2,337 research outputs found

    The labor market impact of immigration in Western Germany in the 1990’s

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    In this article we measure the effects of recent immigration on the Western German labor market looking at both wage and employment effects. Refining administrative data for the period 1987-2001 to account for ethnic German immigrants and immigrants from Eastern Germany, we find that the substantial immigration of the 1990’s had very little adverse effects on native wages and on their employment levels. Instead, it had a sizable adverse employment effect as well as a small adverse wage effect on previous waves of immigrants. These asymmetric results are partly driven by a higher degree of substitution between old and new immigrants in the labor market. In a simple calculation we show that the largest aggregate effect of new immigration on natives and old immigrants comes from the increased costs of unemployment benefits to old immigrants. Those costs could be eliminated in a world of wage flexibility and no unemployment insurance in which immigration would not have any negative employment effect but only moderate wage effects

    CSI Flight Computer System and experimental test results

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    This paper describes the CSI Computer System (CCS) and the experimental tests performed to validate its functionality. This system is comprised of two major components: the space flight qualified Excitation and Damping Subsystem (EDS) which performs controls calculations; and the Remote Interface Unit (RIU) which is used for data acquisition, transmission, and filtering. The flight-like RIU is the interface between the EDS and the sensors and actuators positioned on the particular structure under control. The EDS and RIU communicate over the MIL-STD-1553B, a space flight qualified bus. To test the CCS under realistic conditions, it was connected to the Phase-0 CSI Evolutionary Model (CEM) at NASA Langley Research Center. The following schematic shows how the CCS is connected to the CEM. Various tests were performed which validated the ability of the system to perform control/structures experiments

    Evidence of non-thermal X-ray emission from HH 80

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    Protostellar jets appear at all stages of star formation when the accretion process is still at work. Jets travel at velocities of hundreds of km/s, creating strong shocks when interacting with interstellar medium. Several cases of jets have been detected in X-rays, typically showing soft emission. For the first time, we report evidence of hard X-ray emission possibly related to non-thermal processes not explained by previous models of the post-shock emission predicted in the jet/ambient interaction scenario. HH 80 is located at the south head of the jet associated to the massive protostar IRAS 18162-2048. It shows soft and hard X-ray emission in regions that are spatially separated, with the soft X-ray emission region situated behind the region of hard X-ray emission. We propose a scenario for HH 80 where soft X-ray emission is associated to thermal processes from the interaction of the jet with denser ambient matter and the hard X-ray emission is produced by synchrotron radiation at the front shock.Comment: Accepted for publication in ApJ

    Analisis Finansial USAha Budidaya Tambak Sistem Tradisional Dan Silvofishery Di Area Restorasi Taman Nasional Sembilang Sumatera Selatan

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    Sistem Silvofishery diterapkan untuk meredam laju konversi illegal hutan mangrove menjadi tambak. Silvofishery diyakini mampu mengkombinasikan antara kepentingan konservasi mangrove dengan peningkatan kesejahteraan masyarakat sekitarnya. Penelitian ini bertujuan untuk menentukan analisis USAha dan kelayakan kriteria investasi USAha budidaya tambak tradisonal dan silvofishery bandeng di TNS Sumatera Selatan. Penelitian ini dilaksanakan pada bulan September-Oktober 2013. Metode yang digunakan metode survey dengan teknik kuisioner. Hasil analisis USAha budidaya tambak tradisional dan silvofishery bandeng mendapat keuntungan sebesar Rp. 5.187.370 dan Rp 5.921.000,00/tahun, nilai R/C sebesar 1,4 dan 1,5, nilai PP 4,7dan 4,0 dan nilai ROI sebesar 21% dan 25%. Analisis kelayakan USAha tambak tradisional dan silvofishery menunjukan nilai NPV>0, Net B/C≥1, dan IRR> discount rate, sehingga USAha budidaya tambak silvofishery bandeng mendapatkan keuntungan dan layak dilaksanakan untuk masa yang akan datan

    Host chemical footprints induce host sex discrimination ability in egg parasitoids

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    Trissolcus egg parasitoids, when perceiving the chemical footprints left on a substrate by pentatomid host bugs, adopt a motivated searching behaviour characterized by longer searching time on patches were signals are present. Once in contact with host chemical footprints, Trissolcus wasps search longer on traces left by associated hosts rather than non-associated species, and, in the former case, they search longer on traces left by females than males. Based on these evidences, we hypothesized that only associated hosts induce the ability to discriminate host sex in wasps. To test this hypothesis we investigated the ability of Trissolcus basalis, T. brochymenae, and Trissolcus sp. to distinguish female from male Nezara viridula, Murgantia histrionica, and Graphosoma semipunctatum footprints. These three pentatomid bugs were selected according to variable association levels. Bioassays were conducted on filter paper sheets, and on Brassica oleracea (broccoli) leaves. The results confirmed our hypothesis showing that wasps spent significantly more time on female rather than male traces left by associated hosts on both substrates. No differences were observed in the presence of traces left by non-associated hosts. The ecological consequences for parasitoid host location behaviour are discussed

    Surgical management of a life-threatening retro-pharyngeal haematoma following trans-oesophageal echocardiography = Trattamento chirurgico di un pericoloso ematoma retrofaringeo, sviluppatosi a seguito di un\u2019ecocardiografia transesofagea

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    Nonostante siano state descritte complicanze potenzialmente letali, l\u2019ecocardiografia transesofagea viene considerata una procedura diagnostica sicura. Scopo del presente lavoro \ue8 sottolineare come, nei casi di voluminosi ematomi secondari a tale procedura, possa diventare indispensabile il ricorso alla chirurgia per tutelare la vita del paziente. Nel caso qui descritto, un paziente affetto da spondilosi cervicale e in terapia anticoagulante ha sviluppato, a seguito di un\u2019ecocardiografia transesofagea, un ematoma retrofaringeo tanto voluminoso da determinare un\u2019ostruzione delle vie aeree superiori. Per assicurarne la perviet\ue0 \ue8 stato necessario ricorrere a una tracheotomia, l\u2019ematoma, invece, \ue8 stato drenato per via transcervicale. Il paziente \ue8 guarito completamente in 10 giorni. Il chirurgo otorinolaringoiatrico dovrebbe essere a conoscenza, non solo di questa rara complicanza, ma anche della necessit\ue0 di un suo trattamento chirurgico.Trans-oesophageal echocardiography is generally considered a safe procedure, but occasional life-threatening complications have been reported. The aim of this clinical investigation is to outline the need of surgical management in cases of large retro-pharyngeal haematoma following trans-oesophageal echocardiography. In the case reported here, a patient with cervical spondylosis on anti-coagulant therapy was referred to the Head and Neck Department because of a retro-pharyngeal haematoma with severe upper airway obstruction following transoesophageal echocardiography. Tracheotomy was required to guarantee respiratory function, while trans-cervical surgery was performed to evacuate the haematoma. Total recovery was achieved within 10 days. In conclusion, the head and neck surgeon should consider the need of surgical management in cases of retro-pharyngeal haematoma following trans-oesophageal echocardiography

    Reliabiliy and clinical validity of the italian reflux symptom index

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    Currently, there is no Italian version of the Reflux Symptom Index (RSI). The aim of this study was to develop an Italian RSI and to evaluate its internal consistency, reliability, and clinical validity. The study design used was a cross-sectional survey study. Eighty patients with a Reflux Finding Score (RFS) >7, and 193 asymptomatic subjects were included in the study. For the RSI reliability analysis, the appositely developed Italian RSI was filled twice, with a week interval, by the 80 patients and 80 control subjects. The test-retest reliability was assessed through the Pearson correlation test, whereas the Cronbach's \u3b1 coefficient was used for internal consistency analysis. For the clinical validity assessment, the scores obtained in the pathological group were compared with the data from the asymptomatic individuals through the Student's t test. Finally, the correlation between RSI and RFS in the 80 patients was assessed. All of the patients filled in the entire questionnaire autonomously. The test-retest reliability in the patients, as well as in the control group, was very high (r > 0.90); the internal consistency also showed very high values (\u3b1 = 0.99). The mean RSI score in the patients was 21.1 \ub1 6.6, whereas in the control group it was 6.3 \ub1 5.6; the difference was statistically significant (P = 0.0001). The mean RFS score in the 80 patients was 9.2 \ub1 2.7 and the correlation between RFS score and RSI score was rather high (r = 0.89). The Italian RSI is easily administered, highly reproducible, and exhibits excellent clinical validity

    Microbiota-Derived Natural Products Targeting Cancer Stem Cells: Inside the Gut Pharma Factory

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    Cancer stem cells (CSCs) have drawn much attention as important tumour-initiating cells that may also be crucial for recurrence after chemotherapy. Although the activity of CSCs in various forms of cancer is complex and yet to be fully elucidated, opportunities for therapies targeting CSCs exist. CSCs are molecularly distinct from bulk tumour cells, so they can be targeted by exploiting their signature molecular pathways. Inhibiting stemness has the potential to reduce the risk posed by CSCs by limiting or eliminating their capacity for tumorigenesis, proliferation, metastasis, and recurrence. Here, we briefly described the role of CSCs in tumour biology, the mechanisms involved in CSC therapy resistance, and the role of the gut microbiota in cancer development and treatment, to then review and discuss the current advances in the discovery of microbiota-derived natural compounds targeting CSCs. Collectively, our overview suggests that dietary intervention, toward the production of those identified microbial metabolites capable of suppressing CSC properties, is a promising approach to support standard chemotherapy

    Insect oviposition induces volatile emission in herbaceous plants that attracts egg parasitoid

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    The egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) responded to synomones emitted by leguminous plants induced by feeding and oviposition activity of the bug Nezara viridula (L.) (Heteroptera: Pentatomidae). This was shown by laboratory bioassays using a Y-tube olfactometer. Broad bean leaves (Vicia faba L.) damaged by feeding activity of N. viridula and on which host egg mass had been laid produced synomones that attracted T. basalis. By contrast, undamaged leaves or feeding-damaged leaves without eggs did not attract wasp females. French bean plants (Phaseolus vulgaris L.) also emitted attractive synomones when they were damaged by host feeding and carrying egg masses. Thus, release of feeding- and oviposition-induced synomones does not seem to be plant-specific. Synomone production was shown to be a systemically induced plant physiological response to feeding damage and oviposition. Also, parts of the plant that were left undamaged and did not carry host eggs emitted attractive synomones when other parts of the plant were damaged by feeding, and carrying eggs. Furthermore, wasps were not attracted by N. viridula egg masses offered alone or combined with damaged broad bean leaves. Thus, the attractiveness of feeding-damaged leaves carrying eggs is due to induction by feeding and oviposition rather than due to a combined effect of attractive volatiles released from eggs and damaged leaves. The production of synomones was influenced by the age of the host egg mass, because feeding-damaged leaves bearing egg masses attracted the parasitoid until the eggs were similar to72-96 h old but not once the larvae had hatched from the eggs (similar to120 h old). These results show that annual plants are able to produce synomones as a consequence of feeding and egg mass oviposition by a sucking insect
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