Discover the most talked about and latest scientific content & concepts.

Concept: Marker pen


In recent decades, fresh and minimally processed produce items have been associated with an increasing proportion of foodborne illnesses. Most pathogens associated with fresh produce are enteric (fecal) in origin, and contamination can occur anywhere along the farm-to-fork chain. Microbial source tracking (MST) is a tool developed in the environmental microbiology field to identify and quantify the dominant source(s) of fecal contamination. This study investigated the utility of an MST method based on Bacteroidales 16S rDNA sequences as a means of identifying potential fecal contamination, and its source, in the fresh produce production environment. The method was applied to rinses of fresh produce, source and irrigation waters, and harvester hand rinses collected over the course of one year from nine farms (growing tomatoes, jalapeño peppers, and cantaloupe) in Northern Mexico. Of 174 samples, 39% were positive for a universal Bacteroidales marker (AllBac), including 66% of samples from cantaloupe farms (3.6 log10 genome equivalence copies [GEC]/100 ml), 31% of samples from tomato farms (1.7 log10 GEC/100 ml), and 18% of samples from jalapeño farms (1.5 log10 GEC/100 ml). Of 68 AllBac-positive samples, 46% were positive for one of 3 human-specific markers (BFD, HF183, BVulg), and none were positive for a bovine-specific marker (BoBac). There was no statistically significant correlation between Bacteroidales and generic E. coli across all samples. This study provides evidence that Bacteroidales markers may serve as alternative indicators for fecal contamination in fresh produce production, allowing for determination of both general contamination and that derived from the human host.

Concepts: Bacteria, Microbiology, Escherichia coli, Marker, Tomato, Identification, Mexico, Marker pen


Inhalant use is especially prevalent among antisocial youth and can have serious health consequences. However, the extant literature has not investigated how use of various inhalants may co-occur among incarcerated youth. This study begins to address this gap in the literature by using latent class analyses to form distinct typologies of inhalant use. Study participants were residents (N = 723) of 27 Missouri Division of Youth Services facilities. Interviews assessed psychiatric symptoms, antisocial traits, delinquency, trauma, suicidality, and substance use behaviors. The mean age of the mostly male, ethnically diverse sample was 15.5 (S.D. = 1.2) years old. The study revealed the following classes of inhalant use: (1) severe polyinhalant use; (2) moderate polyinhalant use; (3) gas and permanent marker use; and (4) low-use. Compared to the low-use class, members of the severe polyinhalant use class had experienced more than double the rate of head injuries, the highest rates of traumatic experiences, and the highest rates of mental illness diagnoses. The gas and markers class had the highest rate of reporting hearing voices, followed by the severe polyinhalant use class, and the moderate polyinhalant use class. Results of this study underscore the need to address the high rate of head injuries and mental health diagnoses that contribute to severe polyinhalant use.

Concepts: Psychology, Mental health, Mental disorder, Schizophrenia, Psychiatry, Antisocial personality disorder, Inhalant, Marker pen


Current flow-cytometric plasma cell (PC) gating is based on CD138, CD38 and CD45 expression. CD138 is known for variable expression and loss during storage and processing. Introduction of anti-CD38 and anti-CD138 monoclonal-antibody therapies has limited the use of these markers during follow-up. Hence, additional reliable PC-gating markers are required. Recently, CD229 has been claimed as an alternative PC-gating marker. However, these studies are limited to a small cohort of samples. We evaluated the utility of CD229 as a new PC-gating marker in routine laboratory practice.

Concepts: DNA, Medicine, Flow cytometry, Marker, Expression, Marker pen


Many athletes, coaches, and support staff are taking an increasingly scientific approach to both designing and monitoring training programs. Appropriate load monitoring can aid in determining whether an athlete is adapting to a training program and in minimizing the risk of developing non-functional overreaching, illness, and/or injury. In order to gain an understanding of the training load and its effect on the athlete, a number of potential markers are available for use. However, very few of these markers have strong scientific evidence supporting their use, and there is yet to be a single, definitive marker described in the literature. Research has investigated a number of external load quantifying and monitoring tools, such as power output measuring devices, time-motion analysis, as well as internal load unit measures, including perception of effort, heart rate, blood lactate, and training impulse. Dissociation between external and internal load units may reveal the state of fatigue of an athlete. Other monitoring tools used by high-performance programs include heart rate recovery, neuromuscular function, biochemical/hormonal/immunological assessments, questionnaires and diaries, psychomotor speed, and sleep quality and quantity. The monitoring approach taken with athletes may depend on whether the athlete is engaging in individual or team sport activity; however, the importance of individualization of load monitoring cannot be over emphasized. Detecting meaningful changes with scientific and statistical approaches can provide confidence and certainty when implementing change. Appropriate monitoring of training load can provide important information to athletes and coaches; however, monitoring systems should be intuitive, provide efficient data analysis and interpretation, and enable efficient reporting of simple, yet scientifically valid, feedback.

Concepts: Scientific method, Understanding, Measurement, Science, Heart rate, Marker, Units of measurement, Marker pen


To investigate whether serum neurofilament light (NfL) concentration is increased in familial Alzheimer disease (FAD), both pre and post symptom onset, and whether it is associated with markers of disease stage and severity.

Concepts: Alzheimer's disease, Neurology, Neurodegenerative disorders, Dementia, Unsolved problems in neuroscience, Marker, Marker pen


The impact of toxins on the developing brain is usually subtle for an individual child, but the damage can be substantial at the population level. Numerous challenges must be addressed to definitively test the impact of toxins on brain development in children: We must quantify exposure using a biologic marker or pollutant; account for an ever-expanding set of potential confounders; identify critical windows of vulnerability; and repeatedly examine the association of biologic markers of toxins with intellectual abilities, behaviors, and brain function in distinct cohorts. Despite these challenges, numerous toxins have been implicated in the development of intellectual deficits and mental disorders in children. Yet, too little has been done to protect children from these ubiquitous but insidious toxins. The objective of this review is to provide an overview on the population impact of toxins on the developing brain and describe implications for public health. Expected final online publication date for the Annual Review of Public Health Volume 36 is March 18, 2015. Please see for revised estimates.

Concepts: Psychology, Health, Child, Developmental psychology, Mental disorder, Marker, The Damage, Marker pen


A fundamental challenge in soft-tissue surgery is that target tissue moves and deforms, becomes occluded by blood or other tissue, and is difficult to differentiate from surrounding tissue. We developed small biocompatible near-infrared fluorescent (NIRF) markers with a novel fused plenoptic and NIR camera tracking system, enabling 3D tracking of tools and target tissue while overcoming blood and tissue occlusion in the uncontrolled, rapidly changing surgical environment. In this work, we present the tracking system and marker design and compare tracking accuracies to standard optical tracking methods using robotic experiments. At speeds of 1 mm/s, we observe tracking accuracies of 1.61 mm, degrading only to 1.71 mm when the markers are covered in blood and tissue.

Concepts: Surgery, Tissues, Tissue, Marker, 3D computer graphics, Tracking system, Marker pen, Radio navigation


An innovative insect-based visual sensor is designed to perform active marker tracking. Without any optics and a field-of-view of about 60°, a novel miniature visual sensor is able to locate flickering markers (LEDs) with an accuracy much greater than the one dictated by the pixel pitch. With a size of only 1 cm3 and a mass of only 0.33 g, the lensless sensor, called HyperCube, is dedicated to 3D motion tracking and fits perfectly with the drastic constraints imposed by micro-aerial vehicles. Only three photosensors are placed on each side of the cubic configuration of the sensing device, making this sensor very inexpensive and light. HyperCube provides the azimuth and elevation of infrared LEDs flickering at a high frequency (>1 kHz) with a precision of 0.5°. The minimalistic design in terms of small size, low mass and low power consumption of this visual sensor makes it suitable for many applications in the field of the cooperative flight of unmanned aerial vehicles and, more generally, robotic applications requiring active beacons. Experimental results show that HyperCube provides useful angular measurements that can be used to estimate the relative position between the sensor and the flickering infrared markers.

Concepts: Electromagnetic radiation, Electromagnetic spectrum, Frequency, Marker, Pitch, Infrared, Marker pen, Unmanned aerial vehicle


Emergence of artemisinin-resistant malaria in Southeast Asian countries threatens the global control of malaria. Although K13 kelch propeller has been assessed for artemisinin resistance molecular marker, most of the mutations need to be validated. In this study, artemisinin resistance was assessed by clinical and molecular analysis, including k13 and recently reported markers, pfarps10, pffd and pfmdr2.

Concepts: Immune system, DNA, Malaria, Plasmodium falciparum, Southeast Asia, Artemisinin, Marker, Marker pen


Paper-based micro analytical devices offer significant advantages compared to the conventional microfluidic chips including cost-effectiveness, ease of fabrication, and ease of use while preserving critical features including strong capillary action and biological compatibility. In this work, we demonstrate an inexpensive, rapid method for high-throughput fabrication of paper-based microfluidics by patterning hydrophobic barriers using a desktop pen plotter integrated with a custom-made, low-cost paper feeder. We tested various types of commercial permanent markers and compared their water-resistant capabilities for creating hydrophobic barriers. Additionally, we studied the performance of markers with different types of paper, plotting speeds, and pattern dimensions. To verify the effectiveness of the presented fabrication method, colorimetric analysis was performed on the results of a glucose assay.

Concepts: Biotechnology, Surface tension, Performance, Microfluidics, Capillary action, Marker pen, Lab-on-a-chip, Plotter