436 research outputs found
Becoming a new neuron in the adult olfactory bulb
New neurons are continually recruited throughout adulthood in certain regions of the adult mammalian brain. How these cells mature and integrate into preexisting functional circuits remains unknown. Here we describe the physiological properties of newborn olfactory bulb interneurons at five different stages of their maturation in adult mice. Patch-clamp recordings were obtained from tangentially and radially migrating young neurons and from neurons in three subsequent maturation stages. Tangentially migrating neurons expressed extrasynaptic GABAA receptors and then AMPA receptors, before NMDA receptors appeared in radially migrating neurons. Spontaneous synaptic activity emerged soon after migration was complete, and spiking activity was the last characteristic to be acquired. This delayed excitability is unique to cells born in the adult and may protect circuits from uncontrolled neurotransmitter release and neural network disruption. Our results show that newly born cells recruited into the olfactory bulb become neurons, and a unique sequence of events leads to their functional integration
Effects of Backgrounding and Feedlot System Strategies on May-Born Steer Performance
May-born steers were backgrounded to achieve either a high or low rate of gain. The high rate of gain was achieved by offering steers meadow hay ad libitum and 4 lb/d of a 33% CP (DM) supplement, while the low rate of gain consisted of steers grazing meadow and offered 1 lb/d of the same supplement. After backgrounding, one-half of the steers from each group entered the feedlot in May as short-yearlings, while the remainder grazed upland range until entering the feedlot as long-yearlings in mid-September. Hot carcass weight was greater for steers backgrounded to achieve a high rate of gain, but they also consumed more during the feedlot phase and had fewer carcasses grade USDA average Choice or greater compared with steers backgrounded to achieve a low rate of gain. Long-yearling steers had increased marbling scores and percentage of carcasses grading USDA average Choice or greater compared with short-yearling steers. Furthermore, long-yearlings had increased carcass weight and risk for overweight carcasses
Effects of Prepartum Nutrition on May-Calving Cows and Progeny
May-calving dams grazed either sub-irrigated meadow or upland range from Jan. 5 to May 1 each year for 6 years. Within grazing system, dams received either no supplement or 1 lb/d of a 33% CP supplement from Jan. 5 to April 1. Dams grazing meadow in the prepartum period weighed more and had a greater body condition score prior to calving. They also tended to have greater pregnancy rates in the subsequent breeding season and tended to wean heavier calves than dams grazing upland range. Allowing May-calving dams to graze meadow in late gestation may increase herd profitability through increased dam pregnancy rates and weaned calf value. Furthermore, supplemented dams weaned heavier calves, independent of grazing system. Supplementation of May-calving dams in late gestation may be economical if the income from additional pounds of calf weaned is greater than the supplementation cost
Combinatorial Analysis of mRNA Expression Patterns in Mouse Embryos Using Hybridization Chain Reaction
Multiplexed fluorescent hybridization chain reaction (HCR) and advanced imaging techniques can be used to evaluate combinatorial gene expression patterns in whole mouse embryos with unprecedented spatial resolution. Using HCR, DNA probes complementary to mRNA targets trigger chain reactions in which metastable fluorophore-labeled DNA HCR hairpins self-assemble into tethered fluorescent amplification polymers. Each target mRNA is detected by a probe set containing one or more DNA probes, with each probe carrying two HCR initiators. For multiplexed experiments, probe sets for different target mRNAs carry orthogonal initiators that trigger orthogonal DNA HCR amplification cascades labeled by spectrally distinct fluorophores. As a result, in situ amplification is performed for all targets simultaneously, and the duration of the experiment is independent of the number of target mRNAs. We have used multiplexed fluorescent in situ HCR and advanced imaging technologies to address questions of cell heterogeneity and tissue complexity in craniofacial patterning and anterior neural development. In the sample protocol presented here, we detect three different mRNA targets: Tg(egfp), encoding the enhanced green fluorescent protein (GFP) transgene (typically used as a control); Twist1, encoding a transcription factor involved in cell lineage determination and differentiation; and Pax2, encoding a transcription factor expressed in the mid-hindbrain region of the mouse embryo
Adolescent Positivity and Future Orientation, Parental Psychological Control, and Young Adult Internalising Behaviours during COVID-19 in Nine Countries
The COVID-19 pandemic disrupted many young adults’ lives educationally, economically, and personally. This study investigated associations between COVID-19-related disruption and perception of increases in internalising symptoms among young adults and whether these associations were moderated by earlier measures of adolescent positivity and future orientation and parental psychological control. Participants included 1329 adolescents at Time 1, and 810 of those participants as young adults (M age = 20, 50.4% female) at Time 2 from 9 countries (China, Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States). Drawing from a larger longitudinal study of adolescent risk taking and young adult competence, this study controlled for earlier levels of internalising symptoms during adolescence in examining these associations. Higher levels of adolescent positivity and future orientation as well as parent psychological control during late adolescence helped protect young adults from sharper perceived increases in anxiety and depression during the first nine months of widespread pandemic lockdowns in all nine countries. Findings are discussed in terms of how families in the 21st century can foster greater resilience during and after adolescence when faced with community-wide stressors, and the results provide new information about how psychological control may play a protective role during times of significant community-wide threats to personal health and welfare
Positive Approaches to Phosphorus Balancing in Southwest Missouri: Animal Manure Phosphorus Recycling Initiative
Document presented on July 12, 2001 at Crowder College, Neosho, MO and on November 6 & 7 at Water Quality Research in the White River Basin Conference in Springfield, MO.Opportunities exist to create value added animal waste fertilizer products that can be used in crop production, reducing import demands for phosphorus, and relocating phosphorus from areas of excess supply to areas of need for crop production. This paper focuses on opportunities to recycle poultry litter in southwest Missouri.This project is a cooperative effort of the Food and Agricultural Policy Research Institute at the University of Missouri
and the Natural Resource Conservation Service. The work is supported by EPA grant X997396-01, Region VII U.S. Environmental Protection Agency, under section 104 (b)(3). The Missouri Department of Agriculture appropriated funds to support the work in this report
FAPRI Environmental Projects 2000
Since 1995, the Food and Agricultural Policy
Research Institute at the University of Missouri (FAPRI) has been providing analytical support in several areas around the state as communities try to come to grips with various water quality issues thought to derive from production agriculture's two underlying facts of life.
This report provides a summary of the lessons
learned as the unit has looked at and worked with these communities. It also discusses the specific projects underway in the unit, again focusing on issues directly related to the interface problem.This project is a cooperative effort of the Food and Agricultural Policy Research Institute at the University of Missouri
and the Natural Resource Conservation Service. The work is supported by EPA grant X997396-01, Region VII U.S. Environmental Protection Agency, under section 104 (b) (3). The Missouri Department of Agriculture appropriated funds to support the work in this report
Within- and between-person and group variance in behavior and beliefs in cross-cultural longitudinal data
This study grapples with what it means to be part of a cultural group, from a statistical modeling perspective. The method we present compares within- and between-cultural group variability, in behaviors in families. We demonstrate the method using a cross-cultural study of adolescent development and parenting, involving three biennial waves of longitudinal data from 1296 eight-year-olds and their parents (multiple cultures in nine countries). Family members completed surveys about parental negativity and positivity, child academic and social-emotional adjustment, and attitudes about parenting and adolescent behavior. Variance estimates were computed at the cultural group, person, and within-person level using multilevel models. Of the longitudinally consistent variance, most was within and not between cultural groups—although there was a wide range of between-group differences. This approach to quantifying cultural group variability may prove valuable when applied to quantitative studies of acculturation
Severity and justness do not moderate the relation between corporal punishment and negative child outcomes: A multicultural and longitudinal study
There is strong evidence of a positive association between corporal punishment and negative child outcomes, but previous studies have suggested that the manner in which parents implement corporal punishment moderates the effects of its use. This study investigated whether severity and justness in the use of corporal punishment moderate the associations between frequency of corporal punishment and child externalizing and internalizing behaviors. This question was examined using a multicultural sample from eight countries and two waves of data collected one year apart. Interviews were conducted with 998 children aged 7–10 years, and their mothers and fathers, from China, Colombia, Italy, Jordan, Kenya, Philippines, Thailand, and the United States. Mothers and fathers responded to questions on the frequency, severity, and justness of their use of corporal punishment; they also reported on the externalizing and internalizing behavior of their child. Children reported on their aggression. Multigroup path models revealed that across cultural groups, and as reported by mothers and fathers, there is a positive relation between the frequency of corporal punishment and externalizing child behaviors. Mother-reported severity and father-reported justness were associated with child-reported aggression. Neither severity nor justness moderated the relation between frequency of corporal punishment and child problem behavior. The null result suggests that more use of corporal punishment is harmful to children regardless of how it is implemented, but requires further substantiation as the study is unable to definitively conclude that there is no true interaction effect
Dynamic Analysis of Vascular Morphogenesis Using Transgenic Quail Embryos
Background: One of the least understood and most central questions confronting biologists is how initially simple clusters or sheet-like cell collectives can assemble into highly complex three-dimensional functional tissues and organs. Due to the limits of oxygen diffusion, blood vessels are an essential and ubiquitous presence in all amniote tissues and organs. Vasculogenesis, the de novo self-assembly of endothelial cell (EC) precursors into endothelial tubes, is the first step in blood vessel formation [1]. Static imaging and in vitro models are wholly inadequate to capture many aspects of vascular pattern formation in vivo, because vasculogenesis involves dynamic changes of the endothelial cells and of the forming blood vessels, in an embryo that is changing size and shape.
Methodology/Principal Findings: We have generated Tie1 transgenic quail lines Tg(tie1:H2B-eYFP) that express H2B-eYFP in all of their endothelial cells which permit investigations into early embryonic vascular morphogenesis with unprecedented clarity and insight. By combining the power of molecular genetics with the elegance of dynamic imaging, we follow the precise patterning of endothelial cells in space and time. We show that during vasculogenesis within the vascular plexus, ECs move independently to form the rudiments of blood vessels, all while collectively moving with gastrulating tissues that flow toward the embryo midline. The aortae are a composite of somatic derived ECs forming its dorsal regions and the splanchnic derived ECs forming its ventral region. The ECs in the dorsal regions of the forming aortae exhibit variable mediolateral motions as they move rostrally; those in more ventral regions show significant lateral-to-medial movement as they course rostrally.
Conclusions/Significance: The present results offer a powerful approach to the major challenge of studying the relative role(s) of the mechanical, molecular, and cellular mechanisms of vascular development. In past studies, the advantages of the molecular genetic tools available in mouse were counterbalanced by the limited experimental accessibility needed for imaging and perturbation studies. Avian embryos provide the needed accessibility, but few genetic resources. The creation of transgenic quail with labeled endothelia builds upon the important roles that avian embryos have played in previous studies of vascular development
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