1,721,013 research outputs found
Legal status of immigrants and criminal behavior: evidence from a natural experiment
No full textWe estimate the causal effect of immigrants' legal status on criminal behavior exploiting exogenous variation in migration restrictions across nationalities driven by the last round of the European Union enlargement. Unique individual-level data on a collective clemency bill enacted in Italy five months before the enlargement allow us to compare the post-release criminal record of inmates from new EU member countries with a control group of pardoned inmates from candidate EU member countries. Difference-in-differences in the probability of re-arrest between the two groups before and after the enlargement show that obtaining legal status lowers the recidivism of economically motivated offenders, but only in areas that provide relatively better labor market opportunities to legal immigrants. We provide a search-theoretic model of criminal behavior that is consistent with these results
Gallstone ileus: Endoscopic removal of a gallstone obstructing the lower ileum
No full text2 citazioni su Scopus
http://www.sciencedirect.com/science/article/pii/S1590865808004337
http://www.scopus.com/record/display.url?eid=2-s2.0-67349129737&origin=resultslist&sort=plf-f&src=s&st1=benassai&st2=g&sid=oNVoDQG_UHipYnJz9G131SP%3a210&sot=q&sdt=b&sl=30&s=TITLE-ABS-KEY-AUTH%28benassai+g%29&relpos=5&relpos=5&searchTerm=TITLE-ABS-KEY-AUTH(benassai g)
An 81-year-old presented with a 5-day history of increasing abdominal pain, distension, and vomiting. Her bowels were not active for 2 days, but she was passing flatus.
Laboratory examination showed a haemoglobin of 9.7 g/dL (≤14 g/dL), haematocrit of 29.7% (≥41%), leucocytes of 13.6/nl (≤10.0/nl), creatinine of 3.7 mg/dL (≤1.1 mg/dL).
A plain abdominal X-ray showed small bowel distension; abdominal CT with contrast media showed a large gallstone in the lower ileum. Distended bowel loops were shown as a sign of a small intestinal ileus. Pneumobilia was not present (Fig. 1).
Due to the weakened state of the patient and the concurrent diseases (coronary heart disease, congestive heart failure, renal insufficiency), an operation was considered unsafe and an endoscopic removal of the stone was tried.
Colonoscopy revealed a large gallstone obstructing the distal ileum (about 10 cm above the ileo-cecal valve) The mucosa was diffusely edematous (Fig. 2).
The stone was mobile and it was possible to grab the stone with a Roth net device (US Endoscopy, Mentor, OH, USA), to remove it from the site of impaction and finally retrieve the stone trough the anus.
The stone measured 3.5 cm × 3.5 cm × 3 cm.
The patient rapidly recovered and was discharged 5 days later.
Gallstone ileus occurs almost exclusively in the elderly and accounts for 25% of mechanical small-bowel obstructions in patients over the age of 65, with a mortality of 15%.
Early surgical intervention is the mainstay of treatment for gallstone ileus but has a mortality of 12–50%. Colonoscopic retrieval may be technically possible, carries small risks compared with surgery, and requires a shorter period of rehabilitation [1], [2] and [3]
An automated software pipeline for shotgun lipidomics using direct-infusion, high-resolution mass spectrometry
No full textIn the last ten years, lipidomics has attracted increasing attention as a research tool in a wide range of disciplines including physiology, lipid biochemistry, clinical biomarker discovery and pathology. Lipid metabolism is found to be critically aberrant in several different human diseases such as diabetes, obesity, atherosclerosis and Alzheimer’s disease. All these characteristics make lipids profiling an essential tool not only for investigation of many pathological processes but also in identifying potential biomarkers for establishing preventive or therapeutic approaches for human health. Here we present a direct-infusion mass spectrometry approach (shotgun lipidomics) in order to identify and quantify at least ten lipid species classes using a two-step extraction procedure, enabling both lipidiomics as well as polar metabolite analysis via GC-MS. We developed a new automated data analysis pipeline, which allows for the fast and robust quantification and identification of lipid species from high-resolution MS data. The software is based on the open-source C++ library OpenMS and R scripts, and supports automated ion-mode and adduct detection, isotope- assembly and correction, non-linear mass calibration, an in-house lipid database combining LipidMaps and HMDB for mass-based identification. Quality control plots are created for all major processing steps for each sample, allowing the operator to quickly judge data quality. Spike-in internal standards serve as abundance normalization for their respective lipid class. Additionally, a new robot-based sample preparation method is introduced, which allows standardized sample handling, ensures rapid sample processing, and minimizes potential variations in pipetting or weighing. Furthermore, due to use of glass vials, we show that common background signal (e.g. from tris(ditert-butylphenyl) phosphate) are significantly reduced. To study the effects of lifestyle factors, we investigate the lipidome changes in a mouse model considering four tissue types (WAT, serum, muscle and liver) under normal vs. high-fat diet
A matter of fat: lipidomics applications in human blood and skin
No full textMass-spectrometry based lipidomics aims to identify as many lipid species as possible from complex biological samples. Due to the large combinatorial search-space unambiguous identification of lipid species is far from trivial. Mass ambiguities are common in direct-injection shotgun experiments, where an orthogonal separation (e.g. liquid chromatography) is missing. Using the rich information of available lipid databases, we generated a comprehensive rule set describing mass ambiguities, while taking into consideration the resolving power (and its decay) of different mass analyzers. Importantly, common adduct species and isotopic peaks are accounted for and are shown to play a major role, both for perfect mass overlaps due to identical sum formulae as well as resolvable mass overlaps. We identified known and hitherto unknown mass ambiguities in high- and ultra-high resolution data, while also ranking lipid classes by their propensity to cause ambiguities. Based on this new set of ambiguity rules, guidelines and recommendations for experimentalists and software developers of what constitutes a solid lipid identification in both MS and MS/MS were suggested. For researchers new to the field, our results are a compact source of ambiguities which should be accounted for. These new findings also have implications for the selection of internal standards, peaks used for internal mass calibration, optimal choice of instrument resolution and sample preparation for example in regard to adduct ion formation
A mass spectrometry approach for identification and quantification of both polar and apolar metabolites from a single drop of human capillary blood
No full textIn the global effort of translating systems biology research into clinical applicability, metabolomics and lipidomics harbor great potential for blood-based medical diagnostics.
Our lab has already established a robust analytical pipeline for the identification and quantification of polar metabolites by GC-MS. However, apolar metabolites, and lipids in particular, cover an important part of cell metabolism.
Here we present a combined approach in order to detect (and quantify) both polar metabolites and lipid species from human blood using a two-step extraction procedure. Moreover, we developed a data analysis pipeline, which allows for the fast and robust quantification and identification of lipid species from high-resolution MS data. Isotope-corrected and calibrated mass traces are matched to an in-house database combining data from LipidMaps and HMDB. Internal standards serve as control for mass calibration as well as for abundance normalization for their respective lipid class.
As proof of principle, we combined our approach to a simple, fast, and minimally invasive blood sampling method. Starting from 20 μL human capillary blood of 15 volunteers, about 100 known (+ 200 unidentified) polar metabolites and on average around 300 lipid species covering all main lipid classes were identified and quantified by GC-MS and direct infusion-MS, respectively
On Mass Ambiguities in Shotgun Lipidomics
No full textMass-spectrometry based lipidomics aims to identify as many lipid species as possible from complex biological samples. Due to the large combinatorial search-space unambiguous identification of lipid species is far from trivial. Mass ambiguities are common in direct-injection shotgun experiments, where an orthogonal separation (e.g. liquid chromatography) is missing. Using the rich information of available lipid databases, we generated a comprehensive rule set describing mass ambiguities, while taking into consideration the resolving power (and its decay) of different mass analyzers. Importantly, common adduct species and isotopic peaks are accounted for and are shown to play a major role, both for perfect mass overlaps due to identical sum formulae as well as resolvable mass overlaps. We identified known and hitherto unknown mass ambiguities in high- and ultra-high resolution data, while also ranking lipid classes by their propensity to cause ambiguities. Based on this new set of ambiguity rules, guidelines and recommendations for experimentalists and software developers of what constitutes a solid lipid identification in both MS and MS/MS were suggested. For researchers new to the field, our results are a compact source of ambiguities which should be accounted for. These new findings also have implications for the selection of internal standards, peaks used for internal mass calibration, optimal choice of instrument resolution and sample preparation for example in regard to adduct ion formation
A matter of fat: lipidomics applications in health and disease
No full textAs a branch of metabolomics, lipidomics is aimed at full analysis of lipid species and their biological roles with respect to health and diseases. In the last 10 years, it has attracted increasing attention as a research tool in a wide range of disciplines including physiology, lipid biochemistry, clinical biomarker discovery and pathology. Unless lipids were considered in the past to be only membrane components or an energy store, today we know they play critical roles in cell signaling transduction processes. [1,2] Furthermore, lipid metabolism is found to be critically aberrant in several different human diseases such as diabetes, obesity, atherosclerosis and Alzheimer’s disease. [3–6]
All these characteristics make lipids profiling an essential tool not only for investigation of many pathological processes but also in identifying potential biomarkers for establishing preventive or therapeutic approaches for human health.
Unlike other biomolecules, lipids do not possess a certain individual structure, making lipidomics analysis an analytical challenge in which mass spectrometry (MS) represents a powerful approach.
Here we present a direct infusion MS approach (shotgun lipidomics) in order to detect (and quantify) at least 10 lipid species from human blood using a two-step extraction procedure, in order to detect also polar metabolites.
Moreover, we developed a data analysis pipeline, which allows for the fast and robust quantification and identification of lipid species from high-resolution MS data. Isotope-corrected and calibrated mass traces are matched to an in-house database combining data from LipidMaps and HMDB. Internal standards serve as control for mass calibration as well as for abundance normalization for their respective lipid class.
As proof of principle, we combined our approach to a simple, fast, and minimally invasive blood sampling method. Starting from 20 μL human capillary blood from 15 volunteers, around 300 lipid species covering all main lipid classes were identified (and semi-quantify) by direct infusion-MS. This shotgun MS approach was also applied to different type of biological samples such as cells, different human tissues (liver, muscle, and white adipose tissues) and stratum corneum. This in order to study the effects of lifestyle factors (such as diet) and/or biological active compounds on lipid profile
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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