7,786 research outputs found

    \u3ci\u3eLeucanthiza Dircella\u3c/i\u3e (Lepidoptera: Gracillariidae): A Leafminer of Leatherwood, \u3ci\u3eDirca Palustris\u3c/i\u3e

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    Leatherwood, Dirca palustris (Thymelaeaceae), is an understory shrub ranging throughout most of the eastern and central United States and adjacent Canada. During 1997-1999, we conducted studies to identify and assess the impact of a leafminer that was causing significant damage to leather- wood plants in eastern Gogebic County, Michigan. Leucanthiza dircella was identified as the only insect responsible for the leaf mining activity on leatherwood. In northern Michigan, L. dircella completed one generation per year. Adult moths were captured on yellow sticky panels suspended from leatherwood branches. In 1997 and 1998, most adults were captured during the first sampling period of each year: 6-12 June 1997 and 3-19 May 199B. In 1999, no moths were collected during 5-29 April but adults were collected between 30 April and 22 June 1999. In 1999, initiation of adult flight coincided with D. palustris leaf flush. In 1997, leaf mines were very noticeable by 30 June. The mean number of live L. dircella larvae per mine was 3.5 on 17 July 1997 and then decreased as the season progressed, with most larvae having exited the mines by late August to pupate in the soil. In late August 1997, the mean surface area of a single leaf was 17.8 cm2 and the mean surface area of a single mine was 5.9 cm2. At the end of the 1997 growing sea­son, 31% of the leatherwood leaves contained L. dircella mines, and 11% of the total leaf surface area had been mined. In 1999, only 8% of the leaves in the study area contained L. dircella mines. No leatherwood mortality was evident as a result of L. dircella leaf mining. Seven species of hymenopteran parasitoids were reared from L. dircella larvae, including one braconid in the genus Pholetesor and six eulophids in the genera Chrysocharis, Closterocerus, Pnigalio, and Sympiesis. Three coleopterans that were commonly observed on leatherwood plants during all years included: Glyptina brunnea (Chrysomelidae), Phyllobius oblongus (Curculionidae) and Polydrusus sericeus (Curculionidae)

    PERSONAL WELL-BEING IN URBAN CHINA

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    This paper reports the findings of a survey administering the Personal Well-Being Index in six Chinese cities (N=3390) to ascertain the personal well-being of China's urban population.The specific aims of the study were: (a) ascertain whether Chinese urban residents are satisfied with their lives; (b) validate the PWI using an urban sample that is representative of the urban population and larger in size than that which has been utilized in existing studies for Mainland China; (c) compare the results to existing studies for Hong Kong, Macau, rural China and single city studies which have administered the PWI in Guangdong and Shandong; (d) examine whether the responses to the PWI from participants falls within the narrow range predicted by the ???Theory of Subjective Wellbeing Homeostasis??? and provide further evidence on whether this framework is applicable to Chinese samples; and (e) examine which participant characteristics predict personal well-being, examine whether own income and/or relative income predicts personal well-being and compare these results with previous studies for China and other countries. The data indicated a moderate level of personal well-being (PWI score = 67.1). The PWI demonstrated good psychometric performance in terms of its reliability, validity and sensitivity, consistent with previous published studies. The PWI was within the normative range for non-Western countries and was within the narrow band predicted by the ???Theory of Subjective Wellbeing Homeostasis???. Similar variables were found to predict personal well-being to those found in previous studies for China and elsewhere.China, Personal Wellbeing Index, Subjective Wellbeing

    Low flow controls on benthic and hyporheic macroinvertebrate assemblages during supra-seasonal drought

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    Despite the widely accepted importance of the hyporheic zone as a habitat for stream macroinvertebrates during floods, few data exist regarding community composition and distribution during periods of low flow or drought in perennial streamsi Integrating research on hyporheic invertebrates with results from a long-term study of a U K river provided the opportunity to examine how surface and hyporheic macroinvertebrate communities respond to inter-annual variability in river flow and periods of groundwater drought. Changes in the riverine macroinvertebrate community associated with low flow included a reduction in species richness and the number of individuals per sample, particularly aquatic insects. The hyporheic community was characterized by a relatively homogeneous composition during a period of severe low flow, punctuated by short-term changes associated with variation in water temperature rather than changes in discharge. We present a conceptual model of the processes influencing benthic and hyporheic invertebrates under low-flow conditions. Previous studies have seldom integrated these two assemblages and their interactions. The model presented highlights the potential importance of surface water and hyporheic zone linkages for riverine invertebrate communities under a range of flow conditions

    By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans.

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    Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation

    Laparoscopic Assisted Fusion of the Lumbosacral Spine: A Biomechanical and Histologic Analysis of the Open Versus Laparoscopic Technique in an Animal Model

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    Study Design. An animal model for laparoscopic lumbosacral fusion. Objectives. To compare the biomechanical and histologic results of open to laparoscopic lumbosacral discectomy and fusion in an animal model. Background Data. Early clinical reports of laparoscopic lumbosacral fusions are encouraging, but animal experiments have not been reported. Methods. Ten pigs (50-80 kg) were divided into two groups. Group 1 underwent an open anterior lumbosacral discectomy and fusion at L7-S1 using autologous bone graft and a titanium MOSS (DePuy Motech) cage. Group 2 was identical to Group 1 except that a laparoscopic technique was used. The animals were killed at 3 months, and the lumbosacral spines were harvested for biomechanical and histologic testing. Results. Estimated blood loss and average length of operation, respectively, for the two groups were: Group 1, 50 mL, 2 hours 50 minutes; and Group 2, 40 mL, 3 hours 40 minutes. There were no perioperative or postoperative complications in either group. Motion analysis results showed less motion in lateral bending, flexion, and extension than in the intact specimen in both groups. Tensile testing showed that the stiffness was significantly greater in the open group than in the laparoscopic group (P \u3c 0.004). Histologic examination showed a less extensive discectomy and less bone growth in the implant in the laparoscopic group. Inadequate decortication of end-plates occurred in two animals who underwent laparoscopy. Conclusions. Although lumbosacral discectomy and implant insertion can be performed using the laparoscopic technique, the construct may not have the same biomechanical strength as that attained with the open procedure. Laparoscopic-assisted lumbosacral fusion surgery requires additional investigation before it is widely used in clinical situations

    The Working in Health Access Programme (WHAP): impact on school leaving exam results and applications to Medicine

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    Introduction: Pupils from backgrounds wit socio-economic deprivation are less likely to apply to study medicine than those from more affluent backgrounds. It is unclear whether those who might have the potential to be doctors can be identified at a time when they can be exposedto awareness raising activities to enhance their likelihood of success. Methods: Sixty nine schools from all parts of Scotland with below average participation rates in Higher Education took part. More than 2000 pupils sat tests of cognitive ability (Mill Hill Vocabulary Scale and Raven’s Progressive Matrices) as well as non-cognitive tests assessing characteristics that could influence success as a doctor. Results: The results of the cognitive tests correlated closely with Standard Grade Examinations (sat in Year 11) and less so with Highers (sat in Year 12). The numbers applying to and being admitted to Medicine rose 80% and 300% respectively over the duration of the project. Those receiving an offer differed in personality from those who didn’t. Discussion: Widening Participation activities of the type used in our project successfully increased application and offers for Medicine. The value of psychometric tests in the context of Widening Participation requires further research

    The Restructuring of Technological Capabilities through Corporate Expansion

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    This paper analyses the restructuring of technological capabilities following M&A-based growth in large industrial firms with a substantial technological knowledge base. In particular, we focus on the restructuring of those technological capabilities that are of a general purpose kind (namely ICT) or related to the core capabilities of a firm. We develop and test a conceptual framework grounded on a co-evolutionary view, that relates the motivations and environment for corporate expansion to the firm-specific pattern of restructuring in the composition of corporate technological capabilities. We find that distinct patterns of technological capability restructuring are associated with each combination of the motivations and environment for firm growth. In particular, inter-industry contexts reduce technological relatedness in market motivated expansions, while relatedness has also declined in more recent technology-motivated growth in general. The acquisition of ICT is common as well to both technology-motivated inter-industry deals and more recent market-motivated deals. However, we speculate that any similarities in the outcomes of these alternative motives for firm growth arise for quite different purposes.

    Lipid-free Antigen B subunits from echinococcus granulosus: oligomerization, ligand binding, and membrane interaction properties

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    Background: The hydatid disease parasite Echinococcus granulosus has a restricted lipid metabolism, and needs to harvest essential lipids from the host. Antigen B (EgAgB), an abundant lipoprotein of the larval stage (hydatid cyst), is thought to be important in lipid storage and transport. It contains a wide variety of lipid classes, from highly hydrophobic compounds to phospholipids. Its protein component belongs to the cestode-specific Hydrophobic Ligand Binding Protein family, which includes five 8-kDa isoforms encoded by a multigene family (EgAgB1-EgAgB5). How lipid and protein components are assembled into EgAgB particles remains unknown. EgAgB apolipoproteins self-associate into large oligomers, but the functional contribution of lipids to oligomerization is uncertain. Furthermore, binding of fatty acids to some EgAgB subunits has been reported, but their ability to bind other lipids and transfer them to acceptor membranes has not been studied.<p></p> Methodology/Principal Findings: Lipid-free EgAgB subunits obtained by reverse-phase HPLC were used to analyse their oligomerization, ligand binding and membrane interaction properties. Size exclusion chromatography and cross-linking experiments showed that EgAgB8/2 and EgAgB8/3 can self-associate, suggesting that lipids are not required for oligomerization. Furthermore, using fluorescent probes, both subunits were found to bind fatty acids, but not cholesterol analogues. Analysis of fatty acid transfer to phospholipid vesicles demonstrated that EgAgB8/2 and EgAgB8/3 are potentially capable of transferring fatty acids to membranes, and that the efficiency of transfer is dependent on the surface charge of the vesicles.<p></p> Conclusions/Significance: We show that EgAgB apolipoproteins can oligomerize in the absence of lipids, and can bind and transfer fatty acids to phospholipid membranes. Since imported fatty acids are essential for Echinococcus granulosus, these findings provide a mechanism whereby EgAgB could engage in lipid acquisition and/or transport between parasite tissues. These results may therefore indicate vulnerabilities open to targeting by new types of drugs for hydatidosis therapy.<p></p&gt

    Quality attributes of pistachio nuts as affected by rootstocks and deficit irrigation

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    BACKGROUND: In this work, the influence of two regulated deficit irrigation (RDI) treatments and three different rootstocks on the quality of pistachios was evaluated by analyzing different parameters: morphological analysis, physicochemical analysis and sensory analysis. RESULTS: The results obtained in terms of the choice of rootstock revealed that Pistacia atlantica had increased production yields, nut weight, mineral content, higher intensities of characteristic sensory attributes and a higher degree of consumer satisfaction, than the other rootstocks studied. Moreover, the results established that the application of RDI on pistachio cultivation had no significant influence on production yield, weight, size, colour, water activity or mineral composition. Furthermore, T1 treatment (stem water potential?<?-1.3 MPa) resulted in higher intensities of characteristic sensory attributes and a greater level of satisfaction among international consumers. CONCLUSION: These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied. © 2014 Society of Chemical Industr
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