LLukas22/scidocs huggingface dataset:
Optimal Spectral Feature Detection for Spectrum Sensing at Very Low SNR

Spectrum sensing is one of the enabling functionalities for cognitive radio systems to operate in the spectrum white space. To protect the primary incumbent users from interference, the cognitive radio is required to detect incumbent signals at very low signal-to-noise ratio (SNR). In this paper, we study a spectrum sensing technique based on spectral correlation for detection of television (TV) broadcasting signals. The basic strategy is to correlate the periodogram of the received signal with the a priori known spectral features of the primary signal. We show that this sensing technique is asymptotically equivalent to the likelihood ratio test (LRT) at very low SNR, but with less computational complexity. That is, the spectral correlation-based detector is asymptotically optimal according to the Neyman-Pearson criterion. From the system design perspective, we analyze the effect of the spectral features on the spectrum sensing performance. Through the optimization analysis, we obtain useful insights on how to choose effective spectral features to achieve reliable sensing. Simulation results show that the proposed sensing technique can reliably detect analog and digital TV signals at SNR levels as low as -20 dB.
Genetic and functional characterization of culturable plant-beneficial actinobacteria associated with yam rhizosphere.

Actinobacteria were isolated from the rhizosphere of yam plants from agricultural fields from Yeoju, South Korea and analyzed for their genetic and plant-beneficial functional diversity. A total of 29 highly occurring actinobacterial isolates from the yam rhizosphere were screened for various plant-beneficial traits such as antimicrobial activity on fungi and bacteria; biocontrol traits such as production of siderophore, protease, chitinase, endo-cellulase, and β-glucanase. The isolates were also screened for plant growth-promoting (PGP) traits such as auxin production, phosphate solubilization, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and in vitro Arabidopsis growth promotion. 16S rDNA sequence-based phylogenetic analysis was carried out on the actinobacterial isolates to determine their genetic relatedness to known actinobacteria. BOX-PCR analysis revealed high genetic diversity among the isolates. Several isolates were identified to belong to the genus Streptomyces and a few to Kitasatospora. The actinobacterial strains exhibited high diversity in their functionality and were identified as novel and promising candidates for future development into biocontrol and PGP agents.
Chemical origins of life: Prebiotic RNA unstuck.

The ‘RNA world’ hypothesis describes an early stage of life on Earth, prior to the evolution of coded protein synthesis, in which RNA served as both information carrier and functional catalyst1,2. Not only is there a significant body of evidence to support this hypothesis3, but the ‘ribo-organisms’ from this RNA world are likely to have achieved a significant degree of metabolic sophistication4. From the perspective of the origins of life, the path from pre-life chemistry to the RNA world probably included cycles of template-directed RNA replication, with the RNA templates assembled from prebiotically generated ribonucleotides (Fig. 1)5. RNA seems well suited for the task of replication because its components pair in a complementary fashion. One strand of nucleic acid could thereby serve as a template to direct the polymerization of its complementary strand. Nevertheless, even given abundant ribonucleotides and prebiotically generated RNA templates, significant problems are believed to stand in the way of an experimental demonstration of multiple cycles of RNA replication. For example, non-enzymatic RNA template-copying reactions generate complementary strands that contain 2ʹ,5ʹ-phosphodiester linkages randomly distributed amongst the 3ʹ,5ʹ-linkages (Fig. 2a)6 rather than the solely 3ʹ,5ʹ-linkages found in contemporary biology. This heterogeneity has been generally presumed to preclude the evolution of heritable RNA with functional properties. A second problem with the RNA replication cycle concerns the high ‘melting temperatures’ required to separate the strands of the RNA duplexes formed by template copying7. For example, 14mer RNA duplexes with a high proportion of guanine–cytosine pairs can have melting temperatures well above 90 °C. Such stability would prohibit strand separation and thereby halt progression to the next generation of replication. Yet another difficulty results from the hydrolysis and cyclization reactions of chemically activated mononucleotide and oligonucleotide substrates7, which would deactivate them for template copying. Together, these and other issues have precluded the demonstration of chemically driven RNA replication in the laboratory. Now, two new studies reported in Nature Chemistry — one from the Szostak laboratory and the other from the Sutherland group — offer potential solutions to these problems8,9. Szostak and co-workers have challenged the assumption that backbone homogeneity was a requirement for the primordial RNA replication process, and considered whether RNAs that contain significant levels of 2ʹ,5ʹ-linkages can be tolerated within known ribozymes and aptamers8. They synthesized two well-known functional RNAs — the flavin mononucleotide (FMN) aptamer and hammerhead ribozyme — containing varying amounts (10–50%) of randomly distributed 2ʹ,5ʹ-linkages. Overall, FMN aptamers and hammerhead ribozymes possessing high levels of CHEMICAL ORIGINS OF LIFE
Test cases for plagiarism detection software

HTW Berlin Treskowallee 8 10318 Berlin weberwu@htw-berlin.de http://www.f4.htw-berlin.de/~weberwu Abstract There are numerous plagiarism detection software systems that claim to discover plagiarism of all sorts, given a digital text. This paper first discusses a typology of plagiarism, which makes clear that plagiarism is more than just an exact copy. Then a collection of 42 test cases in German are presented that were developed at the HTW Berlin for testing plagiarism detection software. The test cases have been used in three tests, in 2004, 2007, and 2008 and are available online. The test suite will be extended to include English-language test cases in 2010.
Randomized clinical trial of 3 types of physical exercise for patients with Parkinson disease.

OBJECTIVE
To compare the efficacy of treadmill exercises and stretching and resistance exercises in improving gait speed, strength, and fitness for patients with Parkinson disease.


DESIGN
A comparative, prospective, randomized, single-blinded clinical trial of 3 types of physical exercise.


SETTING
The Parkinson's Disease and Movement Disorders Center at the University of Maryland and the Baltimore Veterans Affairs Medical Center, Geriatric Research Education and Clinical Center.


PATIENTS
A total of 67 patients with Parkinson disease who had gait impairment were randomly assigned to 1 of 3 arms of the trial. INTERVENTIONS; (1) A higher-intensity treadmill exercise (30 minutes at 70%-80% of heart rate reserve), (2) a lower-intensity treadmill exercise (50 minutes at 40%-50% of heart rate reserve), and (3) stretching and resistance exercises (2 sets of 10 repetitions on each leg on 3 resistance machines [leg press, leg extension, and curl]). These exercises were performed 3 times a week for 3 months.


MAIN OUTCOME MEASURES
The primary outcome measures were gait speed (6-minute walk), cardiovascular fitness (peak oxygen consumption per unit time [$$ VO2], and muscle strength (1-repetition maximum strength).


RESULTS
All 3 types of physical exercise improved distance on the 6-minute walk: lower-intensity treadmill exercise (12% increase; P=.001), stretching and resistance exercises (9% increase; P<.02), and higher-intensity treadmill exercise (6% increase; P=.07), with no between-group differences. Both treadmill exercises improved peak $$ VO2 (7%-8% increase; P<.05) more than did the stretching and resistance exercises. Only stretching and resistance improved muscle strength (16% increase; P<.001).


CONCLUSIONS
The effects of exercise were seen across all 3 exercise groups. The lower-intensity treadmill exercise resulted in the greatest improvement in gait speed. Both the higher- and lower-intensity treadmill exercises improved cardiovascular fitness. Only the stretching and resistance exercises improved muscle strength. Therefore, exercise can improve gait speed, muscle strength, and fitness for patients with Parkinson disease. The combination of treadmill and resistance exercises may result in greater benefit and requires further investigation.
Environmental Management, 7,5 ECTS credits, Spring-16

In this course the students an insight into how to create conditions for sustainable development of enterprises and organizations by using different tools for environmental management.
Fast graspability evaluation on single depth maps for bin picking with general grippers

We present a method that estimates graspability measures on a single depth map for grasping objects randomly placed in a bin. Our method represents a gripper model by using two mask images, one describing a contact region that should be filled by a target object for stable grasping, and the other describing a collision region that should not be filled by other objects to avoid collisions during grasping. The graspability measure is computed by convolving the mask images with binarized depth maps, which are thresholded differently in each region according to the minimum height of the 3D points in the region and the length of the gripper. Our method does not assume any 3-D model of objects, thus applicable to general objects. Our representation of the gripper model using the two mask images is also applicable to general grippers, such as multi-finger and vacuum grippers. We apply our method to bin picking of piled objects using a robot arm and demonstrate fast pick-and-place operations for various industrial objects.
A FREQUENCY SELECTIVE ABSORBING GROUND PLANE FOR LOW-RCS MICROSTRIP ANTENNA ARRAYS

An efficient strategy for reducing the signature of an antenna is to substitute the conventional solid ground plane with a patterned ground plane thus letting the incoming energy to pass through the structure except over the operating band of the antenna. However, in a real environment, the energy flowing through the FSS (Frequency Selective Surface) can be intercepted by eventual scatterers located behind the antenna, so to nullify the RCS (Radar Cross Section) reduction. To overcome this drawback, a novel composite structure is proposed which is able to dissipate such energy by placing a thin absorbing layer below the FSS ground. It is shown that a careful analysis has to be performed to accomplish this goal since the transparent antenna array and the backing absorber strongly interact and thus they cannot be separately designed. The optimal value of the foam spacer thickness between the FSS ground and the absorbing layer is investigated by an efficient equivalent transmission line approach. Criteria for enlarging the low-RCS band with respect to the free space design are also provided. An antenna array prototype backed by the thin multilayer structure is finally manufactured and tested. Received 29 January 2012, Accepted 14 March 2012, Scheduled 21 March 2012 * Corresponding author: Filippo Costa (filippo.costa@iet.unipi.it). 318 Costa, Genovesi, and Monorchio
Organic and inorganic–organic thin film structures by molecular layer deposition: A review

The possibility to deposit purely organic and hybrid inorganic-organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD), is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD) technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic-organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications.
Optimizing Viable Leukocyte Sampling from the Female Genital Tract for Clinical Trials: An International Multi-Site Study

BACKGROUND
Functional analysis of mononuclear leukocytes in the female genital mucosa is essential for understanding the immunologic effects of HIV vaccines and microbicides at the site of HIV exposure. However, the best female genital tract sampling technique is unclear.


METHODS AND FINDINGS
We enrolled women from four sites in Africa and the US to compare three genital leukocyte sampling methods: cervicovaginal lavages (CVL), endocervical cytobrushes, and ectocervical biopsies. Absolute yields of mononuclear leukocyte subpopulations were determined by flow cytometric bead-based cell counting. Of the non-invasive sampling types, two combined sequential cytobrushes yielded significantly more viable mononuclear leukocytes than a CVL (p<0.0001). In a subsequent comparison, two cytobrushes yielded as many leukocytes (∼ 10,000) as one biopsy, with macrophages/monocytes being more prominent in cytobrushes and T lymphocytes in biopsies. Sample yields were consistent between sites. In a subgroup analysis, we observed significant reproducibility between replicate same-day biopsies (r = 0.89, p = 0.0123). Visible red blood cells in cytobrushes increased leukocyte yields more than three-fold (p = 0.0078), but did not change their subpopulation profile, indicating that these leukocytes were still largely derived from the mucosa and not peripheral blood. We also confirmed that many CD4(+) T cells in the female genital tract express the α4β7 integrin, an HIV envelope-binding mucosal homing receptor.


CONCLUSIONS
CVL sampling recovered the lowest number of viable mononuclear leukocytes. Two cervical cytobrushes yielded comparable total numbers of viable leukocytes to one biopsy, but cytobrushes and biopsies were biased toward macrophages and T lymphocytes, respectively. Our study also established the feasibility of obtaining consistent flow cytometric analyses of isolated genital cells from four study sites in the US and Africa. These data represent an important step towards implementing mucosal cell sampling in international clinical trials of HIV prevention.
The isospin-symmetry-breaking effects in Ke4 decays

The Fermi-Watson theorem is generalized to the case of two coupled channels with different masses and applied to final-state interaction inKe4 decays. The impact of the considered effect on the phase of ππ scattering is estimated and it is shown that it can be crucial for the scattering length extraction from experimental data on Ke4 decays.
Measurement of vasomotor reserve in the transcranial Doppler-CO(2) test using an ultrasound contrast agent (Levovist).

BACKGROUND AND PURPOSE
Determination of vasomotor reserve (VMR) with the transcranial Doppler-CO(2) (TCD-CO(2)) test is used to assess the risk of impending cerebral ischemia in patients with high-grade stenosis or occlusion of the internal carotid artery. In patients with a poor temporal window, however, this examination is limited. The aim of this study therefore was to examine whether the use of an ultrasound contrast agent (USCA) influences the results of the TCD-CO(2) test.


METHODS
In the first part of the study, 6 control subjects and 20 patients were examined with the TCD-CO(2) test. The VMR was determined first without the application of a contrast agent and then with continuous infusion of an USCA (Levovist, 300 mg/mL, 1 mL/min). In the second part of the study, 2 tests without USCA were performed in each of 13 patients and 2 tests with USCA infusion were performed in each of 12 patients. Statistical analysis included differences between the VMR determined with the 2 comparative measurements (VMR), the mean (M(VMR)), and SD.


RESULTS
Based on the mean difference, the TCD-CO(2) test produced the same results with and without USCA (M(VMR) 1.8%), although the differences showed a wide distribution (2 SDs, +/-20.7%). Similar spreads were seen in repeated determinations of VMR in the same patient without USCA (2 SDs, +/-20.0%), whereas the distribution under continuous USCA infusion was considerably smaller (2 SDs, +/-8.2%).


CONCLUSIONS
The TCD-CO(2) test can be performed with continuous infusion of an USCA without influencing the results. Even with a good temporal window, the results of the TCD-CO(2) test show better reproducibility and thus better reliability if an USCA is used.
Body fat measurement in adolescent girls with type 1 diabetes: a comparison of skinfold equations against dual‐energy X‐ray absorptiometry

AIM
Skinfold measurement is an inexpensive and widely used technique for assessing the percentage of body fat (%BF). This study assessed the accuracy of prediction equations for %BF based on skinfold measurements compared to dual-energy X-ray absorptiometry (DXA) in girls with type 1 diabetes and healthy age-matched controls.


METHODS
We included 49 healthy girls and 44 girls with diabetes aged 12-19 years old, comparing the predicted %BF based on skinfold measurements and the %BF values obtained by a Lunar DPX-L scanner. The agreement between the methods was assessed using an Bland-Altman plot.


RESULTS
The skinfold measurements were significantly higher in girls with diabetes (p = 0.003) despite a nonsignificant difference in total %BF (p = 0.1). A significant association between bias and %BF was found for all tested equations in the Bland-Altman plots. Regression analysis showed that the association between skinfold measurements and %BF measured by DXA differed significantly (p = 0.039) between the girls with diabetes and the healthy controls.


CONCLUSION
The accuracy of skinfold thickness equations for assessment of %BF in adolescent girls with diabetes is poor in comparison with DXA measurements as criterion. Our findings highlight the need for the development of new prediction equations for girls with type 1 diabetes.
Two Distinct Visual Motion Mechanisms for Smooth Pursuit: Evidence from Individual Differences

Smooth-pursuit eye velocity to a moving target is more accurate after an initial catch-up saccade than before, an enhancement that is poorly understood. We present an individual-differences-based method for identifying mechanisms underlying a physiological response and use it to test whether visual motion signals driving pursuit differ pre- and postsaccade. Correlating moment-to-moment measurements of pursuit over time with two psychophysical measures of speed estimation during fixation, we find two independent associations across individuals. Presaccadic pursuit acceleration is predicted by the precision of low-level (motion-energy-based) speed estimation, and postsaccadic pursuit precision is predicted by the precision of high-level (position-tracking) speed estimation. These results provide evidence that a low-level motion signal influences presaccadic acceleration and an independent high-level motion signal influences postsaccadic precision, thus presenting a plausible mechanism for postsaccadic enhancement of pursuit.
A pilot study of the continuous glucose monitoring system: clinical decisions and glycemic control after its use in pediatric type 1 diabetic subjects.

OBJECTIVE
To determine whether the continuous glucose monitoring system (CGMS) (MiniMed, Sylmar, CA) could be used to make clinical decisions and whether it has an impact on glycemia in pediatric type 1 diabetic subjects.


RESEARCH DESIGN AND METHODS
Pediatric subjects were recruited if they had HbA(1c) >8.0% with management problems (n = 35) or episodes of severe or nocturnal hypoglycemia or hypoglycemia unawareness associated with HbA(1c) < or =8.0% (n = 12). A total of 47 patients with a mean HbA(1c) value of 8.6 +/- 1.6% (mean age 11.8 +/- 4.6 years, youngest 2.7 years, and diabetes duration 5.5 +/- 3.5 years) on three to four insulin injections/day (n = 24) or insulin pump therapy (n = 23) were followed with the CGMS for a mean of 69.5 +/- 28 h. Comparisons were made between the number of high (>150 mg/dl) and low (<70 mg/dl) glucose patterns discerned with the sensor or the logbook, and HbA(1c) levels were evaluated.


RESULTS
In patients on injection therapy, 30 high or low glucose patterns were discerned with the logbook records and 120 patterns with the CGMS. Specific alterations of the diabetes regimen were made. An overall significant change in HbA(1c), from 3 months before wearing the sensor to 6 months after (analysis of variance 0.04), was found in the subjects. Post hoc analysis showed a significant change in HbA(1c) from 8.6 +/- 1.5% at baseline to 8.4 +/- 1.3% at 3 months (paired Student's t test 0.03).


CONCLUSIONS
The CGMS can be used by pediatric patients to detect abnormal patterns of glycemia. The information that was obtained could be used to alter the diabetes regimen and impact glycemic outcome.
Probiotics: definition, scope and mechanisms of action.

For a subject area of science, medicine and commerce to be so recently defined and investigated, few can compare to probiotics for the controversy they have incited. Barely a paper is published without the use of a different definition, or challenging the most used one, or proposing a different nuance of it. The situation has become even more surreal with the European Food and Safety Authority banning the word probiotic for use on labels. The reiteration of the FAO/WHO definition by the world's leading group of probiotic experts, should provide relative consistency in the near future, but what are the causes of these aberrations? This review will discuss the rationale for the definition, and the scope of the subject area and why alternatives emerge. While mechanisms of action are not widely proven, in vitro and some in vivo experiments support several. Ultimately, the goal of any field or product is to be understood by lay people and experts alike. Probiotics have come a long way in 100 years since Metchnikoff and 10 years since their globalization, but their evolution is far from over.