2,179 research outputs found
An empirical investigation of fiscal policy in New Zealand
This paper examines the effects of fiscal policy, measured by changes in government spending and net tax (government tax revenue less transfer payments), on New Zealand GDP. The framework of analysis is a structural vector autoregression (VAR) model of the New Zealand economy, employing and extending estimation techniques used by Blanchard and Perotti (2002). This model is then used to examine the dynamic effects of changes in government spending, taxes and transfers on GDP and the contributions of discretionary fiscal policy to New Zealand business cycles.Fiscal policy, business cycle fluctuations, vector autoregression
Streaming Scene Maps for Co-Robotic Exploration in Bandwidth Limited Environments
This paper proposes a bandwidth tunable technique for real-time probabilistic
scene modeling and mapping to enable co-robotic exploration in communication
constrained environments such as the deep sea. The parameters of the system
enable the user to characterize the scene complexity represented by the map,
which in turn determines the bandwidth requirements. The approach is
demonstrated using an underwater robot that learns an unsupervised scene model
of the environment and then uses this scene model to communicate the spatial
distribution of various high-level semantic scene constructs to a human
operator. Preliminary experiments in an artificially constructed tank
environment as well as simulated missions over a 10m10m coral reef
using real data show the tunability of the maps to different bandwidth
constraints and science interests. To our knowledge this is the first paper to
quantify how the free parameters of the unsupervised scene model impact both
the scientific utility of and bandwidth required to communicate the resulting
scene model.Comment: 8 pages, 6 figures, accepted for presentation in IEEE Int. Conf. on
Robotics and Automation, ICRA '19, Montreal, Canada, May 201
Cortically evoked motor responses in patients with Xp22.3-linked Kallmann's syndrome and in female gene carriers
Patients with Kallmann's syndrome show hypothalamic hypogonadism, hyposmia, and congenital mirror movements. As a correlate, a defect of gonadotropic neuron migration into the brain was recently detected. Considering abnormal outgrowth of neurons also as a possible substrate underlying mirror movements, we studied 3 patients and 2 asymptomatic female gene carriers from a kindred with proven linkage to Xp22.3, using focal transcranial magnetic stimulation of motor cortex hand areas with a figure-eight coil. In all 3 affected brothers, bilateral responses could be evoked almost simultaneously in their thenar muscles (slight latency differences were statistically insignificant). In contrast, the mother and the maternal aunt showed only unilateral, normal thenar responses, even with maximum tolerable stimulator output and high signal amplification. Correspondingly, mirror movements were present in the patients, but not in the gene carriers. Bilaterality of cortically evoked hand muscle responses and mirror movements, therefore, behaved as X-chromosomal recessive traits. A likely cause might be a disorder of neuronal outgrowth in the motor system, particularly of inhibitory callosal fibers. For normal anatomical development of the motor system, one intact Xp22.3 gene seems necessary
Prevalence, Enabling Factors, and Clinical Outcome
Background: Striatocapsular infarcts (SCIs) are defined as large subcortical
infarcts involving the territory of more than one lenticulostriate artery. SCI
without concomitant ischemia in the more distal middle cerebral artery (MCA)
territory [isolated SCI (iSCI)] has been described as a rare infarct pattern.
The purpose of this study was to assess the prevalence of iSCI in patients
treated with endovascular thrombectomy (ET), to evaluate baseline and
procedural parameters associated with this condition, and to describe the
clinical course of iSCI patients. Methods: A retrospective analysis of 206
consecutive patients with an isolated MCA occlusion involving the
lenticulostriate arteries and treated with ET was performed. Baseline patient
and procedural characteristics and ischemic involvement of the striatocapsular
and distal MCA territory [iSCI, as opposed to non-isolated SCI (niSCI)] were
analyzed using multivariate logistic regression models. Prevalence of iSCI was
assessed, and clinical course was determined with the rates of substantial
neurological improvement and good functional short- and mid-term outcome
(discharge/day 90 Modified Rankin Scale ≤2). Results: iSCI was detected in 53
patients (25.7%), and niSCI was detected in 153 patients (74.3%). Successful
reperfusion [thrombolysis in cerebral infarction (TICI) 2b/3] [adjusted odds
ration (aOR) 8.730, 95% confidence interval (95% CI) 1.069–71.308] and good
collaterals (aOR 2.100, 95% CI 1.119–3.944) were associated with iSCI. In
successfully reperfused patients, TICI 3 was found to be an additional factor
associated with iSCI (aOR 5.282, 1.759–15.859). Patients with iSCI had higher
rates of substantial neurological improvement (71.7 vs. 37.9%, p < 0.001) and
higher rates of good functional short- and mid-term outcome (58.3 vs. 23.7%, p
< 0.001 and 71.4 vs. 41.7%, p < 0.001). However, while iSCI patients, in
general, had a more favorable outcome, considerable heterogeneity in outcome
was observed. Conclusion: High rates of successful reperfusion (TICI 2b/3) and
in particular, complete reperfusion (TICI 3) are associated with iSCIs. The
high prevalence of iSCI in successfully reperfused patients with good
collaterals corroborates previous concepts of iSCI pathogenesis. iSCI, once
considered a rare pattern of cerebral ischemia, is likely to become more
prevalent with increases in endovascular stroke therapy. This may have
implications for patient rehabilitation and pathophysiological analyses of
ischemic damage confined to subcortical regions of the MCA territory
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Facilitating access to surgical care through a decentralised case-finding strategy: experience in Madagascar
Over two-thirds of the world’s population lack access to surgical care. Non-governmental organisation’s providing free surgeries may overcome financial barriers, but other barriers to care still exist. This analysis paper discusses two different case-finding strategies in Madagascar that aimed to increase the proportion of poor patients, women and those for whom multiple barriers to care exist. From October 2014 to June 2015, we used a centralised selection strategy, aiming to find 70% of patients from the port city, Toamasina, and 30% from the national capital and two remote cities. From August 2015 to June 2016, a decentralised strategy was used, aiming to find 30% of patients from Toamasina and 70% from 11 remote locations, including the capital. Demographic information and self-reported barriers to care were collected. Wealth quintile was calculated for each patient using a combination of participant responses to asset-related and demographic questions, and publicly available data. A total of 2971 patients were assessed. The change from centralised to decentralised selection resulted in significantly poorer patients undergoing surgery. All reported barriers to prior care, except for lack of transportation, were significantly more likely to be identified in the decentralised group. Patients who identified multiple barriers to prior surgical care were less likely to be from the richest quintile (p=0.037) and more likely to be in the decentralised group (p=0.046). Our country-specific analysis shows that decentralised patient selection strategies may be used to overcome barriers to care and allow patients in greatest need to access surgical care
Netazepide inhibits expression of Pappalysin 2 in type-1 gastric neuroendocrine tumors
Background & Aims: In patients with autoimmune atrophic gastritis and achlorhydria, hypergastrinemia is associated with the development of type 1 gastric neuroendocrine tumors (gNETs). Twelve months of treatment with netazepide (YF476), an antagonist of the cholecystokinin B receptor (CCKBR or CCK2R), eradicated some type 1 gNETs in patients. We investigated the mechanisms by which netazepide induced gNET regression using gene expression profiling. Methods: We obtained serum samples and gastric corpus biopsy specimens from 8 patients with hypergastrinemia and type 1 gNETs enrolled in a phase 2 trial of netazepide. Control samples were obtained from 10 patients without gastric cancer. We used amplified and biotinylated sense-strand DNA targets from total RNA and Affymetrix (Thermofisher Scientific, UK) Human Gene 2.0 ST microarrays to identify differentially expressed genes in stomach tissues from patients with type 1 gNETs before, during, and after netazepide treatment. Findings were validated in a human AGS GR gastric adenocarcinoma cell line that stably expresses human CCK2R, primary mouse gastroids, transgenic hypergastrinemic INS-GAS mice, and patient samples. Results: Levels of pappalysin 2 (PAPPA2) messenger RNA were reduced significantly in gNET tissues from patients receiving netazepide therapy compared with tissues collected before therapy. PAPPA2 is a metalloproteinase that increases the bioavailability of insulin-like growth factor (IGF) by cleaving IGF binding proteins (IGFBPs). PAPPA2 expression was increased in the gastric corpus of patients with type 1 gNETs, and immunohistochemistry showed localization in the same vicinity as CCK2R-expressing enterochromaffin-like cells. Up-regulation of PAPPA2 also was found in the stomachs of INS-GAS mice. Gastrin increased PAPPA2 expression with time and in a dose-dependent manner in gastric AGS GR cells and mouse gastroids by activating CCK2R. Knockdown of PAPPA2 in AGS GR cells with small interfering RNAs significantly decreased their migratory response and tissue remodeling in response to gastrin. Gastrin altered the expression and cleavage of IGFBP3 and IGFBP5. Conclusions: In an analysis of human gNETS and mice, we found that gastrin up-regulates the expression of gastric PAPPA2. Increased PAPPA2 alters IGF bioavailability, cell migration, and tissue remodeling, which are involved in type 1 gNET development. These effects are inhibited by netazepide
Five-year analysis on the long-term effects of dabrafenib plus trametinib (D + T) in patients with BRAF V600–mutant unresectable or metastatic melanoma
Background: First-line treatment with D+T demonstrated
prolonged progression-free survival (PFS) and overall survival (OS)
in patients with BRAF V600–mutant unresectable or metastatic
melanoma. With 5 years of follow-up, we report survival and
describe characteristics of patients in the phase 3 COMBI-d and
COMBI-v trials with long-term benefit. Methods: Pooled 5-year
landmark data for patients treated with D+T in the phase 3 COMBId (NCT01584648) and COMBI-v (NCT01597908) trials were
analyzed. The trials enrolled patients with previously
untreated BRAF V600E/K–mutant unresectable or metastatic
melanoma. Patients received D 150 mg twice daily plus T 2 mg
once daily vs either D + placebo (COMBI-d) or vemurafenib
(COMBI-v). The primary endpoints were PFS in COMBI-d and OS
in COMBI-v. Results: The pooled population included 563 patients
who received D+T (COMBI-d, n = 211; COMBI-v, n = 352)
The Bose-Einstein Condensate and Cold Atom Laboratory
© 2020, The Author(s). Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension and eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt and operate experimental setups on microgravity platforms. We describe the design of the payload, motivations for design choices, and capabilities of the Bose-Einstein Condensate and Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds on the heritage of previous devices operated in microgravity, features rubidium and potassium, multiple options for magnetic and optical trapping, different methods for coherent manipulation, and will offer new perspectives for experiments on quantum optics, atom optics, and atom interferometry in the unique microgravity environment on board the International Space Station
Microgravity facilities for cold atom experiments
Microgravity platforms enable cold atom research beyond experiments in typical laboratories by removing restrictions due to the gravitational acceleration or compensation techniques. While research in space allows for undisturbed experimentation, technological readiness, availability and accessibility present challenges for experimental operation. In this work we focus on the main capabilities and unique features of ground-based microgravity facilities for cold atom research. A selection of current and future scientific opportunities and their high demands on the microgravity environment are presented, and some relevant ground-based facilities are discussed and compared. Specifically, we point out the applicable free fall times, repetition rates, stability and payload capabilities, as well as programmatic and operational aspects of these facilities. These are contrasted with the requirements of various cold atom experiments. Besides being an accelerator for technology development, ground-based microgravity facilities allow fundamental and applied research with the additional benefit of enabling hands-on access to the experiment for modifications and adjustments
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