What makes a particle detector click Tjoa, Erickson; López-Gutiérrez, Irene; Sachs, Allison ...
Physical Review D,
06/2021, Letnik:
103, Številka:
12
Journal Article
Recenzirano
Odprti dostop
We highlight fundamental differences in the models of light-matter interaction between the behavior of Fock state detection in free space versus optical cavities. To do so, we study the phenomenon of ...the resonance of detectors with Fock wave packets as a function of their degree of monochromaticity, the number of spatial dimensions, the linear or quadratic nature of the light-matter coupling, and the presence (or absence) of cavity walls in space. In doing so we show that intuition coming from quantum optics in cavities does not straightforwardly carry to the free-space case. For example, in ( 3 + 1 ) dimensions the detector response to a Fock wave packet will go to zero as the wave packet is made more and more monochromatic and in coincidence with the detector's resonant frequency. This is so even though the energy of the free-space wave packet goes to the expected finite value of ℏ Ω in the monochromatic limit. This is in contrast to the behavior of the light-matter interaction in a cavity (even a large one) where the probability of absorbing a Fock quantum is maximized when the quantum is more monochromatic at the detector's resonance frequency. We trace this crucial difference to the fact that monochromatic Fock states are not normalizable in the continuum; thus physical Fock states need to be constructed out of normalizable wave packets whose energy density goes to zero in the monochromatic limit as they get spatially delocalized.
Two series of copolymers were synthesized by emulsion polymerization: poly(styrene‐co‐acrylonitrile) P(S:AN) and P(S:AN‐acrylic acid) P(S:AN‐AA). The monomeric concentrations in both series were: ...0:100, 20:80, 40:60, 50:50 (wt%:wt%), and 1 wt% of AA. The copolymers were dissolved in N,N‐dimethylformamide (4–10 wt%) and were electrospun. Polymeric yarns were collected using a blade collector. The synthesized and fabricated materials were characterized by known techniques. Mechanical and electrical properties of polymeric yarns indicated a dependence of monomeric concentration. Elastic modulus increases as acrylonitrile concentration increases (up to 30 MPa). Yarns were submitted to degradation process into saline solution, where the acrylic acid content kept a constant elastic modulus at long times. The electrical current into yarns was higher when the concentration is 50:50 wt%:wt% (1.2 mA). The cytotoxicity results showed a cell viability close to 100% for yarns without AA.
Operable triple-negative breast cancers (TNBCs) have a higher risk of relapse than non-TNBCs with standard therapy. The GEICAM/2003-11_CIBOMA/2004-01 trial explored extended adjuvant capecitabine ...after completion of standard chemotherapy in patients with early TNBC.
Eligible patients were those with operable, node-positive-or node negative with tumor 1 cm or greater-TNBC, with prior anthracycline- and/or taxane-containing chemotherapy. After central confirmation of TNBC status by immunohistochemistry, patients were randomly assigned to either capecitabine or observation. Stratification factors included institution, prior taxane-based therapy, involved axillary lymph nodes, and centrally determined phenotype (basal
nonbasal, according to cytokeratins 5/6 and/or epidermal growth factor receptor positivity by immunohistochemistry). The primary objective was to compare disease-free survival (DFS) between both arms.
Eight hundred seventy-six patients were randomly assigned to capecitabine (n = 448) or observation (n = 428). Median age was 49 years, 55.9% were lymph node negative, 73.9% had a basal phenotype, and 67.5% received previous anthracyclines plus taxanes. Median length of follow-up was 7.3 years. DFS was not significantly prolonged with capecitabine versus observation hazard ratio (HR), 0.82; 95% CI, 0.63 to 1.06;
= .136. In a preplanned subgroup analysis, nonbasal patients seemed to derive benefit from the addition of capecitabine with a DFS HR of 0.53 versus 0.94 in those with basal phenotype (interaction test
= .0694) and an HR for overall survival of 0.42 versus 1.23 in basal phenotype (interaction test
= .0052). Tolerance of capecitabine was as expected, with 75.2% of patients completing the planned 8 cycles.
This study failed to show a statistically significant increase in DFS by adding extended capecitabine to standard chemotherapy in patients with early TNBC. In a preplanned subset analysis, patients with nonbasal phenotype seemed to obtain benefit with capecitabine, although this will require additional validation.
•Natural biological control of aphids occurs naturally even in a simplified greenhouse agrosystem.•The percentage of greenhouses, rather than hedgerows, was an essential factor in suppressing ...aphids.•Hedgerows positively affected predated aphids in surrounding environments 200 and 300 m.•The presence of hedgerows resulted in changes in arthropod composition populations.
Southern Spain is home to the most intensively grown protected crop area in the EU. The area is currently characterized by greenhouse monocultures and a homogenous landscape. The establishment of hedgerows among greenhouses can enhance the diversity of natural enemies of pests around the greenhouses and help them thrive. However, the effect of hedgerows on pest control has not been addressed. Thus, we used aphid banker plants, i.e. wheat infested with Rhopalosiphum padi (L.), as sentinel plants in the surroundings of three paired greenhouses with and without hedgerows. We assessed the effect of hedgerows on the abundance of aphids and arthropod community populations. In addition, we assessed the importance of the surrounding environment on aphid survival. There were 4.1-fold more aphids on sentinel plants excluded from the action of natural enemies than ones exposed to them, showing that biological control occurs naturally even in a simplified greenhouse agrosystem. Aphid populations were slightly higher (albeit not significantly) in replicates without hedgerows than in those with hedgerows. The percentage of greenhouses, rather than hedgerows, was an essential factor in suppressing aphids, highlighting the importance of using commercial biological control in greenhouses. The presence of hedgerows resulted in changes in arthropod composition populations, i.e. in a lower occurrence of pests and a higher occurrence of natural enemies, especially in the most simplified replicate. We propose increasing the amount of hedgerows for reducing pressure from pests on simplified greenhouse agrosystems.
The amplitude of auditory steady-state responses (ASSRs) generated in the brainstem of rats exponentially decreases over the sequential averaging of EEG epochs. This behavior is partially due to the ...adaptation of the ASSR induced by the continuous and monotonous stimulation. In this study, we analyzed the potential clinical relevance of the ASSR adaptation. ASSR were elicited in eight anesthetized adult rats by 8-kHz tones, modulated in amplitude at 115 Hz. We called independent epochs to those EEG epochs acquired with sufficiently long inter-stimulus interval, so the ASSR contained in any given epoch is not affected by the previous stimulation. We tested whether the detection of ASSRs is improved when the response is computed by averaging independent EEG epochs, containing only unadapted auditory responses. The improvements in the ASSR detection obtained with standard, weighted and sorted averaging were compared. In the absence of artifacts, when the ASSR was elicited by continuous acoustic stimulation, the computation of the ASSR amplitude relied upon the averaging method. While the adaptive behavior of the ASSR was still evident after the weighting of epochs, the sorted averaging resulted in under-estimations of the ASSR amplitude. In the absence of artifacts, the ASSR amplitudes computed by averaging independent epochs did not depend on the averaging procedure. Averaging independent epochs resulted in higher ASSR amplitudes and halved the number of EEG epochs needed to be acquired to achieve the maximum detection rate of the ASSR. Acquisition protocols based on averaging independent EEG epochs, in combination with appropriate averaging methods for artifact reduction might contribute to develop more accurate hearing assessments based on ASSRs.
Vitamin D deficiency is a major global public health problem. Recent epidemiological studies have assessed the relationship between vitamin D and multiple outcomes, including cardiovascular disease. ...However, this evidence is limited and inconclusive. Our purpose in this study was to evaluate the association between dietary vitamin D intake and cardiovascular disease risk in adult Mexican population.
We conducted a cross-sectional analysis with the baseline data from 6294 men and women aged 20-80 years participating in the Health Workers Cohort Study. Data on sociodemographic, lifestyle, and medical history factors were collected with a self-administered questionnaire. Dietary intake was evaluated by using a semi-quantitative food-frequency questionnaire. Cardiovascular disease risk was calculated using a recalibration of the Framingham heart disease prediction score. To evaluate the association between vitamin D intake and 10-year cardiovascular disease risk, odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using multiple logistic regression analysis.
A total of 6294 subjects (1820 men and 4474 women) with a mean age of 42 years, were included. Of these, subjects in the highest quintile of vitamin D intake presented lower levels of triglycerides 14.6 mg/dL (P for trend = 0.001); 2.0 cm less in waist circumference (P for trend = 0.001) and 0.8 points less in the Framingham cardiovascular disease risk score (P for trend = 0.002) compared with the subjects in the lower quintile of vitamin D intake. Additionally, participants in the highest quintile of vitamin D consumption were less likely to develop elevated 10-year cardiovascular disease risk, compared with those in the lowest quintile (OR = 0.51; 95%CI: 0.33, 0.77; P for trend = 0.007).
Our data suggest that higher consumption of vitamin D is associated with a reduced risk of cardiovascular disease in Mexican population.
•Higher dispersion in the UFB-BER reactor increases the degradation kinetic constant.•Degradation rate, mass transfer and kinetics are affected by hydrodynamic behavior.•Hydraulic residence time can ...be reduced and obtain high-quality removal efficiency.
A cylindrical Upflow Fixed Bed Reactor (UFB-BER) with granular activated carbon, steel mesh electrodes and anaerobic microorganisms, was constructed for analyzing how hydrodynamic parameters affect the reactions involved during wastewater treatment processes for azo dye degradation. Dye removal percentage was not compromised by decreasing HRTm (99–90% upon changing HRTm from 4 to 1h in single pass mode). Using the residence time distribution method for hydrodynamic characterization, it was found that a higher dispersion in the reactor occurs for HRTm=1h, than for HRTm=4h. A kinetic analysis suggests that this dispersion effect could be associated to a higher specific reaction rate dependent on the azo dye concentration.
Neurodegenerative diseases are among the leading causes of disability and death worldwide. The disease-related socioeconomic burden is expected to increase with the steadily increasing life ...expectancy. In spite of decades of clinical and basic research, most strategies designed to manage degenerative brain diseases are palliative. This is not surprising as neurodegeneration progresses "silently" for decades before symptoms are noticed. Importantly, conceptual models with heuristic value used to study neurodegeneration have been constructed retrospectively, based on signs and symptoms already present in affected patients; a circumstance that may confound causes and consequences. Hence, innovative, paradigm-shifting views of the etiology of these diseases are necessary to enable their timely prevention and treatment. Here, we outline four alternative views, not mutually exclusive, on different etiological paths toward neurodegeneration. First, we propose neurodegeneration as being a secondary outcome of a primary cardiovascular cause with vascular pathology disrupting the vital homeostatic interactions between the vasculature and the brain, resulting in cognitive impairment, dementia, and cerebrovascular events such as stroke. Second, we suggest that the persistence of senescent cells in neuronal circuits may favor, together with systemic metabolic diseases, neurodegeneration to occur. Third, we argue that neurodegeneration may start in response to altered body and brain trophic interactions established via the hardwire that connects peripheral targets with central neuronal structures or by means of extracellular vesicle (EV)-mediated communication. Lastly, we elaborate on how lifespan body dysbiosis may be linked to the origin of neurodegeneration. We highlight the existence of bacterial products that modulate the gut-brain axis causing neuroinflammation and neuronal dysfunction. As a concluding section, we end by recommending research avenues to investigate these etiological paths in the future. We think that this requires an integrated, interdisciplinary conceptual research approach based on the investigation of the multimodal aspects of physiology and pathophysiology. It involves utilizing proper conceptual models, experimental animal units, and identifying currently unused opportunities derived from human data. Overall, the proposed etiological paths and experimental recommendations will be important guidelines for future cross-discipline research to overcome the translational roadblock and to develop causative treatments for neurodegenerative diseases.
PDF
