370 research outputs found
The Mycetophagidae of the Maltese Islands (Coleoptera)
In the present work, seven species of Mycetophagidae have been confirmed as occurring in Malta. Of these, two represent new records for this territory namely Berginus tamarisci and Typhaeola maculata. Since very little original collecting data exists for most of the other records for Malta, such data is provided for all species, with notes on global distribution and other relevant information.peer-reviewe
The Monotomidae of the Maltese Islands (Coleoptera)
Information is given about four species of Monotomidae which occur in the Maltese Islands, namely Rhizophagus unicolor, Monotoma bicolor, M. brevicollis and M. spinicollis. A previous record of Rhizophagus bipustulatus was found to be incorrect and should refer to R. unicolor. A dichotomous key for the identification of the four species is also providedpeer-reviewe
Reconstruction of Linearly Parameterized Models from Single Images with a Camera of Unknown Focal Length
This paper deals with the problem of recovering the dimensions of an object and its pose from a single image acquired with a camera of unknown focal length. It is assumed that the object in question can be modeled as a polyhedron where the coordinates of the vertices can be expressed as a linear function of a dimension vector, λ. The reconstruction program takes as input, a set of correspondences between features in the model and features in the image. From this information, the program determines an appropriate projection model for the camera (scaled orthographic or perspective), the dimensions of the object, its pose relative to the camera and, in the case of perspective projection, the focal length of the camera. This paper describes how the reconstruction problem can be framed as an optimization over a compact set with low dimension - no more than four. This optimization problem can be solved efficiently by coupling standard nonlinear optimization techniques with a multistart method which generates multiple starting points for the optimizer by sampling the parameter space uniformly. The result is an efficient, reliable solution system that does not require initial estimates for any of the parameters being estimated
Impact of decitabine on immunohistochemistry expression of the putative tumor suppressor genes FHIT, WWOX, FUS1 and PTEN in clinical tumor samples.
BackgroundSince tumor suppressor gene function may be lost through hypermethylation, we assessed whether the demethylating agent decitabine could increase tumor suppressor gene expression clinically. For fragile histidine triad (FHIT), WW domain-containing oxidoreductase (WWOX), fused in sarcoma-1 (FUS1) and phosphatase and tensin homolog (PTEN), immunohistochemistry scores from pre- and post-decitabine tumor biopsies (25 patients) were correlated with methylation of the long interspersed nuclear element-1 (LINE-1) repetitive DNA element (as a surrogate for global DNA methylation) and with tumor regression.ResultsWith negative staining pre-decitabine (score = 0), the number of patients converting to positive staining post-decitabine was 1 of 1 for FHIT, 3 of 6 for WWOX, 2 of 3 for FUS1 and 1 of 10 for PTEN. In tumors with low pre-decitabine tumor suppressor gene scores (≤150), expression was higher post-treatment in 8 of 8 cases for FHIT (P = 0.014), 7 of 17 for WWOX (P = 0.0547), 7 of 12 for FUS1 (P = 0.0726), and 1 of 16 for PTEN (P = 0.2034). If FHIT, WWOX and FUS1 were considered together, median pre- versus post-decitabine scores were 60 versus 100 (P = 0.0002). Overall, tumor suppressor gene expression change did not correlate with LINE-1 demethylation, although tumors converting from negative to positive had a median decrease in LINE-1 methylation of 24%, compared to 6% in those not converting (P = 0.069). Five of 15 fully evaluable patients had reductions in tumor diameter (range 0.2% to 33.4%). Of these, three had simultaneous increases in three tumor suppressor genes (including the two patients with the greatest tumor regression) compared to 2 of 10 with tumor growth (P = 0.25).ConclusionsIn tumors with low tumor suppressor gene expression, decitabine may be associated with increased expression of the tumor suppressor genes FHIT, FUS1, and WWOX, but not PTEN
The Niemann-Pick C1 and caveolin-1 proteins interact to modulate efflux of low density lipoprotein-derived cholesterol from late endocytic compartments
The Niemann-Pick C1 (NPC1) protein has a central role in regulating the efflux of lipoprotein-derived cholesterol from late endosomes/lysosomes and transport to other cellular compartments. Since the NPC1 protein has been shown to regulate the transport of cholesterol to cellular compartments enriched with the ubiquitous cholesterol-binding and transport protein caveolin-1, the present study was performed to determine whether the NPC1 and caveolin-1 proteins interact and function to modulate efflux of low density lipoprotein (LDL)-derived cholesterol from endocytic compartments. To perform these studies, normal human fibroblasts were grown in media with lipoprotein-deficient serum (LPDS) or media with LPDS supplemented with purified human LDL. The results indicated reciprocal co-immunoprecipitation and partial co-localization of the NPC1 and caveolin-1 proteins that was decreased when fibroblasts were grown in media with LDL. Consistent with interaction of the NPC1 and caveolin-1 proteins, a highly conserved caveolin-binding motif was identified within a cytoplasmic loop located adjacent to the sterol-sensing domain (SSD) of the NPC1 protein. To examine the functional relevance of this interaction, fibroblasts were transfected with caveolin-1 siRNA and found to accumulate increased amounts of LDL-derived cholesterol within late endosomes/lysosomes. Together, this report presents novel results demonstrating that the NPC1 and caveolin-1 proteins interact to modulate efflux of LDL-derived cholesterol from late endocytic compartments
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Increased markers of cardiac vagal activity in leucine-rich repeat kinase 2-associated Parkinson's disease.
PurposeCardiac autonomic dysfunction manifests as reduced heart rate variability (HRV) in idiopathic Parkinson's disease (PD), but no significant reduction has been found in PD patients who carry the LRRK2 mutation. Novel HRV features have not been investigated in these individuals. We aimed to assess cardiac autonomic modulation through standard and novel approaches to HRV analysis in individuals who carry the LRRK2 G2019S mutation.MethodsShort-term electrocardiograms were recorded in 14 LRRK2-associated PD patients, 25 LRRK2-non-manifesting carriers, 32 related non-carriers, 20 idiopathic PD patients, and 27 healthy controls. HRV measures were compared using regression modeling, controlling for age, sex, mean heart rate, and disease duration. Discriminant analysis highlighted the feature combination that best distinguished LRRK2-associated PD from controls.ResultsBeat-to-beat and global HRV measures were significantly increased in LRRK2-associated PD patients compared with controls (e.g., deceleration capacity of heart rate: p = 0.006) and idiopathic PD patients (e.g., 8th standardized moment of the interbeat interval distribution: p = 0.0003), respectively. LRRK2-associated PD patients also showed significantly increased irregularity of heart rate dynamics, as quantified by Rényi entropy, when compared with controls (p = 0.002) and idiopathic PD patients (p = 0.0004). Ordinal pattern statistics permitted the identification of LRRK2-associated PD individuals with 93% sensitivity and 93% specificity. Consistent results were found in a subgroup of LRRK2-non-manifesting carriers when compared with controls.ConclusionsIncreased beat-to-beat HRV in LRRK2 G2019S mutation carriers compared with controls and idiopathic PD patients may indicate augmented cardiac autonomic cholinergic activity, suggesting early impairment of central vagal feedback loops in LRRK2-associated PD
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