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101.
102.
Understanding microsite requirements is critical for restoring sustainable rare plant populations and creating meaningful management plans that will enhance native species’ population viability. Natural areas bordered by urban communities have restricted size and constrained management options that confound goals of preserving biodiversity. Using geographical information systems and observational and experimental studies, we determined that current microsites required for seedling establishment within existing habitat of the federally endangered Crenulate leadplant are few and spatially restricted, resulting in little wild seedling recruitment. Experimental and wild seedlings had highest germination rates in litter layers 1–2 cm in depth and survived the longest in litter 0.5–2 cm deep. Fire suppression and aggressive native and exotic plants have accumulated litter up to 33 cm near some of the wild adult Crenulate leadplant. Only 9% of habitat occupied by this taxon at its largest population is conducive to seedling establishment. Similarly, 30% is conducive to seedling establishment in the second largest population. Fire plays a critical role in South Florida ecosystem dynamics and the restoration and preservation of its landscape and biodiversity. When fire is not possible, other management is needed. Manual litter and downed debris removal are recommended at both population sites to improve the probability of Crenulate leadplant seedling establishment and population persistence. 相似文献
103.
We investigated the development of food transfer and independent feeding in cotton-top tamarin (Saguinus oedipus) families. We studied the relationship between infant-directed vocalizations and food transfers on the development of independent feeding in infants. We experimentally tested ten infants (eight twins and two singletons) three times a week for 17 weeks from before weaning through 20 weeks. Food transfers and vocalizations made during tests were recorded and analyzed to determine (1) the role of vocalizations (C- and D- chirps and D-chirp series) in food acquisition, (2) the relationship between food transfers and individual food acquisition, and (3) whether, owing to energetic costs of nursing and carrying twins, food is transferred to twins sooner than to singletons. Infants were more successful in acquiring food via begging when adults produced repeated vocalizations than when adults did not vocalize. Adults emitted more food-related vocalizations in rapid series when in the presence of infants, whereas during feeding in the absence of infants only single unit vocalizations were produced. Begging occurred frequently. Changes over infant age were not significant when all infants were included in analysis. However, when twin data were analyzed alone, begging success changed significantly over months, with successful begging peaking in month 3 (week 12). Begging success rate did not differ between twins and singletons, although twins fed independently sooner and at a higher rate than did singletons. 相似文献
104.
105.
Abstract Herein the first detailed study of sociality and life history in an Australian species of the allodapine bee genus Braunsapis is provided. Colonies of B. protuberans were sampled from the Great Sandy National Park in Queensland from late winter until later summer. Single-female colonies appear to have suffered substantially higher rates of total brood loss, or failure to produce brood, than multifemale colonies, but rearing efficiency in colonies with at least some brood did not differ between these two colony types. There was marked reproductive skew in multifemale colonies and ovary size was strongly linked to relative body size. However, females with smaller body size and smaller ovaries also had lower levels of wing wear, suggesting that they do not specialise in foraging. These patterns are similar to an African species, Braunsapis vitrea , and suggest that colonies may principally comprise a dominant reproductive female who provides food for her juvenile offspring, along with a variable number of subordinate females who may be waiting to inherit their natal nest in the event of their mother's death. However, it is likely that in such events, the remaining female(s) will care for orphaned brood as some single-female colonies contained substantial older brood, even though the sole female had little or no wing wear. Such alloparental care in the case of orphaning may help explain the high level of female bias in sex ratios. 相似文献
106.
Doan JE Windmiller DA Riches DW 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(12):7654-7660
The TNFR, TNF-R1, is localized to lipid raft and nonraft regions of the plasma membrane. Ligand binding sets in motion signaling cascades that promote the activation of p42(mapk/erk2) and NF-kappaB. However, the role of receptor localization in the activation of downstream signaling events is poorly understood. In this study, we investigated the dynamics of TNF-R1 localization to lipid rafts and the consequences of raft localization on the activation of p42(mapk/erk2) and NF-kappaB in primary cultures of mouse macrophages. Using sucrose density gradient ultracentrifugation and a sensitive ELISA to detect TNF-R1, we show that TNF-R1 is rapidly and transiently recruited to lipid rafts in response to TNF-alpha. Disruption of lipid rafts by cholesterol depletion prevented the TNF-alpha-dependent recruitment of TNF-R1 to lipid rafts and inhibited the activation of p42(mapk/erk2), while the activation of NF-kappaB was unaffected. In addition, phosphorylated p42(mapk/erk2), but not receptor interacting protein, I-kappaB kinase-gamma, or I-kappaBalpha was detected in raft-containing fractions following TNF-alpha stimulation. These findings suggest that TNF-R1 is localized to both lipid raft and nonraft regions of the plasma membrane and that each compartment is capable of initiating different signaling responses. We propose that segregation of TNF-R1 to raft and nonraft regions of the plasma membrane contributes to the diversity of signaling responses initiated by TNF-R1. 相似文献
107.
Jazmin Aguado-Sierra Adarsh KrishnamurthyChristopher Villongco Joyce ChuangElliot Howard Matthew J. GonzalesJeff Omens David E. Krummen Sanjiv Narayan Roy C.P. KerckhoffsAndrew D. McCulloch 《Progress in biophysics and molecular biology》2011,107(1):147-155
The development and clinical use of patient-specific models of the heart is now a feasible goal. Models have the potential to aid in diagnosis and support decision-making in clinical cardiology. Several groups are now working on developing multi-scale models of the heart for understanding therapeutic mechanisms and better predicting clinical outcomes of interventions such as cardiac resynchronization therapy. Here we describe the methodology for generating a patient-specific model of the failing heart with a myocardial infarct and left ventricular bundle branch block. We discuss some of the remaining challenges in developing reliable patient-specific models of cardiac electromechanical activity, and identify some of the main areas for focusing future research efforts. Key challenges include: efficiently generating accurate patient-specific geometric meshes and mapping regional myofiber architecture to them; modeling electrical activation patterns based on cellular alterations in human heart failure, and estimating regional tissue conductivities based on clinically available electrocardiographic recordings; estimating unloaded ventricular reference geometry and material properties for biomechanical simulations; and parameterizing systemic models of circulatory dynamics from available hemodynamic measurements. 相似文献
108.
The ability of Streptococcus agalactiae and Streptococcus iniae to attract macrophages of Nile tilapia (Oreochromis niloticus) was investigated. The extracellular products (ECP) from S. agalactiae and S. iniae were tested in vitro for macrophage chemotaxis using blind-well chambers. The macrophages were obtained from the peritoneal cavity 4-5 days after intraperitoneal injection of squalene. Both macrophage chemotactic and chemokinetic activities were demonstrated using the S. agalactiae ECP. However, only chemotactic activity was shown for S. iniae ECP. High-pressure liquid chromatography fractionation revealed that semi-purified S. agalactiae and S. iniae ECPs had estimated molecular weights of 7.54 and 19.2kDa, respectively. The prominent chemotactic activities of ECP from S. agalactiae and S. iniae are likely to be involved in the proinflammatory responses of macrophages to S. agalactiae and S. iniae infections. 相似文献
109.
Amelia C Jones James G Herndon Cynthia L Courtney Lynn Collura Joyce K Cohen 《Comparative medicine》2014,64(3):200-210
In 2008, clinical observations in our colony of sooty mangabeys (Cercocebus atys) suggested a high frequency of type 2 diabetes. Postmortem studies of diabetic animals revealed dense amyloid deposits in pancreatic islets. To investigate these findings, we screened our colony (97 male mangabeys; 99 female mangabeys) for the disease from 2008 to 2012. The overall prevalence of diabetes was 11% and of prediabetes was 7%, which is nearly double that reported for other primate species (less than 6%). Fructosamine and triglyceride levels were the best indicators of diabetes; total cholesterol and glycated hemoglobin were not associated with disease. Increasing age was a significant risk factor: prevalence increased from 0% in infants, juveniles, and young adults to 11% in adults and 19% in geriatric mangabeys. Sex, medroxyprogesterone acetate exposure, and SIV status were unrelated to disease. Weight was marginally higher in prediabetics, but body condition did not indicate obesity. Of the 49 mangabeys that were necropsied after clinical euthanasia or death from natural causes, 22 were diabetic; all 22 animals demonstrated pancreatic amyloid, and most had more than 75% of islets replaced with amyloid. We conclude that type 2 diabetes is more common in mangabeys than in other primate species. Diabetes in mangabeys has some unusual pathologic characteristics, including the absence of altered cholesterol levels and glycated hemoglobin but a robust association of pancreatic insular amyloidosis with clinical diabetes. Future research will examine the genetic basis of mangabey diabetes and evaluate additional diagnostic tools using imaging and serum markers.Abbreviations: HbA1c, glycated hemoglobin; MPA, medroxyprogesterone acetate; YNPRC, Yerkes National Primate Research CenterSooty mangabeys (Cercocebus atys) are Old World NHP that are native to West Africa. Historically their use in research has been limited to infectious disease studies, leprosy studies, and behavioral research.14,25 Over the past 20 to 30 y, they have been used in HIV–AIDS research. Mangabeys are natural hosts of SIVsmm, which is recognized as the origin of HIV2 infection in humans.7,8,30,36,42 SIV typically is nonpathogenic in mangabeys despite high levels of virus replication, which makes this species a unique and invaluable model in AIDS research.7,30,36,42 Our facility maintains a colony of approximately 200 sooty mangabeys. In 2008 clinical observations of relative hyperglycemia, glucosuria, and weight loss in our colony suggested that type 2 diabetes mellitus occurred at a relatively high frequency in this population. Spontaneous diabetes was found in 10% of the colony, and 5% of animals were prediabetic; this incidence is higher than that typically reported for other NHP species, such as cynomolgus macaques (less than 1% to 2%)22 and chimpanzees (less than 1%).37 The prevalence of spontaneous diabetes in humans is typically 8.3%.2,6,22,37 In addition, necropsies revealed that many affected animals had dense amyloid deposits in pancreatic islet cells. Insular amyloidosis was seen on histology, with a total replacement of islets by amyloid deposition in advanced diabetes. Advanced diabetes was determined by increased weight loss and severity of relative hyperglycemia. The increased clinical prevalence of diabetes in our mangabey colony prompted additional characterization of the clinicopathologic profile, risk factors, and prevalence of diabetes in our mangabey colony.The form of diabetes in this mangabey colony is characterized as type 2 diabetes mellitus, as they have hyperglycemia, hypertriglyceridemia, and islet amyloidosis. Type 2 diabetes mellitus is the most common of the 3 forms of diabetes, and has been documented in humans and NHP,22,31,37,55 including rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), Celebes crested macaques (Macaca nigra), bonnet macaques (Macaca radiate), pigtailed macaques (Macaca nemestrina), vervet monkeys (Chlorocebus pygerythrus), squirrel monkeys (Saimiri sciureus), chimpanzees (Pan troglodytes), and woolly monkeys (Lagothrix spp.).1,24,31,52,55 Type 2 diabetes is a chronic metabolic disorder in which insulin resistance occurs in liver, muscle, and adipose tissue. As type 2 diabetes progresses, it also can be characterized as a relative insulin deficiency.1,6,15,22,29,31,37,55 The initial clinical presentation of diabetes in humans and NHP includes polydipsia, polyuria, polyphagia, weight loss, and lethargy.1,6,22,27,31,37,55 Similar presentation was observed in our colony of diabetic mangabeys.Diagnostic criteria of diabetes in NHP species is similar to that for humans and is based on clinical symptoms and routine lab tests, including serum chemistry panel to evaluate persistent fasting hyperglycemia, hypertriglyceridemia, and hypercholesterolemia.2,6,11,16-18,21,22,29,31,37,48-50,52,55 Hypertriglyceridemia and hypercholesterolemia frequently are elevated due to diabetes and therefore are used as supportive diagnostic markers. In addition, the disease is characterized by transient hyperinsulinemia followed by insulin deficiency subsequent to glucose challenge. Urinalysis is used to evaluate glucosuria and ketonuria. These tests are not exclusive for diagnosing diabetes and can be inconsistent between species, thus making conclusive diagnosis challenging. For example, hyperglycemia can be a transient finding associated with recent food intake or stress associated with restraint for blood sample collection or anesthetic access, whereas hypertriglyceridemia can be seen in obese animals and those with other metabolic diseases such as pancreatitis and hypothyroidism.1,22,37,55The typical clinical approach to the diagnosis of diabetes in NHP and other veterinary patients includes evaluation of fructosamine and glycated hemoglobin (HbA1c) levels and glucose tolerance testing. These tests are indices of glycemic control and are used in clinical settings primarily to assess prognosis and response to treatment; they are also useful for the initial diagnosis of diabetes when used in parallel with serum chemistry markers. Fructosamine and HbA1c can both provide information on long-term glycemic control, because fructosamine reflects average blood glucose levels over 2 to 3 wk whereas HbA1c reflects average blood glucose over 2 to 3 mo preceding blood collection. HbA1c is the primary test for diabetes in human medicine,6,31,35,37 whereas fructosamine is commonly used in veterinary medicine. Glucose tolerance testing provides an indirect measure of insulin sensitivity, but it is not frequently used clinically in NHP because of the requirement for prolonged physical restraint or sedation.1,21,22,26,27,34,37,55Prevention and management of diabetes in NHP and humans can be achieved by identifying potential risk factors, including age, weight, sex, genetics, hormone drug exposure, and viral status.1,6,15,22,29,31,37,42,55 Advanced age, obesity, sex, and genetics are associated with diabetes in some species of NHP and humans.1,6,15,22,29,31,37,55 In addition, exposure to drugs such as medroxyprogesterone acetate (MPA) is suspected to be linked to diabetes due to the hormonal effects of progesterone impacting glucoregulatory function.1,6,10,22,23,31,34,55 MPA exposure is of interest, because it is used regularly in our mangabey colony as both a contraceptive and as therapy for endometriosis. In addition, SIV status is being evaluated as a risk factor, because a portion of our colony is SIV positive. Although HIV is not thought to be associated with diabetes in people, SIV pathogenesis in mangabeys differs; therefore it was of interest to explore the possible association of SIV and diabetes in mangabeys.7,30,36,42 Pancreatic insular amyloidosis has been documented to be associated with type 2 diabetes in several species. Amyloidosis is a group of disorders that are caused by extracellular deposition of misfolded proteins that can result in impaired function of any organ.15,20,23,28,32,43,45,48,49 Because a high incidence of pancreatic insular amyloid was noted at necropsy, we sought to document the relationship with clinical diabetes in mangabeys.Spontaneous type 2 diabetes mellitus has been well documented in several species of NHP. Because the literature contains little information regarding the clinicopathologic features (the ‘profile’), risk factors, and prevalence of spontaneous diabetes mellitus in sooty mangabeys, the primary aims of the current study were 1) to determine whether elevated levels of fasting blood glucose, fructosamine, HbA1c, triglycerides, and total cholesterol levels are reliable diagnostic markers of type 2 diabetes mellitus in this NHP species; 2) to determine whether age, sex, MPA exposure, and SIV status influence the risk of diabetes; 3) to determine whether body weight influences diabetic status; 4) to evaluate the relationship between pancreatic amyloidosis and diabetes mellitus; and 5) to characterize the prevalence of diabetes mellitus in the mangabey population at our institution. To our knowledge, this report is the first to describe the natural occurrence of type 2 diabetes mellitus within a captive colony of sooty mangabeys. We hypothesized that blood glucose, fructosamine, HbA1c, triglyceride, and total cholesterol would be reliable diagnostic markers and that age, sex, and MPA exposure would influence the risk of diabetes in this species. 相似文献
110.
Jennifer L. Belsky Alyssa J. Ashley Premal A. Bhatt Karen V. Gilbert Heather R. Joyce Chunhua Pan Horacio Pappa Samir Z. Wahab 《AAPS PharmSciTech》2010,11(2):994-1004
The water-insoluble procedures in US Pharmacopeia (USP) General Chapter Residual Solvents <467>, which are based on European Pharmacopoeia procedures, were optimized and modified before their inclusion in the chapter to improve their scope, performance, and ruggedness.
The optimized procedures use a static headspace introduction system with a gas chromatograph equipped with a flame ionization
detector. This article describes some of the key changes made to the USP published procedures, including use of dimethyl sulfoxide
(DMSO) or dimethylformamide (DMF) as the solvent, addition of 5 mL of water and 1 mL of sample (dissolved in DMSO or DMF)
to the headspace vial, use of a 3:1 GC split ratio, and use of new matrix-matched system suitability solutions. These procedures
were verified with two different active pharmaceutical ingredients—hydroxyzine pamoate and prednisone. In the investigation,
the more polar material (hydroxyzine pamoate) showed greater recoveries for the optimized procedures when prepared in DMSO.
The less polar material (prednisone) typically had greater recoveries in DMF for the optimized procedures. During experimentation,
insights into sample preparation, additional types of headspace instrumentation, solvent purity, and other parameters were
also gained. 相似文献