1,906 research outputs found
Efficient and Effective Query Auto-Completion
Query Auto-Completion (QAC) is an ubiquitous feature of modern textual search
systems, suggesting possible ways of completing the query being typed by the
user. Efficiency is crucial to make the system have a real-time responsiveness
when operating in the million-scale search space. Prior work has extensively
advocated the use of a trie data structure for fast prefix-search operations in
compact space. However, searching by prefix has little discovery power in that
only completions that are prefixed by the query are returned. This may impact
negatively the effectiveness of the QAC system, with a consequent monetary loss
for real applications like Web Search Engines and eCommerce. In this work we
describe the implementation that empowers a new QAC system at eBay, and discuss
its efficiency/effectiveness in relation to other approaches at the
state-of-the-art. The solution is based on the combination of an inverted index
with succinct data structures, a much less explored direction in the
literature. This system is replacing the previous implementation based on
Apache SOLR that was not always able to meet the required
service-level-agreement.Comment: Published in SIGIR 202
Estudio de la frecuencia, distribución y rendimiento diagnóstico en las lesiones neoplásicas sincrónicas del carcinoma colo-rectal
ABSTRACT
To analyse the frequency, characteristics and
diagnosis of synchronic neoplastic lesions in colorectal cancer.
A review was carried out of 384 colorectal
cancers, diagnosed through complete colonoscopy and
resected. The synchronic cancers and the characteristics of the
adenomas were determined: number, size, histological type,
dysplasia, as well as their localisation in the colon and with
respect to the carcinoma.
Twenty-eight synchronic cancers were found
(7.3% of the total); 8 developed tumours and 20 malignant
polyps. In 54.4% of the cases there was a synchronic adenoma.
In patients with synchronic lesions, 43% showed an advanced
adenoma. Twenty percent of the synchronic polyps found were
proximal to the splenic flexure; 41% were distal and 38% had
both localisations. Fifty-nine point one percent of the patients
had some adenoma proximal to the cancer, with criteria of
advanced adenoma in 13.9%. The distribution of the adenomas
was more uniformly spread in the cancers with a proximal
localisation (p = 0.038). Seventeen percent of the distal cancers
presented synchronic lesions with a proximal colon localisation
exclusively. Partial endoscopies would diagnose the distal
cancers, but would omit a synchronic adenoma in 42.3% of the
sigmoidoscopies and 40% of the short colonoscopies.
High rates of carcinoma and synchronic
adenomas were registered. We underline the high index of
advanced adenomas and the frequency of synchronic lesions
proximal to the cancer, which is why incomplete colonoscopies,
although allowing the diagnosis of the distal cancer, omit a high
percentage of synchronic adenomas, including advanced
lesions. All of this confirms the need to perform a complete pre-
, intra- and post operational colonoscopy in resectable
colorectal cancer
Synchronous neoplastic lesions in colorectal cancer. An analysis of possible risk factors favouring presentation
Aim: few data have been published regarding the causes of
synchronous lesions in patients with colorectal cancer. The aim of
our study was to identify potential factors that might be implicated
in the development of multicentric lesions, since this knowledge
could be useful for tailored follow-up once initial synchronous lesions
have been removed.
Methods: we retrospectively reviewed 382 colorectal cancer
cases diagnosed by total colonoscopy and histological study of
surgical specimens. We divided our population into 2 groups,
based on whether they had synchronous lesions or otherwise.
Several data related to personal and family history, habits, symptoms,
and tumor characteristics were assessed. Univariate and
multivariate statistical analyses were performed.
Results: 208 (54.5%) patients had synchronous adenomas
and 28 (7.3%) had synchronous cancer. A multivariate analysis
showed that the following parameters were consistently related
to the presence of multicentric lesions –male gender: OR = 1.97;
CI = 1.13-3.45; p = 0.017; age ≥ 59 years: OR = 2.57;
CI = 1.54-4.29; p < 0.001; personal history of colonic adenomas:
OR = 3.04; CI = 1.04-8.85; p = 0.042; and obstructive tumors:
OR = 0.48; CI = 0.27-0.85; p = 0.012.
Conclusion: our results show that several parameters that are
easy to measure could be considered risk factors for the development
of multicentric lesions. These factors need to be confirmed
with follow-up studies analyzing their role in patients with and
without metachronic lesions once all synchronous lesions have
been removed
Análisis de la posible influencia de las lesiones sincrónicas en el pronóstico del cáncer colorrectal resecado
Aim: To analyze the relationship between synchronous lesions in
patients with colorectal cancer and their prognostic value.
Patients and methods: We have retrospectively reviewed 369 patients
with resected colorectal cancer. We compared the rate of apparently
curative surgery, progression and tumoral relapse, development of
extracolonic cancer and mortality between patients with and without
synchronous cancer. Afterwards, we analyzed the same parameters in
colorectal cancer with and without synchronous adenomas. Finally, we
repeated the analysis after stratification of cancers in 2 groups according
to pTNM staging: 0-I-II stage vs III-IV.
Results: We found synchronous adenomas in 54.7% of our patients
and synchronous cancers in 7.6%. Follow-up period of groups with and
without synchronous lesions were: 70.8 ± 22.9 and 67.2 ± 24.5 months (p
= 0.55) respectivelly. Synchronous cancers showed higher mortality:
35.7 vs. 14.4%: p = 0.006; OR = 3.31 (1.33-8.13), higher tumoral progression
: 39.3 vs. 19.1%: p = 0.011; OR = 2.75 (1.14-6.56) and higher
relapse rate: 10.7 vs. 3.5%: p = 0.096. Stratifying according to stage,
patients with stage 0-I-II and synchronous cancer showed worse prognosis:
mortality = 27.7 vs. 8.1%, p = 0.019; OR = 4.45 (1.2-15.1), tumoral
progression = 27.8 vs. 8.5%, p = 0.02; OR = 4.12 (1.14-14.19), and
extracolonic cancer = 16.7 vs. 6.4% p = 0.095. There were no statistical
differences between cases with and without synchronous adenomas.
Conclusions: Synchronous cancers showed worse prognosis after
resection, with higher rate of tumoral progression and mortality. This difference
is focused on the cases diagnosed in stage 0-I-II, not being found in
III-IV. The presence of synchronous adenomas doesn’t influence prognosis
The Broad Concept of "Spasticity-Plus Syndrome" in Multiple Sclerosis: A Possible New Concept in the Management of Multiple Sclerosis Symptoms
Multiple sclerosis (MS) pathology progressively affects multiple central nervous system (CNS) areas. Due to this fact, MS produces a wide array of symptoms. Symptomatic therapy of one MS symptom can cause or worsen other unwanted symptoms (anticholinergics used for bladder dysfunction produce impairment of cognition, many MS drugs produce erectile dysfunction, etc.). Appropriate symptomatic therapy is an unmet need. Several important functions/symptoms (muscle tone, sleep, bladder, pain) are mediated, in great part, in the brainstem. Cannabinoid receptors are distributed throughout the CNS irregularly: There is an accumulation of CB1 and CB2 receptors in the brainstem. Nabiximols (a combination of THC and CBD oromucosal spray) interact with both CB1 and CB2 receptors. In several clinical trials with Nabiximols for MS spasticity, the investigators report improvement not only in spasticity itself, but also in several functions/symptoms mentioned before (spasms, cramps, pain, gait, sleep, bladder function, fatigue, and possibly tremor). We can conceptualize and, therefore, hypothesize, through this indirect information, that it could be considered the existence of a broad "Spasticity-Plus Syndrome" that involves, a cluster of symptoms apart from spasticity itself, the rest of the mentioned functions/symptoms, probably because they are interlinked after the increase of muscle tone and mediated, at least in part, in the same or close areas of the brainstem. If this holds true, there exists the possibility to treat several spasticity-related symptoms induced by MS pathology with a single therapy, which would permit to avoid the unnecessary adverse effects produced by polytherapy. This would result in an important advance in the symptomatic management of MS
Efficacy of DNA amplification in tissue biopsy samples to improve the detection of invasive fungal disease
AbstractThe performance of a pan-fungal PCR-based technique was evaluated to assess the aetiology of invasive fungal diseases (IFDs). A total of 89 formalin-fixed paraffin-embedded biopsy samples from 84 patients with proven IFD were studied. Culture of tissue was performed in 68 (81%) patients. The sensitivities of the PCR-based technique and microbiological culture of tissues were 89% and 56%, respectively (p <0.01). According to PCR results, Aspergillus species accounted for 67%, Candida species for 13%, zygomycetes for 11%, and rare and emerging fungi for 9%. Aspergillus species were significantly associated with lung samples (79.6%, p <0.01), Mucorales were associated with skin/subcutaneous samples, and Candida species were associated with gastrointestinal samples. Regarding biopsy samples with Aspergillus species, Aspergillus fumigatus DNA was detected in 43 of 50 (86%), and Aspergillus flavus in six of 50 (12%). PCR was positive in 24 of 30 (80%) cases with negative culture. In nine of the 84 patients, the PCR technique failed to amplify the DNA. Six also had negative cultures, and in the remaining three cases culture was positive (Rhizopus microsporus, Rhizopus arrhizus, and Sakseneae vasiformis), suggesting that the PCR technique was not as effective in amplifying the DNA of some species of Zygomycetes. In five cases, there was no correlation between culture results and those obtained with DNA amplification, indicating the possibility of a mixed infection or the presence of colonizer/contaminant microorganisms. In summary, PCR-based techniques for DNA amplification should be implemented in histopathology and microbiology departments, as they appear to be complementary to conventional methods for IFD detection
Analogue mouse pointer control via an online steady state visual evoked potential (SSVEP) brain-computer interface
The steady state visual evoked protocol has recently become a popular paradigm in brain–computer interface (BCI) applications. Typically (regardless of function) these applications offer the user a binary selection of targets that perform correspondingly discrete actions. Such discrete control systems are appropriate for applications that are inherently isolated in nature, such as selecting numbers from a keypad to be dialled or letters from an alphabet to be spelled. However motivation exists for users to employ proportional control methods in intrinsically analogue tasks such as the movement of a mouse pointer. This paper introduces an online BCI in which control of a mouse pointer is directly proportional to a user's intent. Performance is measured over a series of pointer movement tasks and compared to the traditional discrete output approach. Analogue control allowed subjects to move the pointer faster to the cued target location compared to discrete output but suffers more undesired movements overall. Best performance is achieved when combining the threshold to movement of traditional discrete techniques with the range of movement offered by proportional control
Ferromagnetic/superconducting proximity effect in La0.7Ca0.3MnO3 / YBa2Cu3O7 superlattices
We study the interplay between magnetism and superconductivity in high
quality YBa2Cu3O7 (YBCO) / La0.7Ca0.3MnO3(LCMO)superlattices. We find evidence
for the YBCO superconductivity depression in presence of the LCMO layers. We
show that due to its short coherence length superconductivity survives in the
YBCO down to much smaller thickness in presence of the magnetic layer than in
low Tc superconductors. We also find that for a fixed thickness of the
superconducting layer, superconductivity is depressed over a thickness interval
of the magnetic layer in the 100 nm range. This is a much longer length scale
than that predicted by the theory of ferromagnetic/superconducting proximity
effect.Comment: 10 pages + 5 figures, submitted to Phys. Rev.
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