269 research outputs found

    Pollination Characteristics of Blowout Penstemon (\u3ci\u3ePenstemon haydenii\u3c/i\u3e S. Watson)

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    The pollination characteristics of blowout penstemon (Penstemon haydenii S. Wats.), the only officially endangered plant species in Nebraska, were investigated. Cross-pollination was determined to be the major method of pollination, but self-pollination also occurs. Insects increased cross-pollination. The natural habitat of blowout penstemon has greatly decreased during this century, resulting in only a few isolated populations. The opportunity for cross-pollination with other populations no longer exists. Without crosspollination, lowered genetic diversity of the species may result in less vigorous plants and declining populations. Introduction of new genetic material into declining populations may help to assure the continued existence of the species

    Blowouts in the Nebraska Sandhills: The Habitat of \u3ci\u3ePenstemon haydenii\u3c/i\u3e

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    The Nebraska Sandhills is the largest area of sand dunes in the Western Hemisphere, occupying over 5 million ha in northcentral Nebraska. The rolling to steep dunes range in height from a few meters to over 60 m. Soils are poorly developed in wind deposited sand. The continental climate is characterized by 425 to 625 mm of annual precipitation, an average annual temperature of 10 C, and a frost-free period of 130-155 days. Upland vegetation is primarily tall grasses and midgrasses such as sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.], prairie sandreed [CaLamovilfa Longifolia (Hook.) Scribn.], little bluestem [Schizachyrium scoparium (Michx.) Nash], and switchgrass (Panicum virgatum L.). Forbs are common. Wind erosion occurs when the protective cover of vegetation is destroyed. Blowouts are active sites of erosion. Blowouts are irregular or conical craters formed when the deep, loose sands are removed by swirling action of the prevailing northwesterly winds. Blowout penstemon (Penstemon haydenii S. Wats.) is only found on these sites of active wind erosion and is an early successional species. Important associated species in blowouts include blowout grass [Redfieldia flexuosa (Thurb.) Vasey] and lemon scurfpea (Psoralea Lanceolata Pursh). The number of blowouts has decreased with the control of fire and improved range management techniques. Loss of suitable habitat is one of the reasons for the decline of blowout penstemon. At the same time, there are many blowouts in the Sandhills that seem to offer suitable habitat where blowout penstemon is not found

    Blowouts in the Nebraska Sandhills: The Habitat of \u3ci\u3ePenstemon haydenii\u3c/i\u3e

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    The Nebraska Sandhills is the largest area of sand dunes in the Western Hemisphere, occupying over 5 million ha in northcentral Nebraska. The rolling to steep dunes range in height from a few meters to over 60 m. Soils are poorly developed in wind deposited sand. The continental climate is characterized by 425 to 625 mm of annual precipitation, an average annual temperature of 10 C, and a frost-free period of 130-155 days. Upland vegetation is primarily tall grasses and midgrasses such as sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.], prairie sandreed [CaLamovilfa Longifolia (Hook.) Scribn.], little bluestem [Schizachyrium scoparium (Michx.) Nash], and switchgrass (Panicum virgatum L.). Forbs are common. Wind erosion occurs when the protective cover of vegetation is destroyed. Blowouts are active sites of erosion. Blowouts are irregular or conical craters formed when the deep, loose sands are removed by swirling action of the prevailing northwesterly winds. Blowout penstemon (Penstemon haydenii S. Wats.) is only found on these sites of active wind erosion and is an early successional species. Important associated species in blowouts include blowout grass [Redfieldia flexuosa (Thurb.) Vasey] and lemon scurfpea (Psoralea Lanceolata Pursh). The number of blowouts has decreased with the control of fire and improved range management techniques. Loss of suitable habitat is one of the reasons for the decline of blowout penstemon. At the same time, there are many blowouts in the Sandhills that seem to offer suitable habitat where blowout penstemon is not found

    Blowouts in the Nebraska Sandhills: The Habitat of \u3ci\u3ePenstemon haydenii\u3c/i\u3e

    Get PDF
    The Nebraska Sandhills is the largest area of sand dunes in the Western Hemisphere, occupying over 5 million ha in northcentral Nebraska. The rolling to steep dunes range in height from a few meters to over 60 m. Soils are poorly developed in wind deposited sand. The continental climate is characterized by 425 to 625 mm of annual precipitation, an average annual temperature of 10 C, and a frost-free period of 130-155 days. Upland vegetation is primarily tall grasses and midgrasses such as sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.], prairie sandreed [CaLamovilfa Longifolia (Hook.) Scribn.], little bluestem [Schizachyrium scoparium (Michx.) Nash], and switchgrass (Panicum virgatum L.). Forbs are common. Wind erosion occurs when the protective cover of vegetation is destroyed. Blowouts are active sites of erosion. Blowouts are irregular or conical craters formed when the deep, loose sands are removed by swirling action of the prevailing northwesterly winds. Blowout penstemon (Penstemon haydenii S. Wats.) is only found on these sites of active wind erosion and is an early successional species. Important associated species in blowouts include blowout grass [Redfieldia flexuosa (Thurb.) Vasey] and lemon scurfpea (Psoralea Lanceolata Pursh). The number of blowouts has decreased with the control of fire and improved range management techniques. Loss of suitable habitat is one of the reasons for the decline of blowout penstemon. At the same time, there are many blowouts in the Sandhills that seem to offer suitable habitat where blowout penstemon is not found

    Synthesis of new spin labels for Cu-free click conjugation

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    New pyrroline nitroxides attached to a terminal acetylenic sulfone, a dibenzocyclooctyne or a cyclooctyne carboxylic acid were synthesized and tested in Cu-free click reactions to conjugate these new spin labels with 4-azido-TEMPO, azidophenylalanine and an azidophenylalanine-containing protein

    A Latent Profile Analysis of Age of Onset in Pathological Skin Picking

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    Background Pathological Skin Picking (PSP) may begin at any age, but the most common age of onset is during adolescence. Age of onset is a potentially useful clinical marker to delineate subtypes of psychiatric disorders. The present study sought to examine empirically defined age of onset groups in adults with PSP and assess whether groups differed on clinical characteristics. Method Participants were 701 adult respondents to an internet survey, who endorsed recurrent skin picking with tissue damage and impairment. Latent profile analysis (LPA) was conducted to identify subtypes of PSP based on age of onset. Then subgroups were compared on demographic and clinical characteristics. Results The best fitting LPA model was a two-class solution comprised of a large group with average age of onset in adolescence (n = 650; 92.9% of the sample; Mean age of onset = 13.6 years) and a small group with average onset in middle adulthood (n = 50; 7.1% of the sample; Mean age of onset = 42.8 years). Relative to the early onset group, the late onset group reported significantly less focused picking, less skin picking-related impairment, lower rates of co-occurring body-focused repetitive behaviors, and trends towards reduced family history of PSP. Individuals in the late onset group also reported increased rates of comorbid depression, anxiety and posttraumatic stress disorder, and were more likely to report that initial picking onset seemed related to or followed depression/anxiety and physical illness. Conclusion Findings suggest the presence of two distinct PSP age of onset groups: (1) an early onset group with average onset in adolescence, clinical characteristics suggestive of greater picking-related burden and familiality, and a profile more representative of the general PSP population; and (2) a late onset group with average onset in middle adulthood, increased co-occurring affective and trauma conditions, and initial onset associated with or following other mental health and physical problems. Future replication is needed to assess the validity and clinical utility of these subgroups

    Quantitative Histomorphometry of the Healthy Peritoneum

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    The peritoneum plays an essential role in preventing abdominal frictions and adhesions and can be utilized as a dialysis membrane. Its physiological ultrastructure, however, has not yet been studied systematically. 106 standardized peritoneal and 69 omental specimens were obtained from 107 patients (0.1-60 years) undergoing surgery for disease not affecting the peritoneum for automated quantitative histomorphometry and immunohistochemistry. The mesothelial cell layer morphology and protein expression pattern is similar across all age groups. Infants below one year have a thinner submesothelium; inflammation, profibrotic activity and mesothelial cell translocation is largely absent in all age groups. Peritoneal blood capillaries, lymphatics and nerve fibers locate in three distinct submesothelial layers. Blood vessel density and endothelial surface area follow a U-shaped curve with highest values in infants below one year and lowest values in children aged 7-12 years. Lymphatic vessel density is much lower, and again highest in infants. Omental blood capillary density correlates with parietal peritoneal findings, whereas only few lymphatic vessels are present. The healthy peritoneum exhibits major thus far unknown particularities, pertaining to functionally relevant structures, and subject to substantial changes with age. The reference ranges established here provide a framework for future histomorphometric analyses and peritoneal transport modeling approaches. © 2016, EDP Science. All rights reserved

    Albumin-based cancer therapeutics for intraperitoneal drug delivery : a review

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    Albumin is a remarkable carrier protein with multiple cellular receptor and ligand binding sites, which are able to bind and transport numerous endogenous and exogenous compounds. The development of albumin-bound drugs is gaining increased importance in the targeted delivery of cancer therapy. Intraperitoneal (IP) drug delivery represents an attractive strategy for the local treatment of peritoneal metastasis (PM). PM is characterized by the presence of widespread metastatic tumor nodules on the peritoneum, mostly originating from gastro-intestinal or gynaecological cancers. Albumin as a carrier for chemotherapy holds considerable promise for IP delivery in patients with PM. Data from recent (pre)clinical trials suggest that IP albumin-bound chemotherapy may result in superior efficacy in the treatment of PM compared to standard chemotherapy formulations. Here, we review the evidence on albumin-bound chemotherapy with a focus on IP administration and its efficacy in PM

    The relation of C - reactive protein to chronic kidney disease in African Americans: the Jackson Heart Study

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    <p>Abstract</p> <p>Background</p> <p>African Americans have an increased incidence and worse prognosis with chronic kidney disease (CKD - estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m<sup>2</sup>) than their counterparts of European-descent. Inflammation has been related to renal disease in non-Hispanic whites, but there are limited data on the role of inflammation in renal dysfunction in African Americans in the community.</p> <p>Methods</p> <p>We examined the cross-sectional relation of log transformed C-reactive protein (CRP) to renal function (eGFR by Modification of Diet and Renal Disease equation) in African American participants of the community-based Jackson Heart Study's first examination (2000 to 2004). We conducted multivariable linear regression relating CRP to eGFR adjusting for age, sex, body mass index, systolic and diastolic blood pressure, diabetes, total/HDL cholesterol, triglycerides, smoking, antihypertensive therapy, lipid lowering therapy, hormone replacement therapy, and prevalent cardiovascular disease events. In a secondary analysis we assessed the association of CRP with albuminuria (defined as albumin-to-creatinine ratio > 30 mg/g).</p> <p>Results</p> <p>Participants (n = 4320, 63.2% women) had a mean age ± SD of 54.0 ± 12.8 years. The prevalence of CKD was 5.2% (n = 228 cases). In multivariable regression, CRP concentrations were higher in those with CKD compared to those without CKD (mean CRP 3.2 ± 1.1 mg/L vs. 2.4 ± 1.0 mg/L, respectively p < 0.0001). CRP was significantly associated with albuminuria in sex and age adjusted model however not in the multivariable adjusted model (p > 0.05).</p> <p>Conclusion</p> <p>CRP was associated with CKD however not albuminuria in multivariable-adjusted analyses. The study of inflammation in the progression of renal disease in African Americans merits further investigation.</p
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