Search

Ferulate cross-linking of lignin to arabinoxylan contributes to poor cell wall degradability of grass forages. We hypothesized that reduced ferulate ester deposition will result in formation of fewer ferulate cross links and improved degradability. Objectives were to determine if the putative seedling ferulate ester (sfe) maize (Zea mays L.) mutant, selected for reduced ferulate esters in seedling leaves, (i) exhibits reduced ferulate ethers; (ii) alters morphology, yield, and cell wall concentration and composition; and (iii) changes degradability. Four near-isogenic sfe lines and backcrosses to W23 were compared with the inbred W23 in replicated fi eld trials. Leaf blade, sheath, and stem of immature (1-m plant height) and mature (silage) growth stages were analyzed for ferulate esters and ethers, cell wall concentration and composition, and in vitro rumen degradability. The sfe lines were taller and had greater internode cross-sectional area than W23. Plant yield was greater at silage maturity for sfe lines and backcross lines yielded more than sfe. Mature plant parts of sfe lines had lower ferulate ester concentrations than W23. At silage stage sfe lines had less ferulate ethers, small reductions in cell wall concentration, and shifts in composition. Immature samples were inconsistent for cell wall traits and backcross lines were generally intermediate, regardless of maturity. Cell wall degradability was higher for the sfe mutant as hypothesized. Reducing ferulate-mediated cross-linking of lignin to arabinoxylan in the cell walls of maize stover appears to be an effective strategy for improving cell wall degradability, and the sfe mutant may offer an opportunity to identify a gene controlling ferulate deposition in grasses.

Parenting a child with autism spectrum disorder (ASD) can be stressful, and accessing services can add to this stress. Self-efficacy, agency and advocacy are important for parents when accessing and using services. To develop insight into parental advocacy, a meta-synthesis was undertaken to consolidate the literature focussing on parents' experiences of advocating for their child with ASD. A qualitative meta-synthesis was conducted. Fifteen databases were systematically searched by using key terms related to ASD, children, parents/carers, advocacy and qualitative studies. Twenty-four studies were identified and appraised using an adapted version of the Critical Appraisal Skills Programme tool. Data were synthesized into themes through the steps of review, meta-aggregation, integration and interpretation. Two overarching concepts emerged, illustrating both the challenging nature of advocacy and the associated personal and societal benefits. These two concepts are supported by eight themes: a life-long, all-encompassing challenge; advocacy as a parental coping strategy; advocacy involving working to create a future; balancing roles and needs; isolation versus support; personal impacts of advocacy; benefits of advocacy; and the barriers to advocacy. The experience of advocacy for parents with a child with ASD is complex and intensive, presenting both personal and societal benefits, as well as challenges for parents. In supporting individuals with ASD and family well-being, service providers need to have an understanding of the advocating role of parents and ensure that opportunities exist for their voices to be heard during service delivery.

Mathematical models for a Gaussian-beam wave propagating through anisotropic non-Kolmogorov turbulence have been developed in the past by several researchers. In previous publications, the anisotropic spatial power spectrum model was based on the assumption that propagation was in the z direction with circular symmetry maintained in the orthogonal xy -plane throughout the path. In the present analysis, however, the anisotropic spectrum model is no longer based on a single anisotropy parameter—instead, two such parameters are introduced in the orthogonal xyplane so that circular symmetry in this plane is no longer required. In addition, deviations from the 11/3 power-law behavior in the spectrum model are allowed by assuming power-law index variations 3 α < 4 . In the current study we develop theoretical models for beam spot size, spatial coherence, and scintillation index that are valid in weak irradiance fluctuation regimes as well as in deep turbulence, or strong irradiance fluctuation regimes. These new results are compared with those derived from the more specialized anisotropic spectrum used in previous analyses.

Milling yield, or the grain weight from which 100 kg of rolled groats is obtained upon milling, is an important quality characteristic of cultivated oat (Avena sativa L.). Kernel morphology and the groat (caryopsis) percentage of the whole kernel including hull are factors that influence milling yield. We mapped QTLs for kernel area, kernel length, kernel width, and groat percentage in two populations of 137 recombinant inbred lines by RFLP and AFLP analysis to evaluate the prospects of marker-assisted selection (MAS). Phenotypic correlations between kernel morphology traits and groat percentage were not significant. For kernel morphology traits and groat percentage, one to five QTLs were detected, explaining 7.0–60.7% of the total phenotypic variance depending on the trait. One QTL for kernel length in each population and one QTL for kernel width in one population were found at the same location as a QTL for groat percentage, indicating that a change in kernel size or shape could have an influence on groat percentage. The positions and effects of QTLs for kernel morphology and groat percentage were compared to QTLs detected previously for chemical grain composition (oil andβ-glucanconcentration) and agronomic traits to evaluate the selection response on these traits through MAS. Several regions of the oat genome were identified that contained clusters of QTLs influencing two or more traits. While the allele from one parent at a QTL could simultaneously improve two or more traits in one population, it could have opposite effects on the same traits at another QTL or in the other population. Associations among traits were complex and will require careful consideration when employing QTL-marker associations in MAS to avoid negative selection response. Future research to discover candidate genes for those QTL clusters could provide information about trait associations and help in designing selection programs.

The availability of molecular genetic maps in oat (Avena spp.) and improved identification of chromosomes by C-banding are two recent developments that have made locating linkage groups to chromosomes possible in cultivated hexaploid oat, 2n=6x=42. Monosomic series derived from Avena byzantina C. Koch cv Kanota and from Avena sativa L. cv Sun II were used as maternal plants in crosses with the parents, Kanota-1 and Ogle-C, of the oat RFLP mapping population. Monosomic F1 plants were identified by root-tip cell chromosome counts. For marker analysis, DNAs of eight F2 plants from a monosomic F1 were combined to provide a larger source of DNA that mimicked that of the monosomic F1 plant. Absence of maternal alleles in monosomic F1s served to associate linkage groups with individual chromosomes. Twenty two linkage groups were associated with 16 chromosomes. In seven instances, linkage groups that were independent of each other in recombination analyses were associated with the same chromosome. Five linkage groups were shown to be associated with translocation differences among oat lines. Additionally, the results better-characterized the oat monosomic series through the detection of duplicates and translocation differences among the various monosomic lines. The F1 monosomic series represents a powerful cytogenetic tool with the potential to greatly improve understanding of the oat genome.

Maize chromosome addition lines of oat offer the opportunity to study maize gene expression in oat and the resulting phenotypes. Morphological examination of a maize chromosome 3 addition line of oat showed that this line exhibited several morphological abnormalities including a blade-to-sheath transformation at the midrib region of the leaf, a hook-shaped panicle, and abnormal outgrowth of aerial axillary buds. Dominant mutations in the maize liguleless3 (lg3) homeobox gene result in a blade (distal)-to-sheath (proximal) transformation at the midrib region of the leaf. Ectopic expression of the dominant mutant Lg3 allele is believed to cause the phenotype. Therefore, we suspected that the maize lg3 gene, which is located on maize chromosome 3, was involved in the phenotypes observed in the maize chromosome 3 addition line of oat. Genetic analyses of an oat BC1F2family segregating for maize chromosome 3 showed that the presence of a stable maize chromosome 3 was required for the expression of these cell fate abnormalities. RNA expression analysis of leaf sheath tissue from oat plants carrying maize chromosome 3 demonstrated that maize LG3 transcripts accumulated in oat, indicating that this expression is associated with the blade-to-sheath transformation, hook-shaped panicle and outgrowth of aerial axillary bud phenotypes. Our results demonstrate that the maize chromosome addition lines of oat are useful genetic stocks to study expression of maize genes in oat.Key words: liguleless3, homeobox, oat-maize addition line.

We present the first genetic map of wild rice (Zizania palustris L., 2n=2x=30), a native aquatic grain of northern North America. This map is composed principally of previously mapped RFLP (restriction fragment length polymorphism) genetic markers from rice (Oryza sativa 2n=2x=24). The map is important as a foundation for genetic and crop improvement studies as well as a reference for genome organization comparisons among species of Gramineae. A comparative mapping approach with rice is especially useful because wild rice is grouped in the same subfamily, Oryzoideae, and no other mapping comparison has yet been made within the subfamily. As rice is the reference point for mapping and gene cloning in cereals, establishing a consensus map within the subfamily identifies conserved and unique regions. The genomes of wild rice and rice differ in total DNA content (wild rice has twice that of rice) and the number of chromosome pairs (wild rice=15 versus rice=12). The wild rice linkage map reported herein consists of 121 RFLP markers on 16 linkage groups spanning 1805 cM. Two linkage groups consist of only two markers. Colinear markers were found representing all rice linkage groups except #12. The majority of rice loci mapped to colinearly arranged arrays in wild rice (92 of 118). Features of the map include duplication of portions of three rice linkage groups and three possible translocations. The map gives basic information on the composition of the wild rice genome and provides tools to assist in the domestication of this important food source.

Variability for desirable alleles within elite breeding populations is a requirement for long-term genetic improvement. Changes in genetic diversity were evaluated in a recurrent selection programme for enhanced grain yield in oat, Avena sativa L., using coefficient of parentage (r p ) and restriction fragment length polymorphism (RFLP) based genetic similarity (s) estimates. Both r p and s increased during seven cycles of recurrent selection, indicating a reduction in the level of genetic diversity within the population. The relationship between genetic diversity and agronomic performance was also examined. Genetic similarity measures were poor predictors of the near-homozygous progeny performance and general and specific combining ability effects for three agronomic traits in the recurrent selection programme. In addition, there was no apparent trend for preferential selection of progeny from either more similar or more diverse parents within a given cycle of selection. The overall reduction in genetic diversity in this population has not affected selection response for grain yield. Variability remaining at important loci or de novo variation are possible explanations for the continued selection progress.

The current DARPA Free space Optical Experimental Network Experiment (FOENEX) Program is a continuation of the earlier Optical RF Communications Adjunct (ORCA) Program that was designed to bring high data rate networking to the warfighter via airborne platforms. The FOENEX program is headed by the Applied Physics Laboratory (APL) of the Johns Hopkins University. Radio frequency (RF) equipment and networking was designed and built by L3 and the adaptive optics (AO) subsystem was designed and built by AOptix. Phase 0 testing of the FOENEX hybrid system took place during June 2011 at Hollister Air Force Range in California and Phase 2 Final Testing was performed in March and April of 2012 at the Naval Air Weapons Test Range in China Lake, California. The University of Central Florida (UCF) was separately contracted by DARPA to measure path-averaged values of the refractive-index structure parameter 2 C(exp 2)(sub n) , the inner scale of turbulence l0, and the outer scale of turbulence L0 along the propagation path from a Twin Otter aircraft to a ground site (G6) at China Lake, CA. The nominal range to the aircraft from the ground site at G6 was 50 km, but variations in range extended from 30 km to 75 km. Although not part of the original Statement of Work (SoW), UCF also provided the same measurements at Hollister Air Force Range between the Hollister Airport and Fremont Peak over a path length of 17 km. In addition, UCF researchers also provided a comparison of theoretical models with measured quantities from the optical data beam during testing at both sites to ascertain some assessment of system performance. The UCF team took direct measurements of only the beacon beam at Hollister and China Lake which led to path-averaged values for the atmospheric parameters.

Maize (Zea mays L.) kernels are nutritionally deficient in the amino acids lysine, tryptophan, and methionine. Exogenous lysine-plus-threonine (LT) synergistically inhibits root growth of germinating kernels. We tested the hypothesis that the relative growths of seedlings grown on LT-supplemented and unsupplemented media (LT response) is a function of the relative concentrations of kernel methionine and lysine [...]

Core NWR 5 from Northwind Ridge in the western Arctic Ocean contains a climatic record that extends back for over 1 million years. Dark brown beds with abundant planktonic foraminifers represent interglacial conditions, whereas glacial and transitional conditions are represented by lithologies barren or nearly barren of planktonic foraminifers. We conclude that seven, and possibly all nine, interglacials of the Brunhes magnetic chronozone (the last 780,000 years) are represented in NWR 5. For about the last 800,000 years, the western Arctic Ocean apparently had a permanent, thick ice cover and was unable to support significant populations of planktonic foraminifers except during major interglacials when seasonally open and high-productivity surface waters occurred at least along the basin margins. Our results support previous interpretations that climate variations in the Arctic are in phase with glacial/interglacial cycles observed in other proxy records of the Brunhes.

The fetal mouse liver (FL) is an organ of intense, but transient, hematopoietic activity during mid-gestation, with erythropoiesis being predominant during days 11 through 16. It therefore seemed reasonable to expect that hematopoietic cytokines, such as erythropoietin (epo), interleukin-3 (IL-3), and stem cell factor (SCF), may play important roles in maintaining a homeostatic balance of erythropoiesis and apoptosis in liver during ontogeny. First, we determined the effects of these growth factors on hematopoiesis by measuring colony formation and hemoglobin synthesis of cultured FLs. Secondly, we determined the protection from apoptosis afforded by these cytokines, using electrophoretic analysis of DNA and by flow cytometry of FL cells deprived in culture of epo, IL-3, and SCF. Erythropoietin was necessary and alone sufficient for hemoglobin synthesis in colony-forming units- erythroid colonies, but IL-3 was a required cofactor to obtain maximal development of burst-forming units-erythroid colonies. SCF alone caused little colony formation in methylcellulose cultures of FLs, but when combined with epo and IL-3, it had dramatic effects both on the number of colonies and their size. Secondly, indices of apoptosis were determined by measuring DNA fragmentation caused by endogenous nuclease activity in apoptotic cells. Liver cells from cultures without cytokines showed the extensive degradation of DNA to low molecular weight nucleosomal oligomers, which is characteristic of apoptosis. Protection from apoptosis afforded by epo directly corresponded to the level of erythropoiesis in FLs of different gestational age. Erythropoietin was by far the most critical cytokine in sparing FL cells from apoptosis. Analyses of agarose gels showed that SCF and IL-3 alone had no apparent effect in reducing the amount of DNA in fragments, and when combined with epo they had no more protective effect than that provided by epo alone. However, using the more sensitive flow cytometric determination of cells with subdiploid amounts of DNA, SCF, and IL-3 alone had measurable protective effects that were less than those caused by epo. Thus, we show that normal, untransformed cells of the developing hematopoietic system not only require cytokines for proliferation and differentiation, but they have an initial and absolute requirement of them for protection from apoptosis.

The role of grassland ecosystems as net sinks or sources of greenhouse gases (GHGs) is limited by a paucity of information regarding management impacts on the flux of nitrous oxide (N(2)O) and methane (CH(4)). Furthermore, no long-term evaluation of net global warming potential (GWP) for grassland ecosystems in the northern Great Plains (NGP) of North America has been reported. Given this need, we sought to determine net GWP for three grazing management systems located within the NGP. Grazing management systems included two native vegetation pastures (moderately grazed pasture [MGP], heavily grazed pasture [HGP]) and a heavily grazed crested wheatgrass [Agropyron desertorum (Fisch. ex. Link) Schult.] pasture (CWP) near Mandan, ND. Factors evaluated for their contribution to GWP included (i) CO(2) emissions associated with N fertilizer production and application, (ii) literature-derived estimates of CH(4) production for enteric fermentation, (iii) change in soil organic carbon (SOC) over 44 yr using archived soil samples, and (iv) soil-atmosphere N(2)O and CH(4) fluxes over 3 yr using static chamber methodology. Analysis of SOC indicated all pastures to be significant sinks for SOC, with sequestration rates ranging from 0.39 to 0.46 Mg C ha(-1) yr(-1). All pastures were minor sinks for CH(4) (

Combined RF and optical communication within a heavily scintillated atmosphere requires special modems that can accommodate significant signal fading. A hybrid network (10 Gbps 1550 nm FSO and RF transmission) has been developed and a link quality parameter is used to assist the network routers with the path cost calculation algorithm. Fading statistics, determined by field experiments, are emulated in the laboratory network by a statistically-driven VOA. COTS hardware (FEC and a special amplifier) enable a 35 dB dynamic range. The special modem and its performance within a multi-node network are presented.

The most commonly used altitude-dependent model for refractive index fluctuations, over long high-altitude slant paths or ground/space links, is the Hufnagel-Valley model. For the near-ground turbulence portion of the path, this model uses an exponential decay term suggested by Valley to connect ground level turbulence with the original Hufnagel model which was constructed for turbulence above 3 km. However, it has long been observed that refractive-index fluctuations in the first few hundred meters near the ground decrease with altitude raised to the -4/3 power rather than exponentially. Recent and some earlier measurements of refractive-index fluctuations are presented in this paper along with a theoretical modification of the Hufnagel model to account for low-altitude turbulence exhibiting this power-law behavior.

B-PPM formatting for trans-atmospheric optical communication is compared experimentally to OOK (NRZ) at a single channel data rate of 1.25Gbps in deep fading conditions. Unlike low data rate transmission using M-ary PPM formatting, high-speed B-PPM formatting does not benefit from the theoretical improvement that has been realized at low data rate. Although B-PPM can indeed benefit from a threshold set to near-zero, the high speed transmission precludes the implementation of a traditional Maximum Likelihood Detection circuit that compares the integrated power of each slot. At high speed, one has to rely on signal strength alone within the bit period which degrades the contrast between a “one” and a “zero.” Moreover, the need for twice the bandwidth for B-PPM significantly limits available components such as APDs. More important, however, is the fact that during deep fades clock resynchronization dominates at high data rate. The primary question to be ad dressed is: Does B-PPM format ting really provide sufficient margin compared to NRZ to merit its use in deep fading atmospheric conditions? By building a special dual transceiver system, we have been able to propagate both B-PPM and NRZ formatted signals co-linearly on two C-band wavelengths centered close to 1550nm. Under field testing we measured the BER, including signal resynchronization, using special InGaAs, high-speed, multimode pigtailed, APD-based detectors in the receiver. The data were collected on fully instrumented horizontal paths of 1km and 500m with C

Chiropractors are the largest source of office-based care in the United States that does not involve a physician, but people do not view chiropractors as primary providers of health care or advice. Unlike the care given by primary care providers, the majority of care provided by chiropractors is limited to musculoskeletal problems.

Almost one decade after the Institute of Medicine (IOM) defined primary care, only one third of the American public is able to identify any of the medical specialties that provide it, and only 17 percent were able to accurately distinguish primary care physicians from medical or surgical specialists and non-physicians. This lack of discrimination compromises the goal of achieving primary care for all and merits immediate attention.

The public wants and is satisfied by care provided within a patient-physician relationship based on understanding, honesty, and trust. If the U.S. health care system is ever to become patient-centered, it must be designed to support these values and sustain, rather than fracture, the relationships people have with their primary physician.

Growth in the primary care physician workforce (physicians per capita) in the United States has trailed the growth of the specialist physician population in recent years. This has occurred despite calls during the same period for increased production of primary care physicians and educational reforms focusing on primary care.

Family physicians (FPs) provided 30 percent of inpatient newborn care in Maine in the year 2000. FPs cared for a large proportion of newborns, especially those insured by Medicaid and in smaller, rural hospitals where FPs also delivered babies. Family medicine's commitment to serve vulnerable populations of newborns requires continued federal, state, and institutional support for training and development of future FPs.

Family physicians provided nearly 20 percent of labor and delivery care in Maine in the year 2000. A substantial proportion of this care was provided to women insured by Medicaid and those delivering in smaller, rural hospitals and residency-affiliated hospitals. As family medicine explores its future scope, research identifying regional variations in the maternity care workforce may clarify the need for maternity care training in residency and labor and delivery services in practice.

While comprising about 15 percent of the physician workforce, family physicians provided approximately 20 percent of physician office-based mental health visits in the United States between 1980 and 1999. This proportion has remained stable over the past two decades despite a decline in many other types of office visits to family physicians. Family physicians remain an important source of mental health care for Americans.

In two studies about medical errors, family physicians reported health, time, and financial consequences in nearly 85 percent of their error reports. Health consequences occurred when the error caused pain, extended or created illness, or placed patients, their families, and others at greater risk of harm. Care consequences included delayed diagnosis and treatment (sometimes of serious health conditions such as cancer), and disruptions to care that sometimes even resulted in patients needing care in a hospital. Other important consequences were financial and time costs to patients, health care providers, and the health system generally. However, sometimes no consequence was apparent.

Over the past 20 years, family physicians and general practitioners (FP/GPs) and pediatricians have upheld their commitment to preventive care for infants. Non-Metropolitan Statistical Areas (non-MSAs) depend on family physicians for almost one half of their well-infant care. FP/GPs have increased their overall provision of well-infant care despite a decline in delivery of prenatal services. This commitment to child health care demands continued excellence of family physician training in pediatric medicine, preventive care, and child advocacy.

Title VII funding of departments of family medicine at U.S. medical schools is significantly associated with expansion of the primary care physician workforce and increased accessibility to physicians for the residents of rural and underserved areas. Title VII has been successful in achieving its stated goals and has had an important role in addressing U.S. physician workforce policy issues.

More and more often, seniors are faced with outpatient prescription benefits that have annual spending limits, and they may be forced to cut back on use of medications when they run out of benefits before the end of the year. Family physicians can play a valuable role by helping seniors choose the best value medications for their budgets and by checking whether or not seniors can afford their prescriptions.

Under the assumption that small-scale irradiance fluctuations are modulated by large-scale irradiance fluctuations, we developed a heuristic model of irradiance fluctuations for a propagating optical wave in a weakly inhomogeneous medium. This model takes into account the loss of spatial coherence as the optical wave propagates through atmospheric turbulence by eliminating effects of certain turbulent scale sizes that exist between two scale size, hereafter called the upper bound and the lower bound. These mid-range scale size effects are eliminated through the formal introduction of spatial frequency filters that continually adjust spatial cutoff frequencies as the optical wave propagates. By applying a modification of the Rytov method that incorporates an amplitude spatial frequency filter function under strong fluctuation conditions, tractable expressions are developed for the scintillation index of a Gaussian beam wave that are valid under moderate- to-strong irradiance fluctuations. Inner scale effects are taken into account by use of a modified atmospheric spectrum that exhibits a bump at large spatial frequencies. We also include the effect of a finite outer scale in addition to inner scale.

Family physicians, nurse practitioners and physician assistants are distinctly different in their clinical training, yet they function interdependently. Together, they represent a significant portion of the primary care work force. Training capacity for these professions has increased rapidly over the physician assistant decade, but almost no collaborative work force planning has occurred.

We identified patterns of tobacco cessation counseling in primary care practices, including contextual factors that influence its provision.A cross-sectional study was performed using direct observation of outpatient visits.We included 91 outpatient visits by cigarette smokers visiting 20 family physicians in 7 Nebraska community family practices.We measured patterns and quality of tobacco counseling assessed by direct observation.A hierarchy of 5 patterns was discernable, ranging from appropriate to inappropriate provision or nonprovision of tobacco cessation counseling.Since tobacco-specific discussions are appropriate only in approximately three fourths of primary care visits by smokers, clinical practice guidelines that recommend intervention at every visit are unrealistic. However, the finding that only one third of eligible visits addressed tobacco makes it imperative that tobacco cessation counseling be reliably integrated into visits for well care and tobacco-related illnesses that represent teachable moments.

Research to evaluate interventions to promote sleep in critically ill patients has been restricted by the lack of brief, inexpensive outcome measures. This article describes the development and testing of an instrument to measure sleep in critically ill patients. A convenience sample of 70 alert, oriented, critically ill males was studied using polysomnography (PSG), the gold standard for sleep measurement, for one night. In the morning the patients completed the Richards-Campbell Sleep Questionnaire (RCSQ), a five-item visual analog scale. Internal consistency reliability of the RCSQ was .90 and principal components factor analysis revealed a single factor (Eigenvalue = 3.61, percent variance = 72.2). The RCSQ total score accounted for approximately 33% of the variance in the PSG indicator sleep efficiency index (p.001). The data provide support for the reliability and validity of the RCSQ.

Sudden infant death syndrome (SIDS) is a major cause of infant mortality and is associated with the prone sleeping position. The goal of this study was to determine changes in newborn nursery policies and practices regarding infant sleeping position between 1992 and 1999.The researchers conducted telephone interviews with the head nurses in all of the newborn nurseries in Missouri.In 1992 there were 79 hospitals in Missouri with newborn nurseries; in 1999 that number had decreased to 75.During the interviews, the researchers solicited nursery infant sleep position policy and practice, head nurses' opinions about the supine sleep recommendation, and nurses' advice to parents regarding sleep position.In 1992, 32% of the nurseries used the prone position for sleep, and 58% of the head nurses interviewed disagreed with the recommendations of the American Academy of Pediatrics (AAP). By 1999, all newborn nurseries in Missouri placed infants on their backs or sides for sleep. The rate of disagreement with the AAP recommendation had decreased, with 25% of respondents indicating that they disagreed.From 1992 to 1999 nurseries in Missouri have changed from predominantly using prone and lateral positioning to lateral and supine positioning for newborns. Some nurses continue to voice concern about placing infants on their backs and expressed a willingness to place babies prone. Since there is agreement between nurses' usual infant positioning and the advice given to parents, and because both are important influences on infant positioning by parents, future campaigns to decrease SIDS should emphasize correcting nurses' positioning behavior and advising parents to increase infant supine positioning.

Maize chromosome addition lines of oat offer the opportunity to study maize gene expression in oat and the resulting phenotypes. Morphological examination of a maize chromosome 3 addition line of oat showed that this line exhibited several morphological abnormalities including a blade-to-sheath transformation at the midrib region of the leaf, a hook-shaped panicle, and abnormal outgrowth of aerial axillary buds. Dominant mutations in the maize liguleless3 (lg3) homeobox gene result in a blade (distal)-to-sheath (proximal) transformation at the midrib region of the leaf. Ectopic expression of the dominant mutant Lg3 allele is believed to cause the phenotype. Therefore, we suspected that the maize lg3 gene, which is located on maize chromosome 3, was involved in the phenotypes observed in the maize chromosome 3 addition line of oat. Genetic analyses of an oat BC1F2 family segregating for maize chromosome 3 showed that the presence of a stable maize chromosome 3 was required for the expression of these cell fate abnormalities. RNA expression analysis of leaf sheath tissue from oat plants carrying maize chromosome 3 demonstrated that maize LG3 transcripts accumulated in oat, indicating that this expression is associated with the blade-to-sheath transformation, hook-shaped panicle and outgrowth of aerial axillary bud phenotypes. Our results demonstrate that the maize chromosome addition lines of oat are useful genetic stocks to study expression of maize genes in oat.

The precise control of hematopoietic stem cell fate decisions involves molecules that are differentially expressed in the stem cell versus its non-stem progeny. The construction of representative and high quality cDNA libraries containing stem cell-specific sequences is a first step in elucidating stem cell control mechanisms. Automated bioinformatics in conjunction with high-throughput random sequencing and high-density parallel array hybridization studies make it possible to dissect stem cell molecular pathways and networks. It is the differential analysis of these interacting pathways which will provide the greatest insights into the biological differences underlying stem cell behavior.

Free space optical beam propagation is largely limited by the visibility of the channel at a particular location and at a particular time. In the absence of highly scattering particles, such as rain drops and snow flakes, the scintillation is the most severe limitation to system performance in an optical channel. An area of application mathematically similar to optical communications is laser radar. In a laser radar, a beam is transmitted through a channel, the atmosphere in our case, reflected by a target and received either at the same location it was transmitted from (monostatic channel) or another location (bistatic channel). Knowledge of the scintillation of the reflected beam could not only help design an appropriate receiving system, but could also give information about the reflecting object that could be utilized in forming its optical signature. Using our recently developed theory, we calculate the scintillation of a Gaussian beam propagating through atmospheric turbulence and reflected by a point target. The double pass scintillation is investigated for monostatic and bistatic channels and results are compared with our experimental data collected by an eight aperture heterodyne detection system.

Decreased libido disproportionately affects patients with depression. The relationship between depression and decreased libido may be blurred, but treating one condition frequently improves the other. Medications used to treat depression may decrease libido and sexual function. Frequently, patients do not volunteer problems related to sexuality, and physicians rarely ask about such problems. Asking a depressed patient about libido and sexual function and tailoring treatment to minimize adverse effects on sexual function can significantly increase treatment compliance and improve the quality of the patient's life.

The recovery of maize (Zea mays L.) chromosome addition lines of oat (Avena sativa L.) from oat x maize crosses enables us to analyze the structure and composition of individual maize chromosomes via the isolation and characterization of chromosome-specific cosmid clones. Restriction fragment fingerprinting, sequencing, and in situ hybridization were applied to discover a new family of knob associated tandem repeats, the TR1, which are capable of forming fold-back DNA segments, as well as a new family of centromeric tandem repeats, CentC. Analysis of knob and centromeric DNA segments revealed a complex organization in which blocks of tandemly arranged repeating units are interrupted by insertions of other repeated DNA sequences, mostly represented by individual full size copies of retrotransposable elements. There is an obvious preference for the integration/association of certain retrotransposable elements into knobs or centromere regions as well as for integration of retrotransposable elements into certain sites (hot spots) of the 180-bp repeat. DNA hybridization to a blot panel of eight individual maize chromosome addition lines revealed that CentC, TR1, and 180-bp tandem repeats are found in each of these maize chromosomes, but the copy number of each can vary significantly from about 100 to 25,000. In situ hybridization revealed variation among the maize chromosomes in the size of centromeric tandem repeats as well as in the size and composition of knob regions. It was found that knobs may be composed of either 180-bp or TR1, or both repeats, and in addition to large knobs these repeated elements may form micro clusters which are detectable only with the help of in situ hybridization. The association of the fold-back elements with knobs, knob polymorphism and complex structure suggest that maize knob may be consider as megatransposable elements. The discovery of the interspersion of retrotransposable elements among blocks of tandem repeats in maize and some other organisms suggests that this pattern may be basic to heterochromatin organization for eukaryotes.

The precise control of hematopoietic stem cell fate decisions involves molecules that are differentially expressed in the stem cell versus its non-stem progeny. The construction of representative and high quality cDNA libraries containing stem cell-specific sequences is a first step in elucidating stem cell control mechanisms. Automated bioinformatics in conjunction with high-throughput random sequencing and high-density parallel array hybridization studies make it possible to dissect stem cell molecular pathways and networks. It is the differential analysis of these interacting pathways which will provide the greatest insights into the biological differences underlying stem cell behavior.