal zygomycosis where bladder appeared to be the portal of entry for the fungus.     

Does Breastfeeding Help to Reduce the Risk of Childhood Overweight and Obesity? A Propensity Score Analysis of Data from the KiGGS Study

BackgroundCurrent studies suggest that the beneficial effect of breastfeeding on overweight and obesity may have been largely overestimated. We examined the relationship between >4 months of full breastfeeding and overweight/obesity in children living in Germany.MethodsWe analyzed retrospectively collected data on breastfeeding from children aged 3–17 years who participated in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS baseline study) between 2003 and 2006 (n = 13163). To minimize confounding, we applied propensity score matching and multivariate logistic regression analyses to estimate the effect of breastfeeding on childhood overweight and obesity.ResultsAdjusted analyses of the matched dataset (n = 8034) indicated that children who were breastfed for <4 months had a significant reduction in the odds of overweight (OR 0.81 [95% CI 0.71–0.92]) and obesity (OR 0.75 [95% CI 0.61–0.92]) compared to children who were not breastfed or who were breastfed for a shorter duration. Further analyses stratified by age group showed that the association was strongest in children aged 7–10 years (OR 0.67 [95% CI 0.53–0.84] for overweight and OR 0.56 [95% CI 0.39–0.81] for obesity), while no significant effect could be seen in other age groups.DiscussionOur findings support the hypothesis that breastfeeding does have a beneficial effect on childhood overweight and obesity, although the effect seems to be strongest in children of primary school age.     

Can Cognitive Activities during Breaks in Repetitive Manual Work Accelerate Recovery from Fatigue? A Controlled Experiment

Neurophysiologic theory and some empirical evidence suggest that fatigue caused by physical work may be more effectively recovered during “diverting” periods of cognitive activity than during passive rest; a phenomenon of great interest in working life. We investigated the extent to which development and recovery of fatigue during repeated bouts of an occupationally relevant reaching task was influenced by the difficulty of a cognitive activity between these bouts. Eighteen male volunteers performed three experimental sessions, consisting of six 7-min bouts of reaching alternating with 3 minutes of a memory test differing in difficulty between sessions. Throughout each session, recordings were made of upper trapezius muscle activity using electromyography (EMG), heart rate and heart rate variability (HRV) using electrocardiography, arterial blood pressure, and perceived fatigue (Borg CR10 scale and SOFI). A test battery before, immediately after and 1 hour after the work period included measurements of maximal shoulder elevation strength (MVC), pressure pain threshold (PPT) over the trapezius muscles, and a submaximal isometric contraction. As expected, perceived fatigue and EMG amplitude increased during the physical work bouts. Recovery did occur between the bouts, but fatigue accumulated throughout the work period. Neither EMG changes nor recovery of perceived fatigue during breaks were influenced by cognitive task difficulty, while heart rate and HRV recovered the most during breaks with the most difficult task. Recovery of perceived fatigue after the 1 hour work period was also most pronounced for the most difficult cognitive condition, while MVC and PPT showed ambiguous patterns, and EMG recovered similarly after all three cognitive protocols. Thus, we could confirm that cognitive tasks between bouts of fatiguing physical work can, indeed, accelerate recovery of some factors associated with fatigue, even if benefits may be moderate and some responses may be equivocal. Our results encourage further research into combinations of physical and mental tasks in an occupational context.     

Can the tortoise beat the hare? A possible mechanism for the coexistence of competing mosquitoes in bamboo groves

We studied interspecific competition between the larvae of the two mosquitoesAedes albopictus andTripteroides bambusa, which are predominantly found in water-filled bamboo stumps in northern Kyushu, south-western Japan, using microcosms with dead bamboo leaves in the laboratory. We compared short-term competition between single cohorts of the two species and long-term competition involving four cohorts of each species, which were introduced at 6-day intervals. In the single cohort experiment,A. albopictus grew faster thanT. bambusa. However, in the multiple cohort experiment, although the first cohort ofA. albopictus grew faster and began to pupate earlier than that ofT. bambusa, molting rates of later cohorts ofA. albopictus, that were introduced on the 12th and the 18th day, were lower than those ofT. bambusa. The survival rate ofA. albopictus became lower than that ofT. bambusa after the 18th day. The cumulative number of the pupatedT. bambusa individuals exceeded that ofA. albopictus on the 96th day. The final pupation success was higher inT. bambusa than inA. albopictus, especially when additional leaves were supplied on the 48th and the 96th days. The reversed outcomes between short- and long-term interspecific competition and the variation in the lifespans of small aquatic sites may contribute to the coexistence of the two mosquito species in bamboo groves.     

Pharmacological Cognitive Enhancement in Healthy Individuals: A Compensation for Cognitive Deficits or a Question of Personality?

The ongoing bioethical debate on pharmacological cognitive enhancement (PCE) in healthy individuals is often legitimated by the assumption that PCE will widely spread and become desirable for the general public in the near future. This assumption was questioned as PCE is not equally save and effective in everyone. Additionally, it was supposed that the willingness to use PCE is strongly personality-dependent likely preventing a broad PCE epidemic. Thus, we investigated whether the cognitive performance and personality of healthy individuals with regular nonmedical methylphenidate (MPH) use for PCE differ from stimulant-naïve controls. Twenty-five healthy individuals using MPH for PCE were compared with 39 age-, sex-, and education-matched healthy controls regarding cognitive performance and personality assessed by a comprehensive neuropsychological test battery including social cognition, prosocial behavior, decision-making, impulsivity, and personality questionnaires. Substance use was assessed through self-report in an interview and quantitative hair and urine analyses. Recently abstinent PCE users showed no cognitive impairment but superior strategic thinking and decision-making. Furthermore, PCE users displayed higher levels of trait impulsivity, novelty seeking, and Machiavellianism combined with lower levels of social reward dependence and cognitive empathy. Finally, PCE users reported a smaller social network and exhibited less prosocial behavior in social interaction tasks. In conclusion, the assumption that PCE use will soon become epidemic is not supported by the present findings as PCE users showed a highly specific personality profile that shares a number of features with illegal stimulant users. Lastly, regular MPH use for PCE is not necessarily associated with cognitive deficits.     

Can cognitive enhancers reduce the risk of falls in older people with Mild Cognitive Impairment? A protocol for a randomised controlled double blind trial

Background  

Older adults with cognitive problems have a higher risk of falls, at least twice that of cognitively normal older adults. The consequences of falls in this population are very serious: fallers with cognitive problems suffer more injuries due to falls and are approximately five times more likely to be admitted to institutional care. Although the mechanisms of increased fall risk in cognitively impaired people are not completely understood, it is known that impaired cognitive abilities can reduce attentional resource allocation while walking. Since cognitive enhancers, such as cholinesterase inhibitors, improve attention and executive function, we hypothesise that cognitive enhancers may reduce fall risk in elderly people in the early stages of cognitive decline by improving their gait and balance performance due to an enhancement in attention and executive function.     

Latently Infected Cell Activation: A Way to Reduce the Size of the HIV Reservoir?

While antiretroviral drugs can drive HIV to undetectably low levels in the blood, eradication is hindered by the persistence of long-lived, latently infected memory CD4 T cells. Immune activation therapy aims to eliminate this latent reservoir by reactivating these memory cells, exposing them to removal by the immune system and the cytotoxic effects of active infection. In this paper, we develop a mathematical model that investigates the use of immune activation strategies while limiting virus and latent class rebound. Our model considers infection of two memory classes, central and transitional CD4 T cells and the role that general immune activation therapy has on their elimination. Further, we incorporate ways to control viral rebound by blocking activated cell proliferation through anti proliferation therapy. Using the model, we provide insight into the control of latent infection and subsequently into the long term control of HIV infection.     

Can Continuous Positive Airway Pressure Reduce the Risk of Stroke in Obstructive Sleep Apnea Patients? A Systematic Review and Meta-Analysis

Background and Purpose

Obstructive sleep apnea (OSA) has been shown to increase the risk of stroke. Although continuous positive airway pressure (CPAP) is considered the treatment of choice for OSA, whether treating OSA with CPAP reduces the risk of stroke remains unclear. We aimed to evaluate the effects of CPAP on incidence of stroke in patients with OSA.

Materials and Methods

We conducted a systematic review and meta-analysis of all published studies that provided the number of incident strokes in OSA patients in light of their treatment status with CPAP.

Results

We identified 8 relevant studies: one randomized controlled study (RCT), 5 cohort studies, and 2 studies using administrative health data. The two overlapping cohort studies in women and the elderly and the 2 studies using administrative health data had analyzed the impact of CPAP on stroke apart from cardiac events, whereas the others had focused on the overall cardiovascular events. Based on a meta-analysis of the cohort studies, treatment with CPAP was associated with a lower incidence of stroke and cardiac events with relative risks of 0.27 [0.14–0.53], and 0.54 [0.38–0.75], respectively, although this could not be reproduced in the RCT and the studies using administrative data.

Conclusions

Treating with CPAP in patients with OSA might decrease the risk of stroke, although there is some conflicting evidence. Such effect was more pronounced in stroke than in cardiac events. Future studies analyzing stroke apart from cardiac disease would be of interest.     

A method for the isolation of segments from the 5′ ends of retrovirus RNA

A method for the isolation of segments of any desired length from the 5′ end of retrovirus RNA has been tested. The method is based on selection of 5′-specific segments by hybridizing suitably fragmented genomic (35 S) RNA to mercurated strong stop cDNA followed by chromatography on sulfhydryl-agarose. The method has been shown to be effective for Akv viral RNA by observing the T1 oligonucleotide fingerprints of a 5′-enriched fraction. This fingerprint pattern is of lower complexity than that of total 35 S RNA, contains oligonucleotide spots that have previously been assigned as 5′ specific by conventional fingerprinting methods, and does not overlap with the pattern from 3′-specific RNA.